Development of innovative functional beverage with added probiotic bacteria

Cilj ovog rada je razvoj inovativnog funkcionalnog napitka na bazi sirutke izdvojene nakon proizvodnje sira s odabranim autohtonim bakterijama mliječne kiseline (BMK) koje iskazuju specifična svojstva značajna za proces fermentacije ili funkcionalnost konačnog proizvoda. Odabrana četiri autohtona soja BMK: Lactococcus brevis ZG1 koji eksprimira S-protein, Lactobacillus plantarum ZG1C koji sintetizira plantaricin, Lactobacillus fermentum D12 koji proizvodi egzopolisaharide i Lactococcus lactis ZG7-10 s proteolitičkim djelovanjem. Prema rezultatima, očuvan je visok broj bakterijskih stanica dodanih BMK nakon proizvodnje i tijekom skladištenja koncentrirane sirutke priređene liofilizacijom i tekuće sirutke. Analiza sirutke pokazala je da se radi o kiseloj sirutki s niskim udjelima masti i laktoze te su masenom spektrometrijom, prema preliminarnim rezultatima, dokazani peptidi čije se bioaktivno djelovanje mora još ustanoviti. Prisutnost odabranih autohtonih BMK je potvrđena analizom mikrobne populacije sirutke primjenom tehnika nove generacije sekvencioniranja. Prema provedenoj senzorskoj analizi, inovativni napitak na bazi sirutke može se proizvesti kao tekući napitak s dodatkom vanilije ili maline ali i u obliku koncentrirane sirutke nakon liofilizacije.The aim of this study is to develop an innovative functional whey-based beverage extracted after cheese production with selected autochthonous lactic acid bacteria (LAB), each of which exhibits specific properties relevant to the fermentation or functionality of the final product. Four different autochthonous LAB strains were selected: Lactococcus brevis ZG1 expressing S-protein, Lactobacillus plantarum ZG1C synthesizing plantaricin, Lactobacillus fermentum D12 producing exopolysaccharides and Lactococcus lactis ZG7-10 with proteolitic activity. According to the results, a high number of bacterial cells were preserved in samples after production and during storage of freeze-dried (concentrated) whey and liquid whey. Analysis of whey showed that it was acidic whey containing low fat and lactose content, while preliminary results of mass spectrometry, revealed the presence of peptides whose bioactive potential has yet to be established. The presence of selected autochthonous LAB was confirmed by analysis of the whey microbial population using New Generation Sequencing techniques. According to sensory analysis, an innovative whey-based beverage can be produced as a liquid beverage with the addition of vanilla or raspberry, but also in a form of concentrated whey after lyophilization