Esaltazione delle proprietà nutrizionali native del latte e messa a punto di tecnologie per la loro conservazione e valorizzazione

Milk and dairy products (cheese, yoghurt, etc.) can be naturally modified and enriched with nutritional factors useful for consumer health; these food (called “functional”) together with a healthy life style may enhance the consumer health and welfare. The main objectives of the study were: i) define the possible feeding strategies to naturally enrich milk of cows with conjugated linoleic acid (CLA), omega-3 and vitamin B12; ii) set up a quantitative analytical method to detect B12 vitamin in milk and dairy products; iii) evaluate the content of CLA, omega3 and vitamin B12 in milk after thermal treatment and in cheese . Different feeding strategies were tested to obtain milk enriched; the evolution of the microflora during cheese making and its influence on CLA, omega3, fatty acids and vitamin B12 content of dairy products was also evaluated. Results showed that it is possible to modify the cow diet with different fat supplements enhancing the content of CLA and omega-3 fatty acids without significant adverse effects on the total fat content which may be incompatible with the production of high quality milk. In particular it is possible to produce milk with increased content of CLA, omega 3 and stearic acid; at the same time palmitic and myristic acids can be reduced; results showed also that this feeding strategy is more expensive compared to the usual rations utilized for the production of the standard milk. Thermal treatment and cheese making don’t influence the CLA content in dairy products and their content in CLA depends from the content of milk used for production. The analytical method set up for the quantitative analysis of Vitamin B12 in milk and dairy products proved to be satisfactory (sensitive and rapid); cobalamin supplementation of feed for cows caused an increase of Vitamin B12 in milk after four weeks. The most interesting data are relative to the concentration, during cheese making, of Vitamin B12 in whey and in whey cheese (ricotta cheese) where Vitamin B12 is tenfold concentrated respect to the milk used for processing.