Production and characteristics of functional fermented whey based beverages

Količina proizvoda od surutke na tržištu je zanemarljivo mala u odnosu na količinu fermentisanih mlečnih proizvoda. To navodi na zaključak da bi se unapređenjem procesa fermentacije surutke mogli dobiti novi nekonvencionalni proizvodi koji bi zauzeli značajnije mesto u paleti mlečnih proizvoda namenjenih širokoj potrošnji. U tom smislu, cilj ove doktorske disertacije je bio proizvodnja i karakterisanje funkcionalnih fermentisanih napitaka na bazi surutke. U cilju proizvodnje funkcionalnih fermentisanih napitaka na bazi surutke izvršena je selekcija odgovarajuće kulture mikroorganizama, optimizacija procesa fermentacije i karakterizacija proizvedenog fermentisanog napitka. Tokom selekcije, optimizacije i karakterizacije praćeno je: vreme trajanja fermentacije, sadržaj mlečne kiseline, promena pH, preživljavanje mikroorganizama, sadržaj aminokiselina, sadržaj antioksidanasa, viskozitet, sinerezis kao i nutritivni sastav proizvedenog napitka. Takođe je izvršeno in vitro karakterisanje probiotske aktivnosti odabranih mikroorganizama praćenjem sposobnosti preživljavanja u uslovima simuliranog gastričnog soka, antimikrobne aktivnosti i rezistencije na antibiotike primenom klasičnih mikrobioloških tehnika. U sklopu nutritivne karakterizacije praćena je razgradnje proteina surutke nakon fermentacije. Proizvedeni napitak je nutritivno okarakterisan preračunavanjem nutritivne vrednosti proizvoda, što je predstavljalo polaznu tačku njegovog deklarisanja u skladu sa Pravilnikom o deklarisanju RS, označavanju i reklamiranju hrane 85/2013, ali i EU Regulative 1169/2011. Pored toga, u skladu sa nutritivnim sastavom, napitku su dodeljene nutritivne i/ili zdravstvene izjave odobrene od strane EFSA (European Food Safety Authority), prema EU Regulativi 11924/2011 i Direktivi 432/2012. Proizvod je upakovan u specijalno kreiranu ambalažu, koja je u skladu sa propisima za pakovanje mlečnih proizvoda, čime je dobijeni napitak u potpunosti pripremljen za plasman na tržište. Ispitivanje mogućnosti proizvodnje funkcionalnih fermentisanih napitaka na bazi surutke, primenom različitih sojeva bakterija mlečne kiseline pokazalo je da svi sojevi bakterija mlečne kiseline (ukupno 15) testirani u ovom istraživanju mogu biti primenjeni u procesu...Number of whey based products on the market is negligible compared to the number of fermented dairy products, which suggests that the improvement of the whey fermentation process could result in new unconventional products that take up a significant place in the wide range of dairy products intended for direct consumption. In accordance with that, the aim of this PhD thesis was the production and characterisation of functional fermented whey based beverages. In order to produce the functional fermented whey based beverages, selection of microorganisms, optimisation of the fermentation process and the characterisation of the produced beverages were carried out. During the selection, optimisation and characterisation, fermentation time, titratable acidity, pH value, amino acid content, antioxidative activity, viscosity, syneresis, as well as nutritional composition of produced beverages were followed. In vitro characterisation of probiotic character of the selected microorganisms, by tracking ability to survive under simulated gastric juice, antimicrobial activity and resistance to antibiotics using conventional microbiological techniques were also performed. Within the nutritional characterisation, percentage of whey protein degradation obtained after the fermentation, was examined. Manufactured beverages were nutritionally characterised by recalculating the nutritional value, which was the starting point of its declaration in accordance with the Serbian Regulations on declaration, labelling and advertising of food 85/2013. Also, in accordance with the nutritional composition of the beverages, nutritional and/or health claims approved by EFSA (European Food Safety Authority) and according to EU Regulation 1169/2011 and Regulation 432/2012 were given. The product was packaged in a specially created packaging that complies with the regulations for dairy products, and thus obtained beverage was fully prepared for the market. When examining the possibilities of whey based beverages production using different strains of lactic acid bacteria, it has been shown that all strains of lactic acid bacteria (total of 15) tested in this study can be applied in the production of functional fermented whey based..