Studies on the factors affecting the physico-chemical and organoleptic properties of kinnow juice

Four extraction methods, i.e., screw type extractor, superfine pulper, hydr aulic press and rosing machine; three pretreatments i.e., lye treatment of segments, ethrel treatment and chilling of fruit and different levels of ad ditives such as sugar, salt and chatmasala were used for the study. Juices from screw type extractor and superfine pulper were adjudged the first and second by the panelists respectively. Lye treatment of segments resulted in lowering of total soluble solids, total solids, total sugars, ash and acid contents of juice but improved the flavour scores significantly. Ethrel tr eatment of fruit resulted in increases in total soluble solids, reducing su gars, total sugars and decrease in pectin content. Chilling of fruit before extraction of juice had no significant effect on the physico-chemical and organoleptic properties of juice. The juice having 16 degrees Brix (with ad ded sugar), 0.2% common salt or 0.2% chatmasala got the highest organolepti c scores. Total soluble solids, total solids, pH, acid, ash, pectin and sal t contents remained unchanged. The reducing sugars and non-enzymatic browni ng increased significantly, whereas ascorbic acid decreased significantly d uring storage. Juices were found organoleptically acceptable up to six mont hs of storage at room temperature (15-40 degreesC).