Cloud instability and loss of fresh-like appearance are important quality defects of cloudy mixed juices determining consumer acceptability. Therefore, the aim of this study was to investigate the feasibility of high pressure homogenization (HPH) for improving cloud stability, flow behavior and physicochemical characteristics as well as reducing spoilage microorganisms in a cloudy mixed juice, consisting of carrot, apple and peaches. HPH treatments included pressure of 25 MPa, 100 MPa, 140 MPa and 180 MPa, pass of 1 and 2 and inlet temperature of 25 °C and 40 °C, respectively. Results indicated that increasing pressure and pass improved cloud stability, while increasing temperature had negative effect. Herschel Bulkey model could be well fitted to viscosity related data. Compared with control (non-homogenized, NH) sample, HPH at 140 MPa and 25 °C for 1 pass resulted in three times higher flow behavior index. Increasing inlet temperature also resulted in enhancing flow behavior. Besides, total soluble solids content was not affected by HPH, even though pH and color showed slight changes. Compared with NH sample, HPH at 140 MPa resulted in 4 log₁₀ and 3 log₁₀ reductions in total plate count and yeasts and molds count respectively. Thus, HPH at 140 MPa could effectively be used for enhancing cloud stability, improving flow behavior and reducing microorganisms in cloudy mixed juices.

中文翻译：

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高压均质对混合果汁稳定性，流变性，理化特性和微生物减少的影响。

云的不稳定性和新鲜外观的损失是确定消费者可接受性的混浊果汁的重要质量缺陷。因此，本研究的目的是研究高压均质化（HPH）在改善由胡萝卜，苹果和桃子组成的混浊果汁中的云稳定性，流动性和理化特性以及减少腐败微生物的可行性。HPH处理包括分别为25 MPa，100 MPa，140 MPa和180 MPa的压力，通过1和2以及入口温度分别为25°C和40°C。结果表明，增加压力和通过提高了云的稳定性，而增加温度有负面影响。Herschel Bulkey模型可以很好地拟合粘度相关数据。与对照（非均质，NH）样品相比，HPH在140 MPa和25°C下进行1次通过后，其流动性能指数提高了三倍。入口温度升高也导致流动性能增强。此外，即使pH和颜色显示出轻微变化，总可溶性固形物含量也不受HPH的影响。与NH样品相比，140 MPa的HPH导致4 log总平板数减少₁₀和3的对数减少₁₀，酵母和霉菌计数分别减少₁₀。因此，140 MPa的HPH可有效地用于增强浊度稳定性，改善流动性能并减少混浊果汁中的微生物。