猕猴桃营养品质综合评价

郭琳琳1,庞荣丽1,王瑞萍1,乔成奎1,田发军1,王彩霞1,李 君1,庞 涛1,成 昕2*,谢汉忠1*

1中国农业科学院郑州果树研究所·河南省果树瓜类生物学重点实验室,郑州 450009;2农业农村部农产品质量安全中心,北京 100081)

摘 要:【目的】探讨猕猴桃营养品质综合评价指标的筛选和分级综合评价体系的建立,为猕猴桃营养品质综合评价提供技术支撑。【方法】以我国猕猴桃3大主产区6个品种155份猕猴桃果实样品为材料,测定果实可溶性固形物、可溶性总糖、总酸、维生素C、蔗糖、葡萄糖、果糖、柠檬酸、奎宁酸、苹果酸、总酚、叶绿素和类胡萝卜素含量等13个营养品质指标,利用SPSS软件通过相关性分析和主成分分析筛选确定猕猴桃营养品质评价代表性指标,运用层次分析法计算并确定代表性指标权重,结合概率分级法和合理全距等分法建立指标评分标准和综合评价体系。【结果】猕猴桃营养品质指标变异幅度整体较大,变异系数为14.68%~112.94%,其中蔗糖含量的变异系数最大,达112.94%;总酸和柠檬酸含量变异系数相对较小,分别为14.68%和15.85%。通过相关性分析和层次分析,从13项指标中筛选出4项猕猴桃营养品质综合评价代表性指标,分别为可溶性固形物(甜味指标)、总酸(酸味指标)、维生素C(营养功能指标)、类胡萝卜素含量(色泽功能指标),4项指标均符合正态分布,其权重系数分别为56%、20%、20%、8%,每项指标通过概率分级划分为极低、低、中、高、和极高5个等级,采用全距等分法建立4项代表性指标综合评分标准,将155份猕猴桃样品划分为3个等级,即特级、一级和二级。【结论】猕猴桃营养品质综合评价代表指标为可溶性固形物、总酸、维生素C和类胡萝卜素含量,建立的4项营养品质综合评分标准可用于猕猴桃营养品质的科学评价与分级。

关键词:猕猴桃;营养品质;主成分分析;层次分析;综合评价

中国是猕猴桃的起源和分布中心,种质资源丰富[1]。猕猴桃(Actinidia chinensis Planch.)属猕猴桃科(Actinidiaceae)猕猴桃属(Actinidia Lindl.)植物,具有丰富的营养价值,其果实中含有大量的糖、蛋白质、氨基酸等多种有机物和人体必需的多种矿物质及维生素,尤以维生素C 的含量高,远超过柑橘、苹果和梨,故有“水果之王”、“Vc之王”之称[2]

近年来,随着社会主要矛盾的变化,人们生活水平不断提升,不仅要吃得安全,更要吃得营养、吃得健康,所以,为了满足人们对美好生活的需要,猕猴桃营养品质改良方面的研究越来越受到重视,但目前仍存在营养品质育种目标不明确或评价体系不健全的问题。我国现有的猕猴桃品质相关标准有中华人民共和国农业行业标准《猕猴桃等级规格》(NY/T 1794—2009)和《猕猴桃质量等级》(GB/T 40743—2021)2项,主要规定了猕猴桃鲜果通过感官和单果质量进行等级判定的方法,并未对营养指标制定出分级标准和作出综合评价。在猕猴桃营养品质评价研究方面,运用的评价方法主要集中在主成分分析法、聚类分析法、因子分析法等,1种或者2种及以上方法的结合,评价对象主要集中在单一品种(系)或者单一区域的猕猴桃果实。比如,陈璐等[3]以江西省奉新县引进及选育的21 个黄肉猕猴桃品种(系)为试材,运用主成分分析法与聚类分析法共同构建黄肉猕猴桃果实品质评价体系;陈美艳等[4]以四川省53家果园的猕猴桃品种金艳果实为材料,运用因子分析法进行了果实品质评价。由于目前猕猴桃营养品质评价研究涉及的品种和地区较少,评价方法针对性较强,所以建立适用性广泛的猕猴桃营养品质综合评价体系具有重大的意义。

笔者在本研究中以全国猕猴桃主产区的主栽品种共计155份猕猴桃样品为材料,检测猕猴桃果实可溶性固形物、可溶性总糖、总酸、维生素C、蔗糖、葡萄糖、果糖、柠檬酸、奎宁酸、苹果酸、总酚、叶绿素和类胡萝卜素含量等13个营养品质指标,利用SPSS软件通过相关性分析和主成分分析筛选确定营养品质评价代表性指标,再运用层次分析法计算并确定代表性指标权重,结合概率分级法和合理全距等分法建立指标评分标准和综合评价体系,为猕猴桃营养品质的综合评价和分级标准的制定提供技术支持和科学依据。

1 材料和方法

1.1 试验材料

2020 年8—10 月采集全国猕猴桃主产区陕西、河南、四川等省份的6 个品种猕猴桃样品155 份,品种为海沃德、徐香、金艳、翠香、红阳、金桃,详细信息见表1。在猕猴桃商品成熟期,以果园为单位,每个果园同一品种采集1个样品,随机取样,每个样品采集3 kg,包装完好运回实验室。待果实硬度降至0.8~1.0 kg·cm-2时,测定各项指标。

