The jujube is mainly grown in the subtropical and tropical regions of Asia. Due to owning bioactive compounds such as polyphenols, it was considered as medicinal and nutritional plant in traditional medicine. This study aimed to extract phenolic compounds from Ziziphus jujuba using subcritical water (SCW) process. The possible combinations of temperature, time, and fruit-to-solvent ratio were investigated using response surface methodology. The total phenolic compounds (TPC) and radical scavenging capacity (RSC) of 975.94 mg/g and 53.98%, respectively, were recovered at optimum extraction conditions (170 °C, 74.49 min, and fruit-to-solvent ratio of 1:5.29). The extract obtained in SCW optimum conditions was put under thermal treatments including low temperature long time, high temperature short time, cooking, baking, and sterilization. The results showed after baking, the amount of TPC, RSC, and absorbance at 420 nm increased. The quantity of gallic acid, chlorogenic acid, p-coumaric acid, ferulic acid, and rutin increased significantly. The efficiency of SCW extract in retarding lipid oxidation in bulk oil and O/W emulsion model was investigated at 50 °C for 10 days. After 10 days, the peroxide value of bulk oil (1.1 meq O2/kg) containing SCW extract was lower than O/W emulsion model (2.2 meq O2/kg). The subcritical extracted phenolic compounds seem to have good antioxidant activity as well as thermal stability for using in food or drug industries.

中文翻译：

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响应面法优化亚枣水中亚临界水萃取酚类化合物：热稳定性和抗氧化活性的评估

枣主要生长在亚洲的亚热带和热带地区。由于拥有多酚等生物活性化合物，因此被认为是传统医学中的药用和营养植物。这项研究旨在使用亚临界水（SCW）工艺从枣中提取酚类化合物。使用响应曲面方法研究了温度，时间和水果与溶剂比例的可能组合。在最佳提取条件（170°C，74.49 min，水果与溶剂的比例为1：5.29）下，总酚化合物（TPC）和自由基清除能力（RSC）分别为975.94 mg / g和53.98％。 ）。将在SCW最佳条件下获得的提取物置于包括低温长时间，高温短时间，烹饪，烘烤和灭菌在内的热处理中。结果显示，烘烤后，TPC，RSC的量和在420 nm处的吸光度增加。没食子酸，绿原酸，对香豆酸，阿魏酸和芦丁的量显着增加。在50°C下连续10天研究了SCW提取物延缓散装油和O / W乳液模型中脂质氧化的效率。10天后，含SCW提取物的散装油（1.1毫克当量O2 / kg）的过氧化物值低于O / W乳液模型（2.2毫克当量O2 / kg）。亚临界萃取的酚类化合物似乎具有良好的抗氧化活性以及用于食品或药品工业的热稳定性。在50°C下连续10天研究了SCW提取物延缓散装油和O / W乳液模型中脂质氧化的效率。10天后，含SCW提取物的散装油（1.1毫克当量O2 / kg）的过氧化物值低于O / W乳液模型（2.2毫克当量O2 / kg）。亚临界萃取的酚类化合物似乎具有良好的抗氧化活性以及用于食品或药品工业的热稳定性。在50°C下连续10天研究了SCW提取物延缓散装油和O / W乳液模型中脂质氧化的效率。10天后，含SCW提取物的散装油（1.1毫克当量O2 / kg）的过氧化物值低于O / W乳液模型（2.2毫克当量O2 / kg）。亚临界萃取的酚类化合物似乎具有良好的抗氧化活性以及用于食品或药品工业的热稳定性。