食品科学 ›› 2020, Vol. 41 ›› Issue (15): 124-133.doi: 10.7506/spkx1002-6630-20190730-406

• 食品工程 • 上一篇    下一篇

树莓果浆微波泡沫干燥过程能量吸收与利用

秦庆雨,郑先哲,王磊,朱勇,刘辉,张友朋,徐浩   

  1. (东北农业大学工程学院,黑龙江 哈尔滨 150030)
  • 出版日期:2020-08-15 发布日期:2020-08-19
  • 基金资助:
    国家自然科学基金面上项目(31571848;31271911);哈尔滨市科技项目(2017RAXXJ028)

Energy Absorption and Utilization during Microwave Foam Drying of Raspberry Pulp

QIN Qingyu, ZHENG Xianzhe, WANG Lei, ZHU Yong, LIU Hui, ZHANG Youpeng, XU Hao   

  1. (College of Engineering, Northeast Agricultural University, Harbin 150030, China)
  • Online:2020-08-15 Published:2020-08-19

摘要: 干燥均匀性及微波能利用率是评价物料微波能吸收与利用的重要指标,干燥均匀性、干燥过程微波能利用率分别是影响产品品质、加工成本的主要因素。为提高微波泡沫干燥均匀性及微波能利用率,以树莓浆果为实验原料,采用数值模拟分析料层电场强度、温度及微波能吸收分布规律;运用理论分析和单因素试验研究微波强度、料层厚度及循环干燥时间对泡沫果浆干燥特性、干燥均匀性(温度均匀性及含水率均匀性)及微波能利用率的影响规律。结果表明:随微波强度增加,料层电场分布均匀性显著提高(P<0.05),料层电场均匀性及物料吸收特性对温度及含水率分布均匀性影响显著(P<0.05);在微波强度2~6 W/g、料层厚度3~7 mm、循环干燥时间2~6 min条件下,随微波强度增加,干燥均匀度呈逐渐上升的变化趋势,随料层厚度增加和循环干燥时间延长,干燥均匀度呈逐渐下降的变化趋势;随微波强度、料层厚度增加及循环干燥时间延长,泡沫果浆微波能利用率均呈先升高后降低趋势。研究结果可为高品质、高能效的微波干燥浆果果粉工艺研究提供理论参考。

关键词: 树莓浆果, 微波, 泡沫干燥, 能量利用, 均匀性

Abstract: Drying uniformity and microwave energy utilization rate (MEUR) are important indicators for evaluating microwave energy absorption and utilization of materials. Drying uniformity and MEUR during drying are the main factors affecting product quality and processing cost, respectively. During the microwave foam drying of raspberry berries the electric field intensity, temperature and microwave energy absorption distribution pattern of the material layer was analyzed by numerical simulation to improve the drying uniformity and MEUR. The influence of microwave intensity, layer thickness and circulating drying time (CDT) on the drying characteristics, drying uniformity (temperature and water content uniformity) and MEUR of foamed pulp were investigated by theoretical analysis and single-factor experiments. The results indicated that the electric field distribution uniformity (EFDU) of the material layer was significantly improved with the increase of microwave intensity (P < 0.05). The EFDU and absorption characteristics of the material layer had a significant influence on the uniformity of temperature and water content distribution (P < 0.05). Drying uniformity was positively correlated with microwave intensity (2-6 W/g) but negatively with layer thickness (3-7 mm) and CDT (2-6 min). With the increase of microwave intensity, the drying uniformity gradually increased, and with the increase of layer thickness and CDT, the drying uniformity gradually decreased. MEUR increased initially and then decreased with the increase of microwave intensity, layer thickness and CDT. These results provide a theoretical basis for studies on the energy-efficient production of microwave dried berry fruit powder with high quality.

Key words: raspberry berry, microwave, foam drying, energy utilization, uniformity

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