表1 样品信息表
Table 1 The list of samples

品种Cultivar翠香Cuixiang海沃德Hayward省份Province陕西省Shaanxi市(县)乡(镇)Town,County眉县金渠镇,周至县马召镇Jinqu Town,Mei County;Mazhao Town,Zhouzhi County数量Sample size 10总计Total 10 32红阳Hongyang四川省Sichuan河南省Henan陕西省Shaanxi四川省Sichuan 10 12 10 32 53陕西省Shaanxi河南省Henan 10 11金桃Jintao金艳Jinyan 13 19徐香Xuxiang河南省Henan四川省Sichuan河南省Henan陕西省Shaanxi河南省Henan都江堰市虹口镇、龙池镇Hongkou Town,Longchi Town,Dujiangyan City西峡县田关乡Tianguan Town,Xixia County周至县马召镇Mazhao Town,Zhouzhi County苍溪县歧坪镇,都江堰市虹口镇,蒲江县复兴镇、西来镇、新津县兴义镇Qiping Town,Cangxi County;Hongkou Town,Dujiangyan City;Fuxing Town,Xilai Town,Pujiang County;Xingyi Town,Xinjin County眉县金渠镇Jinqu Town,Mei County西峡县丹水镇、五里桥镇、阳城镇Danshui Town,Wuliqiao Town,Yangcheng Town,Xixia County西峡县丹水镇、五里桥镇Danshui Town,Wuliqiao Town,Xixia County蒲江县西来镇Xilai Town,Pujiang County西峡县丹水镇、田关乡Danshui Town,Tianguan Town,Xixia County眉县金渠镇,周至县马召镇Jinqu Town,Mei County;Mazhao Town,Zhouzhi County西峡县丹水镇、田关乡、五里桥镇Danshui Town,Wuliqiao Town,Tianguan Town,Xixia County 13 11 8 14 14 28

1.2 仪器与设备

PAL-1 数显台式电子折光仪(日本ATAGO 公司);809 全自动滴定仪(瑞士万通);861 离子色谱仪(瑞士万通);SPECORD210 紫外可见分光光度计(德国耶拿);2695-2489-2475 型高效液相色谱仪(美国Waters)。

1.3 方法

可溶性固形物含量的测定参照农业行业标准(NY/T 2637-2014)《水果和蔬菜可溶性固形物含量的测定折射仪法》[5]。可溶性总糖含量的测定采用菲林试剂滴定法,每个样品取10 个果实,匀浆后称取20 g,用水洗入250 mL的容量瓶中,加盐酸3.5 mL,放入80 ℃水浴中15 min,冷却后调pH值至中性,定容至250 mL,过滤液即为总糖提取液,用菲林试剂测定总糖含量,以葡萄糖计。维生素C 含量的测定参照GB 5009.86—2016《食品安全国家标准食品中抗坏血酸的测定》[6]。总酸含量的测定参照GB/T 12456—2008《食品中总酸的测定》[7]。有机酸含量的测定参照NY/T 2796—2015《水果及其制品中有机酸的测定离子色谱法》[8]。蔗糖、葡萄糖和果糖含量测定参照GB 5009.8—2016《食品中果糖、葡萄糖、蔗糖、麦芽糖、乳糖的测定高效液相色谱法》[9]。总酚含量的测定参照NY/T 1600—2008《水果、蔬菜及其制品中单宁含量的测定分光光度法》[10]。叶绿素和类胡萝卜素总量测定和计算参照王业勤和李勤生[11]的方法,利用紫外分光光度计在350~700 nm范围内扫描,分别记录470 nm、649 nm、665 nm处的吸光度,按照以下公式计算叶绿素a、b 和总类胡萝卜素含量。

Ca、Cb 和Cxc 分别代表叶绿素a、b 和类胡萝卜素的质量分数(mg·kg-1),A470、A649 和A665 分别代表470、649、665 nm处的吸光度。

1.4 数据处理

采用Excel 进行原始数据处理、层次分析计算,采用SPSS 19.0 分析软件对各项指标进行K-S 正态分布检验、相关性分析、主成分分析、概率分级和全距等分等统计分析。

2 结果与分析

2.1 猕猴桃营养品质指标含量分析

对检测的猕猴桃样品的可溶性固形物、可溶性总糖、总酸、维生素C、蔗糖、葡萄糖、果糖、柠檬酸、奎宁酸、苹果酸、总酚、叶绿素和类胡萝卜素含量等13 项营养品质指标进行数据分析,各指标含量范围、平均值、中值、标准差和变异系数见表2。可以看出,蔗糖含量的变异系数最大,达112.94%,变异幅度为0.01%~5.50%,其次为叶绿素和苹果酸含量,变异系数分别为78.66%和50.00%,变异幅度分别为0.01~19.60 mg·kg-1和0.02%~0.35%,总酸和柠檬酸变异系数相对较小,分别为14.68%和15.85%,变异幅度分别0.72%~1.63%和0.53%~1.34%,其他指标的变异系数范围为16.04%~39.54%,说明13 项营养品质指标的变异幅度均较大。

表2 猕猴桃主要营养品质指标变异情况
Table 2 Variation of main nutritional quality indexes of kiwifruits

指标Index w(维生素C)Vitamin C/(mg·100 g-1)w(蔗糖)Sucrose/%w(果糖)Fructose/%w(总酚)Total phenols/(g·kg-1)w(叶绿素)Chlorophyll/(mg·kg-1)w(类胡萝卜素)Carotenoids/(mg·kg-1)最小值Min最大值Max标准差Standard deviation平均值Mean中值Median变异系数CV/%K-S p值K-S p-value w(可溶性固形物)Total soluble solid/%9.50 20.20 2.31 w(总糖)Total sugar/%4.04 15.39 2.31 w(总酸)Total sourness/%0.72 1.63 0.16 36.0 164.0 28.8 0.01 5.50 0.96 w(葡萄糖)Glucose/%2.10 6.50 0.94 2.10 6.50 0.93 w(柠檬酸)Citric acid/%0.53 1.25 0.13 w(奎宁酸)Quinic acid/%0.38 1.34 0.19 w(苹果酸)Malic acid/%0.02 0.35 0.07 0.503 1.438 0.180 0.01 19.60 3.98 1.20 8.19 1.38 14.40 14.40 16.04 9.26 9.07 24.95 1.09 1.09 14.68 93.3 95.0 30.87 0.85 0.39 112.94 4.03 3.90 23.33 3.83 3.63 24.28 0.82 0.80 15.85 0.70 0.65 27.14 0.14 0.13 50.00 0.760 0.730 23.68 5.06 4.20 78.66 3.49 3.24 39.54 0.439 0.3020.786 0.497 0.000 0.051 0.005 0.252 0.075 0.224 0.066 0.007 0.122

