EFECTO DEL TIEMPO DE ALMACENAMIENTO SOBRE PROPIEDADES FISICOQUÍMICAS Y ANTIOXIDANTES DE PRODUCTOS DERIVADOS DEL FRUTO AGRAZ (VACCINIUM MERIDIONALE SWARTZ)

Abstract

Background: Andean berry is a globose berry, deep purple when it reaches its highest degree of maturity. It fruit has a high antioxidant capacity compared to other Vaccinum berries, attributed to the content of polyphenolic compounds. Objectives: To evaluate the composition, antioxidant activity and some microbiological parameters of frozen pulp of Andean berry (PAC) and freeze-dried pulp of Andean berry (PAL) and analyze their behavior during 60 days of storage. Methods: the variables pH, ° Brix, titratable acidity, % moisture, ash, fat, protein, carbohydrates, total calories and water activity (lyophilized) were measured at intervals of 15 days during storage. Under the same conditions the content of phenols and total anthocyanins by Folin-Ciocalteu and pH differential method respectively was determined. The antioxidant activity by FRAP and ORAC. Results: There were no significant differences (p>0,05) during storage in pH, ° Brix, Aw (lyophilized), % moisture, fat, ash, carbohydrates and total calories for PAC and PAL indicating stability of these variables over time storage. Titratable acidity expressed in mg citric acid/ml, varied significantly p (<0.05) over time storage for PAC and PAL between 1.65 to 1.82 and 4.66 to 4.79 respectively. The protein varied during storage for PAC and PAL between 1.25 to 2.10 g and 4.70 to 5.20 g, and was observed for both a significant increase between day 15 and 60 of storage. PAC and PAL showed significant losses of anthocyanins, total phenols and FRAP value during storage; however the PAL retained until day 60 high content of total phenols: 1046 (mg gallic eq/100 g acid), anthocyanins: 82.64 (mg eq of cyanidin-3-glucoside/100g), reducing capacity (FRAP): 1032.17 mg ascorbic acid equivalents/100 g and ORAC value 33935 umol equivalents Trolox/100g. Conclusions: physicochemical variables analyzed in the PAL were stable and content of polyphenolic compounds retained for longer compared to PAC. Whereas Andean berry has two growing seasons a year in Colombia (May and December), freezedried is a strategy that will allow the producer constant supply of fruit on the market.