Final Report Summary - PROECLAIR (Automated process for stable preservative free pastry base mix for high added value bakery goods to increase the competitiveness of SME bakeries)
Choux pastry is an essential 'building block' since it can be used for a wide range of popular traditional bakery products. Choux paste is mostly prepared in the traditional way and requires skilled personnel. Alternatively, small and medium sized enterprise (SME) bakers use powder mixes that require fewer skills and reduce only partially the preparation time. On the other hand, powder mixes contain a large number of preservatives.
As there are no systems currently available to provide adequate process control the system is not automated and requires a high level of expertise and is time-consuming with a complex two stage preparation process. Also due to its inherent high moisture content, the shelf life of prepared pastry is very short (less than one day) and needs to be used as soon as possible after preparation.
Within the PROECLAIR project, an innovative technology to automise this process was developed. The developed machinery contains an automated process control and should be readily and easily cleanable. To achieve this goal, product had to be adapted to ensure desired shelf life of four weeks at 4 °C. According to our studies at laboratory scale, shelf life in terms of microbial and physic-chemical stability as well as desired baking performance was achieved. However, at pilot scale more efforts are still needed to replicate results obtained at lab scale. One of the main reasons of the low performance of the choux paste at pilot scale is the lack of optimum hygienic conditions in a SME bakery. A different environment and strict hygienic controls are needed. Furthermore, cleaning process still needs to be fully automised to enable its optimisation. Recommendations have been discussed in detailed within the consortium and are to be implemented as soon as a partner for industrial production is found.
Project context and objectives:
Background:
Choux pastry is an essential 'building block' since it can be used for a wide range of popular traditional bakery products. The choux pastry dough is the only dough that is cooked before baking, which is mainly made of water, butter, flour, eggs and other ingredient depending on the recipes. During the baking, the eggs help to form a thin crust surface, while the steam trapped in the dough expands and gives the pastries a puffed hollow shape.
Choux paste is mostly prepared in the traditional way and requires skilled personnel. Alternatively, SME bakers use powder mixes that require less skills and reduce only partially the preparation time. On the other hand, powder mixes contain a large number of preservatives.
As there are no systems currently available to provide adequate process control, the system is not automated and requires a high level of expertise and is time-consuming with a complex two stage preparation process. Also due to its inherent high moisture content, the shelf life of prepared pastry is very short (less than one day) and needs to be used as soon as possible after preparation. Batches are therefore time-consuming yet skilled in preparation and small, due to their need for immediate use in product. It is therefore very difficult for the SME bakers to produce such products cost effectively.
General objective:
The innovative proposed technology development is based on protected intellectual property (IP); it involves incorporating the stages involved in traditional pastry manufacture into a novel integrated process, in one machine affordable to SME bakeries and that enable aseptic filling into pouches for extended shelf life storage. The developed machinery should contain an automated process control and should be readily and easily cleanable.
Technical objectives:
1. Process control and automation: Rheological sensor system to detect, qualify and quantify the point of time for finishing the roasting process for automatic process control (± 15 seconds). To enable immediate automated response for step changes in viscosity in dough. Rheology changes reflect key stages in dough formation.
2. Process automation, enabling non-manual contact with food material after controlled ingredient metering.
3. Automatic clean in place (CIP) system, for rapid cleaning between batches.
4. The development of an aseptic pastry manufacturing system, with a novel aseptic filling and packaging system to enable subsequent chilled storage and distribution after the heating process step with microbiological integrity.
5. Shelf life stability of choux pastry mixes (up to four weeks at 4 °C).
6. Organoleptic comparison by trained taste panels to validate no significant variation from traditional manual production of same recipes.
Achievements:
Product development:
More efforts on product development were needed according to discussions with SME bakers and bakery associations. During the first phase of the project, the following was achieved:
1. Market research (SME bakers): The objective was to obtain first-hand information from the bakers in the mentioned countries to identify their needs, to be able to develop a custom-tailored PROECLAIR system. All results presented in this study have been evaluated and discussed with the bakers associations participating in this project. Furthermore, a general overview of the European bakery industry market and of the European cakes and pastry market are presented.
2. Collection and evaluation of European recipes (France, Hungary, Italy and Germany): These recipes were the starting point to find a standardised recipe.
3. Evaluation of recipe performance, stability study of collected European recipes: Recipes were compared at day 0 and during storage for four weeks at 4 °C in terms of colour, rheological properties, microbial stability and baking performance.
4. Development of a preservative-free standard recipe: Several ingredients and process conditions were tested at lab scale till satisfactory results in terms of colour, rheological properties, microbial stability and baking performance were obtained.
5. Development of rheological test methods to correlate paste with product quality: A lab system was tested and validated at pilot scale using a BG10 form the Zoatec company. The system components were then modified according to the PROECLAIR process requirements.
6. Storage studies involving microbiological stability, physicochemical stability, rheological parameters, baking performance and tests conducted by trained sensory panel.
Process development:
1. Definition of process requirements
2. Definition and design of main process components and required subunits
3. Development of rheological sensor and control system parameters
4. PROECLAIR prototype: Only some components were built for demonstration. These include mixing unit, filling unit, CIP functions, control system for automated production, test protocols (include production process and cleaning optimisation) and shelf life tests.
Principles of industrial design:
1. Concept for large scale production: process requirements
2. Upscaling calculations
3. Piping and instrumentation diagram (PandID) of semi-continuous automated system
4. Economic calculations (return of invest)
5. Business plan.
Project results:
Within the PROECLAIR project, an automated process for manufacturing stable preservative free pastry base mix for high added value bakery goods was intended. The proposed research focussed on the development of a technical solution to increase the competitiveness of SME bakeries throughout Europe.
This novel process was proposed to relieve SME bakeries from mundane but skilled preparation tasks associated with producing higher value baked goods to enable them to focus their resources on producing more efficiently, with reliable quality and, competitively their wide range of products and be more competitive against the threats from industrial bakeries and supermarkets.
