Fruit Quality Analysis and Comprehensive Evaluation of Different Varieties Walnuts and Pecan in Yunnan
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摘要: 为了探究云南主栽核桃和薄壳山核桃果实的品质评价指标,选取27个核桃品种果实,对矿质元素、蛋白脂、粗脂肪等12个营养指标进行变异和相关性分析,并采用主成分和聚类分析方法,进行分类与综合评价。结果表明:12个营养指标的含量变异较为丰富,变异系数的变化范围为5%~83%,其中VC变异系数最大,粗脂肪变异系数最小;9种矿质元素平均含量从高到低依次为:K>P>Mg>Ca>Mn>Na>Fe>Zn>Cu,蛋白质含量均值为15.62%,脂肪含量均值为68.63%,VC的平均含量为4.66 mg/100 g;相关性分析表明,12个营养指标之间,P、Fe、Mg、Ca、Cu均与蛋白质呈极显著(P<0.01)正相关;主成分分析进行综合评价筛选出品质最佳的核桃品种为‘香茶’‘永平’‘晚熟’和‘小圆果’,薄壳山核桃中品种‘卡多’综合表现较好;聚类分析结果显示,可将其分为两大类,即富含矿质元素类群和高脂肪含量类群;相关性分析和主成分分析结果显示,K、Fe、Mg、Ca、Cu元素、蛋白质、脂肪为评价云南不同品种核桃品质的关键性指标。薄壳山核桃适合榨油,22种主栽核桃适合直接食用或开发富矿质元素和高蛋白的功能饮料。研究明确了云南核桃品质评价的关键指标并探明品质特性,提供科学分类方法,为云南核桃品质评价体系的构建奠定理论依据。Abstract: To explore the quality evaluation indicators of walnut and pecan varieties cultured in Yunnan, the contents of 12 nutritional indicators which included in mineral elements, protein, crude fat, and vitamin C of 27 walnut varieties were determined. 12 indicators were comprehensively explored by correlation analysis, principal component analysis and cluster analysis to reveal variation and comprehensive quality of walnut resources in Yunnan Province. Results showed that the variation of the content of 12 indicators was relatively rich, the variation coefficient ranged from 5% to 83%, among which the variation coefficient of vitamin C was the largest and the variation coefficient of crude fat was the smallest. The order of the average contents of 9 mineral elements was K>P>Mg>Ca>Mn>Na>Fe>Zn>Cu. The average contents of protein, fat and vitamin C were 15.62%, 68.63% and 4.66 mg/100 g, respectively. As demonstrated by the results of correlation analysis on 12 indicators, there was a significant positive correlation between protein and P, Fe, Mg, Ca, and Cu. The principal component analysis was used to comprehensively evaluate, showed that the comprehensive quality of walnut varieties 'Xiangcha' 'Yongping' 'Wanshu' and 'Xiaoyuanguo' were the best and the pecan variety 'Kaduo' was the better. The clustering analysis results showed that it can be divided into two major categories, namely the group rich in mineral elements and the group with high fat content. Subsequently, by combining with cluster analysis, K, Fe, Mg, Ca, Cu, protein and fat were determined as the critical indicators to evaluate the quality of walnut and pecan varieties cultured in Yunnan. Pecan varieties were suitable for extracting oil, and 22 main walnut varieties were suitable for direct consumption or the development of functional beverages rich in mineral elements and protein. The study clarified the critical indicators for evaluating the quality of Yunnan walnut and explored its quality characteristics, providing a scientific classification method, and laying a theoretical basis for the construction of the Yunnan walnut quality evaluation system.
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Keywords:
- walnuts /
- quality /
- principal component analysis /
- cluster analysis /
- comprehensive evaluation
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我国核桃栽培历史悠久,是世界核桃起源地之一[1]。随着产业发展,核桃已作为特色优势农产品,在国家产业扶贫和增加农民收益方面发挥重要作用,云南气候和地理条件具有多样性,核桃品种资源丰富品质优异,是我国核桃生产的第一大省,种植面积已超过10万hm2[2]。据统计,截止2022年底,云南核桃产量已达191万吨,综合产值达539亿元,稳居全国首位,主要以普通核桃(Juglans regia Linn.)、薄壳山核桃(Carya illinoensis(Wangenh.)K. Koch)、泡核桃(Juglans sigillata Dode)等种为主,主栽品种有漾濞泡核桃、大姚三台核桃、昌宁细香核桃等,占全省种植面积70%以上,尤其在大理漾濞县境内,近90%的农户均有种植核桃,核桃已成为当地乡村振兴发展战略中的主导产业之一[3−5],占农民收入的40%以上[6]。研究发现,核桃果实中富集了大量人体必需的各种矿物质、蛋白质、维生素以及黄酮和多酚类等活性物质,具有较高的营养价值和药用保健功效[7−10]。因此,深入挖掘和研究当地核桃品质特征[11],综合评价其品质和营养特性[12−14],显得尤为重要。