2.2 猕猴桃营养品质评价指标筛选

为确定猕猴桃的代表性营养品质指标,采用主成分分析法对13项猕猴桃营养品质指标数据进行分析。主成分分析结果见表3和表4,前4个主成分的累积贡献率为76.39%,可以代表13个指标的大部分信息。第1 主成分的贡献率为38.59%,代表指标包括可溶性固形物、总糖、葡萄糖、果糖、维生素C含量,反映猕猴桃的甜味和功能特征;第2主成分的贡献率为13.77%,代表指标包括总酸、柠檬酸和总酚含量,反映猕猴桃的酸味和功能特征;第3 主成分的贡献率为12.71%,代表指标为叶绿素含量,反映猕猴桃的颜色特征;第4主成分的贡献率为11.31%,代表指标为类胡萝卜素含量,反映猕猴桃的颜色和功能特征。

表3 猕猴桃营养品质指标的主成分分析结果
Table 3 Principal component analysis results of kiwifruit nutritional quality indexes

成分Component初始特征值Initial eigenvalues提取平方和Extract sums of squared loadings合计Total合计Total 123456789 5.017 1.790 1.652 1.471方差贡献率Contribution ratio/%38.593 13.772 12.708 11.319累积贡献率Cumula tive/%38.593 52.364 65.072 76.390 10 11 12 13 5.017 1.790 1.652 1.471 0.929 0.708 0.543 0.300 0.262 0.160 0.105 0.036 0.026方差贡献率Contribution ratio/%38.593 13.772 12.708 11.319 7.146 5.449 4.177 2.309 2.012 1.232 0.805 0.279 0.201累积贡献率Cumulative/%38.593 52.364 65.072 76.390 83.536 88.985 93.162 95.471 97.482 98.715 99.520 99.799 100.000

表4 成分矩阵
Table 4 Component matrix

指标Index可溶性固形物含量Total soluble solid content总酸含量Total sourness content维生素C含量Vitamin C content总糖含量Total sugar content总酚含量Total phenols content苹果酸含量Malic acid content柠檬酸含量Citric acid content奎宁酸含量Quinic acid content葡萄糖含量Glucose content果糖含量Fructose content蔗糖含量Sucrose content叶绿素含量Chlorophyll content类胡萝卜素含量Carotenoids content成分Component 1 0.9110.201 2 3 4 0.190-0.022-0.537 0.628 0.913 0.348 0.514-0.428-0.376 0.861 0.888 0.428-0.357 0.347 0.694 0.301 0.199 0.630-0.253 0.689 0.279 0.084 0.095 0.123 0.295 0.077 0.140-0.531 0.207-0.537-0.058 0.419-0.643 0.210 0.170 0.225 0.496-0.147-0.144-0.166-0.075-0.082-0.169-0.082 0.233 0.265 0.247-0.613 0.473 0.768

由表5 可知,可溶性固形物含量与总糖、葡萄糖、果糖含量高度正相关,而且测定方法简便,选择可溶性固形物含量代表甜味指标;总酸与柠檬酸高度正相关,总酸含量测定方法较简便,选择总酸含量代表酸味指标;维生素C和总酚呈高度正相关,且主成分分析中维生素C 含量权重大于总酚,选择维生素C 含量代表营养指标;类胡萝卜素含量权重高于叶绿素含量,选择类胡萝卜素含量作为颜色和功能指标。因此,猕猴桃的营养品质评价指标由可溶性固形物、总酸、维生素C、类胡萝卜素含量4项构成。

表5 猕猴桃营养品质指标间相关性分析
Table 5 Correlation analysis of kiwifruit nutritional quality indexes

注:**表示极显著相关(p<0.01)。
Note:**Correlation is extremly significant difference at p<0.01.

指标Index总酸含量Total sourness content维生素C含量Vitamin C content总糖含量Total sugar content总酚含量Total phenols content苹果酸含量Malic acid content柠檬酸含量Citric acid content奎宁酸含量Quinic acid content葡萄糖含量Glucose content果糖含量Fructose content蔗糖含量Sucrose content叶绿素含量Chlorophyll content类胡萝卜素含量Carotenoids content可溶性固形物含量Total soluble solid content总酸含量Total sourness content维生素C含量Vitamin C content总糖含量Total sugar content总酚含量Total phenols content苹果酸含量Malic acid content柠檬酸含量Citric acid content奎宁酸含量Quinic acid content葡萄糖含量Glucose content果糖含量Fructose content蔗糖含量Sucrose content叶绿素含量Chlorophyll content类胡萝卜素含量Carotenoids content可溶性固形物含量Total soluble solid content 1-0.347**0.513**0.956**0.282 0.363-0.166-0.330 0.814**0.781**0.521**-0.201 0.322 1-0.237-0.321 0.159-0.227 0.763**0.285-0.359-0.356-0.146 0.322-0.296 1 0.504**0.683**0.247-0.275 0.032 0.442**0.366 0.252-0.373 0.164 1 0.299 0.348-0.186-0.379 0.815**0.781**0.552**-0.228 0.278 1 0.024-0.015 0.214 0.242 0.243 0.116-0.151 0.131 1-0.350-0.142 0.446**0.413**0.175-0.323 0.002 1 0.122-0.302**-0.332**-0.266**0.003 0.202*1-0.340-0.366-0.281-0.032 0.182 1 0.961**0.145-0.159 0.361 1 0.139-0.121 0.352 1-0.193-0.124 1 0.149 1

