Contribution to the Reduction of Post-Harvest Losses in the Orange Sector in Senegal through the Production of Quality Orange Vinegar

Abstract

This work aims to study the feasibility of producing vinegar from oranges. Two types of matrices were used: pasteurized juice from fresh oranges and unpasteurized juice from overripe oranges. After juice extraction, parameters such as pH, soluble dry matter content, and total and reducing sugar contents were determined. The juices were then subjected to alcoholic fermentation following three batches: FPJ (from the pasteurized juice of fresh oranges), FNJI and FNJ (from the unpasteurized juice of overripe oranges). FPJ and FNJI were both inoculated with Saccharomyces cerevisiae , while FNJ was not inoculated. After the alcoholic fermentation, acetous fermentation followed for vinegar production. Finally, the mineral profile of the best vinegar product was determined and then compared to those of four vinegars marketed in Senegal. The results showed that the best ethanol contents were obtained in FNJI and FNJ with a maximum of 74.44 ± 0.03 g/L for FNJI, followed by 61.817 ± 0.05 g/L for FNJ. The lowest ethanol content, 43.132 ± 0.1 g/L, was obtained with FPJ. Following the same trend, the best acetic acid content, 6.43% ± 0.03%, was obtained with FNJI, followed by FNJ at 5.13% ± 0.01%, then FPJ at 0.67% ± 0.02%, with respective productivities of 0.17, 0.13, and 0.017 g/L∙h. The evaluation of the mineral profile of vinegar from FNJI has shown that it has the highest levels for all the minerals sought (Iron, Potassium, Calcium, Phosphorus, Magnesium, Manganese) compared to four other vinegars marketed in Senegal (alcohol based vinegar). These results show the importance of the beneficial contribution of native orange microorganisms during the overripening process and confirm the feasibility of manufacturing a quality vinegar with oranges in an overripening state, thus contributing to the reduction of post-harvest losses in the orange sector in Senegal.