微波真空干燥柠檬片护色剂配方优化及其品质变化

许青莲; 税玉儒; 邱叶; 黄博; 廖兴梅; 邢亚阁; 车振明

doi:10.13386/j.issn1002-0306.2021080073

微波真空干燥柠檬片护色剂配方优化及其品质变化

Color-protected Agents Formulation Optimization and Influence on Quality of Microwave Vacuum-Dried Lemon Slices

摘要

摘要: 为保持微波真空干燥（MVD）柠檬片的色泽，优化了柠檬片护色液的成分及其浓度，并分析了其对柠檬片品质变化的影响。以蒸馏水处理组为空白对照组，通过单因素和响应面试验确定了无硫护色剂组成，为0.60%乙二胺四乙酸二钠（EDTA-2Na）、0.38% L-半胱氨酸和0.82%柠檬酸；所处理产品的L^*值及色差值均最优，验证试验得出,柠檬片的平均L^*值为78.52，平均色差值为11.61，预测值与试验值吻合度分别为98.44%和97.33%。此外，分析护色组与对照组柠檬片品质变化可知：护色组的氨基态氮、抗坏血酸、还原糖含量分别为38.61、81.79 mg/100 g、14.75 g/100 g，均高于对照组。护色组与对照组分别检测出58和56种挥发性成分，护色组中柠檬的重要特征香气成分包括α-蒎烯、β-蒎烯、月桂烯和γ-松油烯的相对含量均高于对照组，柠檬醛相对含量略低于对照组。结果表明,护色处理可以有效抑制柠檬片微波真空干燥过程中非酶褐变的发生，还能更大限度保留其原有的营养物质及香气成分。

Abstract: In order to maintain the color of microwave vacuum-dried (MVD) lemon slices, the composition and its concentration of color protection liquid for lemon slices were optimized, and its effects on the quality changes of treated lemon slices were also investigated. In this work, the distilled water treatment group was used as the blank control group, the formulation of color-protected agents without sulfite was decided through the single factor and response surface tests, which included 0.60% EDTA-2Na, 0.38% L-cysteine and 0.82% citric acid, respectively. Moreover, both L^* value and the color difference value of slices treated with this composite color protection liquid were the best among all the samples. Furthermore, the verification test showed that the average values of L^* and color difference value of treated lemon slices were 78.52 and 11.61, respectively. And the agreement between the predicted value and the test value was 98.44% and 97.33%, respectively. On the other hand, the quality changes between lemon slices treated by the color protection liquid and control slices were analyzed. The compared results of the quality changes between treated lemon slices and control samples indicated that the amino nitrogen, ascorbic acid contents and reducing sugar of lemon slices treated with the color protection liquid were 38.61, 81.79 mg/100 g, and 14.75 g/100 g, respectively, which were all higher than that in the control samples. More importantly, 58 and 56 kinds of volatile components were detected in the color protection group and the control group, respectively. The main characteristic aroma components including α-pinene, β-pinene, myrcene, γ-terpinene and citral in the treated lemon were higher than that in the control slices. However, the content of citral was lower than that in the control simple. These results indicated that the color protection treatment could effectively inhibit the nonenzymic browning of the microwave vacuum-dried lemon slices and also retained its original nutrients and aroma components at a greater extent.