Effect of processing treatments on the carotenoids composition of dehydrated carrots

Effect of different blanching (steam. water and microwave) and drying (cabi net and fluidised-bed-drying) methods on the stability of total carotenoids in carrots and their composition was studied. Apparant increases in total carotenoids. when expressed on dry weight basis were found to be due to lea ching of soluble solids, which ranged from 3.9 to 11.0%. When expressed on total insoluble solids basis, the total carotenoids decreased by 9.9 to 10. 6% during blanching operations. Losses of total carotenoids were higher in unblanched carrots as well as in fluidized bed-dried samples as compared to blanched and cabinet-dried ones, respectively. During storage, the losses were higher in fluidized-bed-dried samples than cabinet-dried ones. Also, c arotenoid degradation was fastest In water-blanched samples and least in st eam-blanched samples. Of the carotenoids, beta-carotene degraded fastest, w hile lutein degraded slowest during storage. Development of non-enzymatic b rowning (NEB) during storage was also influenced by the blanching treatment s. Water-blanched samples turned brown at the slowest rate, while unblanche d samples browned at the fastest rate.