The effects of ripening stage and processing systems on vitamin C content in sweet peppers (Capsicum annuum L.)

Abstract

Morrón pepper of ‘Fresno de la Vega’ (Capsicum annuum L.) is a big sweet variety cultivated in the province of León (northwestern Spain). Changes in vitamin C content of this variety of pepper as a function of ripeness, storage and different preservation systems were studied. The ascorbic acid content increases in peppers as they ripen. For green mature, breaker and red peppers values of 107.3±1.84, 129.6±3.11 and 154.3±7.56 mg/100 g edible portion were found. The vitamin C content for green mature and breaker peppers stored at room temperature (20°C) increased up to 10 days of storage, reaching similar values as those obtained for red peppers direct from the plant. However, stored red ripe peppers showed a significant loss in vitamin C content, around 25%. Refrigeration at 4°C for up to 20 days did not change the ascorbic acid content, except for red peppers, which showed losses around 15%.The ascorbic acid content was altered in response to the preservation procedures assayed. Reductions of 12% and 20–25% during the water blanching and canning process, respectively, were observed. Ascorbic acid retention during freezing was 60%, increasing when the product was previously blanched (87%). Dehydration of peppers resulted in an 88% decrease in ascorbic acid content, whereas freeze-drying did not cause significant losses.