2.3 猕猴桃营养品质指标分级

对各项指标进行Kolmogorov-Smirnov正态分布检验,p ≥0.05即呈正态分布,结果见表2,符合正态分布的指标可进行概率分级。筛选出的可溶性固形物、总酸、维生素C、类胡萝卜素含量4项指标均符合正态分布,利用SPSS软件的频次分布将指标分为极低、低、中、高、极高5级(10%,20%,40%,20%,10%)(表6)。

表6 猕猴桃4 项品质评价指标的评分标准
Table 6 Scores of four quality evaluation indexes of kiwifruit

等级Grade可溶性固形物Total soluble solid指标值Index value/%<11.4 11.4~13.2 13.3~15.6 15.7~17.4>17.4得分Score得分Score 10.4 20.8 31.2 41.6 52.0分布Distribution/%10.0 24.2 32.4 23.1 10.3总酸Total sourness指标值Index value/%>1.30 1.21~1.30 1.01~1.20 0.89~1.00<0.88分布Distribution/%6.5 25.3 34.7 23.3 10.2得分Score极低lower低low中medium高high极高higher 48 48 12 16 20维生素C Vitamin C指标值Index value/(mg·100 g-1)<56.5 56.5~78.2 78.3~108 109.0~130.0>130.0分布Distribution/%13.2 20.0 32.8 24.7 9.5 12 16 20类胡萝卜素Carotenoids指标值Index value/(mg·kg-1)<1.72 1.72~2.77 2.78~4.21 4.22~5.26>5.26分布Distribution/%6.2 30.0 35.3 17.5 11.0得分Score 1.6 3.2 4.8 6.4 8.0

2.4 猕猴桃营养品质指标权重确定

层次分析法是一种定性和定量相结合的,系统性、层次化的多目标决策分析方法,其核心是将决策者的经验判断定量化,增强了决策依据的准确性[12]。应用层次分析法解决决策问题时,需要先构造一个有层次的结构模型,一般层次数不受限制,但每层中元素一般不超过9个[13]。根据筛选出的猕猴桃4 项营养品质评价指标贡献及其重要性,并结合生产实践,采用1~9 标度法构建猕猴桃主要营养品质指标的判别矩阵,见表7,采用Excel 计算权重和进行一致性检验[12]

表7 猕猴桃品质评价指标层次结构的判别一致性
Table 7 Discriminant consistency of kiwifruit quality evaluation index hierarchy

注:E1.可溶性固形物含量;E2.总酸含量;E3.维生素C 含量;E4.类胡萝卜素含量。
Note:E1.Total soluble solid content,E2.Total sourness content,E3.Vitamin C content,E4.Carotenoids content.

指标Index E1 E2 E3 E4 CR=0.016 E1 1 1/3 1/3 1/5 E2 E3 E4 311 311 1/3 1/3 5331指标权重Index weight/%52.0 20.0 20.0 8.0

经一致性检验,判别矩阵的CR值为0.016,小于标准0.10,说明通过该方法建立的判断矩阵中各因素的相互关系比较一致,不需要调整。计算得到层次分析最终排序结果权重依次为可溶性固形物含量52.0%、总酸含量20.0%、维生素C含量20.0%、类胡萝卜素含量8.0%。由此可见,可溶性固形物含量对猕猴桃营养品质影响最大,其次是总酸和维生素C含量,类胡萝卜素含量影响最小。其中,可溶性固形物、维生素C和类胡萝卜素含量指标为正向指标,总酸含量为负向指标。将层次分析确定的各指标权重平均分为5级,与指标分级结果结合,正向指标含量从低到高分级,负向指标含量从高到低分级,得分从极低级到极高级依次增加权重的20%,即可溶性固形物含量从极低级到极高级的得分依次为10.4、20.8、31.2、41.6、52.0,总酸含量从极低级到极高级的得分依次为4、8、12、16、20,维生素C含量从极低级到极高级的得分依次为4、8、12、16、20,类胡萝卜素含量从极低级到极高级的得分依次为1.6、3.2、4.8、6.4、8.0。极低级到极高级各项指标之和分别为20、40、60、80、100(表6)。

2.5 猕猴桃营养品质指标综合评价

每个猕猴桃样品的4项评价指标通过指标值查询得分,各指标得分之和即为该样品的营养品质综合得分,满分100 分(表8)。根据全距等分法[14],稍作调整,以高于平均分20%为特级,高于平均分20%至低于平均分20%为一级,以低于平均分20%为二级,最后得到二级、一级和特级3 个等级,平均分为60分,分级点为48分和72分,调整后的分级点为45分和70分,见表8,对应得分区间分别是<45分为二级,45~70 分为一级,>70 分为特级。在本试验中,155 个猕猴桃样品划分为二级的样品有37 个;划分为一级的样品有66个;划分为特级的样品有52个。品种海沃德表现一般,多评为二级,品种徐香、金桃和红阳等表现较好,多评为一级或特级。

表8 猕猴桃营养品质综合评价表
Table 8 Comprehensive evaluation of nutritional quality of kiwifruits

等级Grade特级Super grade一级First grade二级Second grade样品个数Sample sizes 52 66 37分布Distribution/%33.5 42.6 23.9总得分Total Score>70 45~70<45