然而,核桃果实营养品质受核桃品种、立地环境和栽培管理等多重因素的影响,不同品种间矿质元素、脂肪、蛋白质、维生素含量均存在较大差异[15,16−17]。苏为耿等[18]对云南6种核桃的果实特性和营养成分进行分析,结果表明,6个核桃品种在粗脂肪、蛋白质与纤维素含量存在差异;耿树香等[19]分析测定了云南主栽核桃的蛋白质和脂肪酸含量,发现其蛋白质含量10.93%~21.21%,脂肪含量在59.40%~69.86%;刘威等[20]对6种薄壳山核桃的脂肪组成及营养成分进行了分析,结果表明,包括粗脂肪和蛋白质在内的6种营养成分在单株之间存在差异;耿树香等[21]基于脂肪、蛋白质、微量元素、脂肪酸等营养成分对云南主栽核桃和薄壳山核桃进行综合评价,结果表明大理漾泡、金华、密西西比10号3个品种,可用于开发富Fe、富Zn、富Ca核桃蛋白露或蛋白粉。可见,不同品种核桃果实的营养成分存在较大差异[22]。
前人关于核桃营养品质方面的研究主要集中于脂肪、蛋白质、脂肪酸等成分[20,23],鲜见对矿质元素结合其他品质指标进行的综合评价。为此,本研究选取27个核桃品种果实,对其蛋白质、脂肪、VC、9种矿质元素的含量进行变异分析,在此基础上,采用主成分分析方法确定各个品种综合得分,结合相关性和聚类分析筛选出品质佳的核桃品种,明确综合品质评价的关键性指标,综合评价筛选出优质核桃品种,以期为云南核桃品质评价体系的构建奠定理论基础,为当地核桃资源优化利用提供科学依据。
1. 材料与方法
1.1 材料与仪器
核桃带壳干果 云南省内大理漾濞楚雄大姚等核桃主产区市售。试验收集27种不同品种,各1 kg,包括22种核桃品种,分别为‘晚熟’‘小尖嘴’‘大木瓜’‘桐子果’‘滑皮’‘小胖诺’‘圆菠萝’‘高丰’‘大尖嘴’‘小圆果’‘漾早1号’‘娘青’‘四方’‘草果’‘大麻’‘细皮’‘杂果’‘漏米’‘猫头’‘香茶’‘三台’‘永平’,编号为H1~H22以及5种薄壳山核桃品种,即‘云光’‘云星’‘巧克陶’‘欧肯尼’‘卡多’,编号为S1~S5;乙酸、硫酸、高氯酸、浓硝酸为优级纯,石油醚、硫酸铜、硫酸钾、偏磷酸、钼酸铵等均为分析纯 均购自昆明倍捷科技有限公司;内标元素储备液(1000 mg/L) 国家有色金属及电子材料分析测试中心,使用时采用二次去离子超纯水稀释配至所需浓度。
722S分光光度计 上海菁华科教仪器公司;OPTIMA8000电感耦合等离子体原子发射光谱仪 美国Perkin Elmer公司;ED36型石墨消解仪、SWT 2240电子天平 北京莱伯泰科仪器有限公司;FD 115电热鼓风干燥箱 美国BINDER公司。
1.2 实验方法
1.2.1 样品预处理
将核桃干果去壳,用粉碎机将果仁粉碎均匀,在70 ℃烘干至恒重,密闭保存,备用。
1.2.2 蛋白质含量测定
依据GB/T 5009.5-2010标准,准确称取0.5 g核桃仁样品,移入干燥的定氮瓶中,加入0.1 g硫酸铜、1 g硫酸钾及5 mL硫酸进行试样消解,制备试样溶液。加4 mL乙酸钠-乙酸缓冲溶液及4 mL显色剂,水浴中加热15 min。于波长400 nm处测量吸光度值,通过吸光度值与标准曲线比较定量求出样品中蛋白质含量[21]。
1.2.3 粗脂肪含量测定
依据GB/T 5512-2008标准,准确称取5.0 g核桃仁样品置于折好的滤纸筒中,放入索式提取器内,注入石油醚至虹吸管高度以上。水浴温度控制在使提取液每6~8 min回流1次,提取约16 h。提取完毕后,在水浴上蒸干除去残余的石油醚,将提取出的脂肪烘干至恒质量,称量并计算样品粗脂肪含量[21]。
1.2.4 维生素C含量测定
采用钼蓝比色法测定。准确称取核桃仁样品10.0 g,准确加入50 mL草酸-EDTA溶液将样品粉碎匀浆后搅拌提取1 h。将匀浆经9000 r/min离心10 min,过滤获得上清液。取5 mL上清液,依次加入0.5 mL偏磷酸-乙酸溶液、5%硫酸和5%钼酸铵,混匀后于30 ℃水浴15 min,冷却后于4000 r/min离心10 min,上清液于760 nm出测定吸光度,根据VC标准曲线计算VC含量[24]。
1.2.5 矿质元素含量测定
依据NY/T 1653-2008标准,通过电感耦合等离子体原子发射光谱仪,测试核桃仁中K、P、Ca、Mg、Zn、Mn、Fe、Cu、Na含量。准确称取0.5 g粉碎好的核桃仁样品,于40 mL瓷玵涡内,置可调温电热板上炭化完全后,转入马福炉中,550 ℃灰化4 h,取出冷却至室温,用5 mL硝酸溶液溶解残渣,煮沸,转入50 mL容量瓶中,用硝酸溶液定容,混匀。取样液直接测定各元素含量[25]。
1.3 数据处理
数据处理采用Excel 2019、SPSSAU在线软件、OriginPro 2018软件对试验数据进行分析处理,相关性分析采用等距离Pearson相似性分析及双变量显著性分析法(P<0.05),主成分分析使用SPSSAU在线软件及OriginPro软件,聚类分析使用OriginPro 2018软件的“统计-多变量分析-系统聚类”过程完成,采用平方欧式距离(Square Euclidean distance)。
2. 结果与分析
2.1 不同品种云南核桃果仁营养指标含量分析
矿质元素、蛋白质、粗脂肪、维生素都是评价核桃品质的重要营养指标。对27种云南核桃果实中的磷(P)、钾(K)、锌(Zn)、铁(Fe)、锰(Mn)、镁(Mg)、钙(Ca)、铜(Cu)、钠(Na)元素、蛋白质、粗脂肪、维生素C(VC)的含量进行分析(表1,表2),结果表明,测定的9种矿质元素,含量排在前三的为K、P、Mg,变化范围分别介于3430~7370、2230~6780、1000~1980 mg/kg之间;Ca含量在379 mg/kg至999 mg/kg之间。27个品种中K、P、Mg、Ca含量最高的分别为‘晚熟核桃’‘香茶核桃’、薄壳山核桃‘卡多’‘永平核桃’。Na元素含量最高为薄壳山核桃品种‘欧肯尼亚’(126 mg/kg),最低为‘香茶核桃’(10.3 mg/kg),波动范围最大。其余微量元素含量从高到低排列依次为Mn>Fe>Zn>Cu,Mn和Cu的含量波动较大,Mn含量最高的是‘猫头核桃’,为202 mg/kg,Cu含量最高的是‘四方核桃’,为22.6 mg/kg;Fe和Zn的含量分别在43.2~22.4 mg/kg和36.8~13.6 mg/kg之间变化,含量最高的分别为‘小圆果核桃’和薄壳山核桃‘巧克陶’。27种核桃果实中9种矿质元素含量介于6.96~7370 mg/kg之间,各元素含量均值分别为3887.89、4927.41、25.50、31.43、78.96、1636.93、683.15、15.74、44.57 mg/kg。9种矿质元素变异系数由高到底依次为Na、Cu、Mn、P、Zn、Ca、K、Fe、Mg。Fe和Mg元素含量的变异系数较小,在20%以下,说明Fe和Mg元素含量在27个核桃品种间稳定,Na、Mn、Cu等5种微量元素含量种间变异较大。
