Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2001
Publication Date: 4/30/2001
Interpretive Summary: One of the most desirable aspects of strawberries for the consumer is their bright, attractive, red color. Unfortunately, processing and storage of this fruit contribute to the gradual change from the bright red color to an undesirable brown. This change limits the shelf life and marketability of strawberry products. Schemes to increase the retention of red color on processed strawberries would allow processors a larger window to deliver their products to the market. This work studied the effect of water content on the degradation of color present in strawberries. A direct relationship was found between water content and loss of red pigment in strawberries; by adjusting the water content, strawberry pigments were more stable. These results can be used to increase the color shelf life in strawberry products.
Technical Abstract: The stability of pelargonidin 3-glucoside, pelargonidin 3-sophoroside and pelargonidin 3-sophoroside 5-glucoside acylated with malonic and cinnamic acids was determined at varying water activities. Model systems containing purified anthocyanin in pH 3.4 citrate buffer and glycerol were stored at 25 deg C in the dark for 242 days. Changes in pigment, degradation index, and anthocyanin profile as monitored by HPLC were studied. In general, anthocyanin degradation followed first order kinetics and the degree of anthocyanin degradation increased with water activity. Half lives of the anthocyanins ranged from 56 to 934 days. Changes in the chromatographic profile showed hydrolysis of pelargonidin 3-sophoroside to pelargonidin 3-glucoside and hydrolysis of malonic acid from the acylated anthocyanin.