3 讨 论

研究表明,抽样方式不影响调查的准确性,抽样的样本数是影响调查准确性的主要因素[15]。样本量影响着抽样精度,如果抽取样本量少,对生物量总体估计量的代表性就差,抽样精度就低,反之样本量较大时,估计的精度高[16]。有研究者[17]在研究多元参考值范围的估计时提出了样本量不应小于100的标准。本研究采集的155份猕猴桃样品来自于我国猕猴桃三大主产省份的主要县市:河南省西峡县,陕西省眉县和周至县,四川省都江堰市、蒲江县、新津县、苍溪县,品种分别为红心品种红阳,绿肉品种翠香、徐香、海沃德,黄肉品种金桃和金艳等,涵盖市售猕猴桃品种的80%以上。总体而言,研究采集的猕猴桃样本具有很强的代表性,为营养品质评价结果的客观准确奠定了基础。

水果营养品质综合评价中评价指标的选择尤为重要,要尽可能代表果实的全面营养品质特性。本研究营养品质指标的选择从果实的风味、色泽和功能性3方面考虑。其中可溶性固形物、可溶性总糖、蔗糖、葡萄糖、果糖含量与果实甜味有关,总酸、柠檬酸、奎宁酸、苹果酸含量与果实酸味有关;维生素C是人类自身无法合成的必需营养素[18],且在猕猴桃中含量很高;叶绿素和类胡萝卜素是猕猴桃果实中兼具功能性的着色成分;多酚是水果蔬菜中重要的一类次生代谢产物,除了赋予水果蔬菜特有的感官品质外,还具有很好的生物活性[19]。虽然香气成分也是果实营养品质的组成部分,但是水果中香气成分种类繁多,有些组分含量低、稳定性差,在分析研究时容易受影响[20],不能精准定量,所以本研究未涉及。指标分析显示,有10项营养品质指标符合正态分布,此结果也验证了果树科学试验中生物现象的连续性变量或间断性变量大多遵从正态分布这一特点[21]。13 项营养品质指标的变异系数范围为14.68%~112.94%,充分说明不同样品因品种不同或所在产地的生态环境条件和管理习惯的不同而存在营养品质差异性。

应用主成分分析法可以删去多余重复的变量(关系紧密的变量),建立尽可能少的新变量,使得这些新变量互不相关的尽可能保持原有的信息。对海量指标数据进行分析可以避免主观因素的影响,使所得权重更加真实可靠[22]。此分析方法在其他园艺作物的品质评价方面也多有应用[23-24]。本研究利用主成分分析法将13项猕猴桃营养品质指标归纳为4类特征成分,并与相关性分析相结合,筛选出可溶性固形物含量(甜味指标)、总酸含量(酸味指标)、维生素C含量(营养功能指标)、类胡萝卜素含量(色泽功能指标)等4个猕猴桃营养品质综合评价指标。可溶性固形物含量与总酸含量呈极显著负相关,与维生素C含量呈极显著正相关,此与王依等[25]对美味猕猴桃果实品质指标的相关性研究结果相同。陈美艳等[4]研究表明色度角是金桃猕猴桃果实软熟品质的重要指标之一,是衡量黄肉猕猴桃果实成熟度的重要指标,而绿肉猕猴桃果实中同样含有类胡萝卜素,受叶绿素的掩盖,果肉呈现绿色,色度角不能用来衡量绿肉猕猴桃中类胡萝卜素的含量。因此,文中采用紫外可见分光光度法测定类胡萝卜素总量,此法与高效液相色谱法测定不同类胡萝卜素组分相比,操作更简单易行,结果更能反映果实真实的色泽和功能性状。

层次分析方法用于指标权重计算,在苹果[26]、葡萄[27]、油桃[28]、金花梨[29]等果实品质评价方面有广泛的应用。本研究采用层次分析确定了猕猴桃营养品质评价指标的权重结果为可溶性固形物含量>总酸含量=维生素C含量>类胡萝卜素含量,说明甜味指标对猕猴桃营养品质评价影响较大,色泽指标影响相对较小。综合评价结果显示,同品种的样品多划分为同等级,说明同一品种的营养品质总体差异较小;而同品种的样品也可能划分为不同等级,此与样品生长区域的环境条件和管理水平息息相关;不同品种多划分为不同等级,说明品种与营养品质具有很大的关联性。

现行的中华人民共和国农业行业标准《猕猴桃等级规格》(NY/T 1794—2009)和《猕猴桃质量等级》(GB/T 40743—2021)通过分析猕猴桃鲜果的感官和单果质量,对猕猴桃进行分等分级,本研究结果可与现行标准相互补充,将通过等级规格标准判定后的猕猴桃鲜果,再进行营养品质综合评价,保证猕猴桃鲜果从外观到营养的全面衡量,满足营养健康的育种目标和消费需求。

本研究对155个猕猴桃样品的营养品质指标含量数据进行正态分布和主成分分析,筛选出可溶性固形物、总酸、维生素C和类胡萝卜素含量等4个营养品质指标作为猕猴桃营养品质综合评价指标,采用层次分析法计算并确定4 个代表性指标权重,结合概率分级法和合理全距等分法建立指标评分标准和综合评价体系,为猕猴桃营养品质分级标准的建立提供了科学依据。

4 结 论

目前我国针对猕猴桃营养品质综合评价方法及分级标准还没有建立全面完整的体系,从而使我国猕猴桃营养品质评价和分级标准体系不健全。研究结果表明,猕猴桃可用可溶性固形物、总酸、维生素C和类胡萝卜素含量4项指标进行营养品质评价。试验建立的猕猴桃营养品质评价指标分级标准和综合分级标准,可为猕猴桃营养品质综合评价提供科学依据。

参考文献References:

[1] 黄宏文,龚俊杰,王圣梅,何子灿,张忠慧,李建强.猕猴桃属(Actinidia)植物的遗传多样性[J].生物多样性,2000,8(1):1-2.HUANG Hongwen,GONG Junjie,WANG Shengmei,HE Zican,ZHANG Zhonghui,LI Jianqiang.Genetic diversity in the genus Actinidia[J].Biodiversity Science,2000,8(1):1-2.