表 1 云南不同核桃品种的果仁营养成分含量Table 1. Nutrients content of different walnut and pecan varieties in Yunnan Province编号 磷(P,mg/kg) 钾(K,mg/kg) 锌(Zn,mg/kg) 铁(Fe,mg/kg) 锰(Mn,mg/kg) 镁(Mg,mg/kg) H1 4760.00±90.00b 7370.00±88.00a 30.60±0.50e 37.00±0.32d 82.60±3.00g 1820.00±13.00f H2 4760.00±82.00b 4700.00±65.00k 25.40±0.31h 33.40±0.33h 55.80±2.00k 1910.00±11.00cd H3 4560.00±79.00de 5260.00±60.00g 20.70±0.30m 28.40±0.25l 69.20±2.21ij 1880.00±14.00e H4 3030.00±55.00k 4100.00±55.00n 13.60±0.21p 22.40±0.18q 17.60±0.62n 1380.00±10.10n H5 4500.00±87.00def 6870.00±80.00b 22.40±0.32k 35.60±0.26e 32.20±1.00lm 1910.00±12.10cd H6 4000.00±70.00h 4360.00±50.00m 21.00±0.35lm 33.40±0.28h 65.30±2.35j 1640.00±11.50j H7 2300.00±43.00o 3430.00±45.00r 16.70±0.26o 24.80±0.21o 55.60±2.05k 1000.00±6.48s H8 3950.00±73.00h 4400.00±52.00m 19.40±0.31n 35.40±0.34ef 77.60±2.79gh 1720.00±12.95i H9 4500.00±85.00def 5360.00±72.00f 25.10±0.41hi 34.40±0.36g 114.00±4.29d 1900.00±13.88d H10 4480.00±78.00ef 5940.00±76.00d 24.00±0.38j 43.20±0.43a 96.70±3.59f 1920.00±15.84c H11 4180.00±80.00g 4440.00±56.00m 25.20±0.39h 35.10±0.31f 106.00±3.80e 1780.00±13.25g H12 3620.00±64.00j 3880.00±51.50p 21.60±0.32l 37.40±0.39d 99.40±3.71f 1570.00±11.45l H13 4580.00±84.00cde 4550.00±57.00l 30.10±0.48e 34.00±0.31g 79.60±2.79g 1920.00±14.42c H14 4420.00±81.00f 5280.00±66.00fg 20.90±0.29m 31.00±0.31j 29.80±0.74lm 1820.00±11.95f H15 2640.00±47.00m 3830.00±48.00p 32.40±0.49d 24.00±0.20p 125.00±4.75c 1210.00±8.39q H16 4540.00±77.00de 4900.00±61.00j 27.00±0.18g 32.00±0.14i 56.80±1.77k 1720.00±9.43i H17 3920.00±67.00h 6300.00±81.00c 19.50±0.10n 26.50±0.12m 96.60±3.78f 1740.00±10.45h H18 3760.00±69.00i 5160.33±71.50h 19.30±0.30n 28.70±0.30l 28.60±1.25m 1540.00±9.60m H19 3660.00±63.00ij 4160.00±53.00n 25.50±0.40h 29.80±0.24k 202.00±8.19a 1380.00±9.65n H20 6780.00±20.00a 5060.00±32.00i 33.60±0.57c 42.20±0.35b 94.80±0.77f 1960.00±10.67b H21 2230.00±41.00o 5800.00±78.00e 21.60±0.34l 39.00±0.41c 73.00±1.62hi 1600.00±10.35k H22 4603.00±15.00cd 4440.00±22.00m 28.70±0.48f 31.97±0.27i 70.43±2.59ij 1817.00±10.85f S1 2480.00±42.00n 3610.00±39.00q 35.20±0.26b 22.50±0.17q 70.40±2.48ij 1160.00±8.02r S2 2680.00±46.00m 4120.00±47.00n 33.00±0.56cd 23.70±0.24p 34.20±1.32l 1240.00±8.24p S3 2880.00±50.00l 4760.00±58.00k 36.80±0.62a 25.00±0.23o 114.00±3.94d 1380.00±8.75n S4 2490.00±44.00n 4000.00±54.00o 34.60±0.55b 25.60±0.22n 131.00±4.53b 1300.00±8.53o S5 4670.00±34.00bc 6959.67±42.50b 24.50±0.15ij 32.20±0.19i 53.80±1.84k 1980.00±9.35a 编号 钙(Ca,mg/kg) 铜(Cu,mg/kg) 钠(Na,mg/kg) 蛋白质(%) 粗脂肪(%) VC(mg/100 g) H1 736.00±11.30h 17.30±0.40f 55.30±2.20bcde 16.60±0.17i 59.52±0.06p 6.00±0.29f H2 610.00±10.00k 14.20±0.30j 15.80±0.63jkl 18.80±0.16c 65.06±0.18m 2.70±0.03hi H3 650.00±10.10j 13.00±0.28k 20.20±0.80ijkl 15.30±0.21l 69.45±0.07gh 2.70±0.08hi H4 492.00±7.50mn 6.96±0.15p 26.40±1.05ghijkl 14.80±0.24n 69.68±0.27fg 7.00±0.35e H5 860.00±13.10d 16.20±0.35gh 66.80±2.60bcd 13.90±0.12o 70.08±0.49e 9.00±0.45cd H6 728.00±11.10h 21.50±0.45b 29.20±1.15fghijkl 16.60±0.18i 68.36±0.08i 9.70±0.47c H7 508.00±8.00m 12.20±0.26l 63.10±2.40bcd 15.10±0.14lm 64.97±0.28m 2.70±0.13hi H8 894.00±13.00c 15.20±0.34i 49.00±1.95cdef 18.20±0.10de 68.14±0.11ij 2.00±0.09ij H9 610.00±9.10k 22.10±0.49a 33.60±1.30efghijk 17.20±0.11fg 68.20±0.22ij 2.70±0.11hi H10 756.00±11.20g 18.20±0.37e 52.00±1.98cde 18.20±0.20de 65.86±0.12l 3.70±1.85g H11 944.00±14.10b 20.14±0.43c 29.10±1.16fghijkl 16.00±0.3jk 70.87±0.24d 