SHELF-LIFE EXTENSION OF AVOCADO FRUIT (PERSEA AMERICANA) WITH CHITOSAN-SODIUM TRIPOLYPHOSPHATE COMPLEX BASED COATING

Abstract

The aim of this study was to evaluate the effect of chitosan (CH) combined 0.01% sodium tripolyphosphate based coating at different concentrations on booth avocado quality. Avocado fruits were washed with warm water (~ 55°C) for 30 senconds, then dipped in acetic acid 1% (control sample), CH 2.0, 2.5, 3.0% combined TPP 0.01% solutions for 60 seconds. The fruits were dried naturally, and dipped 2nd time for 10 seconds. After natural dry, avocado fruit were stored at 10±2°C. The ethylene and CO2 generation percentage, weight loss was determined every day during the storage period; total sugar and vitamin C contents were determined at the beginning and end points. The results illustrated that, CH and TPP based coating extended the possible storage period of avocado fruit. The CO2 generation reached maximum at day-11 of control sample, while this peak of avocado coated with CH 2, 2.5 and 3% and TPP 0.01% got at day of 17, 21, and 19, respectively. The similar trend and rersult were observed on ethylene generation of these samples, respectively. Furthermore, the control sample showed almost 20% in weight loss at the climacteric peak. It was 3-5 fold when compared to that of avocado fruit coated with CH 2, 2.5 and 3% and TPP 0.01% (about 6.6, 3.8 and 4%, respectively). In addition, the lowest vitamin C content loss was observed in CH 2.5% based coated avocado fruit. The chitosan 2.5% and TPP 0.01% showed the higher potential for prolonging the storage-time of avocado compared to the others.