LAUSR

BACKGROUND The spring grown peanut varieties viz., J87 and TG37A are prone to quality deterioration owing to high temperature and relative humidity during the harvesting. Thus, sorption isotherms of peanut varieties were evaluated at 25, 35 and 45°C and water activity (aw ) range of 0.110-0.975 in order to predict the suitable storage conditions, packaging material and shelf-life. RESULTS The equilibrium moisture content (EMC) increased with increased aw and the isotherms of type II were observed. The monolayer moisture content varied between 3.135-4.235 for J87 and 3.906-5.640% for TG37A variety. The experimental data was fitted to seven mathematical models. The variations in correlation coefficients were 0.879-0.992 and in root mean square was 0.055-1.988. On the basis of statistical parameters, Guggenheim Anderson de Boer (GAB) and Double Log Polynomial (DLP) were considered to be best fitted models. At aw 0.6, critical moisture content (CMC) was 7.59, 7.060 and 5.89% for J87 and 9.06, 8.904 and 7.80% for TG37A at 25, 35 and 45°C respectively. The shelf-life prediction model provided that the aluminum packages had the maximum predicted shelf-life around 1779 days for TG37A and 1077 days for J87 variety at 25°C with initial moisture content of 5.91 and 4.81% respectively. CONCLUSION The EMC and CMC evaluated from sorption study provided the basis for determination of package properties and shelf life. Aluminum packages had the minimum water vapor transmission rate and permeability. Hence, peanuts packaged in these bags, stored at 25°C and 75% relative humidity had the potential to attain maximum storage life. This article is protected by copyright. All rights reserved.