3.30±0.15gh H12 608.00±9.20k 19.60±0.44cd 23.20±0.91hijkl 17.10±0.35gh 66.82±0.39k 2.69±0.09hi H13 724.00±11.00h 22.60±0.47a 14.00±0.55kl 17.40±0.15f 69.11±0.21h 3.30±0.14gh H14 636.00±9.40j 18.20±0.41e 27.60±1.10fghijkl 16.90±0.13h 69.66±0.25fg 2.00±0.10ij H15 678.00±10.50i 7.94±0.17o 22.60±0.90ijkl 10.80±0.09q 73.55±0.30b 6.00±0.29f H16 790.00±12.10f 12.40±0.25l 48.10±1.90cdefg 18.10±0.25e 67.10±0.31k 4.00±0.19g H17 606.00±9.60k 16.70±0.36g 122.00±4.80a 14.90±0.26mn 63.46±0.29o 4.00±0.17g H18 618.00±9.50k 13.30±0.29k 45.00±1.75defgh 15.00±0.31mn 70.23±0.52e 3.30±0.16gh H19 807.00±12.40f 19.40±0.39d 40.70±1.60efghi 16.20±0.08j 69.97±0.47ef 2.70±0.13hi H20 986.00±14.20a 22.60±0.48a 10.30±4.10l 19.40±0.27b 66.97±0.16k 13.90±0.69b H21 840.00±12.00e 15.80±0.33h 37.40±14.50efghij 15.80±0.14k 70.95±0.28d 8.40±0.39d H22 999.00±14.00a 18.13±0.38e 35.00±13.80efghijk 19.87±0.36a 67.96±0.37j 17.00±0.78a S1 379.00±6.00q 9.73±0.20m 28.00±11.00fghijkl 10.20±0.09r 75.59±0.44a 1.30±0.06j S2 460.00±7.00p 12.20±0.27l 39.30±15.10efghi 10.40±0.23r 73.05±0.36c 2.00±0.09ij S3 482.00±7.30no 8.70±0.18n 67.60±26.00bc 11.40±0.11p 70.61±0.31d 2.00±0.05ij S4 470.00±7.40op 8.54±0.19n 126.00±49.00a 9.25±0.18s 73.72±0.42b 1.30±0.06j S5 574.00±8.70l 22.20±0.50a 76.00±30.00b 18.40±0.32d 64.06±0.38n 1.30±0.04j 注:同列不同小写字母代表P<0.05水平差异显著。 表 2 云南不同核桃品种果实矿质元素、蛋白质、脂肪含量变异分析Table 2. Variation analysis of mineral elements, protein and fat content of different walnut and pecan varieties in Yunnan Province指标 P
(mg/kg)K
(mg/kg)Zn
(mg/kg)Fe
(mg/kg)Mn
(mg/kg)Mg
(mg/kg)Ca
(mg/kg)Cu
(mg/kg)Na
(mg/kg)蛋白质
(%)粗脂肪
(%)VC
(mg/100 g)最大值 6780 7370 36.8 43.2 202 1980 999 22.6 126 19.87 75.59 17 最小值 2230 3430 13.6 22.4 17.6 1000 379 6.96 10.3 9.25 59.52 1.3 平均值 3887.89 4927.41 25.5 31.43 78.96 1636.93 683.15 15.74 44.57 15.62 68.63 4.66 标准差 1017.71 1025.58 6 5.74 38.51 279.14 165.06 4.74 28.11 2.89 3.42 3.85 CV(%) 26 21 24 18 49 17 24 30 63 18 5 83 人和动物都不能自身合成维生素,必须从植物中摄入,以满足正常的生长和代谢。27种核桃中VC含量最高的是永平核桃,达17 mg/100 g,含量最低的为薄壳山核桃‘云光’,仅有1.3 mg/100 g,其他核桃的VC含量在这个范围内波动,变异系数为83%;蛋白质含量的变化区间为9.25%~19.87%,最高为‘永平核桃’,其次是‘香茶核桃’,与前者仅相差0.5%;粗脂肪含量最高的是薄壳山核桃‘云光’,为75.59%,‘晚熟核桃’最低,与‘云光’的相差16%,变异系数仅为5%。粗脂肪在不同品种间含量稳定,VC在品种间的含量变化较大。27个品种核桃中蛋白质、粗脂肪、VC含量均值分别为15.6%、68.63%、4.66 mg/100 g。22种主栽核桃和1种薄壳山核桃的蛋白质含量达到GB/T 20398-2006《核桃坚果质量等级标准》中的特级标准(蛋白质≥14%),23个核桃品种的脂肪含量达到特级标准(脂肪≥65%)。
2.2 不同品种云南核桃12个营养指标相关性分析
运用皮尔逊相关系数法对12个营养指标间的相关性进行分析,分析结果见表3,其中有6对指标间的相关性达到显著水平(P<0.05),21对指标间的相关性达到极显著水平(P<0.01),说明评价指标之间具有较强的相关性。对果实核仁12个营养指标进行相关性分析,P与Fe、Mg、Ca、Cu、蛋白质含量呈极显著正相关(P<0.01),与K含量呈显著正相关(P<0.05);K与Mg含量呈极显著正相关(P<0.01),与Fe呈显著正相关(P<0.01);Fe与Mg、Ca、Cu、蛋白质含量呈极显著正相关(P<0.01);Mg与Ca、Cu、蛋白质含量呈极显著正相关(P<0.01);Ca与Cu、蛋白质含量呈极显著正相关(P<0.01);Cu与蛋白质含量呈极显著正相关(P<0.01);Mn仅与Zn含量呈显著正相关(P<0.05);Zn与蛋白质含量呈显著负相关(P<0.05);粗脂肪与P、K、Mg、蛋白质呈极显著负相关(P<0.01),与Fe和Cu元素呈显著负相关(P<0.05);VC仅与Ca呈极显著正相关(P<0.01);Na与其他11个营养指标均无显著相关性。正相关性越显著说明同时获得两种营养元素的高含量资源的可能性较大,反之可能性较小。蛋白质与5种矿质元素呈极显著正相关,脂肪与5种元素和蛋白质呈显著或极显著负相关,以上品种的云南核桃是富含P、Fe、Mg、Ca、Cu元素的高蛋白低油脂核桃资源。