[2] 徐小彪,张秋明.中国猕猴桃种质资源的研究与利用[J].植物学通报,2003,20(6):648-655.XU Xiaobiao,ZHANG Qiuming.Researches and utilizations of germplasm resource of kiwifruit in China[J].Chinese Bulletin of Botany,2003,20(6):648-655.

[3] 陈璐,廖光联,杨聪,黄春辉,钟敏,陶俊杰,曲雪艳,徐小彪.基于主成分分析与聚类分析的黄肉猕猴桃品种(系)主要果实性状的综合评价[J].江西农业大学学报,2018,40(6):1231-1240.CHEN Lu,LIAO Guanglian,YANG Cong,HUANG Chunhui,ZHONG Min,TAO Junjie,QU Xueyan,XU Xiaobiao.Comprehensive evaluation of main fruit characters of yellow flesh kiwifruit cultivars(Strains)based on principal component analysis and cluster analysis[J].Acta Agriculturae Universitatis Jiangxiensis,2018,40(6):1231-1240.

[4] 陈美艳,赵婷婷,刘小莉,韩飞,张鹏,钟彩虹.猕猴桃品种‘金艳’果实品质因子分析与综合评价[J].植物科学学报,2021,39(1):85-92.CHEN Meiyan,ZHAO Tingting,LIU Xiaoli,HAN Fei,ZHANG Peng,ZHONG Caihong.Factor analysis and comprehensive evaluation of fruit quality of‘Jinyan’kiwifruit (Actinidia eriantha × Actinidia chinensis)[J].Plant Science Journal,2021,39(1):85-92.

[5] 中华人民共和国农业部.NY/T 2637—2014.水果和蔬菜可溶性固形物含量的测定折射仪法[S].北京:中国农业出版社,2014.The Ministry of Agriculture of the People's Republic of China.NY/T 2637—2014,Refractometric method for determination of total soluble solids in fruits and vegetables[S].Beijing:China Agriculture Press,2014.

[6] 中华人民共和国国家卫生和计划生育委员会.GB 5009.86—2016.食品安全国家标准食品中抗坏血酸的测定[S].北京:中国标准出版社,2016.National Health and Family Planning Commission of the P.R.C.GB 5009.86—2016,National food safety standard-determination of ascorbic acid in food[S].Beijing:China Standards Press,2016.

[7] 国家质量监督检验检疫总局.GB/T 12456—2008.食品中总酸的测定[S].北京:中国标准出版社,2008.General Administration of Quality Supervision,Inspection and Quarantine of the People’s Republic of China.GB/T 12456—2008,Determination of total acid in food[S].Beijing:China Standards Press,2008.

[8] 中华人民共和国农业部.NY/T 2796—2015.水果及其制品中有机酸的测定离子色谱法[S].北京:中国农业出版社,2015.The Ministry of Agriculture of the People's Republic of China.NY/T 2796—2015,Determination of organic acids in fruits-Ion chromatography[S].Beijing:China Agriculture Press,2015.

[9] 国家食品药品监督管理总局和国家卫生和计划生育委员会.GB 5009.8—2016.食品安全国家标准食品中果糖、葡萄糖、蔗糖、麦芽糖、乳糖的测定[S].北京:中国标准出版社,2016.China Food and Drug Administration and the National Health and Family Planning Commission.GB 5009.8—2016,National food safety standard-determination of fructose,glucose,sucrose,maltose,lactose in food[S].Beijing:China Standards Press,2016.

[10] 中华人民共和国农业部.NY/T 1600—2008.水果、蔬菜及其制品中单宁含量的测定分光光度法[S].北京:中国农业出版社,2008.The Ministry of Agriculture of the People's Republic of China.NY/T 1600—2008,Determination of tannin content in fruits,vegetables and derived product- spectrophotometric method[S].Beijing:China Agriculture Press,2008.

[11] 王业勤,李勤生.天然类胡萝卜素—研究进展、生产、应用[M].北京:中国医药科技出版社,1997.WANG Yeqin,LI Qinsheng.Natural carotenoids-research progress,production and application[M].Beijing:China Medical and Technology Press,1997.

[12] 曹茂林.层次分析法确定评价指标权重及Excel 计算[J].江苏科技信息,2012(2):39-40.CAO Maolin.Determination of the weight of evaluation index and excel calculation with analytic hierarchy process[J].Jiangsu Science and Technology Information,2012(2):39-40.

[13] 邓雪,李家铭,曾浩健,陈俊羊,赵俊峰.层次分析法权重计算方法分析及其应用研究[J].数学的实践与认识,2012,42(7):93-100.DENG Xue,LI Jiaming,ZENG Haojian,CHEN Junyang,ZHAO Junfeng.Research on computation methods of AHP weight vector and its applications[J].Mathematics in Practice and Theory,2012,42(7):93-100.

[14] 王茂丽.香椿优良单株的初步筛选及其综合评价[D].武汉:华中农业大学,2006.WANG Maoli.Preliminary screening and comprehensive evaluation of superior plants of Toona sinensis[D].Wuhan:Huazhong Agricultural University,2006.

[15] 何承苗.龙眼角颊木虱若虫空间分布型及抽样技术初探[J].华东昆虫学报,2008,17(2):104-109.HE Chengmiao.Spatial distribution pattern and sampling techniques of the nymph of Cornegenapsylla sinica Yang et Li[J].Entomological Journal of East China,2008,17(2):104-109.

