3593

3396

كارشناسي ارشد

علوم و صنايع غذايي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1385

دوازده، 1100، [II] ص.: جدول

ص. ع. به فارسي و انگليسي

محمود شيخ زين الدين، شهرام دخاني

صبيحه سليمانيان زاد، محمد شاهدي

86/4/27

ناصر همدمي، نفيسه نيلي

1396/02/25

كتابنامه

كشاورزي

مهندسي كشاورزي

ID3396

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

AbstractSome species of lactic acid bacteria produce exocellular polysaccharides EPS EPS playmajor technological role in the production of fermented dairy products particularlyproduction of yoghurt Their production considerably contributes to texture rheology mouthfeel taste perception and stability of the final products In addition health benefitshave been attributed to some of the bacterial EPS particularly antitumor andimmunomodulating activities The aim of this study was to determine EPS concentration insome of traditional and commercial yoghurts and to investigate EPS effects on physicalcharacteristics of these products Three traditional yoghurt S1 S2 made of mixture of cowand sheep milk and G made of cow milk were compared with a widely distributed industrial yoghurt type I Experimental data showed that there were significant differencesin chemical and physical properties of the yoghurt samples including fat content solid nonfat content pH EPS concentration apparent viscosity extensibility and susceptibility tosyneresis Statiscal analysis showed that amount of EPS and viscosity or decreasingsusceptibility to syneresis were highly correlated p 0 05 where as no direct correlationwere found between SNF or fat content and physical properties of above mentionedsamples To eliminate effect of milk composition on the physico chemical properties ofyoghurt reconstituted skim milk used to prepare yoghurt using four yoghurt samples as thestarter at 37 C and 42 C Result showed that physical properties of yoghurt made bydifferent mix culture were significantly different As expected in general 37 C seemed toproduce better quality yoghurt than 42 C Bacterial mixture in S2 sample produced higheramount of EPS and at the same time highest viscosity among other samples thereforeextensibility and lower syneresis were observed in the yoghurt made by it The resultssuggest that the physical characteristics of yoghurt can be improved by the use of EPS producing starter culture Moreover the Iranian traditional yoghurts are the importantsources for isolation and production of these starters for future trends

محمود شيخ زين الدين، شهرام دخاني

صبيحه سليمانيان زاد، محمد شاهدي

ناصر همدمي، نفيسه نيلي