This project aimed to develop an aseptic pastry manufacturing system, with a novel aseptic filling and packaging system to enable subsequent chilled storage and distribution after the heating process step with microbiological integrity. Further, an automatic clean in place (CIP) system, for rapid cleaning between batches was also aimed at.
Market study: current status
Rheological measurements at Rheotest Messgeräte
Medingen GmbH
According to bakers from France, Germany, Hungary and Italy, SME bakery workshops usually produce a choux pastry base once a week or even once every two weeks due to manpower and time constraints. Freshly baked pastry products have to be sold the same day or must be kept under freezing conditions until use.
Visit to SME Barkers, June 2009 Nyíregyháza, Hungary
The latter requires a large storage area and high energy consumption. Currently, quick deterioration of the fresh paste does not allow bakers to keep the dough for further use even within a short period of time. Therefore, the production of aseptically packed fresh paste with a shelf life of at least four weeks at 4 °C could definitely increase SME bakeries efficiency.
Rheology sensor
The automated PROECLAIR process required the development of a rheological sensor system to detect, qualify and quantify the point of time for finishing the roasting process for automatic process control. After evaluating rheology changes during processing, key stages of dough formation have been identified, enabling an immediate automated response for step changes in viscosity in the dough. Furthermore, process automation resulted in non-manual contact with food material after controlled ingredient metering, thus ensuring high hygienic conditions during pastry manufacturing.
On the course of this project, it was confirmed that no existing machinery or system that fulfils these requirements could be identified.
Shelf life: Baking performance, microbial stability and hygienic requirements
In order to achieve the minimum shelf-life required by the SME bakers, the consortium worked intensively during the first 12 months to develop strategies to achieve microbiological and physical-chemical stability of the product. Accordingly, several laboratory studies have been carried out.
Evaluating baking performance and pastry quality
During the project, several strategies to maintain product quality, including colour, texture and taste without using chemical preservatives have been proposed. Methods to evaluate changes in physical-chemical and sensory attributes have been developed. However, it was concluded that the packaging system to enable the fresh choux paste to achieve the required shelf life cannot be considered aseptic. It was very difficult to obtain aseptic conditions because ingredients are not sterile and could carry spores (e.g. flour). To ensure aseptic conditions, all ingredients supply should comply with the sterility requirements. The treatment at which ingredients are submitted cannot ensure sterility; therefore, it can only be assumed that an 'ultra clean' system is being used.
At an early project stage, it was identified that microbial growth does not represent a major hazard when ingredients are handled under hygienic conditions or have been previously sterilised and the paste is stored under refrigeration (at temperatures less or equal to 4°C). The development of a PROECLAIR unit has taken into account these requirements and the sub-units for the different process steps have been specified. However, due to budget restrictions, not all considerations could be taken into account. The PROECLAIR process has been demonstrated in a SME bakery under usual environmental conditions. This is a very critical point, since an aseptic process requires very strict hygiene conditions and controls, which were not available. Furthermore, after conducting packaging and storage studies, with the final prototype, laboratory results on choux paste microbial stability could not be confirmed. Nevertheless, recommendations for optimal storage conditions including safe limits of microbial growth under cool storage have been set up.
Due to obvious limitations, the consortium agreed that a centralised production of the dough is necessary to pack the choux paste under hygienic (ultra clean) conditions.
The logistic structure for decentralised paste distribution has been only partially agreed between the SME associations (SME-AGs) and their members for post-project exploitation. Final decision within the consortium was to find a new partner able to cover this aspect. Conversations with companies interested in the project results are being conducted.
Shelf life: sensory attributes
According to the project objectives the required shelf-life should be achieved while keeping the organoleptic quality of the product. For this reason, a sensory study on cream puffs was performed at Nofima - descriptive test, International Organisation for Standardisation (ISO) 6564:1985E, the sensory laboratory at Nofima is accredited for the method. During this study, 29 sensory attributes were evaluated. Further, colour attributes were evaluated according to natural colour system (NCS) for the attributes hue, intensity and whiteness. A trained sensory panel of 10 assessors was used. The samples were analysed fresh and after one day of storage and on dough being stored for zero, one, two, three or four weeks. In addition, one day old puffs made on fresh dough with the PROECLAIR recipe and with a control (traditional recipe) were also analysed. Data were analysed by analysis of variance (ANOVA) and principal component analysis (PCA).
The one day old puffs were considered in the test as it is the common practice in SME bakeries and bakers were interested in these results.
This study revealed that the developed product maintains its positive attributes during storage although it significantly differs from the traditional product.
In general, it can be said that:
1. There is a tendency of an increase in attributes normally referred to as positive and decrease in attributes normally referred to as negative as the storage time of the dough increases. There are few differences between fresh puffs and puffs analysed on the day after being baked; although seven attributes give p-values less than 0.05 and 4 p-values in the range 0.05 to 0.10 only crispiness and juiciness give differences that can be considered meaningful.
2. The evaluation of sensory attributes with taste panels should help to validate the process and to ensure no significant variation from traditional manual production of same recipes. Sensory studies were run under optimal laboratory conditions, obtaining very promising results and no major changes in product quality after four weeks storage at 4 °C. However, sensory studies could not be carried out with final product obtained with the PROECLAIR prototype, since product was not microbiologically stable, as explained above. This resulted in a clear loss of product quality. Recommendations to improve hygienic conditions are given in several technical deliverables and a new validation of the product and process after adopting these recommendations would be required.
Overview of project results
In order to provide a better overview of project results, scientific, technological and economic objectives are evaluated against results below.
Scientific objectives:
1. S1: Develop a scientific understanding of the process and materials (including an understanding of natural variation in natural plant based raw materials) at the various stages of the process.
2. S2: Develop a scientific knowledge and understanding of the interdependencies of the various process parameters and material properties such as its viscosity and temperature.
