Title : Mixture design applied for formulation and characterization of vegetalbased fermented products
Abstract:
In recent years, dietary habits around the world have changed with the evolution of food industry. Today, there are different diets that define the eating habits of a person and/or a population. There is an emergence of new so-called alternative diets which promote a reduction in the consumption of dairy products, for health reasons like lactose intolerance and allergy problems, or for a lifestyle choice based on a vegetarian or vegan diet. The dairy products alternatives are part of the diet in many countries, particularly in Asia and Africa, and are considered as appropriate functional food, which may contain probiotics. The Western consumer, these last years, is more aware of the health benefits of plant-based diets, the sustainability of these foods and their impact on the environment. In the meantime, the food industry is interested in these products, in order to propose an issue to feed the growing world population. Our work consists on the formulation of a fermented plant-based dessert, based on plant raw materials which must be easily accessible and can meet consumer expectations. In the first part, we studied the chemical and physicochemical properties of six flours, ingredients considered to be very interesting for their nutritional contributions and functional properties. In the second part, we formulated and characterised a fermented plant product from three selected flours using a mixture design methodology. We demonstrated the possibility of using the flours in the manufacture of a vegetable dessert as well as their suitability for fermentation with lactic acid bacteria, on a laboratory scale that can be extrapolated to an industrial scale. The results obtained did not require the addition of any additives and/or preservatives other than mechanical and thermal treatments. The use of a cocktail of industrial lactic acid bacteria leads to a decrease in pH close to dairy products such as yoghurt to ensure shelf life. Thus, during 4 weeks of storage, the post-acidification, colour, water retention and texture of the products obtained were evaluated at 24h, 15 days and 30 days. The data obtained using a constrained Scheffé design allowed to determine not only the individual effects of the ingredients but also the interactions between the used flours, despite the constraints imposed. The response surface methodology allowed to find the optimal formulation that meets the technical and industrial requirements, depending on the physico-chemical and textural parameters studied.