[16] NELSON R,GOBAKKEN T,NÆSSET E,GREGOURE T G,STAHL G,HOLM S,FLEWELLING J.Lidar sampling-using an airborne profiler to estimate forest biomass in Hedmark County,Norway[J].Remote Sensing of Environment,2012,123:563-578.

[17] 陈彬.确定多指标医学参考值范围的统计方法概述[J].西部医学,2008,20(1):205-206.CHEN Bin.A statistical method for determining the range of medical reference values of multiple indicators overview[J].Medical Journal of West China,2008,20(1):205-206.

[18] 郭琳,陈捷凯,裴端卿.维生素C 与表观遗传调控[J].科学通报,2014,59:2833-2839.GUO Lin,CHEN Jiekai,PEI Duanqing.Vitamin C and epigenetic regulation[J].Chinese Science Bulletin,2014,59:2833-2839.

[19] 陶文扬,孙陪龙,孙玉敬.抗氧化成分在消化过程中变化的研究进展[J].食品科学,2017,38(9):271-279.TAO Wenyang,SUN Peilong,SUNYujing.Recent advances in understanding changes in antioxidants during in vitro digestion[J].Food Science,2017,38(9):271-279.

[20] 黄苏婷,杭方学,陆海勤,李凯,谢彩锋.水果挥发性香气成分研究进展[J].轻工科技,2019,35(2):1-4.HUANG Suting,HANG Fangxue,LU Haiqin,LI Kai,XIE Caifeng.Research progress on volatile aroma components of fruits[J].Light Industry Science and Technology,2019,35(2):1-4.

[21] 华中农学院.果树研究法[M].北京:农业出版社,1979.Huazhong Agricultural College.Research methods for fruit tree[M].Beijing:Agricultural Press,1979.

[22] 肖颍涛,王化全,俞海峰,胡晓侠,柴贤东.基于主成分分析法和模糊综合评价法的配电网评估[J].南方能源建设,2019,6(3):105-112.XIAO Yingtao,WANG Huaquan,YU Haifeng,HU Xiaoxia,CHAI Xiandong.Evaluation of distribution network status based on principal component analysis and correspondence analysis[J].Southern Energy Construction,2019,6(3):105-112.

[23] 冯海萍,苏存录,谢华,杨冬艳.基于主成分分析的宁南山区露地栽培小型甘蓝品种的综合评价[J].中国瓜菜,2020,33(11):68-71.FENG Haiping,SU Cunlu,XIE Hua,YANG Dongyan.Comprehensive evaluation of different iniature cabbage varieties in the mountainous area of southern Ningxia based on principal components analysis[J].China Cucurbits and Vegetables,2020,33(11):68-71.

[24] 李晶,郁继华,武玥,唐中祺,刘泽慈,吕剑.不同小果型西瓜品种品质评价[J].中国瓜菜,2020,33(11):61-67.LI Jing,YU Jihua,WU Yue,TANG Zhongqi,LIU Zeci,LÜ Jian.Quality evaluation of different small fruit watermelon varieties[J].China Cucurbits and Vegetables,2020,33(11):61-67.

[25] 王依,雷靖,陈成,徐明,邴昊阳,雷玉山.美味猕猴桃新品种‘瑞玉’果实品质综合评价[J].西北农林科技大学学报(自然科学版),2018,46(10):101-107.WANG Yi,LEI Jing,CHEN Cheng,XU Ming,BING Haoyang,LEI Yushan.Comprehensive evaluation of fruit quality of a new delicious kiwifruit variety‘Ruiyu’[J].Journal of Northwest A&F University(Natural Science Edition),2018,46(10):101-107.

[26] 聂继云,毋永龙,李海飞,王昆,李静,李志霞,徐国锋.苹果品种用于加工鲜榨汁的适宜性评价[J].农业工程学报,2013,29(17):271-278.NIE Jiyun,WU Yonglong,LI Haifei,WANG Kun,LI Jing,LI Zhixia,XU Guofeng.Suitability evaluation of apple cultivars for fresh juice-processing[J].Transactions of the Chinese Society of Agricultural Engineering,2013,29(17):271-278.

[27] 白世践,李超,户金鸽.层次-关联分析法在引种鲜食葡萄品质综合评价中的应用[J].北方园艺,2016(16):1-8.BAI Shijian,LI Chao,HU Jin’ge.Application of hierarchy-correlation analysis in comprehensive evaluation of fresh grape quality[J].Northern Horticulture,2016(16):1-8.

[28] 黄正金,卫云丽,张春红,闾连飞,李维林,吴文龙.基于层次分析法的5 个黑莓杂交品系的综合评价[J].南京林业大学学报(自然科学版),2019,43(16):135-140.HUANG Zhengjin,WEI Yunli,ZHANG Chunhong,LÜ Lianfei,LI Weilin,WU Wenlong.Comprehensive evaluation of five blackberry hybrid strains by analytic hierarchy process(AHP)[J].Journal of Nanjing Forestry University (Natural Sciences Edition),2019,43(16):135-140.

[29] 刘遵春,包东娥,廖明安.层次分析法在金花梨果实品质评价上的应用[J].西北农林科技大学学报(自然科学版),2006,34(8):125-128.LIU Zunchun,BAO Dong’e,LIAO Ming’an.Application of analytic hierarchy process in evaluating Jinhua pear quality[J].Journal of Northwest A&F University (Natural Science Edition),2006,34(8):125-128.

