超声预处理对荠菜微波干燥品质的影响  

Effects of ultrasonic pretreatment on the microwave drying quality of shepherd's purse(Capsella bursa-pastoris)

作　　者：仇徐亮 冯蕾 聂梅梅 刘春泉[2] 李大婧[2] 张钟元[2] 李建林[1] 邱晓峰 唐冬妹 QIU Xuliang;FENG Lei;NIE Meimei;LIU Chunquan;LI Dajing;ZHANG Zhongyuan;LI Jianlin;QIU Xiaofeng;TANG Dongmei(School of Food and Pharmaceutical Engineering,Nanjing Normal University,Nanjing 210097,China;Institute of Agricultural Products Processing,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;Jiangsu Zhongbao Food Co.,Ltd.,Nantong 226144,China;Youi Food Co.,Ltd.,Suzhou 215105,China)

机构地区：[1]南京师范大学食品与制药工程学院,南京210097 [2]江苏省农业科学院农产品加工研究所,南京210014 [3]江苏中宝食品有限公司,南通226144 [4]苏州优尔食品有限公司,苏州215105

出　　处：《农业工程学报》2024年第6期155-167,共13页Transactions of the Chinese Society of Agricultural Engineering

基　　金：江苏省重点研发计划(现代农业)项目(BE2021318);江苏省农业科技自主创新项目(CX(23)1010)。

摘　　要：为提高荠菜的微波干燥品质,采用不同超声功率(4、6、8和10 W/g)对荠菜进行预处理,研究荠菜的传质特性、微观结构、水分分布、酶活性、微波干燥特性、色泽、复水性、营养成分和风味特性。结果表明:(1)相较于未超声对照组,超声预处理显著降低了荠菜中过氧化物酶(peroxidase,POD)和多酚氧化酶(polyphenol oxidase,PPO)活性(P<0.05),提高了干物质损失率;(2)超声预处理后,荠菜内部细胞间隙及直径增大,荠菜的水分自由度增大,当超声预处理功率为6 W/g时,细胞结构较为完整;(3)超声预处理促使荠菜微波干燥速率提高,超声预处理功率为6 W/g时,荠菜干燥速率较高,有效水分扩散系数为2.1531×10^(−6) m^(2)/s;(4)荠菜微波干燥动力学模型拟合结果显示,Page模型决定系数R^(2)(0.9891~0.9950)较高,均方根误差RMSE(0.0242~0.0351)及卡方值χ^(2)(0.0006~0.0012)较低,拟合效果最佳;(5)超声预处理功率为6 w/g时,微波干制荠菜的复水比较高,叶绿素、总黄酮和总酚含量分别为39.29、24.66、7.70 mg/g,这3种营养成分含量均显著高于未超声对照组(P<0.05);(6)相较于新鲜荠菜,超声预处理提高了微波荠菜干制品中的氮氧化合物、含硫化合物和芳香成分响应值及丰富度、咸味和酸味强度。综合分析,以6 W/g超声功率对荠菜进行预处理,荠菜微波干制品品质最佳。该研究可为荠菜精深加工提供一定的理论依据和技术参考。Shepherd's purse is one types of the most favorite vegetable food with an excellent source of bioactive compounds,such as polyphenols,flavonoids,vitamins and chlorophyll.However,it can deteriorate rapidly during storage,due to the high percentage of moisture.Microwave drying is one of the most efficient and rapid methods to reduce the water activity of food.However,nonuniform temperatures and corona discharges can degrade the product quality during microwave drying.Ultrasonic waves can be expected to serve as the pretreatment on the mass transfer for food drying in recent years.This study aims to explore the effect of ultrasonic pretreatment on the drying quality of shepherd's purse.Four ultrasonic pretreatments(4,6,8 and 10 W/g)were set before the microwave drying.A systematic investigation was then made on the mass transfer,microstructure,water distribution,water state and enzyme activity of the shepherd's purse after the ultrasonic pretreatment.Then,further analysis was carried out on the drying characteristics,color,rehydration property,nutrients(chlorophyll,total phenols,total flavonoids and ascorbic acid)and flavor behavior of the samples after microwave drying.The results showed that the ultrasonic pretreatment significantly decreased the activities of peroxidase(POD)and polyphenol oxidase(PPO)in shepherd's purse,whereas,there was an increase in the loss rate of dry matter and the response value of richness,salty,acidity.At the same time,there were increasing response values of nitrogen and oxygen compounds,sulfur compounds,and aromatic components of dried products.The relaxation of low-field nuclear magnetic resonance showed that there were three states of water(T21,T22 and T23)in the shepherd's purse,which represented the bound,immobile,and free water.The moisture freedom of the shepherd's purse increased at first and then decreased after ultrasonic treatment.But compared with fresh samples,there was an increase in the moisture freedom of the shepherd's purse that was treated with ultrasound.The cavitati

关 键 词：超声 微波干燥 荠菜 微观结构 水分分布 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]