油炒猪里脊肉油脂含量的影响因素及油-水传质研究

The Effect of Stir-frying on the Oil Content of Pork Tenderloin and the Oil-moisture Mass Transfer Process

油炒是我国主要菜肴的烹饪手段,而消费者不希望摄入过多油脂,因此有必要研究影响油炒菜肴油脂含量的因素及机理。影响菜肴油脂含量的参数很多,其中烹饪火候控制是决定油脂含量的前提。为此,选择油炒猪里脊肉为研究对象,以等终点成熟值为研究基准,探索油炒温度、搅拌速度等火候控制手段对油脂含量的影响规律,进而基于传质过程原理构建油-水扩散模型,探索油脂和水分在油炒烹饪过程中的传质规律。结果表明,油炒温度、搅拌速度对猪里脊肉油脂含量都有显著影响(P<0.05)。在油炒温度120℃,油炒时间29 s和搅拌速度0.23 m/s下烹饪猪里脊肉油脂含量平均为6.00 g/100 g,而继续加热,其油脂含量可达10.64 g/100 g,与刚成熟相比增加了77.33%,由此说明在最优火候控制下可获得最低的油脂含量。所构建的传质模型中油脂和水分含量模拟值与试验结果符合程度较高。结果显示油炒温度越高,猪里脊肉油脂和水分有效扩散率越大,分别在2.272×10^(-10)~3.713×10^(-10)m^(2)/s、1.277×10^(-10)~6.343×10^(-10)m^(2)/s之间,说明传质过程中油脂吸入和水分蒸发并不同步。

Stir-frying is the main Chinese cuisine method,and consumers normally don′t expect to intake excessive oil,so it is necessary to study the factors that affect the oil content of stir-frying dishes and the related mechanism.There are many parameters affecting the oil content of cuisine,among which the“Huohou”control is a prerequisite for determining the oil content.Based on the same maturity value sampling method,we studied the effects of“Huohou(cooking time and heating intensity)”control methods,including oil temperature,stirring speed,etc.,on the oil content of pork tenderloin.Then,the oil-moisture diffusion model was constructed in accordance to the Fick′s second law,so as to further explore the mass transfer mechanism of oil and moisture during the stir-frying process.The results indicate that the oil temperature and stirring speed have significant effects on the oil content of pork tenderloin(P<0.05).Under the oil stir-frying temperature of 120℃,a stir-frying time of 29 s and the stirring speed of 0.23 m/s,the average oil content of cooked pork tenderloin is 6.00 g/100g,while the oil content of cooked pork tenderloin can reach 10.64 g/100g by continuous stir-frying,an increase of 77.33%compared to just mature,thus indicating that the lowest oil content could be obtained under optimal“Huohou”control.In addition,the simulated results of oil and moisture content calculated using the oil-moisture mass transfer model were accurate,showing great agreement with the experimental results.Furthermore,our results demonstrated that the effective diffusion rates of oil and moisture in pork tenderloin were increased under higher stir-frying temperature conditions,ranging from 2.272×10^(-10)~3.713×10^(-10)m^(2)/s and 1.277×10^(-10)~6.343×10^(-10)m^(2)/s,which indicates that the absorption of oil and moisture evaporation were not synchronized during the whole mass transfer process.