These objectives have been achieved as documented in deliverables D1.2 D1.3 D1.4 and D1.5 fulfilling the requirements of milestone one. According to the objectives, the traditional process was scientifically characterised and process parameters were identified. A better understanding of the process was obtained and factors affecting the quality of the fresh dough were identified. An overall understanding of physicochemical changes of the raw materials during the process was obtained.
Rheological properties of the dough were characterised. Biological hazards in traditionally produced choux paste were identified. Dough discolouration was not related to microbial growth but to oxidation of certain flour constituents. It was concluded that storage temperatures below 4 °C as well as the removal of oxygen during packaging can control microbial growth. Sources of choux paste deterioration were identified and solutions were proposed. Storage studies with traditional recipes were conducted. Studies on microbiological risks during pastry manufacturing and storage and on its physical-chemical stability were conducted. The influence of ingredients on baking performances and colour, stability, as well as on the effect of different enzymes on the dough rheology, baking performances and shelf life were examined. Several solutions to improve choux paste stability were proposed. Regulatory requirements for aseptic filling and machine classifications were reviewed and recommendations given. A research on cleaning protocols was conducted. Further tests at lab scale were conducted to determine process parameters.
S3: Establishment of a system and protocols to ensure microbiological integrity, robust enough for use in SME bakeries but sufficient to ensure integrity of choux pastry during shelf life.
An overview on product development trials to obtain a stable choux pastry during storage is given in the corresponding reports. Microbiological risks during pastry manufacturing and physical-chemical factors affecting quality stability of the choux paste (e.g. colour and texture) are discussed. Several shelf life studies on traditionally manufactured pastes and on modified recipes were conducted at Nofima and Fraunhofer.
The latter was a requirement of the baker association's members who expressed the need of spending more efforts on product development. Therefore, strategies to improve the overall quality of the fresh paste and its baking performance were proposed. Methodologies were developed and described here and further used along the whole will be used during the whole duration of the project.
Regulatory requirements and specification for stable manufacturing of choux paste and filling process, including CIP cleaning were also considered in this report.
In D3.5 an overview of swab tests and cleaning protocols that is applied at the current PROECLAIR prototype. Literature regarding limitation of microbes for the swab tests is mentioned. The optimised cleaning protocols for choux paste production using the current PROECLAIR prototype are also explained. With this study it could be concluded that the optimised cleaning program gives a relatively good visual result. However, the involved manual cleaning shows that the cleaning process still should be improved in further experiments.
The microbial results reflect the lack of cleanliness of the equipment. Under the current working conditions at the bakery it cannot be expected to have a sterile machine or process, an appropriate environment is urgently needed to ensure the stability of the product. Under current conditions, the equipment could be a source of contamination to the product, resulting in an hygienic risk if paste is stored and not baked the same day. Further improvements in prototype design to tackle problems observed need to be carried out.
In D5.3 the laboratory and report on test trials were summarised. Statistical verification and optimisation of recipe at lab scale will be described, the torque measurement at the PROECLAIR reactor is presented, important aspects on the test trials using the current prototype are explained and discussion regarding the baking results is also mentioned.
It was concluded that the produced choux paste from a normal choux paste production using the clean machine fulfils the expectation of the bakers. The evaluation was conducted by observing the colour, taste, structure and the volume of the baked product. This leads to the conclusion that the PROECLAIR production using the current prototype with the mentioned parameters successfully produced high quality éclairs.
Technical objectives:
T1: Process control and automation. Rheological sensor system to detect, qualify and quantify the point of time for finishing the roasting process for automatic process control (± 15 seconds). To enable immediate automated response for step changes in viscosity in dough. Rheology changes reflect key stages in dough formation. The achievement of this objective is explained along the technical reports, especially in D2.4 D4.2 D4.5 and 4.6. The major deviations from these objectives are explained below.
In D2.4 the set up used for experiments at laboratory scale to standardise the choux paste production. General considerations on process parameters were discussed.
In general, choux paste can be produced with the system used for these experiments, provided by Zoatec. The effect of stirring, pump frequency, vacuum and other relevant parameters still needed to be tested at this stage, especially with relation to baking performance.
In D4.2 the work carried out to develop a low cost, in-line measurement system to monitor rheological changes in the dough mixture during the production process has been detailed. The work has focussed on establishing, at specific points in the production process, the changes that occur in the viscous and elastic properties of the dough mixture and the effect these changes have on the dynamics of the mixing process. Variations in the dynamics of the mixing system result in complimentary changes in the torque being applied by the mixing paddle to maintain the mixing process. Measuring and monitoring the level of torque on the mixer paddle provides a convenient method of monitoring the condition of the viscous and elastic properties of the dough mixture. Two methods of measuring the torque on the mixer paddle have been investigated:
1. direct measurement using a dedicated torque sensor;
2. electronically monitoring the torque output from the mixer drive motor.
The conclusions from the work are:
1. significant rheological changes in the mixture occur at specific stages of the process;
2. rheological changes result in detectable changes in the torque;
3. torque levels can be measured and monitored;
4. electronic monitoring is effective and provides the most cost effective means of torque monitoring.
In D4.5 details of the work carried out to create the overall controlling algorithm and control unit to incorporate the sub units required for the production of choux paste into an automated system are reported.
The production process for creating a traditional choux paste consists of a number of precisely defined steps, or sub units that must be processed consecutively to create a high quality product. The functionality required to achieve each of these steps have been identified and developed into individual algorithms as reported in D4.3 and D4.4. To fully automate the production process a controlling algorithm has been designed to coordinate the operation of each of the sub units in sequence and provide transition from one sub unit to the next.
The controlling algorithm provides a common interface for the user to select the functions and input the necessary parameters to match the requirements of the choux paste recipe.
The system has been made as flexible as possible to allow alternative recipes to be used on the prototype test rig and can process recipes that require considerable more steps than the traditional recipe. The control unit also provides full monitoring and measuring functions enabling each step in the process to be precisely controlled and monitored.
Finally, in D4.6 the control system and algorithms developed to provide the necessary operation features to produce traditional choux paste on the PROECLAIR prototype test rig was evaluated.
