速冻玉米的微波解冻温度变化规律及能量利用研究

Temperature Change and Energy Utilization of Quick-frozen Maize during Microwave Thawing

为探索一种更节能的解冻方式,采用微波场技术对速冻玉米进行解冻,以玉米穗数量为变量,通过连续解冻和间歇解冻两种解冻方式,研究玉米穗不同部位的温度变化规律及其对微波能量吸收效率的影响。结果表明,微波连续解冻和间歇解冻过程中,玉米穗不同部位呈现相同的温度变化趋势,即解冻初期,玉米的表面温度>籽粒温度>玉米轴的中心温度,随着解冻时间的延长,玉米轴的中心温度迅速升高,形成从玉米轴中心到表面的温度梯度。与微波连续解冻相比,微波间歇解冻得到的产品温度分布较均匀,微波吸收效率较高,且吸收效率随着速冻玉米数量的增加而增加,当玉米数量达到4穗时,对微波能量的吸收效率趋于稳定,此时微波能量利用率为50.2%。

To obtain a more energy-efficient thawing approach,quick-frozen maize was thawed by microwave field technology in either a continuous or intermittent mode under conditions of varying number of maize ears in this paper.The regularity of temperature change in different parts of maize ear and its effect on microwave energy absorption were explored.The results showed that different parts of maize ear displayed identical temperature change trend during both continuous and intermittent thawing.The surface of maize ear exhibited the highest temperature,followed by grain temperature and cob temperature during the early stages of thawing.As the thawing time was prolonged,the central temperature of maize cob was promptly elevated,forming a temperature gradient from the central axis of maize cob to the surface of ear.In comparison with continuous thawing,intermittent thawing resulted in more even temperature distribution and higher microwave energy absorption,which rose as the number of maize ear was increased and tended to remain stable at 50.2% until the number of maize ear reached 4.