新疆不同品种桑葚营养品质分析及综合评价

目的 综合评价新疆不同品种桑葚营养品质。方法 以新疆地区11个桑葚品种为研究对象，测定其还原糖、有机酸、矿物元素、氨基酸、抗氧化活性等15项品质指标，并运用主成分分析法和聚类分析法进行综合品质评价。结果 新疆不同桑葚品种各个品质指标之间大多存在显著性差异（P<0.05），其中富马酸含量差异最大，变异系数为100.00%，果糖差异最小，变异系数为7.46%。黑桑1号中黄酮含量、矿物元素总量较高，分别为2.86 mg/g、5860.29 mg/kg；黑桑2号和药桑1号的1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picryl-hydrazyl radical,DPPH）自由基清除能力较强，均为4.18 mmol/L Trolox；粉桑、白桑1号中糖酸比相对较高，分别为12.45%、14.64%；药桑2号中2,2-联氮双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS）自由基清除能力比较强，为4.27 mmol/L Trolox；药桑1号的花青素含量最高，为2.59 mg/g；药桑5号氨基酸总含量最高，为1.349%。利用主成分分析可以将15项品质指标简化为3项主要成分，累计贡献率达到85.432%，可以反映品质指标的绝大部分信息。根据综合评价得分高低，将品种排序为药桑3号>黑桑2号>黑桑1号>药桑1号>药桑2号>药桑6号>药桑5号>药桑4号>白桑2号>白桑1号>粉桑。根据聚类分析可以将11种桑葚分为4类，第一类为：黑桑1号、黑桑2号；第二类为粉桑、白桑1号、白桑2号；第三类为：药桑1号、药桑3号；第四类为：药桑2号、药桑4号、药桑5号、药桑6号。 结论 综合评价得出药桑3号综合品质最优，但其糖酸比在3%左右，风味品质比较差，适合作为保健品开发的果桑品种；粉桑和白桑虽然综合品质较差，但其口感比较好，适合鲜食或者制作成桑葚酒、桑葚干。

Analysis and Comprehensive Evaluation of Nutritional Quality of Different Varieties of Mulberries in Xinjiang

Objective The objective of this study was to evaluate comprehensively evaluation of the nutritional quality of different varieties of mulberry in Xinjiang. Methods 11 mulberry varieties in Xinjiang region were used as research objects to determine 15 quality indexes such as reducing sugar, organic acid, mineral elements, amino acid, antioxidant activity, etc., and comprehensive quality evaluation was carried out using principal component analysis and cluster analysis. Results Most of the significant differences (P<0.05) existed among the individual quality indexes of different mulberry varieties in Xinjiang. The difference of fumaric acid content was the largest with a coefficient of variation of 100.00%, and the difference of fructose content was the smallest with a coefficient of variation of 7.46%. The flavonoid content and total mineral elements in Black Mulberry No.1 were higher, 2.86 mg/g and 5860.29 mg/kg, respectively,which were higher than them in other mulberries. The 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging ability of Black mulberry No.2 and Medicinal Mulberry No.1 were stronger, both were 4.18 mmol/L Trolox. The sugar-acid ratio were 12.45% and 14.64% in Pink Mulberry and White Mulberry No.1, respectively, which were relatively higher than that in other mulberries. The free radical scavenging capacity of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) was relatively stronger in Medicinal Mulberry No.2, with 4.27 mmol/L Trolox. Anthocyanin content of Medicinal Mulberry No. 1 was the highest with 2.59 mg/g. The highest total amino acid content was 1.349% in Medicinal mulberry No. 5. Using principal component analysis, 15 quality indexes could simplified into 3 main components, with a cumulative contribution rate of 85.432%, which could reflect the vast majority of information of quality indexes. Based on the overall rating, the varieties were ranked as Medicine Mulberry No.3 > Black Mulberry No.2 > Black Mulberry No.1 > Medicine Mulberry No.1 > Medicine Mulberry No.2 > Medicine Mulberry No.6 > Medicine Mulberry No.5 > Medicine Mulberry No.4 > White Mulberry No.2 > White Mulberry No.1 > Pink Mulberry. Based on the cluster analysis, the 11 species of mulberry could be classified into four categories, and the first category was: Black Mulberry No.1, Black Mulberry No.2; the second category was Pink Mulberry, White Mulberry No.1, White Mulberry No.2; the third category was: Medicinal Mulberry No.1, Medicinal Mulberry No.3; and the fourth category was: Medicinal Mulberry No.2, Medicinal Mulberry No.4, Medicinal Mulberry No.5, and Medicinal Mulberry No.6. Conclusion The comprehensive quality of the Medicine Mulberry No. 3 was the best via Comprehensive evaluation, but its sugar-acid ratio of about 3%, flavor quality is relatively poor, suitable for health care products as the development of mulberry varieties, Pink Mulberry and White Mulberry although the comprehensive quality of the poorer, but its taste is better, suitable for fresh food or made into mulberry wine and dried mulberries.