CORDIS - EU research results

Science based precision processing for future healthy, structured and tasteful fruit and vegetable based foods: an integrated research and training program

Final Report Summary - HST-FOOD-TRAIN (Science based precision processing for future healthy, structured and tasteful fruit and vegetable based foods: an integrated research and training program.)

A formatted copy of the final publishable report of HST FoodTrain is attached to the final report.

Final Publishable Report
HST FoodTrain is a multi-site Marie Curie initial training network (ITN) for early-stage and experienced researchers, funded under the EC-FP7-People Programme, and started on January 1, 2011. The consortium of HST FoodTrain consists of two universities (Katholieke Universiteit Leuven, Belgium and University of Reading, UK), and four business-oriented partners, including a private research institute (German Institute of Food Technologies, Germany), two large companies (S.A. Coca-Cola Services, Belgium and Unilever R&D Vlaardingen, The Netherlands) and an SME (Hiperbaric, Spain).

HST FoodTrain Objectives
The specific objectives of HST FoodTrain are:
• To train multi-disciplinary experts with multisectoral experience on and insight in the impact of food processing on the composition and (micro)structure of fruit and vegetable based food products and the relation between the latter properties and product quality parameters, such as texture/rheology, flavor and nutrient bio-accessibility.
• To show the use of the gained insight in case studies of complex multi-ingredient plant based food systems to generate specific functionalities by exploiting the endogenous nature of the raw materials involved.
• To develop a methodological approach for impact comparison of conventional and new process technologies and the application of such approaches to fruit and vegetable based products.

HST FoodTrain RESEARCH program
HST FoodTrain provides an integrated research based training program which is built around four interrelated workpackages:
• WP 1: Processing, food structure and physical functionalities
• WP 2: Processing, food structure, composition and nutrient bio-accessibility
• WP 3: Processing, food structure, composition and flavour
• WP 4: Impact comparison of novel processing techniques
In HST FoodTrain a number of fruit and vegetable matrices are studied (either as single ingredient systems or multi-component mixtures thereof). For fruit-based foods, investigated matrices include citrus fruits (Citrus spp.), watermelon (Citrullus lanatus) and mango (Mangifera indica). Tomato (Lycopersicum esculentum), carrots (Daucus carota) and broccoli (Brassica oleracea) are investigated as vegetable matrices. The matrices under study are strategically chosen because of scientific arguments (combinations of nutrients, flavors and structural cell wall polysaccharides as well as specific enzymes involved in conversions thereof), economic factors and know-how transferability to other matrices and products available at the industrial partners. As structure-enabling technologies, HST FoodTrain focuses on mechanical crushing, high-pressure homogenization and the use of enzyme technology. As preservation processes, HST FoodTrain focuses on thermal processes, high pressure processes and pulsed electric field processing. As product functionalities, HST FoodTrain focuses on three functionalities, which are all influenced by the structural organization of the food matrix: namely physical functionalities (such as rheology, texture, cloud stability), health benefits (nutrient retention and nutrient bio-accessibility) and sensorial properties (flavour and colour).
In WP 1, for the vegetable based systems, new processing methods (such as the use of high pressure homogenisation, the use of enzyme technology and the use of ion exchange resins and sequences thereof) were investigated to exploit the endogenous structuring potential of vegetable based systems. It has been demonstrated that by targeted processing certain vegetable based food products can be made more consistent, thicker and creamier, which makes the addition of structuring additives unnecessary. For the fruit based systems, the texture evolution of mango fruit (including different varieties and different ripening stages) upon processing (including freezing and thermal processing) and its relation with changes in cell wall biopolymers (such as pectin) and starch has been elucidated.
In WP 2, for the vegetable based systems, it has been investigated which structural barriers are important for the release of carotenoids during digestion, as well as the impact of processing (thermal treatment, enzymatic treatment, high pressure homogenisation) there upon. Both the organisation and localisation within the chromoplasts substructure as well as the cell wall constitute the main natural structural barriers governing the release and thus the bioaccessibility of carotenoids in tomato and carrot-based products. It is noteworthy that while disrupting the structural barriers naturally present in the plant matrix, processing can create novel process-induced barriers entrapping carotenoids. After carotenoid release from the food matrix, its solubilisation in the oil phase and transfer into mixed micelles during digestion are further crucial steps determining the overall carotenoid bioaccessibility. For the fruit based systems, the influence of thermal processing and subsequent ambient storage on the quality (i.e. colour) and nutrient evolution of orange and mango juice has been studied. In addition, the feasibility of accelerated shelf-life testing has been investigated. As to colour changes, there was only a limited contribution of carotenoid degradation and other mechanisms such as acid-catalysed degradation of sugars and ascorbic acid degradation reactions appeared to be important for colour degradation in pasteurised orange and mango juice during storage.
In WP 3, for the vegetable based matrices, the potential of novel processing techniques (i.e. sequences of cold-break or hot-break processing and high pressure homogenisation) in modulating the flavour profile of vegetable systems containing tomato, carrot and broccoli has clearly been demonstrated. Moreover, optimized process conditions for reducing off-flavour in broccoli puree and the correlation of aroma profile with the microstructure formed due to the process were identified. For the fruit matrix, the effect of sugar content on flavor release of orange juice has been investigated. Overall results suggest that the perceived sensory profile of orange flavour-model varies with sugar content, and it is hypothesised that this may be related to the “salting-out” effect of flavour volatiles into the sample and not due to sweetness enhancement.
In WP 4, the impact of equivalent thermal, high pressure and pulsed electric field processing of tomato, carrot, and watermelon matrices has been compared using (i) a targeted approach by analyzing specific food characteristics/components (e.g. pH, Brix, colour, conductivity, nutrients, enzymes), as well as (ii) a non-targeted fingerprinting approach by headspace GC-MS analysis. For the different technologies, different fingerprint markers have been identified. The main quality-related chemical reactions that occurred after processing and during shelf-life can be classified as oxidation of fatty acids, carotenoid degradation and amino acid degradation.
In conclusion, the research activities performed within HST FoodTrain, showed that (novel) processing techniques can be exploited to obtain safe fruit and vegetable-based products with improved quality characteristics. The results obtained constitute an important set of scientific information that can be used to steer the structural, nutritional, and sensory properties of fruit and vegetable-based products.

