Effect of Minimal Processing on Bioactive Compounds of Fresh-Cut Strawberries

VAN DE VELDE, FRANCO; PIAGENTINI, ANDREA; PIROVANI, MARIA ÉLIDA

STRAWBERRIES CULTIVATION, ANTIOXIDANT PROPERTIES AND HEALTH BENEFITS

Nova Sciences Publishers

Lugar: New York; Año: 2014; p. 269 - 282

Strawberries are an important source of bioactive compounds. Vitamin C and phenolic compounds have high antioxidant effects, beneficial for the maintenance of consumer´s health. The industrial minimal processing of strawberries involves selection, prewash, calyx and peduncle elimination, cutting, washing-disinfection and packaging. Each operation may cause changes in bioactive compounds. The washing-disinfection with peracetic acid was studied on quartered fresh-cut strawberries in order to quantify changes on bioactive compounds in `Camarosa´and `Selva´ cultivars. The loss of phenolics was constant within the experimental region assayed, but anthocyanins and ascorbic acid losses increased with concentration and time. The vitamin C loss was different for each cultivar. For ?Camarosa?, the loss was 10% when fruits were washed with peracetic acid up to 100 mg L-1 with immersion times from 10 to 120 s. However, in the case of ?Selva?, vitamin C loss was affected by processing variables. Stronger concentrations and longer times resulted in larger vitamin C losses. In general, cutting induces phenolic compounds biosynthesis, and these compounds are accumulated during storage. Whole without hull, halved and quartered ?Camarosa? strawberries were stored at 2°C during 15 d, 6°C -10 d , 13°C ? 9d and 20°C -3 d. On processing day, ascorbic acid, vitamin C, phenolics and anthocyanins were higher in hulled strawberries, decreasing with the degree of wounding. However, there were not significant differences on the antioxidant capacity of the strawberries with different cutting styles. During storage, the loss of ascorbic acid was lower in strawberries with a lesser degree of cutting and lower temperature. However, vitamin C remained constant through storage regardless of the cutting style and temperature. The mechanical injury produced an accumulation of phenolics which was expressed as a transient increase during the storage at different temperatures. The greater the mechanical injury practiced, the higher the peak. The phenolic peak was 23% higher than the initial content for quartered strawberries. Higher temperatures did not modify the magnitude of the transient increase but resulted in earlier occurrence. The antioxidant capacity reflected the same behavior experimented by phenolics. The anthocyanins decreased with time for all cutting styles. However, this reduction was lower in quartered strawberries compared with hulled ones, due to the synthesis of phenolics (including anthocyanins). All these results point out the importance of the technological processes to obtain the fresh-cut strawberries with high health potential.