膨化饲料中常用淀粉源理化性质比较研究

Comparison Research on Physicochemical Properties of Starch Sources in Extruded Feed

淀粉在水产膨化饲料加工过程中起着膨胀和黏合的双重作用,来源不同的淀粉其加工特性也不同,为了对淀粉源进行系统研究和科学评价,本试验以水产膨化饲料常用的面粉、木薯淀粉、碎米、大麦、豌豆、高粱和预糊化淀粉7种淀粉源为试验材料,测定分析其基本成分、溶解度、膨胀度、持水能力、脱水收缩、糊化特性、热力学特性等理化特性,并运用主成分分析简化理化性质指标,构建量化评价体系。结果表明:不同淀粉源在理化性质上差异显著(P<0.05);各理化性质指标之间存在不同程度的相关性,糊化温度与淀粉总量呈正相关(R=0.841,P<0.01);峰值黏度与淀粉总量和膨胀度呈极显著正相关(R=0.925,P<0.01);糊化时间与膨胀度呈极显著负相关(R=0.852,P<0.01);相变热焓与膨胀度呈极显著正相关(R=0.823,P<0.01);采用主成分分析方法提取了3个主成分,累计方差贡献率达92.17%,能够代表所测定18种理化性质中绝大部分信息,7种淀粉源具有不同的特点,高粱具有较高的起始温度、峰值温度、回生值和最终黏度,木薯淀粉表现出高峰值黏度,大麦、豌豆和预糊化淀粉表现出高溶解度,豌豆的析水率最低,碎米持水能力最好。结果显示,为生产低淀粉水产膨化饲料,建议选择木薯淀粉、碎米、预糊化淀粉作为淀粉源。

Starch plays a dual role of expansion and adhesion in the processing of aquatic extruded feed,and the processing characteristics of starch from different sources are also different.In order to systematically study and scientifically evaluate the starch sources,seven starch sources commonly used in aquatic extruded feed,including wheat flour,cassava starch,broken rice,barley,pea,sorghum and pre-gelatinized starch were used as experimental materials.The physical and chemical properties such as basic components,solubility,swelling degree,water holding capacity,dehydration shrinkage,gelatinization characteristics and thermal characteristics were measured and analyzed,and the principal component analysis was applied to simplify the physical and chemical property indexes and construct a quantitative evaluation system.The results showed that the physical and chemical properties of the different starch sources were significantly different(P<0.05).The pasting temperature was positively correlated with the total starch content,the peak viscosity was significantly positively correlated with total starch and swelling degree,the pasting temperature was positively correlated with the total amount of starch(R=0.841,P<0.01).The peak viscosity was positively correlated with the total contents of starch and the swelling degree(R=0.925,P<0.01).There was a significant negative correlation between pasting temperature and swelling power(R=0.852,P<0.01).The enthalpy change of gelatinization was positively correlated with the swelling power(R=0.823,P<0.01).Three principal components were extracted by principal component analysis method,and the cumulative variance contribution rate was 92.17%,which could represent most of the information in the original 18 physicochemical properties.Seven starch sources had different characteristics,sorghum had high onset temperature,peak temperature,regeneration value and final viscosity,cassava starch showed high peak viscosity,barley,pea and pregelatinized starch showed high solubility,pea had the lowest water precipitation and broken rice had the best water holding capacity.The results show that cassava,broken rice and pregelatinized starch are recommended as starch sources for the production of low-starch aquatic puffed feed.