HST FoodTrain TRAINING program
Within HST FoodTrain a combination of local and networkwide training activities are offered to the recruited research fellows, including:
• Local training of both scientific/technological skills as well as complementary skills by specialized lectures, tutorials or workshops available at every host
• Networkwide training of both scientific/technological skills, as well as complementary skills, through the organization of a yearly 5-days winterschool and the organization of a final HST FoodTrain event.
• Intersectoral activities to expose the recruited fellows to the academic sector and to private companies via research secondments and intersectoral visits.

HST FoodTrain socio-economic impact
The HST FoodTrain ITN has impacted on
(i) the scientific progress beyond the state of the art on the insight in and quantification of the relation between processing, food structure, physical functionality, health aspects and flavor. The obtained mechanistic insights in and quantifications of the effects of processing on the food functionalities mentioned form the scientific basis for future development of new fruit and vegetable based food products combining enhanced health benefits with excellent flavor/sensory and physical functionalities.
(ii) the career prospects of the fellows by the extensive training program in complementary skills (project and team management skills, communication and presentation skills, creativity and entrepreneurship skills) they received and their exposure to both academia and the private sector via secondments and intersectoral visits. HST FoodTrain has provided them hands-on experience with academic and industry-driven research and the skills to develop and manage an integrated research project taking advantage of the complementarity and synergy between both environments. This will increase their ability to transfer between institutions and sectors during their careers. In addition, fellows did set up an initial network of formal and informal contacts in academia and industry which can be expanded in their further career.
(iii) the consolidation of the long-term collaboration between the academic and the industrial partners of the consortium.

HST FoodTrain contact details:
• KU Leuven Laboratory of Food Technology, Belgium
Ann Van Loey (
• S.A. Coca-Cola Services, Belgium
Olivier Buysschaert (
• German Institute of Food Technologies, Germany
Stefan Töpfl (
• Unilever R&D Vlaardingen, The Netherlands
Lucy Bialek ( Jaap Nijsse (
• University of Reading, UK
Stephen Elmore (
• Hiperbaric, Spain
Carole Tonello (