The control system has been developed around a Zoamatic control unit which runs on a commercially available programmable logic controller (plc). The system provides full access to all the functional elements of the test rig enabling the system to be run in full automatic production mode or in a manual mode where the user has free access to change functionality at any point. The system has been created to be as flexible as possible to allow a wide variety of different recipes and products to be produced on the prototype test rig.
The different requirements for each recipe can be programmed into a ladder type recipe that progresses from step to step as each phase of the production process is completed. The system allows storage of the recipes to make switching between recipes as simple and straightforward as possible. The system also incorporates full monitoring and measuring of all the operational parameters and provides a simple graphical method of monitoring current values and the status of all elements of the test rig.
T2: Process automation, enabling non-manual contact with food material after controlled ingredient metering
The achievement of this objective is explained along the technical reports explained above in T1. Complementary reports to this objective are D3.4 D3.5 and D5.3.
Within D3.4 the process of building the sub-units for filling and packaging is described. The integrated CIP cleaning sub units are also explained.
The filling aggregate and the sub unit for CIP cleaning are required to support the PROECLAIR prototype system. The overall system for choux paste packaging includes the filling aggregate and the nitrogen bottle.
The filling aggregate main function is to support the filling and packaging of the choux paste produced into a stand bag. The filling aggregate is to be attached to the PROECLAIR prototype machine. The nitrogen bottle attached to the filling aggregates. The nitrogen flows to fill the empty headspace at choux paste stand bag before the stand bag is finally welded or closed. In order to easier the process, a protocol indicating step by step packaging process and the required signals was integrated to the centralised control system of the PROECLAIR prototype reactor. The sub units built for CIP aim to support the cleaning process. The sub units for the CIP process include the spray nozzles, boosting pump and the cleaning agent inlet.
D3.5 and D5.3 partially contributed to this objective. Achievements are explained in the scientific objective S3.
T3: Automatic CIP (clean in place) system, for rapid cleaning between batches
Achievement of this objective has been largely explained above in D.5.3. Deliverables 3.3 and 3.4 also largely contributed to it.
D3.3 summarises the theoretical background about the cleaning process at the PROECLAIR reactor, common cleaning agents for cleaning process, the conceptual design of cleaning process to be applied at the reactor, the description of cleaning process at the mixing reactor and presents preliminary cleaning trials conducted at different stages of the project.
In D3.4 the process of building the sub-units for filling and packaging is described. The integrated CIP cleaning sub units are also explained.
T4: The development of an aseptic pastry manufacturing system, with a novel aseptic filling and packaging system to enable subsequent chilled storage and distribution after the heating process step with microbiological integrity.
Achievement of this objective has been largely explained above in D3.4 D3.5 and D.5.3. As already discussed, final system cannot be considered aseptic.
T5: Shelf life stability of choux pastry mixes (16 to 24 weeks at 4 °C). Organoleptic comparison by trained taste panels will be regularly undertaken to validate no significant variation from traditional manual production of same recipes.
This objective was adjusted at the beginning of the project. Bakers considered at maximum storage time of four weeks at 4 C as reasonable. Furthermore, the process needs to be 100 % aseptic and sterility conditions were not given and are very difficult to reach in SME bakeries, justifying a maximum of four weeks storage time.
Contributions to these objectives are reported in D2.4 D2.5 D4.1 and D5.3. D2.4 partially contributed to this objective as explains set up used for experiments at laboratory scale to standardise the choux paste production and includes general considerations on process parameters. In D2.5 ongoing studies on product development and microbial stability of the choux paste are presented. According to task .2.5 microbial testing of fresh product in comparison with work package one (WP1) should be performed. At this stage, it was considered that microbial stability of the product using the proposed packaging strategy should be first tested at laboratory scale. Further validation was carried out with the integrated system at a later stage. In D4.1 the strategy used to validate the cleanliness of the PROECLAIR prototype is described. This was achieved by running microbiological test off-line. Further, a sampling plan to validate the microbial stability of the choux paste during storage is proposed. Finally, results presented in D5.3 also contributed to this objective. As explained above, the laboratory and report on test trials are summarised. Statistical verification and optimisation of recipe at lab scale are described.
Economic objectives:
E1: The cost of a standard machine with 5 to 10 kg choux pastry /batch less than EUR 10 000
This objective cannot be achieved. The cost of a small unit is much more expensive. Only a mixing unit of 10 l costs circa EUR 70 000, not considering the fully automised dosing and cleaning systems. It was concluded that the PROECLAIR system is only profitable at larger scale, since aseptic production and packaging at small scale is not realistic.
E2: Collective profit increase by SME-AG members of over EUR 40 million per annum, after five years post project
This calculation could not be confirmed within the project. Conversations with project partners are being carried out and profit will depend on negotiation results.
Technology transfer:
The prototype demonstration as the part of PROECLAIR's final meeting was conducted at the Siegel's bakery in Zazenhausen, Germany. The aim of the demonstration is to transfer the technology knowledge of the current prototype operation system. PROECLAIR's partners were involved directly in the choux paste production. The promotion material for the technology transfer was represented in the hand-out which was given to the participants during the demonstration.
In general:
1. research and technological development (RTD) team explained participants hygiene requirements for PROECLAIR production and general features of the PROECLAIR prototype;
2. the control system and process requirements were explained. Bakers tested software features;
3. a batch production was conducted to demonstrate all production steps. Choux paste was subsequently filled in stand-bags;
4. bakers tested features of piping bags;
5. eclairs were baked at 230 °C for approximately 25 to 30 min. Very good results were obtained. Product fulfills baker's expectations;
6. CIP cleaning of the machine was conducted.
Overall conclusion:
After validation of PROECLAIR system, it was concluded that the developed process can only be economically applied in a central location at a larger scale. The main reason is that very strict hygienic standards and controls need to be introduced and current SME bakeries are not able to establish such system. The efficiency of the process is also diminished by the size of the prototype. Therefore a larger unit may be desirable. Furthermore, secondary markets are aimed at and new products have to be developed by using this same equipment.
