EVALUATION OF CAROTENOID LOSSES ON INDUSTRIAL DEHYDRATION AND LYOPHILIZATION OF SPINACH

The presence of five carotenoids was confirmed in the spinach cultivar ''Nova Zelandia'': beta-carotene, violaxanthin, lutein, zeaxanthin and neoxanthin. The only provitamin A carotenoid was beta-carotene which accounted for 28% of the total carotenoid content. Losses on dehydration and lyophilization were not considerable. Beta-carotene decreased 12% and violaxanthin, lutein and zeaxanthin did not change significantly in both drying processes. Neoxanthin had an unexpected increase on air drying; this did not happen in lyophilization. The vitamin A values (retinol equivalents) were overestimated by 14 and 16% in fresh and dehydrated samples, respectively, when the beta-carotene isomers were not separated. Loss in retinol equivalents due to dehydration was 12% when calculated whithout isomer separation and 14% with separation. With freeze-drying, a significant loss of 13% was observed only when the calculation was based on the unseparated beta-carotene concentration361839