基于主成分分析的玉米DDGS物理特性评价

Quality Evaluation of Physical Properties of Corn DDGS Based on Principal Component Analysis

为对玉米DDGS的物理特性进行分析及量化评价,以国内外8个玉米DDGS为试验材料,测定分析其容重、热物理特性、摩擦特性、粉碎特性及色差指标参数,并运用主成分分析法简化物理特性指标,构架评价体系,得到每种样品的综合得分。结果表明:样品各物理特性指标间存在不同程度的差异;各物理特性指标之间存在不同程度的相关性,比热与热导率呈极显著正相关,与导温系数呈极显著负相关;热导率与平均粒径呈显著正相关;导温系数与容重呈极显著负相关;摩擦系数与休止角呈极显著正相关,与平均粒径呈极显著负相关;L*、b*与平均粒径呈极显著正相关;L*与b*呈极显著正相关。通过主成分分析提取了3个主成分,累积方差贡献率达到87.415%;主成分分析的结果表明进口玉米DDGS的物理特性较好。

In order to analyze and quantify the physical （DDGS）, 8 DDGS samples from home and abroad were taken properties of corn distillers dried grains with solubles as materials to evaluate their qualities. Principal corn- ponent analysis （PCA） was used to establish a comprehensive evaluation model with indexes including the density, the thermal physical properties, friction characteristics, grinding characteristics and color. Score of each sample was obtained by PCA. The results showed that there were different degrees of variation in physical properties between samples. There were correlations between different indexes. The specific heat was very significantly positively correla- ted with the thermal conductivity, and it was very significantly negatively correlated with the thermal diffusivity. The thermal conductivity was significantly positively correlated with the geometric mean particle size. The thermal diffusiv- ity was very significantly negatively correlated with the density. The friction coefficient was very significantly positive- ly correlated with the angle of repose, and it was very significantly negatively correlated with the geometric mean par- ticle size. L ＊ and b ＊ value were very significantly positively correlated with the geometric mean particle size. L ＊ value was very significantly positively correlated with b ＊ value. The first three principal components, which con- tained 87. 415% information of the initial indexes, were extracted by PCA. According to the result of PCA, DDGS from abroad had better physical properties.