摘" " 要:【目的】毛花獼猴桃贛綠1號具有生理成熟后不易落果的特性。探明其果實(shí)留樹后熟期間的品質(zhì)變化,為獼猴桃的留樹后熟技術(shù)應(yīng)用提供理論基礎(chǔ)?!痉椒ā恳悦ǐJ猴桃贛綠1號品種為研究對象,從果實(shí)生理成熟期開始,每隔10 d隨機(jī)采集果實(shí),直至果實(shí)皺縮不宜食用。果實(shí)運(yùn)回實(shí)驗室后立即測定其果實(shí)外觀及內(nèi)在品質(zhì)指標(biāo)。最后利用主成分分析法對贛綠1號果實(shí)品質(zhì)進(jìn)行綜合評價,篩選最佳留樹時間?!窘Y(jié)果】贛綠1號果實(shí)留樹后熟期間,單果質(zhì)量和硬度呈下降趨勢,分別下降了23.72%和90.51%;抗壞血酸、可滴定酸、可溶性固形物、可溶性糖及各色素含量均呈現(xiàn)先增后降的趨勢。其中,抗壞血酸與可滴定酸含量(w,后同)在盛花后192 d達(dá)到峰值1 282.22 mg·100 g-1、1.26%;可溶性固形物與可溶性糖含量在盛花后210 d達(dá)到峰值18.41%、10.87%;盛花后210 d各色素含量迅速下降。通過主成分分析綜合評價:盛花后192~210 d的果實(shí)品質(zhì)最佳?!窘Y(jié)論】贛綠1號果實(shí)留樹后熟期間,果實(shí)外觀指標(biāo)均呈現(xiàn)下降趨勢,內(nèi)質(zhì)品質(zhì)呈現(xiàn)先增后降趨勢,留樹21~39 d的果實(shí)綜合品質(zhì)最佳。
關(guān)鍵詞:毛花獼猴桃;贛綠1號;留樹后熟;果實(shí)品質(zhì);主成分分析
中圖分類號:S663.4 文獻(xiàn)標(biāo)志碼:A 文章編號:1009-9980(2024)11-2250-11
Dynamic changes and evaluation of fruit quality during on-vine ripening in Ganlü No. 1 kiwifruit (Actinidia eriantha)
ZHENG Kexin, LIAO Guanglian, YE Bin, JIA Dongfeng, HUANG Chunhui, ZHONG Min, XU Xiaobiao*
(College of Agronomy/Institute of Kiwifruit, Jiangxi Agricultural University, Nanchang 330045, Jiangxi, China)
Abstract: 【Objective】 The present experiment was undertaken to explore the dynamic changes in the appearance and intrinsic quality of Ganlü No. 1 (Actinidia eriantha) fruit on different on-vine ripening times, comprehensively evaluate the fruit quality on different times, and identify the best time for on-vine ripening. Kiwifruit is a respiratory climacteric fruit, which is easy to soften and decay after maturity and has a short edible window period. The on-vine fruit is still a living organism, and it will generally undergo physiological maturity on the vine and then fully mature with the best taste. The methods of on-vine ripening can improve the fruit flavor. Ganlü No. 1 fruit has the characteristics of not being easy to drop after physiological maturity. So, it was used to explore new storage methods for kiwifruit. 【Methods】 The fruits of Ganlü No. 1 were collected from the physiological maturing stage (SSC ≥ 6.5%) (October 26, 2022) until the fruits were too ripen to be edible, with a total of six times: 171, 180, 192, 201, 210 and 222 days after full bloom (DAFB). The changes in hardness, color, ascorbic acid, titratable acid, soluble sugar, soluble solids, chlorophyll and carotenoids were measured, and the best time for on-vine ripening was evaluated by the principal component analysis. 【Results】 During the on-vine ripening period, the Ganlü No. 1 fruit surface gradually smoothed, the color of the fruit surface became deepened-brown, and the exocarp began to lose water and shrink on 222 DAFB. The whole flesh was tender green on 171 DAFB, and the color of the flesh near the core began to change from tender green to dark green on 180 DAFB and gradually spread to the exocarp until the whole flesh turned dark green on 222 DAFB, and the flesh gradually became transparent. The core color gradually turned yellow, from light green to pale yellow. The flesh’s L* and b* values showed an overall decreasing trend. Notably, the b* value showed a significant decrease, dropping from its