Sustainable VALOrization of Buttermilk: nutritionAl Benefits, functional value in food products and consumer perception – VALOBAB

The project is based on the triangle of sustainable development (environment, society and economy); it associates different scientific domains: dairy process engineering, food science and physical chemistry, sensory analysis, nutrition and metabolism.

- A process has been set up at INRA-STLO laboratory (INRA Dairy Platform) and successfully transferred to ENILIA-ENSMIC (platform Philolao, Actalia) to produce a fraction that is highly enriched in milk PL (>31 g per 100 g of dry matter) from butterserum. Several operation conditions of the coagulation phase are proposed to industries to value buttermilk PL in dairy specialities.
- The variability and bio-physico-composition of industrial buttermilks and butterserums, as well as their bioactive lipid profile (notably sphingolipids), have been characterized. These byproducts are concentrated sources of SM (3.4-21 mg/g dry matter and contain bioactive ceramides (ratio to SM 1:5 in buttermilk and 1:10 in butterserum).
- The organization and properties of milk PL are affected by their physicochemical environment. Buttermilk fractions rich in milk PL can be used as functional ingredients and thereby substitute some additives. The ingredient produced in VALOBAB project presents excellent emulsifying properties.
- To date, French consumers appear to have a poor knowledge on milk ingredients and therefore have limited opinion on their potential effects. The impact of milk PL on lipid metabolism, inflammation and intestinal microbiota has been studied in humans in VALOBAB project.

Clinical studies will be carried out in humans as well as the work of eco-design processes.

4 publications:
- Buttermilk processing : Gassi et al. 2016, Int Dairy J, 52 :26-34; Lambert et al. 2016, Food Res Int, 83 :121-130.
- Microstructure of industrial buttermilks and butterserums: Lopez et al. 2015. Dairy Sci Technol 95 :863-893.
- Impact of milk polar lipids on digestion and postprandial lipid metabolism in mice: Lecomte et al. 2015, J Nutr, doi: 10.3945/jn.115.212068.
1 submitted publication on the bioactive lipid composition of buttermilk (Bourlieu et al. submitted to Food Chem 2016).
Publications ongoing on buttermilk processing, physicochemical properties of milk polar lipids and impact of milk polar lipids on metabolism in humans.

The growing occurrence of excessive weight gain in Western countries is associated with metabolic and cardiovascular diseases. This is due to combined genetic and environmental factors, among which nutrition plays a major role. In this context, obesity is associated with an array of patho-physiological disorders including altered lipid metabolism and inflammation. Dietary strategies can be successful in alleviating such metabolic disorders. Moreover, consumers are more than ever willing to consume “good food” regarding both pleasure and health promotion. In this context, Polar Lipids (PL) are important dietary microcomponents widely used in the food industry for emulsification, foaming and formulation, providing pleasant texture properties to food products. Soybean and egg lecithin are the main commercial sources of PL while milk polar lipids (MPL) are only seldom used. However, conversely to other sources, MPL present a unique polar lipid profile, rich in sphingolipids, and in mammalian milks, a unique natural structure under the form of Milk Fat Globule Membrane (MFGM) constituted of many bioactive polar lipids and proteins. These components can beneficially impact on lipid metabolism, in particular through (i) the ability of sphingolipids to lower cholesterol absorption and triacylglycerol hydrolysis previously demonstrated in mice and in vitro and (ii) the lower fatty acid content of polar lipid molecules compared with triacylglycerols. Buttermilk, a byproduct of the buttermaking industry that has been of low value up to date in human nutrition, is a major source of such MPL.
The strategy of project VALOBAB will lay within the triangle of sustainable development to address the question of the feasibility of buttermilk value-adding through sustainable processing in order to provide a buttermilk microconstituent rich in MPL of functional value. The project will investigate the benefits of such buttermilk-derived fraction regarding (i) functional properties in different newly formulated dairy food products to lower triacylglycerol and/or other PL source intake while bringing appreciated sensory properties to consumers, and (ii) nutritional properties regarding lipid metabolism including cholesterol and triacylglycerol absorption but also inflammation, with the aim of slowing down metabolic diseases of nutritional origin. Thereby, VALOBAB project will help dairy industry to add value to buttermilk by taking into account its nutritional, biochemical and structural specificities and its ability to be processed in a sustainable manner.