Estimation of some essential constituents of sorts of locally produced juices

Abstract

This research was conducted to evaluate the quality of some local juices in the Libyan market by estimating some of the essential constituents, which were moisture content, ash content, pH, acidity percent, sugar percent, and vitamin C percent. 15 samples were collected, with 5 Kinds of juices from 3 different local companies. The acidity was estimated using volumetric methods and was expressed as an equivalent percent of citric acid, and the results were in the range of 0.16 - 0.38%, 0.13 - 0.24%, 0.14 - 0.47%, for the juices of Judy, Al-Rayhan and Al-Mazraa companies, respectively. The percent of vitamin C was also estimated using volumetric methods (redox titrations) and using a standard iodine solution, and the range of results were as follows: 38.75 - 66.80 mg/100 ml, 14.09 - 43.33 mg/100 ml, 3.52 - 32.67 mg/100 ml. However, the levels of vitamin C were significantly low in cocktail, grape and mango samples from Al-Mazraa company, compared to the results of other juices, as well as the Libyan standard specifications. The percent of sugar in juice samples was estimated by measurement of density, and it was expressed as an equivalent percent of glucose sugar. The results of juice samples were close and similar to previous studies, and the sugar percent ranged from 9.26-24.73%. This study showed that the studied juices contained concentrations within the permissible limits regarding the components that were estimated.