表 3 云南不同核桃品种果实12个营养指标相关性分析Table 3. Correlation analysis of 12 nutrition indicators of different varieties walnut and pecan in Yunnan Province指标 P K Zn Fe Mn Mg Ca Cu Na 蛋白质 粗脂肪 VC P 1 K 0.471* 1 Zn 0.004 −0.118 1 Fe 0.647** 0.468* −0.089 1 Mn −0.057 −0.181 0.386* 0.089 1 Mg 0.858** 0.670** −0.138 0.731** −0.132 1 Ca 0.581** 0.246 −0.08 0.706** 0.165 0.564** 1 Cu 0.671** 0.375 −0.12 0.725** 0.154 0.693** 0.543** 1 Na −0.27 0.305 0.021 −0.242 0.154 −0.153 −0.266 −0.217 1 蛋白质 0.741** 0.312 −0.386* 0.714** −0.098 0.737** 0.632** 0.710** −0.342 1 粗脂肪 −0.526** −0.564** 0.324 −0.451* 0.09 −0.505** −0.217 −0.449* −0.156 −0.668** 1 VC 0.361 0.104 0.023 0.318 −0.118 0.248 0.630** 0.231 −0.241 0.345 −0.108 1 注:*表示在0.05水平上显著,P<0.05;**表示在0.01水平上极显著,P<0.01。 2.3 核桃果仁12个营养指标的主成分分析与综合评价
主成分分析法用少数变量尽可能多地反映原来变量的信息,一般认为累积方差贡献率大于85%,就可以保留大部分重要信息[25]。对12个营养指标进行主成分分析,前5个成分的累积贡献率达86.39%,说明提取5个成分可以反映27种核桃果实品质评价的主要信息(表4)。第1主成分特征值为5.379,蛋白质含量、粗脂肪含量以及矿质元素Mg、P、Fe、Ca、Cu、K含量的载荷值较大,方差贡献率为44.82%;第2主成分特征值为1.743,Na和K元素含量、粗脂肪含量、VC含量载荷值较大,方差贡献率为14.52%;第3主成分特征值为1.450,Zn、Mn元素含量的载荷值较大,方差贡献率为12.08%;第4主成分中VC含量的载荷值较大,方差贡献率为8.02%;第5主成分中矿质元素Zn和Na含量的载荷值较大,方差贡献率为6.94%。5个主成分中营养指标的载荷值正值越大,表明此指标对该主成分的影响是正向的,载荷值负值的绝对值越大,说明负向的影响越大。
表 4 云南不同核桃品种12个营养指标载荷值和贡献率Table 4. Eigenvalues and cumulative variance proportion of 12 nutrition indicators of different varieties walnut and pecan in Yunnan Province指标 PC1 PC2 PC3 PC4 PC5 P 0.87 0.064 0.066 0.062 −0.277 K 0.582 −0.558 0.284 0.351 −0.128 Zn −0.227 0.468 0.607 0.298 −0.425 Fe 0.856 0.133 0.138 −0.086 0.01 Mn −0.063 0.399 0.742 −0.368 0.299 Mg 0.895 −0.13 0.08 0.064 −0.269 Ca 0.745 0.429 0.025 0.159 0.331 Cu 0.81 0.097 0.163 −0.286 −0.04 Na −0.252 −0.604 0.544 0.235 0.358 蛋白质 0.893 −0.002 −0.211 −0.246 0.095 粗脂肪 −0.648 0.521 −0.072 0.117 −0.16 VC 0.449 0.43 −0.221 0.602 0.350 特征根 5.379 1.743 1.450 0.963 0.833 方差贡献率(%) 44.82 14.52 12.08 8.02 6.94 累积贡献率(%) 44.82 59.35 71.43 79.45 86.39 用Z1、Z2、Z3、Z4、Z5分别代表这5个主成分,X1、X2、X3……X10、X11、X12分别代表12个指标,可得到如下的线性方程:
Z1=0.375X1+0.251X2−0.098X3+0.369X4−0.027X5+0.386X6+0.321X7+0.349X8−0.109X9+0.385X10−0.279X11+0.194X12
Z2=0.048X1−0.423X2+0.354X3+0.100X4+0.303X5−0.099X6+0.325X7+0.074X8−0.457X9−0.002X10+0.395X11+0.326X12
Z3=0.054X1+0.236X2+0.504X3+0.114X4+0.616X5+0.066X6+0.021X7+0.136X8+0.451X9−0.175X10−0.060X11−0.184X12
Z4=0.064X1+0.358X2+0.304X3−0.088X4−0.375X5+0.065X6+0.162X7−0.292X8+0.239X9−0.250X10+0.119X11+0.614X12
Z5=−0.303X1−0.140X2−0.466X3+0.011X4+0.328X5−0.295X6+0.363X7−0.044X8+0.393X9+0.105X10−0.175X11+0.384X12
同时,分别以第1、2、3、4、5主成分对应方差贡献率a1、a2、a3、a4、a5作为权数,构建的综合(综合得分值)评价模型为:C=a1Z1+a2Z2+a3Z3+a4Z4+a5Z5。将27个不同品种山核桃果仁中12种营养指标的试验数据代入对应的表达式中,得到各品种核桃仁的综合得分值见表5。
表 5 云南不同核桃品种的果仁品质综合得分及排序Table 5. Comprehensive scoring values and ranking of different varieties walnut and pecan in Yunnan Province品种 Z1 Z2 Z3 Z4 Z5 综合得分 排序 H1 2.515 −1.558 1.480 0.929 −0.249 1.316 3 H2 1.236 −0.386 −0.818 −0.691 −1.128 0.307 14 H3 0.171 −0.379 −0.809 −0.209 −0.84 −0.175 19 H4 −2.203 −0.833 −3.047 0.404 0.571 −1.626 23 H5 1.562 −0.801 −0.114 2.201 0.104 0.873 5 H6 1.073 0.709 −1.032 −0.046 0.647 0.579 10 H7 −2.592 −1.316 −1.434 −1.058 1.67 −1.731 24 H8 0.950 −0.057 −0.483 −0.887 0.804 0.398 12 H9 1.358 −0.021 0.768 −1.154 −0.662 0.648 9 H10 2.348 −0.646 0.891 −0.609 −0.042 1.174 4 H11 1.078 1.374 0.325 −0.756 0.166 0.779 6 H12 0.445 0.356 −0.353 −1.847 0.228 0.088 16 H13 1.449 1.015 0.122 −0.815 −1.273 0.761 7 H14 0.711 −0.721 −1.183 −0.381 −1.077 −0.039 17 H15 −3.357 2.054 0.308 0.537 0.272 −1.281 21 H16 0.732 −0.191 −0.281 0.296 −0.161 0.323 13 H17 0.169 −2.896 1.422 0.399 1.35 −0.055 18 H18 −0.740 −0.961 −1.328 0.248 −0.195 −0.724 20 H19 −0.416 1.656 1.746 −1.931 1.403 0.24 15 H20 4.343 2.560 0.444 1.046 −0.42 2.809 1 H21 0.457 0.433 −0.483 0.677 1.164 0.399 11 H22 2.405 2.043 −0.754 1.777 1.276 1.753 2 S1 −4.573 1.074 −0.098 0.160 −1.443 −2.307 27 S2 −3.579 0.247 −0.424 0.612 −1.275 −1.92 26 S3 −3.188 0.067 1.688 0.582 −0.56 −1.398 22 S4 −4.380 −0.265 2.597 0.664 0.525 −1.85 25 S5 2.023 −2.555 0.850 −0.148 −0.854 0.656 8 通过综合得分对27种核桃进行综合评价,综合得分排名前三的依次为‘香茶核桃’‘永平核桃’‘晚熟核桃’,之后依次为‘小圆果核桃’‘滑皮核桃’‘漾早1号核桃’‘四方核桃’、薄壳山核桃‘卡多’等。
