اثر پايداركننده ها و شرايط پيش پخت بر ويژگي هاي فيزيكي و حسي كنسرو دو رقم برنج بومي و رقم باسماتي طي نگهداري

چكيده انگليسي :

Effect of Stabilizers and Pre Cooking Condition on Physical and Sensory Properties of Rice Can Made of Two Iranian and Basmati Cultivars During Storage Hamid amiri marvili Hamid amiri63@gmail com December 21 2010 College of Agriculture Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor s A nasirpour E mail address ali nasirpour@cc iut ac ir Abstract Cultivated rice Oryza sativa L at present sustains two thirds of the world s population Rice is a cereal mainly consumed as a whole grain It is composed about 90 dry base of starch and gelatinization features strongly influence cooked rice texture Many rice cultivars provide differentent chemico physical properties such as appearance flavor and texture with different degrees of palatability Various products of rice is produced and One of the most important products from rice canned rice Canned rice is a ready to eat product consumed as a whole grain cereal product It is produced by packing cleaned milled rice into a can together with liquid such as soup or water wet pack or without liquid dry pack and then sterilized Starch gelatinization in rice kernels during thermal processing by steam contribute to texture changing During storage or cooling starch in the cooked rice undergoes retrogradation Amylose fraction retrogrades after cooking and during storage while the amylopectin remains in an amorphous state The amylopectin fraction maybe recrystalizes during storage and contributes to starch retrogradation During the storage this factors lead to reduced eating quality of cooked rice In the present work physico chemical properties and hydration kinetics of two Iranian rice cultivars Tarom Hashemi Tarom mahali mazandaran and one Indian rice cultivar Basmati was studied Then after physical and sensory properties of canned rice produced by the 3 cultivars were investigated In order to improve cooked rice texture and reducing retrogradation of the product during storage two types of stabilizers Xanthan Mono di glyceride were used The result of Physico Chemical properties shows that Basmati cultivar had the larger seed length lower bulk density higher 1000 kernel weight higher amylose and protein content L B length breath and elongation ratio were observed to be highest in Basmati and lowest in Iranian cooked rice In addition basmati had the higher water absorption during soaking and cooking and lower solid liberation to water during cooking These properties make Basmati cultivar suitable for canned rice Modeling of hydration kinetics shows that the Page Modified Page and logarithmic models are well fit soaking characteristic of the samples In start of storage Basmati had more hardness and lowest cohesivness in compare to Iranian cultivar During storage hardness for all cultivar increased and cohesivness deacresed Result of color measurement shows that that basmati had the highest b value positive yellowness and Tarom mazandaran had the higher L lightness value FT IR and texture result show that additives can reduce starch retrogradation during storage Finally sensory properties of the samples revealed that Basmati had the best appearance texture and total acceptance while Tarom hashemi had the best aroma and taste Key word Canned rice soaking precooking Retrogradation xanthan mono di glycerides

اميري مرويلي، حميد

اثر پايداركننده ها و شرايط پيش پخت بر ويژگي هاي فيزيكي و حسي كنسرو دو رقم برنج بومي و رقم باسماتي طي نگهداري

واگشتگي , زانتان , مونو-دي-گليسريد