Proizvodnja svježeg kozjeg sira uz dodatak autohtonih probiotičkih bakterija mliječne kiseline

master's thesis

• Title (english): Production of fresh goat cheese using autochthonous probiotic lactic acid bacteria
• Author: Hrvoje Kozjak
• Mentor: Blaženka Kos (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: 2011-04-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Cilj ovog diplomskog rada je bio istražiti utjecaj autohtonih probiotičkih bakterija Enterococcus faecium A7 i Lactobacillus fermentum A8 na fizikalno-kemijska i senzorska svojstva svježeg kozjeg sira proizvedenog uz dodatak ovih bakterija i komercijalne starter kulture. Za proizvodnju svježeg sira korišteno je pasterizirano svježe mlijeko s prosječno 3,54 % mliječne masti. U radu je određivan fizikalno-kemijski sastav svježeg kozjeg mlijeka, trajanje fermentacije, prinos, prosječna pH vrijednost i senzorska svojstva svježeg sira tijekom 10 dana čuvanja pri + 4°C. Također je određivan broj živih stanica probiotičkih bakterija tijekom 10 dana čuvanja svježeg sira pri + 4°C. Utvrđeno je da dodatak probiotičkih bakterija nije imao utjecaja na trajanje fermentacije i prinos svježeg sira. Prosječna pH vrijednost svježeg sira s dodatkom probiotičkih bakterija bila je manja nego u svježem siru proizvedenom s komercijalnom starter kulturom, a bez dodatka probiotičkih bakterija. Broj živih stanica probiotičkih bakterija je nakon 10 dana čuvanja ostao visok i iznosio je 4,23 x 107 CFU g-1. Parametri senzorske procjene izgleda, konzistencije i mirisa su nakon 10 dana čuvanja bili bolji u svježem siru s dodatkom probiotičkih kultura, nego u siru proizvedenom samo s komercijalnom starter kulturom.

Abstract (english)

The aim of this graduate thesis was to investigate the influence of the autochthonous probiotic bacteria Enterococcus faecium A7 and Lactobacillus fermentum A8 on the physico-chemical and sensoric properties of fresh goat cheese produced with these bacteria and with commercial starter culture. Fresh pasterized goat milk with 3,54 % of milk fat was used for the fresh goat cheese production. Physico-chemical parameters of fresh goat milk, fermentation time, yield, average pH value and sensoric properties during 10 days of storage at + 4°C were determined. The viable count of the probiotic bacteria during 10 days of storage at + 4°C was also determined. It has been shown that probiotic bacteria did not have any influence on the fermentation time and yield of fresh goat cheese. Average pH value of fresh cheese with the probiotic bacteria was lower than in fresh cheese produced with commercial starter cultures without the probiotic bacteria.The viable count of the probiotic bacteria remained high during 10 days of storage. Sensoric properties (apperance, consistency and scent) during 10 days of storage were better in fresh goat cheese produced with the probiotic bacteria than in fresh goat cheese produced only with commercial starter cultures.

• Keywords: svježi kozji sir; Enterococcus faecium; Lactobacillus fermentum; probiotik; senzorska svojstva
• Keywords (english): fresh goat cheese; Enterococcus faecium; Lactobacillus fermentum; probiotic; sensoric properties
• Language: croatian
• URN:NBN: urn:nbn:hr:159:270500
• Study programme: Title: Biotechnology; specializations in: Biochemical Engineering; Course: Biochemical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo (diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-30 08:11:24