2.4 不同品种核桃果实中12个营养指标的聚类分析
聚类分析是将样本划分为不同的类群进行相似性评价,可以综合、客观和科学的体现研究对象之间的关系[26−27]。采用欧氏距离离差平方和方法,以12个营养指标主成分分析的综合得分值对27种核桃进行聚类分析(图1),结果显示27种核桃聚为2个大群组(Ⅰ和Ⅱ),排名前19的聚类在群组Ⅰ中,其中‘香茶核桃’单独聚为1个小类,‘香茶核桃’的P、Cu含量是最高的,Mg、Ca、蛋白质、VC含量也较高,综合表现最好;其次为综合排名2~4的‘永平核桃’‘晚熟核桃’‘小圆果核桃’聚为1个小类,‘永平核桃’的Ca、蛋白质、VC含量最高,‘晚熟核桃’的K含量是最高的,‘小圆果核桃’Fe含量最高,Mg含量也较高,这3个品种的综合表现仅次‘香茶核桃’;其余的15种核桃聚在3个小类中。在群组Ⅱ中,聚集了综合品4的‘永平核桃’‘晚熟核桃’‘小圆果核桃’聚为1个小类,‘永平核桃’的Ca、蛋白质、VC含量最质稍差的4种薄壳山核桃和4种主栽核桃(‘大麻’‘圆菠萝’‘桐子果’‘漏米’),这8个品种的脂肪含量较高,VC含量均较低,其中4种薄壳山核桃(‘云星’‘云光’‘欧肯尼亚’‘巧克陶’)的P、K、Mg、Ca元素的含量都较低。由此表明,群组Ⅰ中均为高K、Fe、Mg、Cu、Ca元素及高蛋白核桃品种,适合直接食用或开发富含矿质元素的蛋白饮料。群组Ⅱ中平均脂肪含量为71.24%,为典型的高脂肪核桃品种。此外,薄壳山核桃的脂肪含量均较高,是优良的油脂资源。结合相关性分析和主成分分析的结果,同时考虑品质指标可标准化检测,以便客观准确的对云南不同品种核桃果实品质进行评价,最终选用K、Fe、Mg、Ca、Cu、蛋白质、粗脂肪为评价云南不同品种核桃果实品质优劣的关键性指标,可对云南核桃进行综合全面的品质评价。
3. 结论
27种核桃果实中的矿质元素含量在6.96~7370 mg/kg,其中P、K、Mg、Ca的含量较高,其余微量元素含量依次为:Mn> Na>Fe>Zn>Cu,蛋白质、脂肪的平均含量分别为15.62%、68.63%,VC的平均含量为4.66 mg/100 g。12个营养指标中,Na元素和VC的变异系数较大(>60%),Mg元素和蛋白质变异系数较小,分别为17%、18%,脂肪变异系数最小,为5%。皮尔逊相关性分析结果显示,12个营养指标之间有较强的相关性,结合主成分分析和聚类分析结果,最终确定K、Fe、Mg、Ca、Cu、蛋白质、脂肪为评价云南不同品种核桃果实品质优劣的关键性指标。同时,基于上述营养指标筛选出的核桃资源将为今后特征品质发掘和种质改良提供研究基础和物质材料。
本研究采用主成分分析和聚类分析对云南核桃主产区收集的27个不同品种核桃果实,对12项营养指标进行系统分析,最终将其分为两大类富含矿质元素类群和高脂肪含量类群,明确了K、Fe、Mg、Ca、Cu、蛋白质、脂肪为核桃果实品质评价的关键性指标,该结果为云南核桃营养品质评价体系的构建与核桃产业的高质量发展奠定了理论基础。
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表 1 云南不同核桃品种的果仁营养成分含量
Table 1 Nutrients content of different walnut and pecan varieties in Yunnan Province
编号 磷(P,mg/kg) 钾(K,mg/kg) 锌(Zn,mg/kg) 铁(Fe,mg/kg) 锰(Mn,mg/kg) 镁(Mg,mg/kg) H1 4760.00±90.00b 7370.00±88.00a 30.60±0.50e 37.00±0.32d 82.60±3.00g 1820.00±13.00f H2 4760.00±82.00b 4700.00±65.00k 25.40±0.31h 33.40±0.33h 55.80±2.00k 1910.00±11.00cd H3 4560.00±79.00de 5260.00±60.00g 20.70±0.30m 28.40±0.25l 69.20±2.21ij 1880.00±14.00e H4 3030.00±55.00k 4100.00±55.00n 13.60±0.21p 22.40±0.18q 17.60±0.62n 1380.00±10.10n H5 4500.00±87.00def 6870.00±80.00b 22.40±0.32k 35.60±0.26e 32.20±1.00lm 1910.00±12.10cd H6 4000.00±70.00h 4360.00±50.00m 21.00±0.35lm 33.40±0.28h 65.30±2.35j 1640.00±11.50j H7 2300.00±43.00o 3430.00±45.00r 16.70±0.26o 24.80±0.21o 55.60±2.05k 1000.00±6.48s H8 3950.00±73.00h 4400.00±52.00m 19.40±0.31n 35.40±0.34ef 77.60±2.79gh 1720.00±12.95i H9 4500.00±85.00def 5360.00±72.00f 25.10±0.41hi 34.40±0.36g 114.00±4.29d 1900.00±13.88d H10 4480.00±78.00ef 5940.00±76.00d 24.00±0.38j 43.20±0.43a 96.70±3.59f 1920.00±15.84c H11 4180.00±80.00g 4440.00±56.00m 25.20±0.39h 35.10±0.31f 106.00±3.80e 1780.00±13.25g H12 3620.00±64.00j 3880.00±51.50p 21.60±0.32l 37.40±0.39d 99.40±3.71f 1570.00±11.45l H13 4580.00±84.00cde 4550.00±57.00l 30.10±0.48e 34.00±0.31g 79.60±2.79g 1920.00±14.42c H14 4420.00±81.00f 5280.00±66.00fg 20.90±0.29m 31.00±0.31j 29.80±0.74lm 1820.00±11.95f H15 2640.00±47.00m 3830.00±48.00p 32.40±0.49d 24.00±0.20p 125.00±4.75c 1210.00±8.39q H16 4540.00±77.00de 4900.00±61.00j 27.00±0.18g 32.00±0.14i 56.80±1.77k 1720.00±9.43i H17 3920.00±67.00h 6300.00±81.00c 19.50±0.10n 