Otimização da desidratação osmótica do sapoti (Achras zapota L.)

Abstract

The Sapodilla (Achras zapota L.), is widely appreciated in northeastern Brazil, but owing to its perishability requires application of technological processes that enhance your shelf life, preserving their quality characteristics. The preservation by moisture control aims to reduce losses generated by metabolic reactions that occur in these fruits after harvest, among these treatments highlights the osmotic dehydration process, which has been used primarily as a pretreatment to some conventional processes. Therefore, this research aims to optimize the osmotic dehydration of said fruit. In its implementation kinetic studies were performed using a factorial design 22 to determine the influence of the independent variables: osmotic agent concentration and immersion time on the diffusion coefficients of water and sucrose. Further, with the goal of reducing solid incorporation was applied 23 factorial design to evaluate the influence of independent variables: temperature, immersion time and concentration of osmotic solution on water loss (WL), solid gain (SG) and DEI (Dehydration Efficiency Index). The drying was completed in oven with forced ventilation at 60°C ± 0,5°C. From the results of these steps proceeded up the optimization process by evaluating the response surface figures generated using the 23 planning to determine the best temperature, immersion time and concentration of the osmotic solution. The two trials with better values of DEI were subjected to sensory analysis and the selected product was subjected to analyzes of chemical composition, physico-chemical, microbiological and structural. The results showed: the greatest influence of immersion time on the diffusion coefficient of water and sucrose; maximum WL and SG in osmotic solution concentration of 60°Brix; significant influence of temperature and osmotic solution concentration on the WL and SG; significant influence osmotic solution concentration and immersion time on the DEI; the best conditions using DEI as parameters were 34°C, 56°Brix, 210 minutes and 40°C, 50°Brix; 165 minutes. The product prepared at 40°C, 50°Brix, 165 minutes showed higher scores on sensory attributes and compliance with the microbiological standards; dehydration caused reduced turgor and rupture the cell walls of the sapodilla.