Dao Uyen Ha, Lamphun Jitlada Na, Tongdonyod Sitthidat, Taya Sirinya, Phongthai Suphat, Klangpetch Wannaporn
Division of Food Science and Technology, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai 50100, Thailand.
Functional Food Research Unit, Multidisciplinary Research Institute, Chiang Mai University, Chiang Mai 50200, Thailand.
Foods. 2024 Sep 21;13(18):2995. doi: 10.3390/foods13182995.
Pigmented rice grass juice (RGJ) is a good source of bioactive compounds, but fresh juice has a relatively short shelf life of only 7 days at 4 °C. The objectives of this study were to determine the optimal growth stage of pigmented rice grass, investigate the optimal condition of high-pressure processing (HPP) for bacterial inactivation in inoculated RGJ using response surface methodology (RSM), and evaluate quality changes in uninoculated HPP-treated juice during storage at 4 °C compared with heat-treated (85 °C/10 min) and untreated samples. Results revealed that the optimal growth stage of rice grass was 9 days with the highest total anthocyanin content of 158.92 mg/L. The optimal condition of HPP was determined to be 612 MPa, 11 min, and 36 °C, and inactivated K12 and with 6.43 and 5.02 log reductions, respectively, meeting FDA regulations. The lethality of bacteria after HPP treatment can be explained by damage to the cell membrane and the leakage of intracellular constituents such as protein and nucleic acid. During 12 weeks of storage at 4 °C, total plate counts and yeast and mold counts in uninoculated HPP-treated juice were not detected. Moreover, HPP did not significantly change phytochemical properties ( < 0.05), caused a minor impact on physicochemical properties of RGJ, and maintained the durability of juice samples during storage. Analysis of the phytochemical profile revealed that HPP treatment could preserve most of the phenolic compounds in RGJ and especially increase the contents of protocatechuic acid, 4-hydroxybenzoic acid, syringic acid, transcinnamic acid, isorhamnetin-3-o-glucoside, quercetin, and cyanidin-3-glucoside ( < 0.05). Overall, HPP is a potential pasteurization technique for microbial inactivation and nutritional preservation for rice grass juice.
黑米草汁（RGJ）是生物活性化合物的良好来源，但鲜榨汁在4℃下的保质期相对较短，仅为7天。本研究的目的是确定黑米草的最佳生长阶段，使用响应面法（RSM）研究接种RGJ中细菌灭活的高压处理（HPP）最佳条件，并评估与热处理（85℃/10分钟）和未处理样品相比，未接种HPP处理的果汁在4℃储存期间的质量变化。结果表明，黑米草的最佳生长阶段为9天，总花青素含量最高，为158.92mg/L。确定HPP的最佳条件为612MPa、11分钟和36℃，分别使K12和 灭活6.43和5.02个对数级，符合美国食品药品监督管理局（FDA）的规定。HPP处理后细菌的致死率可以通过细胞膜损伤和蛋白质、核酸等细胞内成分的泄漏来解释。在4℃储存12周期间，未接种HPP处理的果汁中未检测到总平板计数以及酵母菌和霉菌计数。此外，HPP没有显著改变植物化学性质（<0.05），对RGJ物理化学性质的影响较小，并在储存期间保持了果汁样品的耐久性。植物化学图谱分析表明，HPP处理可以保留RGJ中的大部分酚类化合物，尤其是增加原儿茶酸、4-羟基苯甲酸、丁香酸、反式肉桂酸、异鼠李素-3-o-葡萄糖苷、槲皮素和花青素-3-葡萄糖苷的含量（<0.05）。总体而言，HPP是一种用于黑米草汁微生物灭活和营养保存的潜在巴氏杀菌技术。
