Tsegay Zenebe Tadesse
College of Dryland Agriculture and Natural Resources Department of Food Science and Post-Harvest Technology Mekelle University Mekelle 231 Ethiopia.
Food Sci Nutr. 2020 Jul 2;8(8):4449-4462. doi: 10.1002/fsn3.1745. eCollection 2020 Aug.
Fruits and fermentation methods are important sources of organic acids that determine organoleptic properties, microbiological and biochemical stability of fruit wines. This study is aimed at investigating total titrable acidity and organic acids of fruit wines produced by response surface optimization of cactus pear and fruits blend and cactus pear fruit alone. The predictive mathematical model of the blended fruit wine is well fitted ( = 0.9618 and absolute average deviation (AAD) = 2.06%). The optimum values of fermentation temperature, inoculum concentration, and fruitjuice concentration to produce predictive total titrable acidity of 0.8% (w/v citric acid) were 24°C, 10% (v/v), and 10.7% (v/v), respectively. The blended fruit wine was with lower total titrable acidity (w/v citric acid) of 0.83 ± 0.058% compared to wine produced from cactus pear fruit alone 1.06 ± 0.27%. The high performance liquid chromatography (HPLC) analysis of both produced wines revealed the difference in concentration of citric (±3.35 mg/ml), L-tartaric (± 3.71 mg/ml), and L-ascorbic acid (± 0.07 mg/ml). Citric acid was predominant organic acid in both fruit wines, and its content in the cactus pear is 7.09 ± 0.07 mg/ml and blended fruit wine 4.74 ± 0.07 mg/ml.
水果和发酵方法是决定果酒感官特性、微生物和生化稳定性的有机酸的重要来源。本研究旨在通过对仙人掌梨与其他水果混合以及单独使用仙人掌梨果实进行响应面优化，来研究果酒的可滴定酸度总量和有机酸。混合果酒的预测数学模型拟合良好（R² = 0.9618，绝对平均偏差（AAD）= 2.06%）。为使预测的可滴定酸度总量达到0.8%（以柠檬酸计，w/v），发酵温度、接种物浓度和果汁浓度的最佳值分别为24°C、10%（v/v）和10.7%（v/v）。与单独用仙人掌梨果实酿造的酒（1.06±0.27%，以柠檬酸计，w/v）相比，混合果酒的可滴定酸度总量较低，为0.83±0.058%。对两种酿造的酒进行高效液相色谱（HPLC）分析，结果显示柠檬酸（±3.35mg/ml）、L-酒石酸（±3.71mg/ml）和L-抗坏血酸（±0.07mg/ml）的浓度存在差异。柠檬酸是两种果酒中的主要有机酸，其在仙人掌梨中的含量为7.09±0.07mg/ml，在混合果酒中的含量为4.74±0.07mg/ml。
