不同产地紫米营养成分比较及其相关性分析

Comparison of Nutritional Components and Correlation Analysis in Different Purple Rice Varieties

为评价不同品种紫米淀粉、脂肪、花青素、多酚、氨基酸和矿质元素间的差异,探究不同营养成分之间的关系,选取云南墨江(MJ)、湖南新化(HN)、贵州黎平(GZ)和陕西汉中(SX)4个产地的紫米,并与红米(R)、黑米(B)进行比较。结果显示,不同产地紫米成分含量存在差异,具有不同营养特征。HN紫米的淀粉含量最低(68.13%),脂肪(2.38%)、矿质元素Fe、K、Mg、Mn、Na、P、Zn含量最高,其中Mn(80.37 mg/kg)、Na(10.75 mg/kg)元素显著高于其他产地;MJ和SX紫米花青素(533.03 mg/kg,412.54 mg/kg)、多酚(340.55 mg/100 g,387.91 mg/100 g)含量显著高于其他产地,而GZ紫米花青素(156.55 mg/kg)和多酚(239.23 mg/100 g)显著低于其他产地紫米。SX紫米氨基酸总量(74.37 g/kg)与必需氨基酸(total essential amino acids,ΣEAA,26.09 g/kg)含量最高,与其他紫米差异不显著。紫米成分间相关性分析显示,花青素与多酚呈极显著正相关(0.625),二者分别与Ca呈显著负相关(–0.571,–0.549)。Asp、Gly与Fe、Ca呈显著正相关,大部分元素间呈显著正相关。不同有色稻米间,红米淀粉(74.73%)含量最高,花青素(9.05 mg/kg)、氨基酸总量(55.94 g/kg)、ΣEAA(19.78 g/kg)、Fe(6.51 mg/kg)、Mg(609.41 mg/kg)、P(1746.72 mg/kg)元素含量最低,与紫米和黑米差异显著(P<0.05)。黑米花青素(533.03 mg/kg)、多酚(453.53 mg/100 g)含量显著高于(P<0.05)其他有色稻;黑米和紫米氨基酸含量差异不显著(P>0.05),但显著高于(P<0.05)红米。有色稻ΣEAA与非必需氨基酸总量(total non-essential amino acid,ΣNEA)比例在0.54左右。主成分分析将3种有色稻分为红米、紫黑米两组,前3个主成分可以解释总方差的91%。第一主成分(PC1)贡献率为67.5%,代表矿质元素,说明产地是有色稻米成分组成差异的主要原因。第二主成分(PC2)占总方差的18.2%,主要为总花青素含量、氨基酸等。

In this study,four purple rice from Mojiang County(MJ),Xinhua County(HN),Hunan,Liping County(GZ),Guizhou and Hanzhong County(SX),Shaanxi were selected to evaluate the differences in starch,fat,anthocyanins,polyphenols,amino acids and elements between different origins,to determine the relationship among nutrient compo-nents,and to compare with red rice and black rice.The nutritional characteristics of the purple rice of different origins were different.Purple rice from HN had the lowest starch content(68.13%),highest fat,Fe,K,Mg,Mn,Na,P and Zn elements content,among which Mn(80.37 mg/kg)and Na(10.75 mg/kg)were significantly higher than other origins(P<0.05).Anthocyanins(533.03 mg/kg,412.54 mg/kg),polyphenols(340.55 mg/100 g,387.91 mg/100 g)content in purple rice from MJ and SX were significantly higher than those from the other origins(P<0.05),while anthocyanins(156.55 mg/kg)and polyphenols(239.23 mg/100 g)in purple rice from GZ were significantly lower(P<0.05)than those from the other origins. SX purple rice had the highest content of total amino acids (74.37 g/kg) and total essential amino acids (ΣEAA, 26.09 g/kg), which was not significantly different from other purple rice. Correlation analysis between the components of purple rice showed that anthocyanins was positively correlated with polyphenols (0.625), and both were negatively correlated with Ca (-0.571, -0.549), respectively. Asp and Gly were significantly positively correlated with Fe and Ca, respectively, and among most of each elements was significantly positively correlated. Among colored rice, red rice had the highest starch content (74.73%) , but the lowes content of anthocyanins (9.05 mg/kg), total amino acids (55.94 g/kg), ΣEAA (19.78 g/kg), Fe (6.51 mg/kg), Mg (609.41 mg/kg), and P (1746.72 mg/kg), which were signifi-cantly different with purple rice and black rice (P<0.05). The contents of anthocyanin (533.03 mg/kg) and polyphenols (453.53 mg/100g) of black rice were significantly higher (P<0.05) than that of other colored rice. The difference in amino acid content between black rice and purple rice was not significant (P>0.05), but significantly higher than that of red rice (P<0.05).. The ratio of ΣEAA/ΣNEA was about 0.54 among colored rice. Principal component analysis (PCA) divided the three colored rice into two groups. red rice, purple and black rice. The first three principal components could explain 91% of the total variance. The contribution of the first principal component (PC1) was 67.5%, which repre-sented mineral elements, indicating that the origin was the main reason for the difference in the composition of colored rice. The second principal component (PC2) accounted for 18.2% of the total variance, mainly including total anthocya-nin and amino acids.This study could provide some reference for nutritional evaluation of purple rice.