highest value of 27.81 on 171 DAFB to the lowest value of 9.79 on 210 DAFB, a reduction of 64.8%. The L* value also showed a significant decline from its highest value of 56.99 on 171 DAFB to the lowest value of 40.32 on 210 DAFB, representing a reduction of 29.25%. This indicated a decline in brightness, with the color becoming darker and more yellowish. Conversely, the a* value showed an overall increasing trend, from its lowest value of -11.7 on 171 DAFB to its highest value of 3.09 on 210 DAFB, representing a change of -126.41%. This increase signified a deepening of the red hue in the flesh. These changes in chromatic aberration values were consistent with the observed fruit appearance. The fruit shape index, single fruit quality and hardness showed a decreasing trend. The pulp hardness decreased significantly from the highest value of 155.61 g on 171 DAFB to the lowest value of 14.76 g on 210 DAFB, a decrease of 90.51%. The contents of ascorbic acid, titratable acid, soluble solids, soluble sugars and pigments increased first and then decreased. The content of AsA increased from 947.89 mg·100 g-1 on 171 DAFB to its highest value of 1 282.22 mg·100 g-1 on 192 DAFB with an increase of 24.12%, decreased to 905.17 mg·100 g-1 on 201 DAFB with a decrease of 29.41%, increased to 1 028.95 mg·100 g-1 on 210 DAFB, and decreased to its lowest value of 897.66 mg·100 g-1 on 222 DAFB. The titratable acid content increased slowly without significant difference from 171 DAFB to 180 DAFB, but from 180 DAFB to 192 DAFB, it increased significantly to its highest value of 1.26% on 192 DAFB. From 192 DAFB to 210 DAFB, it slowly decreased to 1.21% on 210 DAFB. However, from 210 DAFB to 222 DAFB, it declined sharply to its lowest value of 1.02% on 222 DAFB, a decrease of 15.7%. The contents of soluble solids and sugars showed an increased trend from 171 DAFB to 210 DAFB, reached their highest value on 210 DAFB, and then decreased rapidly. Notably, the soluble solids content increased significantly from its lowest value of 7.46% on 171 DAFB to its highest value of 18.41% on 210 DAFB, an increase of 146.78%. The soluble sugar content also increased significantly from its lowest value of 6.42% on 171 DAFB to its highest value of 10.87% on 210 DAFB, an increase of 40.94%. The contents of chlorophyll a, b and carotenoids all showed the “decreasing-increasing-decreasing” trend, and the overall trend decreased. From 180 DAFB to 201 DAFB, they increased significantly to 2.73, 1.68 and 1.62 mg·100 g-1 on 201 DAFB, an increase of 52.51%, 37.93% and 44.64%, respectively. From 210 DAFB to 222 DAFB, they decreased sharply to their lowest value of 1.48, 0.77 and 0.92 mg·100 g-1 on 222 DAFB, a decrease of 45.79%, 61.5% and 43.21%, respectively, and the rate of decline showed chlorophyll b>chlorophyll a>carotenoids. Principal component analysis was carried out on six quality indexes of Ganlü No. 1 on six on-vine ripening times, and three principal components were extracted, with a cumulative contribution rate of 98.143%. The variance contribution rate of the first principal component was 50.52%, in which