Effects of air-drying temperature on physico-chemical properties, antioxidant capacity and total phenolic content of red pepper (Capsicum annuum, L. var. Hungarian)

ANTONIO VEGA-GÁLVEZ; KARINA DI SCALA; KATIA RODRÍGUEZ; ROBERTO LEMUS-MONDACA; MARGARITA MIRANDA; JESSICA LÓPEZ; MARIO PÉREZ-WON

FOOD CHEMISTRY

Elsevier

Año: 2009 vol. 117 p. 647 - 653

0308-8146

Red pepper has been recognized as an excellent source of antioxidants, being rich in ascorbic acid and other phytochemicals. Drying conditions, particularly temperature, leads to pepper modifications that can cause quality degradation. In this work, the effects of process temperatures between 50 and 90C on physico-chemical properties, rehydration, colour, texture, vitamin C, antioxidant capacity and total phenolics during the drying of red pepper were studied. The rehydration ratio decreased with temperature and the maximum Water Holding Capacity was achieved at 50º C. Both, vitamin C content and the total phenolic content decreased as air-drying temperature decreased. The radical scavenging activity showed higher antioxidant activity at high temperatures (i.e. 80 and 90C) rather than at low temperatures (i.e. 50, 60 and 70C). Chromatic parameters (L*, a*, b*, C* and Hº), non-enzymatic browning compounds and extractable colour were affected by drying temperature, which contributed to the discolouring of pepper during this process.