Currently, the consortium is negotiating to establish a partnership with a larger company.
Potential impact:
The potential project impact has been explained in deliverables D7.4 and D7.10.
Project website: http://www.proeclair.eu
As there are no systems currently available to provide adequate process control the system is not automated and requires a high level of expertise and is time-consuming with a complex two stage preparation process. Also due to its inherent high moisture content, the shelf life of prepared pastry is very short (less than one day) and needs to be used as soon as possible after preparation.
Within the PROECLAIR project, an innovative technology to automise this process was developed. The developed machinery contains an automated process control and should be readily and easily cleanable. To achieve this goal, product had to be adapted to ensure desired shelf life of four weeks at 4 °C. According to our studies at laboratory scale, shelf life in terms of microbial and physic-chemical stability as well as desired baking performance was achieved. However, at pilot scale more efforts are still needed to replicate results obtained at lab scale. One of the main reasons of the low performance of the choux paste at pilot scale is the lack of optimum hygienic conditions in a SME bakery. A different environment and strict hygienic controls are needed. Furthermore, cleaning process still needs to be fully automised to enable its optimisation. Recommendations have been discussed in detailed within the consortium and are to be implemented as soon as a partner for industrial production is found.
Project context and objectives:
Background:
Choux pastry is an essential 'building block' since it can be used for a wide range of popular traditional bakery products. The choux pastry dough is the only dough that is cooked before baking, which is mainly made of water, butter, flour, eggs and other ingredient depending on the recipes. During the baking, the eggs help to form a thin crust surface, while the steam trapped in the dough expands and gives the pastries a puffed hollow shape.
Choux paste is mostly prepared in the traditional way and requires skilled personnel. Alternatively, SME bakers use powder mixes that require less skills and reduce only partially the preparation time. On the other hand, powder mixes contain a large number of preservatives.
As there are no systems currently available to provide adequate process control, the system is not automated and requires a high level of expertise and is time-consuming with a complex two stage preparation process. Also due to its inherent high moisture content, the shelf life of prepared pastry is very short (less than one day) and needs to be used as soon as possible after preparation. Batches are therefore time-consuming yet skilled in preparation and small, due to their need for immediate use in product. It is therefore very difficult for the SME bakers to produce such products cost effectively.
General objective:
The innovative proposed technology development is based on protected intellectual property (IP); it involves incorporating the stages involved in traditional pastry manufacture into a novel integrated process, in one machine affordable to SME bakeries and that enable aseptic filling into pouches for extended shelf life storage. The developed machinery should contain an automated process control and should be readily and easily cleanable.
Technical objectives:
1. Process control and automation: Rheological sensor system to detect, qualify and quantify the point of time for finishing the roasting process for automatic process control (± 15 seconds). To enable immediate automated response for step changes in viscosity in dough. Rheology changes reflect key stages in dough formation.
2. Process automation, enabling non-manual contact with food material after controlled ingredient metering.
3. Automatic clean in place (CIP) system, for rapid cleaning between batches.
4. The development of an aseptic pastry manufacturing system, with a novel aseptic filling and packaging system to enable subsequent chilled storage and distribution after the heating process step with microbiological integrity.
5. Shelf life stability of choux pastry mixes (up to four weeks at 4 °C).
6. Organoleptic comparison by trained taste panels to validate no significant variation from traditional manual production of same recipes.
Achievements:
Product development:
More efforts on product development were needed according to discussions with SME bakers and bakery associations. During the first phase of the project, the following was achieved:
1. Market research (SME bakers): The objective was to obtain first-hand information from the bakers in the mentioned countries to identify their needs, to be able to develop a custom-tailored PROECLAIR system. All results presented in this study have been evaluated and discussed with the bakers associations participating in this project. Furthermore, a general overview of the European bakery industry market and of the European cakes and pastry market are presented.
2. Collection and evaluation of European recipes (France, Hungary, Italy and Germany): These recipes were the starting point to find a standardised recipe.
3. Evaluation of recipe performance, stability study of collected European recipes: Recipes were compared at day 0 and during storage for four weeks at 4 °C in terms of colour, rheological properties, microbial stability and baking performance.
4. Development of a preservative-free standard recipe: Several ingredients and process conditions were tested at lab scale till satisfactory results in terms of colour, rheological properties, microbial stability and baking performance were obtained.
5. Development of rheological test methods to correlate paste with product quality: A lab system was tested and validated at pilot scale using a BG10 form the Zoatec company. The system components were then modified according to the PROECLAIR process requirements.
6. Storage studies involving microbiological stability, physicochemical stability, rheological parameters, baking performance and tests conducted by trained sensory panel.
Process development:
1. Definition of process requirements
2. Definition and design of main process components and required subunits
3. Development of rheological sensor and control system parameters
4. PROECLAIR prototype: Only some components were built for demonstration. These include mixing unit, filling unit, CIP functions, control system for automated production, test protocols (include production process and cleaning optimisation) and shelf life tests.
Principles of industrial design:
1. Concept for large scale production: process requirements
2. Upscaling calculations
3. Piping and instrumentation diagram (PandID) of semi-continuous automated system
4. Economic calculations (return of invest)
5. Business plan.
Project results:
Within the PROECLAIR project, an automated process for manufacturing stable preservative free pastry base mix for high added value bakery goods was intended. The proposed research focussed on the development of a technical solution to increase the competitiveness of SME bakeries throughout Europe.
This novel process was proposed to relieve SME bakeries from mundane but skilled preparation tasks associated with producing higher value baked goods to enable them to focus their resources on producing more efficiently, with reliable quality and, competitively their wide range of products and be more competitive against the threats from industrial bakeries and supermarkets.
This project aimed to develop an aseptic pastry manufacturing system, with a novel aseptic filling and packaging system to enable subsequent chilled storage and distribution after the heating process step with microbiological integrity. Further, an automatic clean in place (CIP) system, for rapid cleaning between batches was also aimed at.