indexes of positive load were soluble sugar content (0.895), titratable acid content (0.731) and soluble solid content (0.935), and index of negative load was pulp hardness (-0.741), with all of indexes having high absolute loads. The variance contribution rate of the second principal component was 27.59%, and the total chlorophyll and carotenoid contents (0.766) had a high positive load. The variance contribution rate of the third principal component was 20.034%, and the ascorbic acid content (0.898) had a major positive effect. According to the comprehensive score of principal components, 192 DAFB had the highest comprehensive quality score of 1.112. 210 DAFB and 201 DAFB were listed second and third, respectively. 180, 171, 222 DAFB ranked 4-6 in sequence. 【Conclusion】 During the on-vine ripening period of Ganlü No. 1 fruits, the appearance indexes showed a decreasing trend, and the intrinsic quality showed a trend of first ascending and then descending. The content of AsA reached a peak of 1 282.22 mg·100 g-1 on 192 DAFB, and the content of soluble sugar reached a peak of 10.87% on 210 DAFB. The comprehensive evaluation of principal component analysis showed that the comprehensive quality of the fruit was the best after 21-39 days during the on-vine ripening period.
Key words: Actinidia eriantha; Ganlü No. 1; On-vine ripening; Fruit quality; Principal component analysis
毛花獼猴桃(Actinidia eriantha)屬于獼猴桃科(Actinidiaceae)獼猴桃屬(Actinidia),是中國特有的野生寶貴資源,主要分布在中國長江以南的丘陵生態(tài)地形區(qū)域[1-2]。毛花獼猴桃不僅具有較強(qiáng)的生長勢、抗逆性、抗病蟲害能力,而且適應(yīng)范圍廣,市場潛力大[3-5],被認(rèn)為是繼中華獼猴桃(A. chinensis)和美味獼猴桃(A. deliciosa)之后極具開發(fā)潛力的優(yōu)良漿果種類[2]。
中國是獼猴桃生產(chǎn)大國,但獼猴桃產(chǎn)業(yè)各環(huán)節(jié)發(fā)展不均衡,果實(shí)品質(zhì)不穩(wěn)定、優(yōu)果率低、貯藏保鮮技術(shù)不成熟等問題突出。其中貯藏保鮮效果差是導(dǎo)致中國獼猴桃國際競爭力弱的主要原因之一,也是制約獼猴桃健康可持續(xù)發(fā)展的關(guān)鍵因素[6]。獼猴桃采后具有典型的呼吸躍變和生理后熟特點(diǎn),成熟后易軟化腐爛、不耐貯藏[7]。在產(chǎn)業(yè)應(yīng)用中,獼猴桃多采用冷藏來延緩果實(shí)后熟、維持果實(shí)品質(zhì)及延長貨架期。然而,獼猴桃冷藏保鮮需要消耗電力、設(shè)施、空間、管理等諸多資源,且消費(fèi)者更傾向于購買完全成熟的獼猴桃[8]。留樹后熟技術(shù)就是解決上述突出問題的新途徑之一。留樹后熟是通過延遲采收來貯藏保鮮的技術(shù),留樹果實(shí)仍然是生命體,在樹上一般會經(jīng)歷生理成熟,隨后完全成熟,口感達(dá)最佳,最后逐漸衰老的過程,具有提升果實(shí)品質(zhì),延長鮮果供應(yīng)期和增收的作用[9-10]。因此,留樹后熟不僅能節(jié)省資源,還能立即售賣和食用[8]。留樹后熟已廣泛應(yīng)用于柑橘[11]、杧果[12]和葡萄柚[13]等果樹作物上,在獼猴桃上尚未見相關(guān)研究報道。
前期研究發(fā)現(xiàn),毛花獼猴桃果實(shí)生理成熟后可長期留樹[14],但果實(shí)留樹后熟期間的品質(zhì)變化及品質(zhì)最佳留樹時間尚不清楚。據(jù)此,筆者在本研究中以毛花獼猴桃贛綠1號為材料,通過測定其果實(shí)留樹后熟過程中不同時期外在及內(nèi)在品質(zhì)的變化,并利用主成分分析探明贛綠1號果實(shí)品質(zhì)最佳的留樹后熟時期,為獼猴桃的留樹后熟技術(shù)應(yīng)用提供理論基礎(chǔ)。
1 材料和方法
1.1 材料
供試材料樣品來源于江西省奉新縣農(nóng)業(yè)農(nóng)村局的獼猴桃園(28?70' N,115?38' E)。獼猴桃園栽培株行距為3 m×4 m,栽培架式為水平大棚架,單主干雙主蔓多側(cè)蔓整形。以毛花獼猴桃贛綠1號為試驗材料,單株小區(qū),3次生物學(xué)重復(fù),在果實(shí)生理成熟期[可溶性固形物含量(w,后同) ≥ 6.5%[15],2022-10-26]進(jìn)行首次采樣,之后每隔10 d每株采集果樣15個,直至果實(shí)太皺縮不宜食用為止。分別于盛花后(DAFB)171、180、192、201、210、222 d共 6個時期采集果樣,各時期的氣候特征如圖1所示。采回立即測定果實(shí)硬度、單果質(zhì)量等外觀指標(biāo),之后將果樣除去果皮、種子和果心,用液氮速凍后,于-80 ℃保存?zhèn)溆谩?/p>
1.2 指標(biāo)測定與方法
隨機(jī)選取10個果實(shí),使用千分之一電子天平測量其單果質(zhì)量;使用游標(biāo)卡尺測量果實(shí)的橫徑、縱徑和側(cè)徑,果形指數(shù)=縱徑/橫徑;采用質(zhì)構(gòu)儀(型號為TA-XTplus)測量果實(shí)的果皮與果肉的硬度;采用色差儀(型號為CHROMA METER CR-400)測量果肉色差值;采用手持?jǐn)?shù)顯糖度計測定可溶性固形物含量;參照李合生[16]的方法測定葉綠素含量;采用蒽酮比色法測定可溶性糖含量,采用NaOH中和滴定法測定果實(shí)可滴定酸含量[17];采用鉬藍(lán)比色法測定抗壞血酸含量(AsA)[18]。
