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A study of sensory and nutritional quality of virgin olive oil in relation to variety, ripeness and extraction technology

Objective

1. Research on sensory quality of virgin olive oil:

The main objectives were:

- to set-up of a standard terminology describing the sensory profile of virgin olive oil;

- the standardization of sensory analysis of olive oil including sampling, tasting procedure and the statistical processing of sensory data;

- to determine the sensory profiles of virgin olive oil differing in origin, technology and shelf-life.

2. Research on consumer preferences:

The main objectives were:

- identification of critical sensory parameters for consumer preference;

- evaluation, in sensory terms, of differences in preference between a traditional (Italian) and a potential (English) consumer of virgin olive oil;

- identification of physical and physico-chemical parameters related to sensory quality and preference.

3. Shelf-life studies:

The main objectives were:

- shelf-life evaluation, and possibly modelling, in terms of sensory profile variation;

- identification of sensory parameters related to the freshness and stability of virgin olive oil.

4. Nutritional studies

The main objectives of this part of the study were:

- to obtain experimental evidence and to carry out a quantitative evaluation of in vivo antioxidant activity of virgin olive oil;

- the set-up of a routine analytical index related to antioxidant activities.

5. Chemical analysis and technological studies:

Although not indicated as specific tasks of this project, a considerable amount of work has been devoted to the chemical analysis of oil and to the standardization of the technological process. These are an essential support of the sensory and nutritional studies.
A study has been made of sensory quality and nutritional quality of virgin olive oil in relation to variety, ripeness and extraction technology.
Partial results so far demonstrate that variety (or, in other terms, origin) has the strongest impact on the sensory profile of virgin olive oil. Neither the degree of ripeness nor the extraction method have such a deep effect on sensory quality.

Research on consumer preferences demonstrated that differences in sensory profiles cannot be considered as indicators of quality levels, but only as descriptors of variety.

Shelf life studies found that no significant variations of the sensory profile was evident in a 1.5 year storage of smaples. This means that virgin oil has a very good stability at the storage conditions that were chosen in the first set of experiments. This had led to reprogramming of all shelf life experiments, with the inclusion of worst case conditions.

With respect to nutritional studies an interesting result has been achieved with the setting of new analytical methods for the determination of phenolic compounds in virgin olive oil. These compounds are at the same time a good natural preservative against oil oxidation and an indicator of oil freshness and of its keepability. Thus a rapid test for phenols, based on their redox state, may become the single, most effective measure of oil nutritional, sensory and technological quality.

Chemical analysis have been carried out to characterize the oils and to find correlations with sensory descriptors and preferences. However, a complete picture will only result after the analysis of the third year samples.
Concerning thetechnological aspects, continuous effort has been made to standardize the operating conditions and procedures so as to produce comparable samples.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Biagini Farmaceutici SpA
Address
Località Ai Conti
55020 Castelvecchio Pascoli Lucca
Italy

Participants (6)

Campden and Chorleywood Food Research Association (CCFRA)
United Kingdom
Address
Station Road
GL55 6LD Chipping Campden
Eleourgiki
Greece
Address
37-39 Pireos
10553 Athens
Instituto de la Grasa y sus Derivados Caracterizacion y Calidad de los Alimentos & Procesos Industriales
Spain
Address
4 Avenida Padre Garcia Tejero
41012 Sevilla
Stazione Sperimentale per le Industrie degli Oli e dei Grassi
Italy
Address
Giuseppe Colombo 79
20133 Milano
UNILEVER Research Vlaardingen
Netherlands
Address
Po Box 114
3130 AC Vlaardingen
Università degli Studi di Milano
Italy
Address
Via Celoria 2
20133 Milano