Utjecaj količine inokuluma na rast i preživljavanje Lactobacillus acidophilus u sirutki

master's thesis

• Title (english): Influence of inoculation level on growth and viability Lactobacillus acidophilus in whey
• Author: Marina Miloš
• 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: 2008-06-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Sirutka je nutritivno visokovrijedan proizvod koji je nedovoljno iskorišten u prehrani ljudi. Fermentacijom sirutke može se dobiti senzorski prihvatljiviji proizvod, a kad se fermentacija provodi sa probiotičkim bakterijama dodatno se povećava njegova nutritivna i zdrastvena vrijednost. U radu je ispitivan utjecaj dodatka različitih količina inokuluma (2%, 4% i 6%) probiotičke bakterije Lactobacillus acidophilus La-5 na trajanje fermentacije rekonstituirane slatke sirutke te broj živih bakterijskih stanica tijekom fermentacije i 28 dana čuvanja uzoraka u hladnjaku. Fermentacija se odvijala na 37°C. Tijekom fermentacije i čuvanja praćena je pH- vrijednost, titracijska kiselost i broj živih stanica bakterija. Fermentacija s 6% inokuluma trajala je najkraće (u prosjeku 13,25 sati), dok je fermentacija s 2% inokuluma trajala najduže (u prosjeku 15,5 sati). Broj živih bakterijskih stanica se tijekom fermentacije, za sve uzorke, povećao za oko 1,3 log10CFU/mL i na kraju fermentacije je iznosio oko 8,5 log10CFU/mL. Količina inokuluma nije utjecala na preživljavanje bakterija u sirutki tijekom čuvanja uzoraka. Prosječno smanjenje broja bakterijskih stanica tijekom čuvanja bilo je 0,32 log10/mL.

Abstract (english)

Whey is nutritive valuable product but poorly used in human diet. By whey fermentation with lactic acid bacteria acceptable product is produced and if whey is fermented with probiotic bacterium it has increased nutritive and health value. Influence of different inoculation levels (2%, 4%, 6%) of probiotic bacteria Lactobacillus acidophilus La-5 on fermentation time of reconstituted sweet whey and viable cells count in the end of fermentation and during 28 days cold storage was object of the research. Fermentation was conducted at 37°C. Changes of pH- values, titratable acidity and viable cells count were measured during fermentation and storage. The highest inoculate level (6%) of lactobacili reduced fermentation time for 2.25 hours compared to lowest inoculate level (2%). Fermentation time with lowest inoculate level lasted in average 15.5 hours whereas fermentation time with highest inoculate level lasted in average 13.25 hours. Viable cells count during fermentation has increased for 1.3 log10CFU/mL and was in average 8.5 log10CFU/mL. Viable cells count during cold storage has decreased for 0.32 log10CFU/mL.

• Keywords: fermentacija; Lactobacillus acidophilus; preživljavanje; sirutka
• Keywords (english): fermentation; Lactobacillus acidophilus; viability; whey
• Language: croatian
• URN:NBN: urn:nbn:hr:159:719943
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-04 07:25:14