Utjecaj temperature i prisutnosti glukoze na fermentaciju sojinog mlijeka mješovitom BCT kulturom

master's thesis

• Title (english): Influence of the temperature and glucose on the fermentation of soymilk with mixed BCT culture
• Author: Galja Pletikapić
• Mentor: Rajka Božanić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Milk and Milk Products); Zagreb
• Defense date and country: 2007-01-16, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Sojino mlijeko je fermentirano sa mješovitom BCT kulturom (Lactobacillus casei, Bifidobacterium spp. i Streptococcus thermpohilus). Fermentacija se provodila na dvije različite temperature (37 i 41 °C), sa i bez dodatka glukoze te uz različite koncentracije inokuluma. Tijekom fermentacije i čuvanja (28 dana na +4°C) pratio se pad pH, te broj pojedinih bakterija standardnim mikrobiološkim tehnikama. Primijećeno je da povišena temperatura skraćuje vrijeme trajanja fermentacije za 60-70 minuta, dok dodatak glukoze neznatno utječe na vrijeme trajanja fermentacije (skraćuje 20 minuta). Niti povišena temperatura, niti dodatak glukoze nisu bitno utjecali na zastupljenost pojedinih bakterijskih vrsti u proizvodu. Povišena koncentracija inokuluma je neznatno poboljšala rast bakterijskih vrsta Lactobacillus casei i Bifidobacterium spp. te skratila vrijeme fermentacije. Najbolji rast pokazivao je Streptococcus thermophilus (oko108 st/mL), a najslabije su rasli laktobacili (oko 105 -106 st/mL). Tijekom čuvanja proizvod je bio relativno stabilan. Do većeg pada pH i broja bakterija došlo je tek u posljednjem tjednu čuvanja. Temperatura i dodatak glukoze nisu utjecali na izgled i konzistenciju proizvoda dobivenog fermentacijom.

Abstract (english)

Soymilk is fermented with mixed BCT culture (Lactobacillus casei, Bifidobacterium spp. and Streptococcus thermophilus). Fermentation was performed on two different temperatures (37 and 41 °C), with and without glucose, and with different concentrations of inoculume. During the fermentation and storage (28 days on +4°C) we have observed the change of pH values and the growth of particular bacterial species with standard microbiological techniques. We noticed that higher temperature reduces time of fermentation, while the addition of glucose has slight influence on duration of fermentation (reducing 20 minutes). Neither higher temperature nor addition of glucose does not affect proportions of certain bacterial species in product. Higher concentration of inoculume has slightly increased the growth of bacterial species Lactobacillus casei and Bifidobacteria spp. and has had a small influence on the duration of the fermentation. The best growth has shown Streptococcus thermophilus (about 108 CFU/mL) while the most inferior growth has shown Lactobacilli (about 105 -106 CFU/mL). During the fermentation the product was mainly stable. The remarkable decrease of pH and the number of bacteria was noticed in the last week of storage. Temperature and addition of glucose did not significantly affect the aspect and consistency of product made by fermentation.

• Keywords: Bifidobacterium spp.; fermentacija; Lactobacillus casei; sojino mlijeko; Streptococcus thermophilus
• Keywords (english): Bifidobacterium spp.; fermentation; Lactobacillus casei; soymilk; Streptococcus thermophilus
• Language: croatian
• URN:NBN: urn:nbn:hr:159:700431
• Study programme: Title: Biotechnology; specializations in: Biochemical-Microbiology; Course: Biochemical-Microbiology; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko-mikrobiološki (diplomirani inženjer biotehnologije; smjer biokemijsko-mikrobiološki)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-06 10:26:41