Market study: current status
Rheological measurements at Rheotest Messgeräte
Medingen GmbH
According to bakers from France, Germany, Hungary and Italy, SME bakery workshops usually produce a choux pastry base once a week or even once every two weeks due to manpower and time constraints. Freshly baked pastry products have to be sold the same day or must be kept under freezing conditions until use.
Visit to SME Barkers, June 2009 Nyíregyháza, Hungary
The latter requires a large storage area and high energy consumption. Currently, quick deterioration of the fresh paste does not allow bakers to keep the dough for further use even within a short period of time. Therefore, the production of aseptically packed fresh paste with a shelf life of at least four weeks at 4 °C could definitely increase SME bakeries efficiency.
Rheology sensor
The automated PROECLAIR process required the development of a rheological sensor system to detect, qualify and quantify the point of time for finishing the roasting process for automatic process control. After evaluating rheology changes during processing, key stages of dough formation have been identified, enabling an immediate automated response for step changes in viscosity in the dough. Furthermore, process automation resulted in non-manual contact with food material after controlled ingredient metering, thus ensuring high hygienic conditions during pastry manufacturing.
On the course of this project, it was confirmed that no existing machinery or system that fulfils these requirements could be identified.
Shelf life: Baking performance, microbial stability and hygienic requirements
In order to achieve the minimum shelf-life required by the SME bakers, the consortium worked intensively during the first 12 months to develop strategies to achieve microbiological and physical-chemical stability of the product. Accordingly, several laboratory studies have been carried out.
Evaluating baking performance and pastry quality
During the project, several strategies to maintain product quality, including colour, texture and taste without using chemical preservatives have been proposed. Methods to evaluate changes in physical-chemical and sensory attributes have been developed. However, it was concluded that the packaging system to enable the fresh choux paste to achieve the required shelf life cannot be considered aseptic. It was very difficult to obtain aseptic conditions because ingredients are not sterile and could carry spores (e.g. flour). To ensure aseptic conditions, all ingredients supply should comply with the sterility requirements. The treatment at which ingredients are submitted cannot ensure sterility; therefore, it can only be assumed that an 'ultra clean' system is being used.
At an early project stage, it was identified that microbial growth does not represent a major hazard when ingredients are handled under hygienic conditions or have been previously sterilised and the paste is stored under refrigeration (at temperatures less or equal to 4°C). The development of a PROECLAIR unit has taken into account these requirements and the sub-units for the different process steps have been specified. However, due to budget restrictions, not all considerations could be taken into account. The PROECLAIR process has been demonstrated in a SME bakery under usual environmental conditions. This is a very critical point, since an aseptic process requires very strict hygiene conditions and controls, which were not available. Furthermore, after conducting packaging and storage studies, with the final prototype, laboratory results on choux paste microbial stability could not be confirmed. Nevertheless, recommendations for optimal storage conditions including safe limits of microbial growth under cool storage have been set up.
Due to obvious limitations, the consortium agreed that a centralised production of the dough is necessary to pack the choux paste under hygienic (ultra clean) conditions.
The logistic structure for decentralised paste distribution has been only partially agreed between the SME associations (SME-AGs) and their members for post-project exploitation. Final decision within the consortium was to find a new partner able to cover this aspect. Conversations with companies interested in the project results are being conducted.
Shelf life: sensory attributes
According to the project objectives the required shelf-life should be achieved while keeping the organoleptic quality of the product. For this reason, a sensory study on cream puffs was performed at Nofima - descriptive test, International Organisation for Standardisation (ISO) 6564:1985E, the sensory laboratory at Nofima is accredited for the method. During this study, 29 sensory attributes were evaluated. Further, colour attributes were evaluated according to natural colour system (NCS) for the attributes hue, intensity and whiteness. A trained sensory panel of 10 assessors was used. The samples were analysed fresh and after one day of storage and on dough being stored for zero, one, two, three or four weeks. In addition, one day old puffs made on fresh dough with the PROECLAIR recipe and with a control (traditional recipe) were also analysed. Data were analysed by analysis of variance (ANOVA) and principal component analysis (PCA).
The one day old puffs were considered in the test as it is the common practice in SME bakeries and bakers were interested in these results.
This study revealed that the developed product maintains its positive attributes during storage although it significantly differs from the traditional product.
In general, it can be said that:
1. There is a tendency of an increase in attributes normally referred to as positive and decrease in attributes normally referred to as negative as the storage time of the dough increases. There are few differences between fresh puffs and puffs analysed on the day after being baked; although seven attributes give p-values less than 0.05 and 4 p-values in the range 0.05 to 0.10 only crispiness and juiciness give differences that can be considered meaningful.
2. The evaluation of sensory attributes with taste panels should help to validate the process and to ensure no significant variation from traditional manual production of same recipes. Sensory studies were run under optimal laboratory conditions, obtaining very promising results and no major changes in product quality after four weeks storage at 4 °C. However, sensory studies could not be carried out with final product obtained with the PROECLAIR prototype, since product was not microbiologically stable, as explained above. This resulted in a clear loss of product quality. Recommendations to improve hygienic conditions are given in several technical deliverables and a new validation of the product and process after adopting these recommendations would be required.
Overview of project results
In order to provide a better overview of project results, scientific, technological and economic objectives are evaluated against results below.
Scientific objectives:
1. S1: Develop a scientific understanding of the process and materials (including an understanding of natural variation in natural plant based raw materials) at the various stages of the process.
2. S2: Develop a scientific knowledge and understanding of the interdependencies of the various process parameters and material properties such as its viscosity and temperature.
These objectives have been achieved as documented in deliverables D1.2 D1.3 D1.4 and D1.5 fulfilling the requirements of milestone one. According to the objectives, the traditional process was scientifically characterised and process parameters were identified. A better understanding of the process was obtained and factors affecting the quality of the fresh dough were identified. An overall understanding of physicochemical changes of the raw materials during the process was obtained.
