Abstract
Orange is the main fruit crop in Egypt and most varieties are available during winter. Use of hazardous chemicals and their environmental effect has received great attention worldwide. The aim of this study was to substitute chemicals with natural materials as a means to reduce contamination of foods. The present study was carried out in Egypt during 2009 and 2010. Navel orange fruits were sampled and treated with five different post-harvest dipping treatments (control, seaweed extracts at 2% and 4% and calcium chloride at 2% and 4%). One group of each treatment was stored at room temperature (21 +/- 2(degrees)C and 65-75% RH) for 45 days and the second group was at cold temperature (7(degrees)C and 65-75% RH) for 75 days. Soluble solids content, total sugars and reducing sugars content were increased in 4% seaweed extract treated fruit stored either at room temperature or in cold storage. Generally, seaweed extracts are recommended to improve fruit quality and storability of Navel orange fruit, compared with chemicals that are of consumer concern.