棕榈油对淀粉物料微波膨化的影响

研究了棕榈油对淀粉物料微波膨化产品的质量和质构的影响。结果表明，棕榈油的添加减弱了微波的加热效果，且随着油含量的增加，温升速率逐渐减小，含油物料微波膨化过程中的加热段延长了10－20s，膨化段和固化段相应推迟10－20s，物料的膨化速度随着含油量的增加而减小。微波处理90s后，对照样及含油量为0.05,0.10,0.15和0.20mL/g的产品其膨化率分别为4.44,4.17,3.43,2.88和2.10。随着含油量的增加，产品的孔隙率逐渐增大，在含油量大于0.15mL/g后，这种增加程度加深，产品的质构变粗糙，向淀粉物料中添加棕榈油可以改善微波膨化产品的脆度，且在添加量为0.05mL/g时产品的硬度最小。添加棕榈油后的产品色泽与油含量有关，与微波膨化无关。

Effects of Palm Oil on the Microwave Expansion of Starchy Materials

This paper researches the effects of palm oil on the state and quality of starchy products expanded by microwave. The results show that the addition of palm oil weakens the heating intensity of microwave, and the increasing rate of temperature decreases with the increasing of oil content in samples. The heating stage during the expanding procedure of samples with oil lasts 10～20 s longer，the expanding and solidifying stages are late for 10～20 s correspondingly. Furthermore, the expanding speed decreases generally with the increasing of oil content. After heated by microwave for 90 s, the expanding ratios of product without palm oil and products with 0.05, 0.10, 0.15 and 0.20 mL/g palm oil are 4.44, 4.17, 3.43, 2.88 and 2.10, respectively. With the increasing of oil content, the hole ratio of products increases, and when oil content is more than 0.15 mL/g, the increasing degree becomes larger and the texture of products becomes rough. The addition of palm oil into starchy materials can improve the crispness degree of products, and the hardness is the smallest when oil content is 0.05 mL/g. The color of products is related to oil content and has nothing to do with microwave expansion.