Rheological properties of the dough were characterised. Biological hazards in traditionally produced choux paste were identified. Dough discolouration was not related to microbial growth but to oxidation of certain flour constituents. It was concluded that storage temperatures below 4 °C as well as the removal of oxygen during packaging can control microbial growth. Sources of choux paste deterioration were identified and solutions were proposed. Storage studies with traditional recipes were conducted. Studies on microbiological risks during pastry manufacturing and storage and on its physical-chemical stability were conducted. The influence of ingredients on baking performances and colour, stability, as well as on the effect of different enzymes on the dough rheology, baking performances and shelf life were examined. Several solutions to improve choux paste stability were proposed. Regulatory requirements for aseptic filling and machine classifications were reviewed and recommendations given. A research on cleaning protocols was conducted. Further tests at lab scale were conducted to determine process parameters.
S3: Establishment of a system and protocols to ensure microbiological integrity, robust enough for use in SME bakeries but sufficient to ensure integrity of choux pastry during shelf life.
An overview on product development trials to obtain a stable choux pastry during storage is given in the corresponding reports. Microbiological risks during pastry manufacturing and physical-chemical factors affecting quality stability of the choux paste (e.g. colour and texture) are discussed. Several shelf life studies on traditionally manufactured pastes and on modified recipes were conducted at Nofima and Fraunhofer.
The latter was a requirement of the baker association's members who expressed the need of spending more efforts on product development. Therefore, strategies to improve the overall quality of the fresh paste and its baking performance were proposed. Methodologies were developed and described here and further used along the whole will be used during the whole duration of the project.
Regulatory requirements and specification for stable manufacturing of choux paste and filling process, including CIP cleaning were also considered in this report.
In D3.5 an overview of swab tests and cleaning protocols that is applied at the current PROECLAIR prototype. Literature regarding limitation of microbes for the swab tests is mentioned. The optimised cleaning protocols for choux paste production using the current PROECLAIR prototype are also explained. With this study it could be concluded that the optimised cleaning program gives a relatively good visual result. However, the involved manual cleaning shows that the cleaning process still should be improved in further experiments.
The microbial results reflect the lack of cleanliness of the equipment. Under the current working conditions at the bakery it cannot be expected to have a sterile machine or process, an appropriate environment is urgently needed to ensure the stability of the product. Under current conditions, the equipment could be a source of contamination to the product, resulting in an hygienic risk if paste is stored and not baked the same day. Further improvements in prototype design to tackle problems observed need to be carried out.
In D5.3 the laboratory and report on test trials were summarised. Statistical verification and optimisation of recipe at lab scale will be described, the torque measurement at the PROECLAIR reactor is presented, important aspects on the test trials using the current prototype are explained and discussion regarding the baking results is also mentioned.
It was concluded that the produced choux paste from a normal choux paste production using the clean machine fulfils the expectation of the bakers. The evaluation was conducted by observing the colour, taste, structure and the volume of the baked product. This leads to the conclusion that the PROECLAIR production using the current prototype with the mentioned parameters successfully produced high quality éclairs.
Technical objectives:
T1: Process control and automation. Rheological sensor system to detect, qualify and quantify the point of time for finishing the roasting process for automatic process control (± 15 seconds). To enable immediate automated response for step changes in viscosity in dough. Rheology changes reflect key stages in dough formation. The achievement of this objective is explained along the technical reports, especially in D2.4 D4.2 D4.5 and 4.6. The major deviations from these objectives are explained below.
In D2.4 the set up used for experiments at laboratory scale to standardise the choux paste production. General considerations on process parameters were discussed.
In general, choux paste can be produced with the system used for these experiments, provided by Zoatec. The effect of stirring, pump frequency, vacuum and other relevant parameters still needed to be tested at this stage, especially with relation to baking performance.
In D4.2 the work carried out to develop a low cost, in-line measurement system to monitor rheological changes in the dough mixture during the production process has been detailed. The work has focussed on establishing, at specific points in the production process, the changes that occur in the viscous and elastic properties of the dough mixture and the effect these changes have on the dynamics of the mixing process. Variations in the dynamics of the mixing system result in complimentary changes in the torque being applied by the mixing paddle to maintain the mixing process. Measuring and monitoring the level of torque on the mixer paddle provides a convenient method of monitoring the condition of the viscous and elastic properties of the dough mixture. Two methods of measuring the torque on the mixer paddle have been investigated:
1. direct measurement using a dedicated torque sensor;
2. electronically monitoring the torque output from the mixer drive motor.
The conclusions from the work are:
1. significant rheological changes in the mixture occur at specific stages of the process;
2. rheological changes result in detectable changes in the torque;
3. torque levels can be measured and monitored;
4. electronic monitoring is effective and provides the most cost effective means of torque monitoring.
In D4.5 details of the work carried out to create the overall controlling algorithm and control unit to incorporate the sub units required for the production of choux paste into an automated system are reported.
The production process for creating a traditional choux paste consists of a number of precisely defined steps, or sub units that must be processed consecutively to create a high quality product. The functionality required to achieve each of these steps have been identified and developed into individual algorithms as reported in D4.3 and D4.4. To fully automate the production process a controlling algorithm has been designed to coordinate the operation of each of the sub units in sequence and provide transition from one sub unit to the next.
The controlling algorithm provides a common interface for the user to select the functions and input the necessary parameters to match the requirements of the choux paste recipe.
The system has been made as flexible as possible to allow alternative recipes to be used on the prototype test rig and can process recipes that require considerable more steps than the traditional recipe. The control unit also provides full monitoring and measuring functions enabling each step in the process to be precisely controlled and monitored.
Finally, in D4.6 the control system and algorithms developed to provide the necessary operation features to produce traditional choux paste on the PROECLAIR prototype test rig was evaluated.
The control system has been developed around a Zoamatic control unit which runs on a commercially available programmable logic controller (plc). The system provides full access to all the functional elements of the test rig enabling the system to be run in full automatic production mode or in a manual mode where the user has free access to change functionality at any point. The system has been created to be as flexible as possible to allow a wide variety of different recipes and products to be produced on the prototype test rig.
