摘要
本试验旨在探求不同热处理对豆渣蛋白质分子结构的影响及其与营养价值、瘤胃降解特性及瘤胃非降解蛋白质的小肠消化率的相关关系。将采集到的新鲜豆渣进行不同温度(100、115、130℃)和不同时间(2、4、6 h)的热处理,共计9种不同程度热处理样品。采用常规化学分析方法并结合康奈尔净碳水化合物-净蛋白质体系(CNCPS)、尼龙袋技术及改进的三步体外法对不同热处理的豆渣进行营养价值评定,并利用傅里叶变换红外光谱(FTIR)技术分析豆渣蛋白质分子结构的变化,进而探求它们之间的相关关系。结果表明:1)随着温度的升高以及加热时间的延长,豆渣中可溶性蛋白和非蛋白氮含量显著减少(P<0.05),中性洗涤不溶蛋白含量显著增加(P<0.05),同时使干物质瘤胃有效降解率及小肠可消化蛋白含量显著降低(P<0.05)。2)不同热处理对豆渣蛋白质分子结构中酰胺Ⅰ带峰高、峰面积,酰胺Ⅱ带峰高、峰面积,α-螺旋、β-折叠的峰高以及α-螺旋和β-折叠的峰高比值均有显著影响(P<0.05)。3)酰胺Ⅰ带峰高、峰面积,酰胺Ⅱ带峰高、峰面积,α-螺旋、β-折叠的峰高以及α-螺旋和β-折叠的峰高比值可以有效地估测不同热处理豆渣的蛋白质营养价值、瘤胃降解参数及小肠消化率,并建立回归方程。其中,不同热处理豆渣蛋白质分子结构对缓慢降解蛋白质含量(R2=0.67)、干物质有效降解率(R2=0.66)、粗蛋白质快速降解部分含量(R2=0.63)、小肠消化率(R2=0.63)拟合最好。综上所述,不同热处理对豆渣蛋白质分子结构、营养价值和瘤胃降解特性及小肠消化率均有影响,100℃、2 h处理的豆渣的营养价值最高。不同热处理豆渣中蛋白质分子结构与其营养价值、瘤胃降解特性及小肠消化率之间存在相关关系,初步证明利用FTIR技术得到的豆渣光谱信息能直接反映其热损害程度。
The objective of this experiment was to explore the effects of different heat treatments on protein molecular structure of okara and their relationships with nutritional value,ruminal degradability characteristics and small intestine digestibility of rumen undegraded protein.Fresh okara were treated at different temperatures(100,115 and 130 ℃) and different time(2,4 and 6 h),and got 9 kinds of different heat treated samples.This experiment used conventional chemical analysis methods combined with Cornell net carbohydrates-net protein system(CNCPS),nylon bag technology and a modified three-step in vitro method to evaluate the nutritive values of different heat treated okara.Fourier transform infrared spectroscopy(FTIR) technology was used to analyze the changes of protein molecular structure and then to explore the correlation between them.The results showed as follows:1) with increasing temperature and time,the contents of soluble protein and non-protein nitrogen in the okara significantly reduced(P<0.05),the content of neutral detergent insoluble protein significantly increased(P<0.05),and the rumen effective degradability of dry matter and intestinal digestibility protein content significantly reduced(P<0.05).2) Amide Ⅰ band peak height and peak area,amide Ⅱ band peak height and peak area,peak height of α-helix and β-sheet,and peak height ratio of α-helix to β-sheet in protein molecular structures of okara had significant effects(P< 0.05).3) Amide Ⅰ band peak height and peak area,amide Ⅱ band peak height and peak area,peak height of α-helix and β-sheet,and peak height ratio of α-helix to β-sheet could effectively estimate protein nutritional value,rumen degradation parameters and intestinal digestibility of different heat treated okara,and regression equations were established.Among these,the protein molecular structure of different heat treated okara could estimate slow degradation protein(R2=0.67),dry matter effective degradation rate(R2=0.66),crude protein rapid degradation part(R2=0.63),sm
作者
李昕
徐宏建
王楠
么恩悦
李洋
张永根
LI Xin;XU Hongjian;WANG Nan;YAO Enyue;LI Yang;ZHANG Yonggen(College of Animal Science and Technology of Northeast Agricultural University,Harbin 150030,China)
出处
《动物营养学报》
CAS
CSCD
北大核心
2019年第1期395-408,共14页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家奶牛产业技术体系(CARS-36)
