5759

5374

كارشناسي ارشد

علوم و صنايع غذايي

اصفهان:دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1389

چهارده،159ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

صبيحه سليمانيان زاد، محمود شيخ زين الدين

علي نصيرپور

28/1/90

مهدي كديور، حميدرضا رحماني

مهندسي كشاورزي

ID5374

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Effect of Microencapsulation on Stability and Release Rate of a Native Lactobacillus plantarum Compared with Lactobacillus casei Under Different Stresses Safura Akbari s akbari@ag iut ac ir March 15 2011 Department of Food Science and Technology Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Sabihe Soleimanian Zad soleiman@cc iut ac ir Mahmood Sheikh Zeinoddin zeinodin@cc iut ac ir Abstract At present people know a lot about the benefits of functional foods and a large part of the food bazaar has been allocated to this group of foods The functional foods which contain probiotic microbes are more favourable To achieve the beneficial effects a minimum of 6 Log cfu mL should be colonised in the epitellial cells in colon Microencapsulation technology is one of the suggested methods to protect the probiotics against the harsh conditions of food process storage and gastrointestinal fluid Simulation of different stresses effects during the food processing on the microcapsules seems necessary to estimate the usability of the microcapsules in different products and during the storage time Because of this selection of a suitable bed with specific characteristics similar to the food should be considered Also it is essential to study the survival ability of native species against the processing stresses to improve the beneficial effects of peobiotics on the consumers In this project after optimization of the microencapsulation method the microcapsules were prepared and photographed by Reflection optical microscopy and Scanning electron microscopy SEM to characterise their morphological characteristics and finally the optimum process parameters were introduced Afterwards native Lactobacillus plantarum A7 and commercial Lactobacillus casei ATCC 39392 were simultaneously encapsulated and then 1g of both microencapsulated cultures were separately transferred to distilled water and skimmed milk to evaluate their stability and release rate of the cells to different processing environments At the same time Non encapsulated cells with the same ratio were studied too The results showed that 200 rpm 20 aggitation time for emulsion forming and 5 aggitation time for capsules forming were the best The microcapsules had spherical shape with a smooth surface Totally L plantarum had a good stability to different processing conditions and during storage period compared with the commercial L casei In this study skimmed milk medium because of its protein and sugar contents had better protective effects to the stresses except homogenization in comparison with distilled water Since skimmed milk is the base of dairy products It could be said that dairy products are appropriate beds for the encapsulated probiotics This bed can also protect the structure of microcapsules Among the exerted stresses 90 C and pH 3 were the most fatal stresses and homogenization had no significant effect on the encapsulated cells p 0 05 Evaluation of the release rate showed that although the encapsulated cells were counted lower than the inoculated number but the products which contain them can be called as probiotic In conclusion microencapsulation can protect the minimum number of probiotics in the food under different process and also L plantarum because of its high stability to the exerted stresses is a good choice for using in the probiotic dairy products Keywords Microencapsulation probiotic Reflection optical microscopy Scanning electron microscopy SEM Lactobacillus plantarum A7 Lactobacillus casei ATCC 39392

صبيحه سليمانيان زاد، محمود شيخ زين الدين

علي نصيرپور

مهدي كديور، حميدرضا رحماني