PHYSICOCHEMICAL CHARACTERIZATION OF THE ORANGE JUICE WASTE WATER OF A CITRUS BY-PRODUCT

Abstract

Large quantities of wastes are produced during the industrial transformation of citrus fruit, and these constitute a serious problem. However, instead of disposing of them, they can be used to obtain by-products rich in bioactive compounds. One such by-product is the orange juice waste water generated in the process of obtaining citrus fiber. The aim of this study was to characterize the physicochemical and microbiological properties of the orange juice waste water of a citrus by-product by determining the pH, soluble solids, color, reduction of residual nitrite and total antioxidant activity, along with the content of phenolic compounds, organic acids and sugars. The orange juice waste water decreases the nitrite levels and shows a high capacity to reduce the formation of free radicals. Narirutin and hesperidin were the most concentrated phenolic compounds, whereas the main sugar was glucose. Five organic acids were identified, the main one being succinic acid. PRACTICAL APPLICATIONS The orange juice waste water can be suitable for applications on the food industry. It is an important source of phenolic compounds in which antioxidant properties could be very appreciated in a big number of food processing to avoid its oxidation during processing but also during storage period. Another important effect of orange juice waste water is the reduction of residual nitrite level in foods in which the nitrite is added as an additive, for example, in meat products industry; the reduction of residual nitrite level could reduce the possibility to nitrosamine formation. One other important reason for their suitability is their natural origin, which consumers find comforting and which is beneficial for the environment.