بررسي ويژگي هاي فيزيكي و حسي شير غني شده با ويتامين D3 ريز پوشينه شده

چكيده انگليسي :

78 Physical and Sensory Properties of Enriched Milk with Microencapsulated Vitamin D3 Samaneh yari s yari@ag iut ac ir August 2014 Department of Food Science and Technology Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Ali Nasirpour ali nasirpour@cc iut ac ir Milad Fathi mfathi@cc iut ac irAbstractVitamin D is a group of steroid compounds with the characteristics of antirachitic It is fat soluble vitamin It can function the same as hormones Vitamin D3 is a natural form of vitamin D It enhances calcium andphosphor absorptions in body and plays an important role in supporting bones Since vitamin D decreasesduring storage and food processing it is necessary to produce stable forms One methods for stabilizing ismicroencapsulation Thus microcapsules of vitamin D3 can be considered as an effective approach topreserve vitamin D3 from environmental factors particularly oxygen To achieve this goal complexcoacervation of gelatin and Arabic gum utilized Lactose as a cryoprotectant used in production ofmicrocapsules The Response Surface Methodology was used to determine the ratio of gelatin Arabic gum lactose and duration of acidification The procedure was implemented to achieve the highest efficiency ofmicrocapsulation To produce microcapsules vitamin D3 was added to olive oil at 25 C Olive oil wasmixed with gelatin solution for 5 min at 6000 rpm using homogenizer to produce o w emulsion Afterforming the emulsion Arabic gum solution was added to the emulsions at 3000 rpm for 2 min and aqueoussolution of lactose was added to the mixture Mixture temperature was adjusted at 50 C and mixed for 5min at 50 C then acidified to pH 4 Finally the obtained microcapsules were freezed at 18 C and thenfreeze dried at 45 C for 24 h Microcapsulated oil was extracted by hexane and microcapsulationefficiency was estimated Based on the results the quadratic model was the best model to describe theefficiency Optical microscope images of microcapsules showed cores were completely surrounded by wallmaterials In SEM image microcapsules were spherical and had almost smooth surfaces Obtainedmicrocapsules was added to the whole milk Physicochemical and sensory properties of milk fortified bymicrocapsules and that of fortified by vitamin D3 crystalline were compared in 7 days Acidity and pH ofthe samples were within normal range during 7 days The viscosity of milk enriched with microcapsules ofvitamin D3 was higher than the other sample There was no significant difference in the sensorycharacteristics of two enriched milks and non enriched milk It is worthwhile to mention that due tooxidation of vitamin D3 the amount of this vitamin decreases in milk fortified with vitamin D3 crystalline The study indicated that fortifying milk with microcapsules containing vitamin D3 releases vitamin D3gradually The amount of release was 7 15 in 7 days Considering the results of the research the shelf life of fortified milk can be enhanced by this method So it is possible to utilize microcapsules of vitaminD3 instead of crystallized vitamin D3 for milk fortification Keywords Vitamin D3 Microencapsulation Milk Physical properties Fortification

ياري، سمانه

بررسي ويژگي هاي فيزيكي و حسي شير غني شده با ويتامين D3 ريز پوشينه شده

خصوصيات فيزيكي