Modified Atmosphere Storage of Avocados: Effects on Storage life and Fruit Quality

Abstract

Modified atmosphere packaging depleted in O2 and enriched in CO2 used in conjunction with refrigeration may provide an effective means of retarding deterioration, maintaining quality and extending the postharvest life of avocados. Mature pre-climacteric avocados (cv. Fuerte) were packaged in a range of plastic films and stored at temperatures of 4, 7 and 10°C. The treated fruits along with the controls were ripened at 20±0.5°C and the relative humidity of 90-95%. Optimum storage duration, fruit injury and weight loss were determined during storage and ripening of fruits. In packs sealed with the micro-pores film MY-15, the O2 concentration decreased to 4.0-6.5% and the CO2 increased to 6.5-11.0% during storage. Fruits sealed in polyethylene packs were stored well up to 28 days at 4°C and 35 days at 7°C without chilling injury whereas the air stored fruits showed chilling injury after 21 and 28 days of storage at both temperatures, respectively. Modified atmosphere plays a significant role in retaining vitamin C, total sugars, oil, pH and flesh firmness of the fruit during storage. Modified atmospheres tended to cause an increase in the amount of palmitic and palmitoleic acids and decrease in the percentage of oleic, linoleic and linolenic acids. Among the tested films, low density polyethylene and micro-perforated film MY-15 and MD-15 were found to be suitable in extending the shelf life of avocados at low temperatures. Best results were obtained using microperforated film MY-15 and the fruits stored well for six weeks in modified atmospheric conditions with 4.8% O2 + 8.4% CO2 at 7°C. Commercial application of these packaging techniques would help to maintain the quality of avocados throughout the distribution and marketing chain.