1.3 數(shù)據(jù)處理
數(shù)據(jù)采用Microsoft Excel 2016軟件進(jìn)行初步的數(shù)據(jù)分析并制作相應(yīng)柱形和折線圖;利用IBM SPSS Statistics 25軟件進(jìn)行差異顯著性分析和主成分分析,差異性分析選擇鄧肯法和LSD法,顯著性水平為0.05。
2 結(jié)果與分析
2.1 果實(shí)外觀和色澤的變化
分析果實(shí)外觀與橫切、縱切面在留樹后熟過程中的變化,發(fā)現(xiàn)贛綠1號果實(shí)表面逐漸光滑,果面顏色褐色加深,盛花后222 d外果皮開始失水皺縮;盛花后171 d整個果肉為嫩綠色,盛花后180 d靠近果心的果肉顏色開始從嫩綠色變?yōu)樯罹G色,并逐漸向外果皮擴(kuò)散,直至盛花后222 d整個果肉變?yōu)樯罹G色,且果肉逐漸變得透明;果心顏色逐漸變黃,從淺綠色逐漸變?yōu)榈S色(圖2-A)。
在留樹后熟過程中(圖2-B),贛綠1號果肉的L*值、b*值整體都呈下降的趨勢,L*值從最高值(盛花后171 d的56.99)顯著下降到最低值(盛花后210 d的40.32),下降幅度達(dá)29.25%;b*值從最高值(盛花后171 d的27.81)顯著下降到最低值(盛花后210 d的9.79),下降幅度達(dá)64.8%;a*值整體呈上升的趨勢,從最低值(盛花后171 d的-11.7)顯著上升到最高值(盛花后210 d的3.09),而后下降至盛花后222 d的-4.00。L*、b*值下降,表明果實(shí)隨著留樹時間的增長,果肉亮度逐漸降低,果肉顏色逐漸加深、變黃;a*值上升,表明果肉紅色加深。果實(shí)表型與色差值表現(xiàn)一致,果肉顏色從嫩綠變?yōu)槠S深綠。
2.2 果實(shí)縱橫徑、硬度、單果質(zhì)量及果形指數(shù)的變化
由表1可見,贛綠1號果實(shí)在留樹后熟過程中,果形指數(shù)在盛花后171~210 d呈下降的趨勢,盛花后210 d達(dá)最低值1.79。單果質(zhì)量和硬度整體都呈下降的趨勢,單果質(zhì)量在盛花后171~180 d顯著下降了23.72%;而盛花后180~222 d趨于平穩(wěn),無顯著差異;果皮硬度在盛花后171 d達(dá)最高(573.24 g),盛花后222 d顯著下降到最低(162.45 g),下降幅度達(dá)71.66%;果肉硬度盛花后171 d最高(155.61 g),盛花后210 d顯著下降到最低,為14.76 g,下降幅度達(dá)90.51%。
2.3 果實(shí)營養(yǎng)品質(zhì)的變化
2.3.1 果實(shí)AsA含量的變化 由圖3可見,贛綠1號果實(shí)在留樹后熟過程中,AsA含量從盛花后171 d的947.89 mg·100 g-1上升至最高值(盛花后192 d的1 282.22 mg·100 g-1),上升了24.12%;盛花后201 d下降至905.17 mg·100 g-1,下降幅度達(dá)到29.41%;盛花后210 d上升至1 028.95 mg·100 g-1,最后在盛花后222 d下降至最低值897.66 mg·100 g-1。果實(shí)AsA含量整體呈先上升后下降的趨勢。
2.3.2 果實(shí)可滴定酸含量的變化 由圖4可見,贛綠1號果實(shí)在留樹后熟過程中,可滴定酸含量從盛花后171~180 d上升緩慢且無顯著差異,盛花后180~192 d顯著上升,于盛花后192 d到達(dá)最高值1.26%;盛花后192~210 d緩慢下降至1.21%;盛花后210~222 d急速下降至最低值1.02%,下降幅度達(dá)15.7%??傻味ㄋ岷肯壬仙笙陆担傮w呈下降的趨勢。
2.3.3 果實(shí)可溶性固形物和可溶性糖含量的變化 由圖5可見,贛綠1號果實(shí)在留樹后熟過程中,可溶性固形物和可溶性糖含量變化趨勢基本一致,盛花后171~210 d呈上升的趨勢并在盛花后210 d達(dá)到最高值,而后迅速下降??扇苄怨绦挝锖繌淖畹椭担ㄊ⒒ê?71 d的7.46%)顯著上升到最高值(盛花后210 d的18.41%),上升幅度高達(dá)146.78%;果實(shí)可溶性糖含量從最低值(盛花后171 d的6.42%)顯著上升到最高值(盛花后210 d的10.87%),上升幅度達(dá)40.94%??扇苄怨绦挝锖涂扇苄蕴呛肯壬仙笙陆担傮w呈上升的趨勢。其中,盛花后192~222 d的變化趨勢表明可溶性糖以外的可溶性固形物迅速消耗。
2.4 果肉葉綠素和類胡蘿卜素含量的變化
由圖6可見,贛綠1號果實(shí)在留樹后熟過程中,葉綠素a、葉綠素b、類胡蘿卜素含量的整體變化趨勢基本一致,都是呈下降-上升-下降的趨勢,總體呈現(xiàn)下降。盛花后180~201 d葉綠素a、葉綠素b、類胡蘿卜素含量分別顯著上升至2.73、1.68、1.62 mg·100 g-1,分別上升了52.51%、37.93%和44.64%;盛花后210 d后葉綠素a、葉綠素b、類胡蘿卜素含量急劇分別下降至最低值(盛花后222 d的1.48、0.77、0.92 mg·100 g-1),分別下降了45.79%、61.5%、43.21%,下降速度為葉綠素b>葉綠素a>類胡蘿卜素,果實(shí)轉(zhuǎn)變?yōu)辄S綠色。
2.5 贛綠1號果實(shí)留樹后熟期間品質(zhì)的綜合評價
通過對6個留樹后熟時期的贛綠1號毛花獼猴桃的6項品質(zhì)指標(biāo)進(jìn)行主成分分析(表2),發(fā)現(xiàn)前3個主成分的特征值大于1,累計方差貢獻(xiàn)率達(dá)到98.143%。第一主成分的方差貢獻(xiàn)率為50.52%,其中正向載荷的指標(biāo)為可溶性糖含量(0.895)、可滴定酸含量(0.731)、可溶性固形物含量(0.935),負(fù)向載荷的指標(biāo)為果肉硬度(-0.741),這些指標(biāo)都擁有絕對值較高的載荷值;第二主成分的方差貢獻(xiàn)率為27.59%,葉綠素+類胡蘿卜素含量(0.766)有較大的正向載荷;第三主成分的方差貢獻(xiàn)率為20.034%,抗壞血酸含量(0.898)對其產(chǎn)生主要的正向影響。根據(jù)(表2、表3)主成分的特征向量和載荷矩陣,Xi的系數(shù)=其載荷/[其主成分的特征值](例:Y1中的X1的系數(shù)=0.324/[3.031]≈0.186),可得到3個主成分的得分函數(shù)表達(dá)式(Y1、Y2、Y3)。
Y1=0.186X1+0.514X2+0.420X3+0.537X4-0.426X5+0.235X6;
Y2=0.221X1-0.315X2+0.485X3-0.009X4+0.512X5+0.595X6;
Y3=0.820X1+0.033X2+0.206X3-0.300X4-0.022X5-0.441X6;
綜合得分=0.505 2Y1+0.275 9Y2+0.200 34Y3。
