Effects of Sterilization Temperature on the Quality of Carrot Purees

Carrot puree, vacuum-packed in retortable glass jar, was processed at 115, 120, and 125degreesC, and F-0 value of 6 to evaluate thermal processing effect,on food components and sensory qualities of carrot puree. Sterilization of carrot puree at 115, 120, and 125degreesC required 44, 24, and 18 min, respectively. Physicochemical compositions of carrot purees were: moisture 88.82-90.92%, soluble solid 8.47-8.80 degreesBrix, dietary fiber 0.98-1.47%, and pH 5.31-5.66. Hunter's L, a, and b values of carrot purees decreased significantly after sterilization (p<0.05). Contents of vitamins (P-carotene, total carotene, thiamin, riboflavin, and ascorbic acid) and free amino: acids generally decreased slightly after sterilization, whereas sugar contents increased. Sucrose content and color preference of carrot puree sterilized at 125degreesC were the highest. Judging from nutritional values and sensory evaluations, sterilization at 125degreesC for 18 min was the optimal processing condition for minimizing quality impairment of retort carrot purees.