梯度恒温水热处理饲料的糊化时间温度特性研究  

Time and temperature characteristics of feed gelatinization by gradient isothermal hydrothermal treatment

作　　者：金楠[1] 段恩泽[1] 王红英[1] 方鹏[1] 祁忠贤 陈计远 Jin Nan;Duan Enze;Wang Hongying;Fang Peng;Qi Zhongxian;Chen Jiyuan(National R&D Center for Agro-processing Equipment,College of Engineering,China Agricultural University,Beijing 100083,China)

机构地区：[1]中国农业大学工学院国家农产品加工技术装备研发分中心

出　　处：《农业工程学报》2019年第14期300-307,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目“畜禽养殖绿色安全饲料饲养新技术研发”(2018YFD0500600)

摘　　要：糊化作为淀粉热加工过程中的一种功能特性,在以淀粉源原料为主的饲料工业中应用广泛,而时间和温度是饲料调质等热加工中2个相互依存的重要工艺参数。为探究饲料糊化过程中对时间和温度的敏感性、掌握饲料糊化变性规律,该文以育肥猪配合饲料粉料为研究对象,基于饲料糊化的黏度特性,利用快速黏度分析仪(rapid visco analyzer,RVA)在25~95℃范围内测定了5、10、15℃/min 3个升温速率对饲料糊化行为的影响,并在此基础上,采用自定义的RVA梯度恒温加热程序对饲料进行水热处理,分析饲料糊化的时间和温度依赖性,利用黏度差值Δμ及其导数分析得到饲料糊化的温度阈值。结果显示:饲料的糊化行为受升温速率影响(P<0.05),当升温速率由5增加到15℃/min,峰值黏度由295增加到364 mPa·s,起始糊化温度由71.90增加到72.85℃;72、78和86℃3个温度阈值将饲料糊化过程中黏度的增长趋势划分为4个阶段;温度梯度范围为64~95℃、恒温保持时间分别为1、3、5和10 min的梯度恒温加热程序,证实了饲料糊化的温度依赖性和时间依赖性,且在饲料糊化的不同阶段所表现出的温度和时间依赖性显著程度不同;过长的恒温或加热处理时间会降低饲料糊化过程中的黏度值,使饲料的糊化表现出剪切稀化现象;在育肥猪配合饲料调质工艺参数的设定中,调质温度选择高于起始糊化温度72℃为宜,且延时熟化保持能带来更好的调质效果。研究结果为饲料糊化过程的研究提供了一种新思路,也为配合饲料调质等热加工过程的工艺优化提供参考。Gelatinization,as a functional property during thermal processing of starch,is applied extensively in starch-based feed industry.Furthermore,time and temperature are two interdependent process parameters in feed thermal processing including conditioning.In order to explore the sensitivity of feed to time and temperature in the process of gelatinization and to grasp the regularity of feed gelatinization and denaturation,the formula feed for finishing pigs was taken as the research material in this study,and the proximate composition of the feed,including moisture,starch,crude protein,ash,NDF,ADF,was determined.Based on viscosity characteristics of feed gelatinization,apparent viscosities of samples were measured during different hydrothermal treatments by RVA(rapid visco analyzer).Temperature scanning tests for feed-deionized water suspension were performed from 25 to 95℃at three heating rates of 5,10,15℃/min,and the derivative of viscosity was calculated for analysis of critical temperatures.Then,for gradient isothermal heating of feed-deionized water suspension within 64 to 95℃and holding time of 1,3,5 and 10 minutes respectively,a programmed stepwise temperature increase at constant heating rate was written to the custom configuration in RVA.The viscosity gradient and viscosity difference(Δμvalue)before and after isothermal heating were used to determine the temperature thresholds.The results showed that:the gelatinization behavior of feed was affected by heating rate(P<0.05).When the heating rate increased from 5 to 15℃/min,the peak viscosity increased from 295 to 364 mPa·s and the temperature on the onset of gelatinization increased from 71.90 to 72.85℃.A fast heating rate would increase the lag between the measured and the actual temperature of samples.Three temperature thresholds of 72,78 and 86℃were obtained,which corresponded to the irreversible swelling of amorphous regions,the disruption of crystalline structure and the disintegration of amylose-lipid complexes of the starch source in fee

关 键 词：饲料 温度 农产品 糊化 梯度恒温加热 水热处理 时间温度依赖性 RVA 

分 类 号：S816.9[农业科学—饲料科学]