Surveying the Effect of Quince seed Mucilage as a Fat Replacer on Texture and Physicochemical Properties of Semi Fat Set Yoghurt

Hydrocolloids or gums are used in the food industries to control and improve the functionality traits of food products such as bulking, gelling agent, syneresis control, and emulsion or suspension stability. Use of hydrocolloids such as guar, xanthan, carrageenan and pectin as fat mimetic in food products had been studied. Quince seed mucilage is a complex of a cellulosic fraction with accompanying with arabinose, a mixture of methylated and unmethylated aldobionic acids and xylose. After extraction, quince seed mucilage before incubation in amounts of 0.03%, 0.05% and 0.1% (w/w) were added to milk. Tests for measuring acidity, syneresis, color and the texture profile analysis test were done for semi fat samples containing quince seed mucilage and semi fat and full fat blank samples. The acidity, color and texture properties: cohesiveness, adhesiveness, stringiness, in semi fat yogurts containing quince seed mucilage had no significant difference with semi fat and full fat blank samples. The amounts of syneresis in samples containing quince seed hydrocolloid were decreased in comparison with semi fat blank samples. In texture properties, the amounts of hardness, gumminess and chewiness in yogurts containing quince seed hydrocolloid were lower than semi fat and full fat blank samples. It seems that negative charge of quince seed mucilage in interaction with positive charge of casein micelles leads to decrease the syneresis but this hydrocolloid did not make a gel to increase hardness, gumminess and springiness in yogurts containing quince seed mucilage.