26.50±0.12m 96.60±3.78f 1740.00±10.45h H18 3760.00±69.00i 5160.33±71.50h 19.30±0.30n 28.70±0.30l 28.60±1.25m 1540.00±9.60m H19 3660.00±63.00ij 4160.00±53.00n 25.50±0.40h 29.80±0.24k 202.00±8.19a 1380.00±9.65n H20 6780.00±20.00a 5060.00±32.00i 33.60±0.57c 42.20±0.35b 94.80±0.77f 1960.00±10.67b H21 2230.00±41.00o 5800.00±78.00e 21.60±0.34l 39.00±0.41c 73.00±1.62hi 1600.00±10.35k H22 4603.00±15.00cd 4440.00±22.00m 28.70±0.48f 31.97±0.27i 70.43±2.59ij 1817.00±10.85f S1 2480.00±42.00n 3610.00±39.00q 35.20±0.26b 22.50±0.17q 70.40±2.48ij 1160.00±8.02r S2 2680.00±46.00m 4120.00±47.00n 33.00±0.56cd 23.70±0.24p 34.20±1.32l 1240.00±8.24p S3 2880.00±50.00l 4760.00±58.00k 36.80±0.62a 25.00±0.23o 114.00±3.94d 1380.00±8.75n S4 2490.00±44.00n 4000.00±54.00o 34.60±0.55b 25.60±0.22n 131.00±4.53b 1300.00±8.53o S5 4670.00±34.00bc 6959.67±42.50b 24.50±0.15ij 32.20±0.19i 53.80±1.84k 1980.00±9.35a 编号 钙(Ca,mg/kg) 铜(Cu,mg/kg) 钠(Na,mg/kg) 蛋白质(%) 粗脂肪(%) VC(mg/100 g) H1 736.00±11.30h 17.30±0.40f 55.30±2.20bcde 16.60±0.17i 59.52±0.06p 6.00±0.29f H2 610.00±10.00k 14.20±0.30j 15.80±0.63jkl 18.80±0.16c 65.06±0.18m 2.70±0.03hi H3 650.00±10.10j 13.00±0.28k 20.20±0.80ijkl 15.30±0.21l 69.45±0.07gh 2.70±0.08hi H4 492.00±7.50mn 6.96±0.15p 26.40±1.05ghijkl 14.80±0.24n 69.68±0.27fg 7.00±0.35e H5 860.00±13.10d 16.20±0.35gh 66.80±2.60bcd 13.90±0.12o 70.08±0.49e 9.00±0.45cd H6 728.00±11.10h 21.50±0.45b 29.20±1.15fghijkl 16.60±0.18i 68.36±0.08i 9.70±0.47c H7 508.00±8.00m 12.20±0.26l 63.10±2.40bcd 15.10±0.14lm 64.97±0.28m 2.70±0.13hi H8 894.00±13.00c 15.20±0.34i 49.00±1.95cdef 18.20±0.10de 68.14±0.11ij 2.00±0.09ij H9 610.00±9.10k 22.10±0.49a 33.60±1.30efghijk 17.20±0.11fg 68.20±0.22ij 2.70±0.11hi H10 756.00±11.20g 18.20±0.37e 52.00±1.98cde 18.20±0.20de 65.86±0.12l 3.70±1.85g H11 944.00±14.10b 20.14±0.43c 29.10±1.16fghijkl 16.00±0.3jk 70.87±0.24d 3.30±0.15gh H12 608.00±9.20k 19.60±0.44cd 23.20±0.91hijkl 17.10±0.35gh 66.82±0.39k 2.69±0.09hi H13 724.00±11.00h 22.60±0.47a 14.00±0.55kl 17.40±0.15f 69.11±0.21h 3.30±0.14gh H14 636.00±9.40j 18.20±0.41e 27.60±1.10fghijkl 16.90±0.13h 69.66±0.25fg 2.00±0.10ij H15 678.00±10.50i 7.94±0.17o 22.60±0.90ijkl 10.80±0.09q 73.55±0.30b 6.00±0.29f H16 790.00±12.10f 12.40±0.25l 48.10±1.90cdefg 18.10±0.25e 67.10±0.31k 4.00±0.19g H17 606.00±9.60k 16.70±0.36g 122.00±4.80a 14.90±0.26mn 63.46±0.29o 4.00±0.17g H18 618.00±9.50k 13.30±0.29k 45.00±1.75defgh 15.00±0.31mn 70.23±0.52e 3.30±0.16gh H19 807.00±12.40f 19.40±0.39d 40.70±1.60efghi 16.20±0.08j 69.97±0.47ef 2.70±0.13hi H20 986.00±14.20a 22.60±0.48a 10.30±4.10l 19.40±0.27b 66.97±0.16k 13.90±0.69b H21 840.00±12.00e 15.80±0.33h 37.40±14.50efghij 15.80±0.14k 70.95±0.28d 8.40±0.39d H22 999.00±14.00a 18.13±0.38e 35.00±13.80efghijk 19.87±0.36a 67.96±0.37j 17.00±0.78a S1 379.00±6.00q 9.73±0.20m 28.00±11.00fghijkl 10.20±0.09r 75.59±0.44a 1.30±0.06j S2 460.00±7.00p 12.20±0.27l 39.30±15.10efghi 10.40±0.23r 73.05±0.36c 2.00±0.09ij S3 482.00±7.30no 8.70±0.18n 67.60±26.00bc 11.40±0.11p 70.61±0.31d 2.00±0.05ij S4 470.00±7.40op 8.54±0.19n 126.00±49.00a 9.25±0.18s 73.72±0.42b 1.30±0.06j S5 574.00±8.70l 22.20±0.50a 76.00±30.00b 18.40±0.32d 64.06±0.38n 1.30±0.04j 注:同列不同小写字母代表P<0.05水平差异显著。 表 2 云南不同核桃品种果实矿质元素、蛋白质、脂肪含量变异分析
Table 2 Variation analysis of mineral elements, protein and fat content of different walnut and pecan varieties in Yunnan Province
指标 P
