6942

6484

كارشناسي ارشد

علوم و صنايع غذايي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1390

شانزده، 116ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

محمود شيخ زين الدين، محمد شاهدي

صبيحه سليمانيان زاد

21/5/91

مهدي كديور، مسعود عليخاني

1396/09/18

كتابنامه

كشاورزي

مهندسي كشاورزي

ID6484

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Effect of Fat Content and Local and Industrial Starter Culture on the Shelf Life and Organoleptic Properties of Yoghurt lham Saemi Arani mail address elisa Agri yahoo com Feb Department college of Food science and Technology Isfahan University of Technology Isfahan Iran Degree M Sc Language Farsi Mahmood sheikh zeinoddin zeinodin cc iut ac ir Mohammad shahedi shahedim cc iut ac irAbstract The objective of this study was to evaluate potential of autochtonous yoghurt starter to producee opolysaccharides to improve the te ture of low fat yogurt as a popular and healthy food This studywas performed in two sections microbiological and technological In microbiological section fourindiginous locally isolated strains of Lactobacillus delbrueckii bulgaricus coded Is Is Is and IB Microbial collection Food biotechnology Lab Isfahan University of Technology along with a purecommercial strain of Streptococcus thermophillus Hansen Co Denmark were used as four starterculture samples A commercial strain of L bulgaricus coded Hansen Co Denmark was also usedas a positive control Technological section of this study was carried out in three stages In the firststage yogurt prepared from local and industrial starter cultures using restructured skimmed milkcontaining and percent fat and total solid of and percent Physical properties of producedyogurts includin viscosity syneresis tensile and penetration were evaluated at first seventh andfourteenth days of cold storage Results of this stage showed that local starters IS and IB hadbetter performance in terms of physical properties than other starters Statistical Analysis of the resultsshowed that fat total solids and e starter had a signi cant e ects p on physical properties of theyoghurt samples In the second stage Yoghurt was prepared from using IS IB and the commercialstrain as the posi ve control Results showed that fat and starters signi cantly P e ectedthe physical proper es of the products Yogurts made by using IS ranked the best in terms of physicalproperties In the third sec on of the research one percent sucrose with percent dried milk was usedinorder to study the variation of nutrient media of starters Results of this section showed that physicalincluding sucrose so that sucrose can be used as a good substiuent to increase the total solid of milk Inaddition studying the amount of polysaccaride splashed by local or industrial starters in second andthird stages of the e periment showed that local starters specially IS produced more amounts ofe opolysaccaride than industrial starters as it can be recognized that ability of these local starters inproduction of e opolysaccarides could have been able to make good tissue properties in yoghurts Infinal section produced yoghurts in second and third sections of the search were studied The results ofthis section showed that yoghurts produced from local starters had more advantages than thosedproduced from industrial starters in terms of flavor Smell Tissue and appearale Finally results of thisstudy showed that local starters can be good sulostituents for imported industrial starters And can be asufficient solution to remove the disadvantages in production of yoghurt with industrial starters bymaking desirable tissue properties in many case Keywords Yoghurt Starter culture Lactic acid bacteria Physical property

محمود شيخ زين الدين، محمد شاهدي

صبيحه سليمانيان زاد

مهدي كديور، مسعود عليخاني