Abstract The increase in temperature during ohmic heating (OH) at 20 kHz of conventional beef (CB) and wagyuu beef (WB) was evaluated by analyzing the effects on drip loss due to cooking, shrinkage and microstructure changes. The effects of parallel and series current directions, temperature (5–65 °C), frequency (50 Hz–20 kHz), and chemical composition on the EC values of samples were evaluated. A mathematical explanation of the effect of current direction on EC was provided. A low drip loss due to cooking and shrinkage were found in both beef treated by OH at 20 kHz and 50 V. A good temperature uniformity independent of the current direction was obtained in CB. Increasing the frequency caused a drop in resistance and an increase in heating rate, thereby decreasing the heating time needed for beef muscles, especially for CB, due to its high water and low fat content. A large amount of endogenous fat in WB does not generate heat as quickly as CB muscles due to the poor conductivity of fat; therefore, the presence of fat decreases EC, resulting in uneven heating.

中文翻译：

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牛肉在 20 kHz 的欧姆加热和低频和高频电导率分析

摘要 通过分析蒸煮、收缩和微观结构变化对滴水损失的影响，评估了传统牛肉 (CB) 和和牛牛肉 (WB) 在 20 kHz 欧姆加热 (OH) 期间温度的升高。评估了并联和串联电流方向、温度 (5–65 °C)、频率 (50 Hz–20 kHz) 和化学成分对样品 EC 值的影响。提供了电流方向对 EC 影响的数学解释。在 20 kHz 和 50 V 下用 OH 处理的两种牛肉中发现由于烹饪和收缩导致的低滴漏损失。在 CB 中获得了与电流方向无关的良好温度均匀性。增加频率导致阻力下降和加热速率增加，从而减少牛肉肌肉所需的加热时间，尤其是CB，由于其高水分和低脂肪含量。WB中大量的内源性脂肪由于脂肪的导电性较差，发热不如CB肌肉快；因此，脂肪的存在会降低 EC，从而导致加热不均匀。