Application of lactic acid bacteria for development of innovative potato protein-based yogurt alternatives

master's thesis

• Title (croatian): Primjena bakterija mliječne kiseline u razvoju inovativnih proizvoda sličnih jogurtu na bazi proteina krumpira
• Author: Kristina Crnko-Kovač
• Mentor: Jasna Novak (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Antibiotic, Enzyme, Probiotic and Starter Cultures Technology); Zagreb
• Defense date and country: 2021-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

The aim of this thesis was to develop innovative potato protein-based dairy fermented alternatives. The composition of nutrient media with modified sources of carbon and nitrogen, essentially from potato, has been optimized to select potential starter cultures in industrial production from a collection of 119 microorganisms, mostly lactic acid bacteria (LAB) and several strains of yeast and fungi. The tested strains were isolated from the plant microenvironments primarily potatoes or their peel as a sustainable source. Additionally, after defining the composition of the non food-grade media, a food-grade food matrix for the laboratory-scale fermentation process was developed. Finally, 4 LAB strains were selected, Leuconostoc pseudomesenteroides, Lactococcus lactis subsp. lactis, Leuconostoc mesenteroides subsp. mesenteroides and Lactococcus lactis subsp. cremoris, for the fermentation process. Strain growth was monitored by determining the number of bacterial colonies (CFU mL-1) and the optical density of the cell suspension (OD600), and by measuring the acidification rate in the experimental media using iCinac instrument. Innovative products have been developed using two different potato protein concentrates, Protafy and KMC Food. Sensory analysis of 4 innovative products was conducted by an expert panel. This work is a contribution to research aimed at the sustainability of potato production using LAB, which are among the most industrially important microorganisms.

Abstract (croatian)

Cilj ovog rada bio je razvoj inovativnih fermentiranih proizvoda na bazi proteina krumpira kao alternativa jogurtu. Optimiran je sastav hranjivih medija s modificiranim izvorima dušika, prvenstveno porijeklom iz krumpira, te ugljika za odabir potencijalnih starter kultura u industrijskoj proizvodnji iz kolekcije mikroorganizama od ukupno 119 sojeva od kojih većina pripada rodovima bakterija mliječne kiseline (BMK), a preostali sojevima kvasca ili funga. Analizirani sojevi su dio mikrobne populacije biljnih mikrookoliša, prvenstveno krumpira i nusproizvoda poput kore krumpira kao sekundarne sirovine. U konačnici odabrana su 4 soja BMK, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides subsp. mesenteroides i Leuconostoc pseudomesenteroides, za proces fermentacije inovativnih prehrambenih proizvoda, te je definiran sastav prehrambenog matriksa kao temelj za fermentaciju. Rast sojeva praćen je određivanjem broja bakterijskih kolonija (CFU mL-1) i optičke gustoće suspenzije stanica (OD600), te mjerenjem brzine zakiseljavanja u eksperimentalnim medijima pomoću iCinac uređaja. Inovativni proizvodi su razvijeni korištenjem dva različita koncentrata proteina krumpira komercijalnog naziva Protafy i KMC Food. Senzorsku analizu 4 inovativna proizvoda proveo je stručni panel. Ovaj rad je doprinos istraživanjima s ciljem održivosti proizvodnje krumpira primjenom BMK koji su među industrijski najznačajnijim mikroorganizmima.

• Keywords: dairy alternatives; lactic acid bacteria; innovative products; potato proteins; sustainability
• Keywords (english): mliječne alternative; bakterije mliječne kiseline; inovativni proizvodi; proteini krumpira; održivost
• Language: english
• URN:NBN: urn:nbn:hr:159:269718
• Study programme: Title: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra nutricionizma (magistar/magistra nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-05-26 12:33:38