(mg/kg)K
(mg/kg)Zn
(mg/kg)Fe
(mg/kg)Mn
(mg/kg)Mg
(mg/kg)Ca
(mg/kg)Cu
(mg/kg)Na
(mg/kg)蛋白质
(%)粗脂肪
(%)VC
(mg/100 g)最大值 6780 7370 36.8 43.2 202 1980 999 22.6 126 19.87 75.59 17 最小值 2230 3430 13.6 22.4 17.6 1000 379 6.96 10.3 9.25 59.52 1.3 平均值 3887.89 4927.41 25.5 31.43 78.96 1636.93 683.15 15.74 44.57 15.62 68.63 4.66 标准差 1017.71 1025.58 6 5.74 38.51 279.14 165.06 4.74 28.11 2.89 3.42 3.85 CV(%) 26 21 24 18 49 17 24 30 63 18 5 83 表 3 云南不同核桃品种果实12个营养指标相关性分析
Table 3 Correlation analysis of 12 nutrition indicators of different varieties walnut and pecan in Yunnan Province
指标 P K Zn Fe Mn Mg Ca Cu Na 蛋白质 粗脂肪 VC P 1 K 0.471* 1 Zn 0.004 −0.118 1 Fe 0.647** 0.468* −0.089 1 Mn −0.057 −0.181 0.386* 0.089 1 Mg 0.858** 0.670** −0.138 0.731** −0.132 1 Ca 0.581** 0.246 −0.08 0.706** 0.165 0.564** 1 Cu 0.671** 0.375 −0.12 0.725** 0.154 0.693** 0.543** 1 Na −0.27 0.305 0.021 −0.242 0.154 −0.153 −0.266 −0.217 1 蛋白质 0.741** 0.312 −0.386* 0.714** −0.098 0.737** 0.632** 0.710** −0.342 1 粗脂肪 −0.526** −0.564** 0.324 −0.451* 0.09 −0.505** −0.217 −0.449* −0.156 −0.668** 1 VC 0.361 0.104 0.023 0.318 −0.118 0.248 0.630** 0.231 −0.241 0.345 −0.108 1 注:*表示在0.05水平上显著,P<0.05;**表示在0.01水平上极显著,P<0.01。 表 4 云南不同核桃品种12个营养指标载荷值和贡献率
Table 4 Eigenvalues and cumulative variance proportion of 12 nutrition indicators of different varieties walnut and pecan in Yunnan Province
指标 PC1 PC2 PC3 PC4 PC5 P 0.87 0.064 0.066 0.062 −0.277 K 0.582 −0.558 0.284 0.351 −0.128 Zn −0.227 0.468 0.607 0.298 −0.425 Fe 0.856 0.133 0.138 −0.086 0.01 Mn −0.063 0.399 0.742 −0.368 0.299 Mg 0.895 −0.13 0.08 0.064 −0.269 Ca 0.745 0.429 0.025 0.159 0.331 Cu 0.81 0.097 0.163 −0.286 −0.04 Na −0.252 −0.604 0.544 0.235 0.358 蛋白质 0.893 −0.002 −0.211 −0.246 0.095 粗脂肪 −0.648 0.521 −0.072 0.117 −0.16 VC 0.449 0.43 −0.221 0.602 0.350 特征根 5.379 1.743 1.450 0.963 0.833 方差贡献率(%) 44.82 14.52 12.08 8.02 6.94 累积贡献率(%) 44.82 59.35 71.43 79.45 86.39 表 5 云南不同核桃品种的果仁品质综合得分及排序
Table 5 Comprehensive scoring values and ranking of different varieties walnut and pecan in Yunnan Province
品种 Z1 Z2 Z3 Z4 Z5 综合得分 排序 H1 2.515 −1.558 1.480 0.929 −0.249 1.316 3 H2 1.236 −0.386 −0.818 −0.691 −1.128 0.307 14 H3 0.171 −0.379 −0.809 −0.209 −0.84 −0.175 19 H4 −2.203 −0.833 −3.047 0.404 0.571 −1.626 23 H5 1.562 −0.801 −0.114 2.201 0.104 0.873 5 H6 1.073 0.709 −1.032 −0.046 0.647 0.579 10 H7 −2.592 −1.316 −1.434 −1.058 1.67 −1.731 24 H8 0.950 −0.057 −0.483 −0.887 0.804 0.398 12 H9 1.358 −0.021 0.768 −1.154 −0.662 0.648 9 H10 2.348 −0.646 0.891 −0.609 −0.042 1.174 4 H11 1.078 1.374 0.325 −0.756 0.166 0.779 6 H12 0.445 0.356 −0.353 −1.847 0.228 0.088 16 H13 1.449 1.015 0.122 −0.815 −1.273 0.761 7 H14 0.711 −0.721 −1.183 −0.381 −1.077 −0.039 17 H15 −3.357 2.054 0.308 0.537 0.272 −1.281 21 H16 0.732 −0.191 −0.281 0.296 −0.161 0.323 13 H17 0.169 −2.896 1.422 0.399 1.35 −0.055 18 H18 −0.740 −0.961 −1.328 0.248 −0.195 −0.724 20 H19 −0.416 1.656 1.746 −1.931 1.403 0.24 15 H20 4.343 2.560 0.444 1.046 −0.42 2.809 1 H21 0.457 0.433 −0.483 0.677 1.164 0.399 11 H22 2.405 2.043 −0.754 1.777 1.276 1.753 2 S1 −4.573 1.074 −0.098 0.160 −1.443 −2.307 27 S2 −3.579 0.247 −0.424 0.612 −1.275 −1.92 26 S3 −3.188 0.067 1.688 0.582 −0.56 −1.398 22 S4 −4.380 −0.265 2.597 0.664 0.525 −1.85 25 S5 2.023 −2.555 0.850 −0.148 −0.854 0.656 8 -
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