The different requirements for each recipe can be programmed into a ladder type recipe that progresses from step to step as each phase of the production process is completed. The system allows storage of the recipes to make switching between recipes as simple and straightforward as possible. The system also incorporates full monitoring and measuring of all the operational parameters and provides a simple graphical method of monitoring current values and the status of all elements of the test rig.
T2: Process automation, enabling non-manual contact with food material after controlled ingredient metering
The achievement of this objective is explained along the technical reports explained above in T1. Complementary reports to this objective are D3.4 D3.5 and D5.3.
Within D3.4 the process of building the sub-units for filling and packaging is described. The integrated CIP cleaning sub units are also explained.
The filling aggregate and the sub unit for CIP cleaning are required to support the PROECLAIR prototype system. The overall system for choux paste packaging includes the filling aggregate and the nitrogen bottle.
The filling aggregate main function is to support the filling and packaging of the choux paste produced into a stand bag. The filling aggregate is to be attached to the PROECLAIR prototype machine. The nitrogen bottle attached to the filling aggregates. The nitrogen flows to fill the empty headspace at choux paste stand bag before the stand bag is finally welded or closed. In order to easier the process, a protocol indicating step by step packaging process and the required signals was integrated to the centralised control system of the PROECLAIR prototype reactor. The sub units built for CIP aim to support the cleaning process. The sub units for the CIP process include the spray nozzles, boosting pump and the cleaning agent inlet.
D3.5 and D5.3 partially contributed to this objective. Achievements are explained in the scientific objective S3.
T3: Automatic CIP (clean in place) system, for rapid cleaning between batches
Achievement of this objective has been largely explained above in D.5.3. Deliverables 3.3 and 3.4 also largely contributed to it.
D3.3 summarises the theoretical background about the cleaning process at the PROECLAIR reactor, common cleaning agents for cleaning process, the conceptual design of cleaning process to be applied at the reactor, the description of cleaning process at the mixing reactor and presents preliminary cleaning trials conducted at different stages of the project.
In D3.4 the process of building the sub-units for filling and packaging is described. The integrated CIP cleaning sub units are also explained.
T4: The development of an aseptic pastry manufacturing system, with a novel aseptic filling and packaging system to enable subsequent chilled storage and distribution after the heating process step with microbiological integrity.
Achievement of this objective has been largely explained above in D3.4 D3.5 and D.5.3. As already discussed, final system cannot be considered aseptic.
T5: Shelf life stability of choux pastry mixes (16 to 24 weeks at 4 °C). Organoleptic comparison by trained taste panels will be regularly undertaken to validate no significant variation from traditional manual production of same recipes.
This objective was adjusted at the beginning of the project. Bakers considered at maximum storage time of four weeks at 4 C as reasonable. Furthermore, the process needs to be 100 % aseptic and sterility conditions were not given and are very difficult to reach in SME bakeries, justifying a maximum of four weeks storage time.
Contributions to these objectives are reported in D2.4 D2.5 D4.1 and D5.3. D2.4 partially contributed to this objective as explains set up used for experiments at laboratory scale to standardise the choux paste production and includes general considerations on process parameters. In D2.5 ongoing studies on product development and microbial stability of the choux paste are presented. According to task .2.5 microbial testing of fresh product in comparison with work package one (WP1) should be performed. At this stage, it was considered that microbial stability of the product using the proposed packaging strategy should be first tested at laboratory scale. Further validation was carried out with the integrated system at a later stage. In D4.1 the strategy used to validate the cleanliness of the PROECLAIR prototype is described. This was achieved by running microbiological test off-line. Further, a sampling plan to validate the microbial stability of the choux paste during storage is proposed. Finally, results presented in D5.3 also contributed to this objective. As explained above, the laboratory and report on test trials are summarised. Statistical verification and optimisation of recipe at lab scale are described.
Economic objectives:
E1: The cost of a standard machine with 5 to 10 kg choux pastry /batch less than EUR 10 000
This objective cannot be achieved. The cost of a small unit is much more expensive. Only a mixing unit of 10 l costs circa EUR 70 000, not considering the fully automised dosing and cleaning systems. It was concluded that the PROECLAIR system is only profitable at larger scale, since aseptic production and packaging at small scale is not realistic.
E2: Collective profit increase by SME-AG members of over EUR 40 million per annum, after five years post project
This calculation could not be confirmed within the project. Conversations with project partners are being carried out and profit will depend on negotiation results.
Technology transfer:
The prototype demonstration as the part of PROECLAIR's final meeting was conducted at the Siegel's bakery in Zazenhausen, Germany. The aim of the demonstration is to transfer the technology knowledge of the current prototype operation system. PROECLAIR's partners were involved directly in the choux paste production. The promotion material for the technology transfer was represented in the hand-out which was given to the participants during the demonstration.
In general:
1. research and technological development (RTD) team explained participants hygiene requirements for PROECLAIR production and general features of the PROECLAIR prototype;
2. the control system and process requirements were explained. Bakers tested software features;
3. a batch production was conducted to demonstrate all production steps. Choux paste was subsequently filled in stand-bags;
4. bakers tested features of piping bags;
5. eclairs were baked at 230 °C for approximately 25 to 30 min. Very good results were obtained. Product fulfills baker's expectations;
6. CIP cleaning of the machine was conducted.
Overall conclusion:
After validation of PROECLAIR system, it was concluded that the developed process can only be economically applied in a central location at a larger scale. The main reason is that very strict hygienic standards and controls need to be introduced and current SME bakeries are not able to establish such system. The efficiency of the process is also diminished by the size of the prototype. Therefore a larger unit may be desirable. Furthermore, secondary markets are aimed at and new products have to be developed by using this same equipment.
Currently, the consortium is negotiating to establish a partnership with a larger company.
Potential impact:
The potential project impact has been explained in deliverables D7.4 and D7.10.
Project website: http://www.proeclair.eu
