干燥方式对苹果干品质特性及风味的影响

宋娟; 张海燕; 曾朝珍; 袁晶; 慕钰文; 康三江; 文鹏程

doi:10.13386/j.issn1002-0306.2023090258

干燥方式对苹果干品质特性及风味的影响

Effects of Drying Methods on Quality Characteristics and Flavor of Dried Apples

摘要

摘要: 为探究提高静宁苹果干零食品质的加工方式，本研究探讨了5种干燥方式（热风干燥、太阳能干燥、真空冷冻干燥、微波-压差膨化干燥和热泵干燥）对苹果干能耗、抗氧化活性、微观结构和风味的影响。结果表明，和其它4种方式相比，在能耗方面，真空冷冻干燥的单位能耗最高（69.48±1.69 kW·h/kg），而太阳能干燥的单位能耗最低（19.60±1.36 kW·h/kg）；在硬脆度方面，热风干燥的苹果干具有最高的硬度、最低的脆度，而真空冷冻干燥的苹果干硬度最低、脆度较高；在色差方面，真空冷冻干燥苹果干的L^*值最高（72.91±0.59），ΔE值最接近鲜样（10.48±0.30）；此外，真空冷冻干燥能有效降低苹果干中抗氧化物质的损失，与鲜样相比，其抗坏血酸、总酚和总黄酮的含量分别降低了35.22%、39.27%和32.02%。同时，总抗氧化能力、羟自由基清除率和超氧阴离子清除率也分别降低了23.50%、57.24%和10.56%；在微观结构方面，真空冷冻干燥的苹果干细胞层呈较规律的海绵状多孔性结构，质地较好；在风味方面，鉴定出5种干燥方式的苹果干有96种挥发性物质，其中真空冷冻干燥的苹果干更加芳香、口感更加丰富。综合考虑，真空冷冻干燥是提高苹果干零食品质特性和风味的推荐方法，对苹果干制品的工业化生产有现实的指导意义。

Abstract: To investigate the processing methods that could improve the quality of Jingning dried apple snacks, the effects of five drying methods (hot air drying, solar drying, vacuum freeze drying, microwave-pressure puffing drying, and heat pump drying) on energy consumption, antioxidant activity, microstructure, and flavor of dried apples were studied. The results showed that compared with the other four drying methods, in terms of energy consumption that vacuum freeze drying had the highest unit energy consumption (69.48±1.69 kW·h/kg), while solar drying had the lowest unit energy consumption (19.60±1.36 kW·h/kg). In terms of hardness and crispness, dried apples that were dried by hot air drying were found to have the highest levels of hardness and lowest levels of crispness, while those that were dried by vacuum freeze drying were found to have the lowest levels of hardness and a higher degree of crispness. In terms of colour difference, vacuum freeze drying had the highest L^* value (72.91±0.59) and the ΔE value was closest to the fresh samples (10.48±0.30). In addition, compared with fresh samples, vacuum freeze drying effectively slowed down the loss of antioxidant activity of dried apples, with the contents of ascorbic acid, total phenols and total flavonoids decreased by 35.22%, 39.27% and 32.02%, respectively. Meanwhile, the total antioxidant capacity, hydroxyl radical scavenging rate and superoxide anion scavenging rate decreased by 23.50%, 57.24% and 10.56%, respectively. In terms of microstructure, the cell layer of dried apples with vacuum freeze drying preserved a regular sponge-like porous structure with good texture. In terms of flavor, 96 volatile substances were identified in five types of dried apples, while it made the dried apples with vacuum freeze drying more aromatic and richer in taste. In conclusion, vacuum freeze drying is recommended as a method to improve the quality and flavor of high-quality dried apples, and provides significance in guiding the industrialized production of dried apple products.