摘要
采用低场核磁共振技术研究了固态渗透(solid osmotic dehydration,SSD)和液态渗透(liquid osmotic dehydration,LOD)过程中草莓水分的流失规律。结果表明,在糖渍72 h的过程中,2种糖渍方式下草莓水分含量均逐渐降低;在渗糖72 h时,SSD和LOD处理的草莓水分含量分别由91.83%下降至74.56%、79.90%。2种渗透方式的弛豫时间T 22与T 23值均伴随着渗透过程而变小,表示SSD和LOD都使得草莓中不易流动水和自由水的流动性减小;同时峰面积A 22值均逐渐减小,表示2种渗透方式均减少了不易流动水的水分含量。然而在LOD处理过程中,草莓中自由水峰面积在渗透过程中呈下降趋势,但下降不显著(P>0.05),同时弛豫时间T 21峰位置逐渐右移,表示随着渗透时间的延长,草莓中结合水的流动性增强;相反,在SSD处理中,草莓中自由水峰面积在渗透72 h后显著下降(P<0.05),相比0 h,下降幅度达55.35%,并伴随着渗透时间的延长,草莓中结合水的流动性减弱。另外,建立了低场核磁共振峰积分面积总和(A 21+A 22+A 23)与草莓的含水率的线性拟合模型,线性关系显著(P<0.05),R 2均大于0.90,拟合效果较好。该研究从水分的角度探究了SSD和LOD对草莓的影响,为草莓干制作中渗糖方式的选择提供参考。
The law of water loss in strawberries during solid osmotic dehydration(SSD)and liquid osmotic dehydration(LOD)was studied by low-field nuclear magnetic resonance(LF-NMR).Results showed that the moisture content of strawberries decreased gradually during the 72 h osmotic dehydration.At the end of the osmotic dehydration procedures,the moisture content of the strawberries treated with SSD and LOD decreased from 91.83%to 74.56%and 79.90%,respectively.The relaxation time T 22 and T 23 values modes decreased with the osmotic dehydration process in both two osmotic dehydration methods,indicating that both SSD and LOD reduced the fluidity of immobilized water and free water in strawberries.At the same time,the peak area A 22 value gradually decreased,indicating that the two infiltration methods reduced the moisture content of the immobilized water.During the LOD,the free water peak area in strawberries showed a downward trend during the permeation process,but the decline was not significant(P>0.05).At the same time,the position of the T 21 peak gradually shifted to the right,indicating that with the prolongation of LOD time,the fluidity of bound water in strawberries increased.While the peak area of free water in strawberries decreased significantly after 72 h of infiltration(P<0.05)in the SSD treatment and,compared with 0 h,the decrease range was 55.35%,and the fluidity of bound water in strawberries was weakened with the extension of osmotic dehydration time.In addition,a linear fitting model between the sum of peak integral areas of low field NMR(A 21+A 22+A 23)and the moisture content of strawberries was established.The linear relationship was significant(P<0.05).R 2 was greater than 0.90,and the fitting effect was great.This study explored the effects of SSD and LOD on strawberries from the perspective of moisture and provided a reference for the selection of osmotic dehydration methods in preserved strawberries production.
作者
王锐
牛丽影
胡丽丽
李大婧
张钟元
聂梅梅
肖亚冬
刘春菊
吴海虹
肖丽霞
WANG Rui;NIU Liying;HU Lili;LI Dajing;ZHANG Zhongyuan;NIE Meimei;XIAO Yadong;LIU Chunju;WU Haihong;XIAO Lixia(School of Food Science and Engineering,Yangzhou University,Yangzhou 225000,China;Institute of Agro-product Processing,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2023年第18期134-139,共6页
Food and Fermentation Industries
基金
江苏省重点研发项目(BE2021316)
芜湖市科技成果转化项目(2021cg05)。
关键词
草莓
液态渗透
固态渗透
低场核磁共振
水分迁移
strawberry
liquid osmotic dehydration
solid osmotic dehydration
low-field nuclear magnetic resonance
moisture migration
