射频技术处理糙米自由基与脂肪酶的作用效果研究  

Effect of radio frequency technology on free radicals and lipase of brown rice

作　　者：王岚峰 史锋 黄金荣 李永富 WANG Lanfeng;SHI Feng;HUANG Jinrong;LI Yongfu(School of Food Science and Technology,National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing,Wuxi 214122,China;State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China;Engineering Research Center for Bioactive Products Processing Technology of Jiangsu Province,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学,粮食发酵与食品生物制造国家工程研究中心,江苏无锡214122 [2]江南大学,江南大学食品科学与技术国家重点实验室,江苏无锡214122 [3]江苏省生物活性制品加工工程技术研究中心,江苏无锡214122

出　　处：《食品与发酵工业》2024年第4期59-67,共9页Food and Fermentation Industries

基　　金：“十三五”国家重点研发计划重点专项(2018YFD0400501)。

摘　　要：采用射频技术适度灭活糙米脂肪酶并控制自由基强度,改善其贮藏稳定性。考察极板间距、温度、补水率及保温时间等因素对糙米脂肪酶灭活率和自由基强度的影响,通过正交实验分别得到最高脂肪酶灭活率和最低自由基强度的工艺参数,最终通过对比2个最优工艺参数条件下处理的糙米和未处理糙米在37℃下贮藏28 d过程中的变化,用以分析射频处理对糙米贮藏稳定性的改善效果。通过单因素和正交实验,得到了脂肪酶灭活率最高(样品Ⅰ)的最佳加工参数:极板间距145 mm、温度105℃、补水率4.5%;自由基强度最低(样品Ⅱ):极板间距145 mm、温度95℃、补水率4.5%,得到的样品Ⅰ和样品Ⅱ的脂肪酶灭活率分别为62.65%和41.77%,而自由基强度分别为0.891和0.699。在加速贮藏期间,样品Ⅰ和样品Ⅱ的脂肪酸峰值分别为22.42、24.00 mg/100 g,均处于<25 mg/100 g的稻谷宜存品质范围内,而对照样品峰值为33.17 mg/100 g,已经超标;样品Ⅱ的过氧化值峰值浓度低于样品Ⅰ与未处理样品,且在可接受范围内。贮藏期间,射频处理的2个糙米样品自由基强度呈增加趋势,在射频样品中以样品Ⅱ的自由基强度峰值最低,此外,样品Ⅱ的己醛峰值浓度也较低,且多不饱和脂肪酸的氧化速率最慢。在控制自由基强度的前提下,适度灭活糙米脂肪酶能够改善糙米的贮藏稳定性,仅追求较高脂肪酶灭活率而忽略自由基强度增加并不能改善糙米贮藏稳定性。This study aimed to inactivate brown rice lipase and control the free radical intensity by radio frequency(RF)technology to improve its storage stability.The effects of electrode gap,temperature,water supplementation rate,and incubating time on lipase inactivation rate and free radical intensity of brown rice were investigated,and the optimal processing parameters for the highest lipase inactivation rate and the lowest free radical intensity were obtained by orthogonal experiments,respectively.Finally,the effect of RF treatment on the storage stability of brown rice was analyzed by comparing the changes of two RF-treated brown rice samples under optimal processing parameters and one untreated brown rice sample during 28-day storage at 37°C.Results showed that the best processing parameters with the highest lipase inactivation rate(sample I)were obtained by single factor and orthogonal experiments,which were an electrode gap of 145 mm,temperature of 105℃,and water supplementation rate of 4.5%.The best processing parameters with the lowest free radical intensity(sampleⅡ)were an electrode gap of 145 mm,temperature of 95℃,and water supplementation rate of 4.5%.The lipase inactivation rate of the resulting sampleⅠand sampleⅡwere 62.65%and 41.77%,respectively,while the free radical intensities were 0.891 and 0.699,respectively.During accelerated storage,the peak fatty acids value of samplesⅠandⅡwere 22.42 and 24.00 mg/100 g,respectively,both were within the suitable storage quality range of<25 mg/100 g of rice,while the peak fatty acids value of the untreated sample was 33.17 mg/100 g,which exceeded the standard.The peak peroxide value of sampleⅡwas lower than those of sampleⅠand the untreated sample,and it was within the acceptable range.During the storage period,the free radical intensity of two brown rice samples treated with RF showed an increasing trend,and the free radical intensity of sampleⅡwas the lowest in the samples treated with RF.Furthermore,the final hexanal concentration of sample�

关 键 词：糙米 射频加热 脂肪酶灭活 自由基强度 贮藏稳定性 

分 类 号：TS210.1[轻工技术与工程—粮食、油脂及植物蛋白工程]