式中,X1~X6分別對應(yīng)標(biāo)準(zhǔn)化后的AsA、可溶性糖、可滴定酸、可溶性固形物、果肉硬度、葉綠素+類胡蘿卜素含量等品質(zhì)指標(biāo)。各得分值與相應(yīng)特征值的方差貢獻(xiàn)率的乘積相加得出不同時期獼猴桃的綜合得分,以此來評價不同留樹后熟時期贛綠1號毛花獼猴桃果實(shí)的綜合品質(zhì)。通過計算,得到綜合得分和綜合排名結(jié)果如表4所示,不同留樹后熟時期的贛綠1號毛花獼猴桃果實(shí)綜合品質(zhì)排名為:192 d>210 d>201 d>180 d>171 d>222 d,即留樹21 d>39 d>30 d>9 d>0 d>50 d。
3 討 論
果實(shí)品質(zhì)高低是決定贛綠1號留樹后熟是否可行的重要因素。筆者在本研究中通過果實(shí)的外觀及內(nèi)在品質(zhì)指標(biāo)綜合評價,發(fā)現(xiàn)與多項獼猴桃果實(shí)后熟研究結(jié)果的總體趨勢一致,且果實(shí)顏色、質(zhì)地變化相似。果實(shí)軟化成熟是一個極其復(fù)雜的生理過程,受淀粉降解和細(xì)胞壁成分、結(jié)構(gòu)變化等的影響[20-22]。然而果實(shí)硬度可以在一定程度上反映這種變化,因此成為獼猴桃成熟的典型指標(biāo)[22-23]。有研究發(fā)現(xiàn)金艷、徐香、金魁獼猴桃在后熟過程中硬度不斷下降[24-25],且Burdon等[23]對海沃德的研究發(fā)現(xiàn),在后熟前期果實(shí)硬度顯著下降,后熟后期緩慢下降。本研究材料從盛花后171~180 d硬度迅速下降,盛花后201~222 d平緩下降,與上述變化趨勢基本一致。當(dāng)成熟獼猴桃果實(shí)硬度達(dá)到可采收硬度標(biāo)準(zhǔn)時,果實(shí)開始發(fā)生成熟軟化,內(nèi)含物隨之發(fā)生一系列變化[26]。后熟前期果實(shí)硬度的快速降低主要是與淀粉降解及細(xì)胞壁(主要為果膠)降解有關(guān),消除了淀粉支撐和維持細(xì)胞膨壓的作用[27-29]。后熟后期的果肉的軟化則可能是細(xì)胞呼吸作用程度相對顯著加強(qiáng),果肉細(xì)胞蛋白質(zhì)組成崩解,以及果肉細(xì)胞內(nèi)含物(糖、TA、AsA、色素)逐漸被消耗殆盡后的結(jié)果[30-32],同時影響著其他品質(zhì)指標(biāo)。
AsA也稱為維生素C,是植物中含量最豐富的抗氧化劑之一[33]。有研究發(fā)現(xiàn)奉黃1號[34]、徐香[9]、海沃德[35]等獼猴桃的AsA和可滴定酸含量隨采摘期的延后總體呈下降趨勢,本研究與此研究結(jié)果一致。而海沃德[35]獼猴桃在0 ℃冷藏完成生理后熟的過程中,隨著貯藏時間的延長,AsA和可滴定酸含量在20~100 d上升。本研究在盛花后171~210 d,AsA含量也上升,于盛花后192 d達(dá)到峰值1 282.22 mg·100 g-1。關(guān)于這個峰值,有研究發(fā)現(xiàn)葉綠體產(chǎn)生活性氧(ROS)時,AsA在濃度為20 mmol·L-1或更高的水平。而AsA在光保護(hù)中起著核心作用,包括光合作用和呼吸產(chǎn)生的ROS清除劑、紫黃質(zhì)脫環(huán)氧化酶的輔因子和光系統(tǒng)Ⅱ電子供體[33],此時AsA上升很可能是在為后熟期間呼吸高峰做準(zhǔn)備。
果實(shí)的葉綠素中含有豐富的鐵元素,有解毒、抗氧化、延緩衰老,美容養(yǎng)顏等功效[36]。類胡蘿卜素是多種天然色素的總稱,有維持視覺、增強(qiáng)免疫,保護(hù)皮膚等作用[37]。有研究發(fā)現(xiàn)奉黃1號不同采收期的總?cè)~綠素、類胡蘿卜素含量隨采摘期的延后總體呈下降趨勢,與本研究結(jié)果總體趨勢一致[34]。而秦美[38]獼猴桃在20 ℃貯藏后熟過程中,各色素含量均迅速下降,下降幅度表現(xiàn)出:葉綠素b>葉綠素a>類胡蘿卜素;在0 ℃貯藏過程中,L*和b*值逐漸減小,a*值逐漸增大,果實(shí)的亮度下降,果肉轉(zhuǎn)變?yōu)辄S綠色并趨于透明;本研究與秦美這兩種貯藏溫度下色素和色差研究結(jié)果基本一致。關(guān)于色素的下降,有研究表明獼猴桃后熟后期果肉細(xì)胞呼吸作用程度顯著加強(qiáng),蛋白質(zhì)組成崩解,色素逐漸被消耗[38]。關(guān)于葉綠素含量的變化,有研究發(fā)現(xiàn)與葉綠體細(xì)胞壁和超微結(jié)構(gòu)的變化直接相關(guān),其降解過程中MDcase和Chlase酶可能發(fā)揮重要作用[39]。
可溶性固形物、可溶性糖含量是獼猴桃重要營養(yǎng)指標(biāo),其含量水平?jīng)Q定獼猴桃的食用口感[40]。有研究表明海沃德獼猴桃在冷藏條件下,隨著采收期的延后獼猴桃果實(shí)可溶性固形物含量顯著增加[35]。而張佳佳等[41]發(fā)現(xiàn)華特果實(shí)后熟前期呼吸作用加強(qiáng),加速分解積累的有機(jī)物(淀粉),使得可溶性固形物和可溶性糖含量上升,果實(shí)口感風(fēng)味增加;后熟后期可溶性固形物成為主要供能底物來源,使得果實(shí)可溶性固形物和可溶性糖含量下降。本研究表明,從盛花后171~210 d果實(shí)可溶性固形物和可溶性糖含量上升,盛花后210 d達(dá)到峰值10.87%后迅速下降,與華特整體趨勢基本一致。淀粉降解還會受到乙烯的調(diào)控和低溫的誘導(dǎo)[42],有研究發(fā)現(xiàn)β-淀粉酶基因(BAM3.2,BAM3L)、淀粉磷酸化酶基因(PHS2,PHS2.1)可能參與低溫誘導(dǎo)的淀粉降解, AdDof3和AcbHLH137分別調(diào)控AdBAM3L和AcBAM3靶基因的表達(dá),從而促進(jìn)淀粉降解[43-45]。
因留樹后熟時期不同,果實(shí)品質(zhì)均有各自的特點(diǎn),需綜合性地進(jìn)行評價與分析。目前主成分分析已被廣泛應(yīng)用在有關(guān)果實(shí)品質(zhì)的數(shù)據(jù)分析和綜合評價中[46]。通過主成分分析綜合評價,果實(shí)品質(zhì)綜合得分排名前三(得分均大于0.6)的時期為:盛花后192、210、201 d,即留樹21、39、30 d。有關(guān)貯藏研究發(fā)現(xiàn),徐香掛樹預(yù)貯7 d的獼猴桃冷藏出庫時AsA含量、可食狀態(tài)下感官得分最高[9];秦美在采后20 ℃貯藏,僅能保鮮12 d左右[38];華特采后20 ℃貯藏,約6 d內(nèi)完全軟化,在完全軟化后的6~12 d保持營養(yǎng)物質(zhì)相對穩(wěn)定[41];而本研究贛綠1號可以留樹貯藏達(dá)39 d。與其他品種獼猴桃相比,贛綠1號毛花獼猴桃生理成熟后不易落果,留樹時間長,耐貯性較好。目前,獼猴桃采后貯藏催熟的相關(guān)設(shè)備不夠齊全,貯藏、催熟技術(shù)不夠規(guī)范[47]。留樹后熟具有不占室內(nèi)貯藏空間、省去貯藏環(huán)節(jié)、減少果實(shí)損傷和對第2年產(chǎn)量影響不大等優(yōu)點(diǎn)[11]。在品質(zhì)方面,留樹預(yù)貯可以提高獼猴桃果實(shí)可溶性固形物含量,降低可滴定酸含量,提高淀粉降解速率,風(fēng)味品質(zhì)更佳[9]。在生產(chǎn)方面,市場需要即食的獼猴桃[47]。毛花獼猴桃掛樹后熟期間,不同樹體不同位置果實(shí)成熟存在差異,可自由挑選、隨摘即食,有利于發(fā)展農(nóng)家樂、旅游觀光等產(chǎn)業(yè),讓人們品嘗到更鮮嫩可口的獼猴桃,且節(jié)約貯藏成本[8]。但長時間留樹貯藏,果實(shí)會在樹上進(jìn)入后熟階段,導(dǎo)致采后貯藏時間大大縮短[7]。正常采后貯藏也可以通過冷藏、氣調(diào)等方法減緩果實(shí)成熟、衰老,貯存更長時間。
