The Effect of Some Physical and Chemical Factors on the Apple Quality by Using Shellac as Coating Material

Abstract

The extension of apple shelf-life is an important goal to be attained. A golden delicious apple have been used to be coating by shellac with concentrations 3, 5, 7 and 9% in absolute ethanol. The coated apples were stored at 5, 25 and 37°C for various periods of storage. It was found that, the weight loss percentages of apples were decreased by using the shellac as coating material as compared with the control (untreated apples). There is a proportional relationship between weight loss and temperature degree but a reversal relationship has been found between the shellac solution concentration and the weight loss percentage. Increasing in total soluble solids has been associated with weight loss, therefore, the high concentration of shellac solution reduce the weight loss in treated apples especially at lower temperature (5°C). Decreasing in titratable acidity has been observed during the storage, especially in the control. The decreasing has been restricted by using high concentration of shellac solution. The present study also refer to the apple expire date at different time, temperature and shellac solution concentrations.