Comprehensive trait evaluation for kiwifruit nutritional quality

GUO Linlin1, PANG Rongli1, WANG Ruiping1, QIAO Chengkui1, TIAN Fajun1, WANG Caixia1, LI Jun1,PANG Tao1,CHENG Xin2*,XIE Hanzhong1*

(1Zhengzhou Fruit Research Institute,Chinese Academy of Agricultural Sciences/Henan,China;2Henan Key Laboratory of Fruit and Cucurbit Biology,Zhengzhou 450009,Henan,China;2The Center for Agri-Food Quality&Safety,MARA,Beijing 100081,China)

Abstract:【Objective】The evaluation on nutritional trait is an important procedure for kiwifruit breeding and comprehensive utilization.In order to provide technical support for comprehensive evaluation of kiwifruit nutritional traits,the nutritional quality indexes of kiwifruit were determined and the establishment of classification system was discussed in this study.【Methods】155 kiwifruit fruit samples from three major kiwifruit producing areas (Shanxi province, Sichuan province and Henan province)were collected in September, 2020.The cultivars of kiwifruit samples were Cuixiang, Hayward, Hongyang,Jintao,Jinyan and Xuxiang.Thirteen nutritional quality indexes including total soluble solids,total sugar, total acid, vitamin C, sucrose, glucose, fructose, citric acid, quinic acid, malic acid, total phenols, chlorophylls and carotenoids were determined after ripening and softening.A refractometer was used to determine the content of total soluble solids according to NY/T 2637—2014.Phenanthroline titration was used to determine total soluble sugar content.2, 6-dichloroindophenol titration was used to determine vitamin C content according to GB 5009.86-2016.The method of NaOH neutralization was used for determination of total acid content according to GB/T 12456—2008.The content of organic acids was determined by Metrohm 861 IC according to NY/T 2796—2015.Sucrose,glucose and fructose contents were determined by Waters 2695-2489-2475 HPLC according to GB 5009.8-2016.Folin-ciocalteu colorimetry determination of total phenol was conducted according to NY/T 1600—2008.The total contents of chlorophylls and carotenoids were determined by colorimetry.The SPSS software was used to extract the representative indexes of kiwifruit nutritional quality evaluation by correlation and principal component analysis.The weight of representative indexes was by analytic hierarchy process(AHP).The index scoring standard and comprehensive evaluation system were determined by the probability classification analysis and the reasonable full-distance equal analysis.【Results】The variation range of kiwifruit nutritional quality indexes varied greatly, with the variation coefficient ranging from 14.68% to 112.94%.The sucrose value had the largest variation coefficient of 112.94%.However, the total acid and citric acid had a relatively lower variation coefficient,which was 14.68%and 15.85%,respectively.There was a significant correlation among the nutritional quality indexes.The total soluble solids had a very significant positive correlation to total sugar, sucrose, glucose and fructose contents(p<0.01).There was a very significant positive correlation between total acid and citric acid content(p<0.01).Vitamin C showed a very significant positive correlation to total sugar,glucose and total phenol content (p<0.01).Four principal factors were extracted from the 13 indexes, which contributed to 38.59%, 13.77%, 12.71% and 11.31% of variation, respectively, with a cumulative percentage of 76.39%.The 1st principal component represented indexes including total soluble solids,total sugar,glucose, fructose and vitamin C, which reflected the sweet taste and functional characteristics of kiwifruit.And the 2nd principal component included total acid, citric acid and total phenol, which reflected sour taste and functional characteristics of kiwifruit.The third principal component included chlorophyll,which reflected the color characteristics of kiwifruit.The fourth principal component was carotenoids,which reflected the color and functional characteristics of kiwifruit.Four representative indexes (total soluble solids, total acid, vitamin C and carotenoids) were screened as evaluation indexes of kiwifruit nutritional quality by correlation analysis and AHP, which represented sweet index, sour index, nutritional function index and color function index,respectively.The total soluble solids had the greatest impact on the nutritional quality of kiwifruit, followed by total acid and vitamin C, and carotenoids had the least impact.The total soluble solids, vitamin C and carotenoid indexes were positive, however, total acid was a negative index.The four indexes were in line with normal distribution, and their weight coefficients were 56%, 20%, 20%, and 8%, respectively.These four indexes could be divided into 5 grades (lower, low, medium, high, and higher) and the scoring standards of them were also established.The scores of the four indexes from lower to higher were 10.4-52.0,4.0-20.0,4.0-20.0 and 1.6-8.0,respectively.The total score of each sample was the sum of the four index scores,and the full scores was 100.The 155 kiwifruit samples were divided into 3 grades, including super grade (>70 scores), first grade(45-70 scores)and second grade(<45 scores).There were 37 kiwifruit samples classified as second grade,66 kiwifruit samples classified as first grade and 52 kiwifruit samples in super grade.【Conclusion】The representative indexes of comprehensive evaluation of kiwifruit nutritional quality were total soluble solids, total acid, vitamin C and carotenoids.The established four comprehensive nutritional quality scoring standards could be used for evaluation and classification of kiwifruit nutritional quality.

Key words:Kiwifruit;Nutritional quality;Principal component analysis;AHP;Comprehensive evaluation

中图分类号:S663.4

文献标志码:A

文章编号:1009-9980(2022)10-1864-09

DOI:10.13925/j.cnki.gsxb.20220289

收稿日期2022-05-24

接受日期:2022-07-12

基金项目中国农业科学院科技创新工程专项经费项目(CAAS-ASTIP-2022-ZFRI-09);中国农业科学院科技创新工程重大科研任务(CAAS-XTCX20190025-4);河南省科技攻关项目(212102110403)

作者简介郭琳琳,女,高级实验师,主要从事果品品质评价工作。Tel:13613714325,E-mail:guolinlin@caas.cn

*通信作者Author for correspondence.Tel:0371-65330935,E-mail:hellen1231@126.com;E-mail:xiehanzhong@caas.cn