4 結(jié) 論
贛綠1號果實(shí)留樹后熟期間,果實(shí)外觀指標(biāo)均呈現(xiàn)下降趨勢,內(nèi)在品質(zhì)呈現(xiàn)先增后降趨勢。各色素含量于盛花后210 d后迅速下降,幅度表現(xiàn)出:葉綠素b>葉綠素a>類胡蘿卜素,果肉顏色從嫩綠變?yōu)槠S深綠。AsA含量于盛花后192 d達(dá)到峰值1 282.22 mg·100 g-1,可溶性糖含量于盛花后210 d達(dá)到峰值10.87%。通過主成分分析綜合評價,果實(shí)留樹21~39 d果實(shí)綜合品質(zhì)最佳。本試驗結(jié)果可為開創(chuàng)新的更環(huán)保的留樹后熟獼猴桃貯藏手段提供理論依據(jù)。
參考文獻(xiàn)References:
[1] LIAO G L,XU X B,HUANG C H,ZHONG M,JIA D F. Resource evaluation and novel germplasm mining of Actinidia eriantha[J]. Scientia Horticulturae,2021,282:110037.
[2] 黃宏文. 獼猴桃屬 分類 資源 馴化 栽培[M]. 北京:科學(xué)出版社,2013:2-78.
HUANG Hongwen. Actinidia taxonomy germplasm domestication cultivation[M]. Beijing:Science Press,2013:2-78.
[3] 鄒梁峰. 毛花獼猴桃雄株核心種質(zhì)構(gòu)建及遺傳多樣性分析[D]. 南昌:江西農(nóng)業(yè)大學(xué),2019.
ZOU Liangfeng. Establishiment of the core collection of male germplasm resources of Actinidia eriantha and analysis of its genetic diversity[D]. Nanchang:Jiangxi Agricultural University,2019.
[4] LIAO G L,XU Q,ALLAN A C,XU X B. L-Ascorbic acid metabolism and regulation in fruit crops[J]. Plant Physiology,2023,192(3):1684-1695.
[5] 王海令,曹家樂,廖光聯(lián),黃春輝,賈東峰,曲雪艷,徐小彪. 毛花獼猴桃AeAPX基因家族鑒定與表達(dá)分析[J]. 果樹學(xué)報,2022,39(12):2225-2240.
WANG Hailing,CAO Jiale,LIAO Guanglian,HUANG Chunhui,JIA Dongfeng,QU Xueyan,XU Xiaobiao. Identification and expression analysis of AeAPX gene family in Actinidia eriantha[J]. Journal of Fruit Science,2022,39(12):2225-2240.
[6] 袁云香. 獼猴桃的儲藏與保鮮技術(shù)[J]. 北方園藝,2011(6):168-170.
YUAN Yunxiang. Technology of storage and fresh-keeping of kiwifruit[J]. Northern Horticulture,2011(6):168-170.
[7] 王明召,陽廷密,張素英,門友均,唐明麗,易顯榮,萬保雄,婁兵海. ‘紅陽’獼猴桃不同時期采收果實(shí)品質(zhì)及貯藏效果研究[J]. 中國果樹,2018(4):31-33.
WANG Mingzhao,YANG Tingmi,ZHANG Suying,MEN Youjun,TANG Mingli,YI Xianrong,WAN Baoxiong,LOU Binghai. Study on fruit quality and storage effect of ‘Hongyang’ kiwifruit in different harvest periods[J]. China Fruits,2018(4):31-33.
[8] TILAHUN S,CHOI H R,PARK D S,LEE Y M,CHOI J H,BAEK M W,HYOK K,PARK S M,JEONG C S. Ripening quality of kiwifruit cultivars is affected by harvest time[J]. Scientia Horticulturae,2020,261:108936.
[9] 屈魏,高萌,冉昪,李歡,舒雪瑤,饒景萍. 掛樹預(yù)貯對‘徐香’獼猴桃采后耐貯性和冷敏性的影響[J]. 食品科學(xué),2020,41(23):197-204.
QU Wei,GAO Meng,RAN Bian,LI Huan,SHU Xueyao,RAO Jingping. Effect of tree-hanging pre-storage on postharvest storability and cold sensitivity of ‘Xuxiang’ kiwifruits[J]. Food Science,2020,41(23):197-204.
[10] 孫建城,王登亮,劉春榮,吳雪珍,吳群,程慧林. 柑橘留樹保鮮技術(shù)研究進(jìn)展[J]. 中國果樹,2021(7):1-6.
SUN Jiancheng,WANG Dengliang,LIU Chunrong,WU Xuezhen,WU Qun,CHENG Huilin. Research progress of citrus on-tree storage[J]. China Fruits,2021(7):1-6.
[11] 陶愛群,易干軍,石雪暉,姜小文. 柑橘留樹保鮮研究進(jìn)展[J]. 廣東農(nóng)業(yè)科學(xué),2012,39(24):45-49.
TAO Aiqun,YI Ganjun,SHI Xuehui,JIANG Xiaowen. Overview of citrus storage on tree[J]. Guangdong Agricultural Sciences,2012,39(24):45-49.
