Hamden Zeineb, El-Ghoul Yassine, Alminderej Fahad M, Saleh Sayed M, Majdoub Hatem
Laboratory of Interfaces and Advanced Materials, Faculty of Sciences of Monastir, University of Monastir, Monastir 5000, Tunisia.
Department of Chemistry, College of Science, Qassim University, Buraidah 51452, Saudi Arabia.
Antioxidants (Basel). 2022 Jun 13;11(6):1155. doi: 10.3390/antiox11061155.
Dates are very rich in various nutritious compounds, especially reducing sugars. Sugars ensure both anaerobic and aerobic fermentation, carried out respectively for the production of bioethanol and vinegar. Currently, the world production of dates is constantly increasing owing to the significant improvement in production conditions following the continuous scientific and technological development of this field. The Kingdom of Saudi Arabia is one of the most important world producers of dates, occupying the second place by producing 17% of the total world production. This is why it has become a national priority to find new ways to exploit and further valorize dates and palm waste in the development of new and sustainable products. The present study was designed to explore the possible study of a variety of date palm by-products in the production of bioethanol and vinegar via Saccharomyces cerevisiae. Different parameters of bioethanol and vinegar production, including pH, time, fermentation temperature, and yeast concentration, were studied and optimized. Chemical, physicochemical, purity behavior, and antioxidant performance were carried out via NMR, FTIR, and antioxidant activity essays (TPC, DPPH, FRAP, and β-carotene bleaching test) with the aim to evaluate the potential of the bioethanol and vinegar samples extracted from date palm by-products. Khalas date vinegar revealed significantly more phenolic content (5.81 mg GAE/mL) (p < 0.05) than the different kinds of vinegar tested (Deglet Nour and Black dates; 2.3 and 1.67 mg GAE/mL, respectively) and the commercial vinegar (1.12 mg GAE/mL). The Khalas date vinegar generally showed a higher carotenoid value and better antioxidant activity than the other vinegars extracted from other date varieties and commercially available vinegar. The results confirmed the high quality of the bioethanol and vinegar products, and the efficiency of the developed production processes.
椰枣富含多种营养化合物，尤其是还原糖。糖类可确保分别用于生产生物乙醇和醋的厌氧发酵和好氧发酵。目前，由于该领域持续的科技发展使生产条件显著改善，全球椰枣产量不断增加。沙特阿拉伯王国是世界上最重要的椰枣生产国之一，产量占世界总产量的17%，位居第二。正因如此，探索新方法来开发和进一步提升椰枣及棕榈废料的价值，以开发新的可持续产品，已成为该国的一项国家优先事项。本研究旨在探索通过酿酒酵母利用多种椰枣副产品生产生物乙醇和醋的可能性。研究并优化了生物乙醇和醋生产的不同参数，包括pH值、时间、发酵温度和酵母浓度。通过核磁共振（NMR）、傅里叶变换红外光谱（FTIR）以及抗氧化活性测定（总酚含量、二苯基苦味酰基自由基清除能力、铁离子还原抗氧化能力和β-胡萝卜素漂白试验）对化学、物理化学、纯度行为和抗氧化性能进行了检测，旨在评估从椰枣副产品中提取的生物乙醇和醋样品的潜力。哈拉斯椰枣醋的酚类含量（5.81毫克没食子酸当量/毫升）显著高于所测试的其他种类的醋（德吉莱特努尔椰枣醋和黑椰枣醋，分别为2.3和1.67毫克没食子酸当量/毫升）以及市售醋（1.12毫克没食子酸当量/毫升）（p<0.05）。哈拉斯椰枣醋的类胡萝卜素值通常更高，抗氧化活性也优于从其他椰枣品种中提取的其他醋以及市售醋。结果证实了生物乙醇和醋产品的高品质以及所开发生产工艺的效率。
