Use of ethanol to improve convective drying and quality preservation of fresh and sucrose and coconut sugar-impregnated strawberries

Abstract

Strawberries are among the most consumed fruits due to their sensory attributes and nutritional richness. However, they are highly perishable due to their high moisture content, soft texture and high physiological activity after harvest. To overcome such challenges, this work evaluated the influence of osmotic dehydration (OD) using coconut sugar or sucrose solution and ethanol pre-treatment (ET) on the drying kinetics and qualitative parameters of strawberries. The strawberries were cut into 13 mm cubes. Osmotic dehydration was performed using osmotic solutions of sucrose or coconut sugar at 60% for 300 min. Non- and osmo-dehydrated samples were submitted to ET, totaling 6 treatments. Convective drying was carried out at 60 °C. ET reduced drying time and increased the preservation of acidity and anthocyanins in non-osmo-dehydrated strawberries. OD decreased the drying rate, shrinkage, acidity and anthocyanin content, and increased the hardness of the samples. The use of coconut sugar instead of sucrose during OD showed little influence on the drying kinetics of the samples, however, it resulted in browner and healthier dried strawberries.