[12] KIENZLE S,CARLE R,SRUAMSIRI P,TOSTA C,NEIDHART S. Occurrence of alk (en) ylresorcinols in the fruits of two mango (Mangifera indica L.) cultivars during on-tree maturation and postharvest storage[J]. Journal of Agricultural and Food Chemistry,2014,62(1):28-40.
[13] BURNS J K,ALBRIGO L G. Time of harvest and method of storage affect granulation in grapefruit[J]. HortScience,1998,33(4):728-730.
[14] 徐小彪,廖光聯(lián),黃春輝,賈東峰,鐘敏,曲雪艷,劉青,高歡. 甜香型毛花獼猴桃新品種贛綠1號的選育[J]. 果樹學(xué)報,2024,41(2):358-361.
XU Xiaobiao,LIAO Guanglian,HUANG Chunhui,JIA Dongfeng,ZHONG Min,QU Xueyan,LIU Qing,GAO Huan. A novel sweet aromatic cultivar of Actinidia eriantha ‘Ganlü No. 1’[J]. Journal of Fruit Science,2024,41(2):358-361.
[15] LIAO G L,LI Z Y,HUANG C H,ZHONG M,TAO J J,QU X Y,CHEN L,XU X B. Genetic diversity of inner quality and SSR association analysis of wild kiwifruit (Actinidia eriantha)[J]. Scientia Horticulturae,2019,248:241-247.
[16] 李合生. 植物生理生化實(shí)驗原理和技術(shù)[M]. 北京:高等教育出版社,2000:130-138.
LI Hesheng. Principles and techniques of plant physiological biochemical experiment[M]. Beijing:Higher Education Press,2000:130-138.
[17] 曹建康,姜微波,趙玉梅. 果蔬采后生理生化實(shí)驗指導(dǎo)[M]. 北京:中國輕工業(yè)出版社,2007:35-36.
CAO Jiankang,JIANG Weibo,ZHAO Yumei. Postharvest physiological and chemical experiment guidance for fruits and vegetables[M]. Beijing:China Light Industry Press,2007:35-36.
[18] 高俊鳳. 植物生理學(xué)實(shí)驗指導(dǎo)[M]. 北京:高等教育出版社,2006:203-204.
GAO Junfeng. Experimental guidance for plant physiology[M]. Beijing:Higher Education Press,2006:203-204.
[19] 王利群,戴雄澤. 色差計在辣椒果實(shí)色澤變化檢測中的應(yīng)用[J]. 辣椒雜志,2009,7(3):23-26.
WANG Liqun,DAI Xiongze. Application of colorimeter for testing its color change during the development of hot pepper (Capsicum annuum L.) fruit[J]. Journal of China Capsicum,2009,7(3):23-26.
[20] ZHANG B,CHEN K S,BOWEN J,ALLAN A,ESPLEY R,KARUNAIRETNAM S,F(xiàn)ERGUSON I. Differential expression within the LOX gene family in ripening kiwifruit[J]. Journal of Experimental Botany,2006,57(14):3825-3836.
[21] BRUMMELL D A,DAL CIN V,CRISOSTO C H,LABAVITCH J M. Cell wall metabolism during maturation,ripening and senescence of peach fruit[J]. Journal of Experimental Botany,2004,55(405):2029-2039.
[22] WANG D D,YEATS T H,ULUISIK S,ROSE J K C,SEYMOUR G B. Fruit softening:Revisiting the role of pectin[J]. Trends in Plant Science,2018,23(4):302-310.
[23] BURDON J,PIDAKALA P,MARTIN P,BILLING D. Softening of ‘Hayward’ kiwifruit on the vine and in storage:The effects of temperature[J]. Scientia Horticulturae,2017,220:176-182.
[24] 楊丹,王琪凱,張曉琴. 貯藏溫度對采后‘金艷’獼猴桃品質(zhì)和后熟的影響[J]. 北方園藝,2016(2):126-129.
YANG Dan,WANG Qikai,ZHANG Xiaoqin. Effect of different storage temperatures on the quality and postharvest ripening of ‘Jinyan’ kiwifruit[J]. Northern Horticulture,2016(2):126-129.
[25] 張計育,莫正海,黃勝男,劉永芝,郭忠仁. 不同儲藏溫度對獼猴桃果實(shí)后熟過程中品質(zhì)的影響[J]. 江蘇農(nóng)業(yè)科學(xué),2013,41(11):295-297.
ZHANG Jiyu,MO Zhenghai,HUANG Shengnan,LIU Yongzhi,GUO Zhongren. Effects of different storage temperatures on the quality of kiwifruit during ripening[J]. Jiangsu Agricultural Sciences,2013,41(11):295-297.
[26] ITAI A,TANAHASHI T. Inhibition of sucrose loss during cold storage in Japanese pear (Pyrus pyrifolia Nakai) by 1-MCP[J]. Postharvest Biology and Technology,2008,48(3):355-363.
[27] SCHR?DER R,ATKINSON R. Kiwifruit cell walls:Towards an understanding of softening?[J]. New Zealand Journal of Forestry Science,2006,36(1):112-129.
[28] ZHANG Q Y,GE J,LIU X C,WANG W Q,LIU X F,YIN X R. Consensus co-expression network analysis identifies AdZAT5 regulating pectin degradation in ripening kiwifruit[J]. Journal of Advanced Research,2022,40:59-68.
[29] MOCHIZUKI T,KUROSAKI T. Histochemical changes of starch in kiwifruit (Actinidia chinensis Planch.) during fruit growth and storage[J]. Nippon Shokuhin Kogyo Gakkaishi,1988,35(4):221-225.
[30] 陳金印,曾榮,李平. 獼猴桃采后生理及貯藏技術(shù)研究進(jìn)展[J]. 江西農(nóng)業(yè)大學(xué)學(xué)報(自然科學(xué)版),2002,24(4):477-483.
CHEN Jinyin,ZENG Rong,LI Ping. Advance of research on postharvest physiology of kiwifruit and its storage technology[J]. Acta Agriculturae Universitis Jiangxiensis,2002,24(4):477-483.
