VITALAB – Nutzbarmachung von Nebenströmen der Obst- und Milchverarbeitung für die Entwicklung innovativer Lebensmittel mit erhöhtem Vitamingehalt durch Milchsäurebakterien
An adequate supply of vitaminB9 (also known as folate ) is particularly important for pregnant women, as a deficiency massively increases the risk of neural tube defects and other foetal malformations. In addition, an undersupply is associated with the development of certain types of cancer, Alzheimer's and cardiovascular diseases. Unfortunately, the daily folic acid intake worldwide is well below the recommendations. In addition, unlike in Brazil and other non-European countries, there is no mandatory fortification of foods in Germany, as supplementation with folic acid is causing increasing concern about undesirable side effects due to excessive intake of the synthetic form of the vitamin. The aim of the VITALAB project is therefore to biotechnologically enrich whey with folates by adding fruit by-products with the help of selected folate-producing lactic acid bacteria (LAB). VITALAB was launched in spring 2020 as part of the Bioeconomy International 2017 initiative, which is jointly funded by the German Federal Ministry of Education and Research (BMBF) and the São Paulo Research Foundation (FAPESP). The project has a duration of 36 months and is being carried out by the Chair of Pharmaceutical and Biochemical Technology and the Chair of Food and Experimental Nutrition at the School of Pharmaceutical Sciences, University of São Paulo (USP), São Paulo, Brazil and the Chair of Analytical Food Chemistry at the TUM School of Life Sciences, Technical University of Munich (TUM).
Fruit and milk processing is a huge industry in Brazil and the valuable by-products (e.g. fruit peel, egg yolk) are currently wasted or not reused in large quantities. These side streams are therefore to be used as substrates for fermentation in order to optimise folate production. This innovative process therefore represents an interesting alternative for bio-enrichment and increasing the folate content in food. The development of these products not only increases the supply of this important vitamin in Germany and Brazil, but also reduces waste in food production and processing. This supports the Global Initiative against Food Losses and Waste of the Food and Agriculture Organisation of the United Nations (FAO). Waste reduction is also of great importance for sustainable consumption and production, number 12 of the 17 Sustainable Development Goals of the United Nations. In addition, goal number 2 is also addressed, namely "No Hunger", as "hidden hunger" due to vitamin deficiencies can be reduced.
Furthermore, the project is part of the internationalisation strategies of TUM and USP. The USP project partner has extensive experience in food microbiology and investigates pathogenic and beneficial microbes in food. Recent research of the group has focussed on the study and application of lactic acid bacteria and probiotic strains, which are capable of producing a variety of beneficial bioactive compounds such as vitamins, proteolytic enzymes and other antimicrobial peptides. The TUM group has many years of experience in the development of analytical methods for bioactive trace substances, especially for folates. For folates, the TUM group has developed a stable isotope dilution assay (SIDA) that covers all relevant vitamers and the polyglutamate forms. In addition to analysing the folate content in foods, the TUM group has also investigated the bioavailability of folates from foods in various human studies.
VITALAB consists of six different work packages (WP), of which the Chair of Analytical Food Chemistry in cooperation with the ZIEL Institute for Nutrition & Health at TUM covers package 2 (exact quantification of the total folate content and folate vitamin distribution) and the human study (WP 5). In addition, the sensory evaluation (WP 6) will be carried out at TUM. The group at USP, namely Prof. Bernadette Dora Gombossy de Melo Franco, Prof. Susana Marta Isay Saad and M.Sc. Ana Clara Candelária Cucick will be responsible for package 1 (screening of lactic acid bacteria for folate production) and the optimisation of technological processes for maximum folate content (WP 3). In addition, the bioavailability of folates from the product will be determined in animal models (WP 4) under the supervision of the USP.
- WP 1: Screening of lactic acid bacteria (LAB) for folate production
Lactic acid bacteria are analysed for their folate production in conventional culture media. Folate synthesis is then tested on whey to which various industrial fruit by-products are added. To this end, the folates formed are first determined using microbiological analysis methods. The fruit by-products, which were selected according to their availability in the fruit industry in the state of São Paulo, come from the processing of dragon fruit (pitahaya), passion fruit and grapes.
- WP 2: Precise quantification of the total folate content and folate vitamin distribution
Stable isotope dilution analysis (SIDA) using stable isotopologues of folate vitamers, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, is used for the products with the highest folate content. In this way, a precise determination of the content of promising strain-substrate combinations is achieved. This also enables the determination of individual folate vitamers and the prediction of the bioavailability of the folates produced.
- WP 3: Optimisation of technological processes for maximum folate content
The physical, chemical and microbiological properties of whey and fruit by-products as well as the optimal time, temperature and pH conditions for in situ folate production will be determined.
- WP 4: Evaluation of the bioavailability of folates from the product in animal models
Two protocols for evaluating the bioavailability of the folates formed in the whey products will be carried out in mice. One is a depletion-repletion model in which the animals are initially exposed to a vitamin deficiency and the other is a prevention study in which the animals are fed a low-vitamin diet together with the test products.
- WP 5: Assessment of the Bioavailability of Folate from the Product in Human Studies
The bioavailability of folate in the products is determined through a human study. Promising products with high folate content are tested on six volunteers in short-term studies. Blood plasma samples are collected, and plasma folate curves are measured using SIDA.
- WP 6: Evaluation of the Sensory Properties of the Produced Products
The products that have shown promising results in animal and human studies are finally tested for their sensory acceptance.
Figure 1: Workflow of VITALAB.