8841

8202

كارشناسي ارشد

علوم و صنايع غذايي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1392

سيزده،104ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمد شاهدي، علي نصيرپور

17/2/93

ناصر همدمي، آذرشاه پيري

مهندسي كشاورزي

ID8202

105 Effect of pH Temperature and Storage Time on the Interactions between Food Simulant and Yoghurt drink with Polyethylene terephthalate and Polyethylene Bottles Hajar Zaremoaiedy h zaremoaiedy@ag iut ac ir December 30 2013 Department of Food Science and Technology Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Mohammad Shahedi shahedim@cc iut ac ir Ali Nasirpour ali nasirpour@cc iut ac irAbstractPackaging has a major role in food processing Plastics have a special position in the world today becauseof their various applications such as food packaging But they are not quite inert and have the ability toreact with food Migration of low molecular material to food is important because of food qualityreduction and health affect In the other hand flavor absorption by packaging materials also decrease foodaroma and change package mechanical properties Both of these reasons reduce food quality In this studypolyethylene terephethalate and polyethylene interactions with yoghurt drink in three different pH 3 5 4and 4 5 and in three storage conditions sun room and frozen was evaluated On the study of migration overall migration of both polymers specific migration of Terephthalic acid TPA from PET and 1 hexene from PE measured by HPLC and GC Instruments Lactic acid was used as yoghurt drink foodsimulant and sampling was done monthly during the specified time period Then migration effect onmechanical property was evaluated by tensile test In the case of flavor absorption by PET and PEpolymers bottles filled by yoghurt drink and the concentration of Acetaldehyde absorbed by bottles atthree month storage at mentioned condition were measured Results showed that rate of both polymersoverall migration in all of treatments was lower than EU standards Specific migration of TPA and 1 hexene increased with decreasing pH over time Maximum immigration was seen in frozen state andminimum was at room condition Tensile strength decreased with increasing specific migration for twopolymers Result of absorption experiments showed Acetaldehyde absorption rate dependent to time andpH The highest absorption was seen in frozen state Tensile test results showed that tensile strength wasdecreased when absorption increased Keywords Packaging Polyethylene Terephthalate Polyethylene Migration Absorption Mechanical properties

محمد شاهدي، علي نصيرپور

ناصر همدمي، آذرشاه پيري