Changes in color of calcium enriched apple slices irradiated with UV-C light

GÓMEZ, PAULA; SALVATORI, DANIELA; ALZAMORA, STELLA M.

New Orleans, Louisiana, EEUU

Congreso; IFT 2010 Annual Meeting.; 2010

Institute of Food Technologists

In recent years there has been a growing interest in designing functional foods using vegetable matrices impregnated with physiologically active components. Previous studies have demonstrated the feasibility of the incorporation of calcium in fruit matrices by atmospheric impregnation processes. The development of fortified fruit products requires the application of appropriate conservation technologies to ensure microbiological safety during storage without compromising quality. UV-C light is an emerging technology that can be evaluated to extend the shelf life of these products. The objective of this work was to study the changes in color of calcium enriched apple slices irradiated with UV-C light and to evaluated the use of an antibrowning pretreatment in order to minimize enzymatic browning during refrigerated storage. Apple slices (3 cm diameter and 0.6 cm thickness) were impregnated at atmospheric pressure in aqueous solutions containing 12.6 % (w/w) glucose and 5.4 % (w/w) calcium salts. Prior to impregnation samples were treated with an antibrowning solution containing 1% (w/v) ascorbic acid + 0.1 (w/v) calcium chloride. For UV-C irradiation, they were placed at 10 cm distance from two germicidal lamps (253.7 nm, 15 W) at different exposure times (2-20 min) (UV-C dose: 1-11 KJ/m2). Slices impregnated and irradiated (with or without antibrowning solution) were compared to a control (fresh apple) throughout a week of storage at 4-5ºC. At selected intervals (0, 3 and 7 days), tristimulus color measurements were made on ten treated samples for each condition. Apple slices impregnated with calcium and irradiated with UV-C light showed a significant increased in surface browning during storage, being slightly higher in samples irradiated at higher UV-C dose. The antibrowning pretreatment was effective to reduce browning of treated samples. Changes in color of apple slices caused by calcium impregnation process and UV-C light radiation can be minimized applying a suitable antibrownig pretreatment.