[31] 顧子民. 獼猴桃果實(shí)生長過程中種子發(fā)育及其激素含量的變化[D]. 楊凌:西北農(nóng)林科技大學(xué), 2022.
GUN Zimin. Changes of seed development and hormone content in kiwifruit during fruit growth[D]. Yangling:Northwest A amp; F University,2022.
[32] 饒景萍,郭衛(wèi)東,彭麗桃,任小林. 獼猴桃后熟軟化影響因素的研究[J]. 西北植物學(xué)報,1999,19(2):303-309.
RAO Jingping,GUO Weidong,PENG Litao,REN Xiaolin. Study on the factors of kiwifruit ripening and softening[J]. Acta Botanica Boreali-Occidentalia Sinica,1999,19(2):303-309.
[33] SMIRNOFF N. Ascorbate biosynthesis and function in photoprotection[J]. Philosophical Transactions of the Royal Society of London. Series B,Biological Sciences,2000,355(1402):1455-1464.
[34] 陳雙雙,賀艷群,徐小彪,賈東峰,陶俊杰,梅奕陽,黃春輝. 不同采收期對‘奉黃1號’獼猴桃果實(shí)品質(zhì)的影響[J]. 江西農(nóng)業(yè)大學(xué)學(xué)報,2021,43(6):1259-1268.
CHEN Shuangshuang,HE Yanqun,XU Xiaobiao,JIA Dongfeng,TAO Junjie,MEI Yiyang,HUANG Chunhui. Effect of different harvest time on fruit quality of ‘Fenghuang No. 1’ kiwifruit[J]. Acta Agriculturae Universitatis Jiangxiensis,2021,43(6):1259-1268.
[35] 吳彬彬,饒景萍,李百云,賴勤毅,張海燕. 采收期對獼猴桃果實(shí)品質(zhì)及其耐貯性的影響[J]. 西北植物學(xué)報,2008,28(4):4788-4792.
WU Binbin,RAO Jingping,LI Baiyun,LAI Qinyi,ZHANG Haiyan. Effect of harvest date on fruit quality and storage duration of kiwifruit[J]. Acta Botanica Boreali-Occidentalia Sinica,2008,28(4):4788-4792.
[36] 申申,段君祿,李宇,王承,傅佳佳,王鴻博. 竹葉中葉綠素的提取工藝及其功能性應(yīng)用研究[J]. 化工新型材料,2018,46(1):117-120.
SHEN Shen,DUAN Junlu,LI Yu,WANG Cheng,F(xiàn)U Jiajia,WANG Hongbo. Research on the extraction and functional application of chlorophyll from bamboo leaves[J]. New Chemical Materials,2018,46(1):117-120.
[37] 田清尹,岳遠(yuǎn)征,申慧敏,潘多,楊秀蓮,王良桂. 植物觀賞器官中類胡蘿卜素代謝調(diào)控的研究進(jìn)展[J]. 生物技術(shù)通報,2022,38(12):35-46.
TIAN Qingyin,YUE Yuanzheng,SHEN Huimin,PAN Duo,YANG Xiulian,WANG Lianggui. Research progress in the regulation of carotenoid metabolism in plant ornamental organs[J]. Biotechnology Bulletin,2022,38(12):35-46.
[38] 張媛娥,雷生姣,夏辛珂,胡彪,陳鈺亭. 獼猴桃加工中葉綠素研究進(jìn)展[J]. 食品科技,2021,46(2):44-50.
ZHANG Yuane,LEI Shengjiao,XIA Xinke,HU Biao,CHEN Yuting. Research progress of chlorophyll in kiwifruit processing[J]. Food Science and Technology,2021,46(2):44-50.
[39] 任亞梅. 獼猴桃果實(shí)葉綠素代謝及生理特性研究[D]. 楊凌:西北農(nóng)林科技大學(xué),2009.
REN Yamei. Study on chlorophyll metabolism and physiological characteristics of kiwifruit[D]. Yangling:Northwest A amp; F University,2009.
[40] 劉科鵬,黃春輝,冷建華,陳葵,嚴(yán)玉平,辜青青,徐小彪. ‘金魁’獼猴桃果實(shí)品質(zhì)的主成分分析與綜合評價[J]. 果樹學(xué)報,2012,29(5):867-871.
LIU Kepeng,HUANG Chunhui,LENG Jianhua,CHEN Kui,YAN Yuping,GU Qingqing,XU Xiaobiao. Principal component analysis and comprehensive evaluation of the fruit quality of ‘Jinkui’ kiwifruit[J]. Journal of Fruit Science,2012,29(5):867-871.
[41] 張佳佳,鄭小林,勵建榮. 毛花獼猴桃‘華特’果實(shí)采后生理和品質(zhì)變化[J]. 食品科學(xué),2011,32(8):309-312.
ZHANG Jiajia,ZHENG Xiaolin,LI Jianrong. Physiological and quality changes in Actindia eriantha Benth ‘Walter’ fruit during storage at normal temperature[J]. Food Science,2011,32(8):309-312.
[42] 冉欣雨,黃文俊,鐘彩虹. 獼猴桃果實(shí)淀粉代謝研究進(jìn)展[J]. 果樹學(xué)報,2024,41(2):325-337.
RAN Xinyu,HUANG Wenjun,ZHONG Caihong. Advance in starch metabolism research of kiwifruit[J]. Journal of Fruit Science,2024,41(2):325-337.
[43] ZHANG A D,WANG W Q,TONG Y,LI M J,GRIERSON D,F(xiàn)ERGUSON I,CHEN K S,YIN X R. Transcriptome analysis identifies a zinc finger protein regulating starch degradation in kiwifruit[J]. Plant Physiology,2018,178(2):850-863.
[44] 劉璐,王康,韓一璐,楊民杰,陳偉,曹士鋒,施麗愉. 獼猴桃AcbHLH137功能鑒定及對淀粉降解基因AcBAM3轉(zhuǎn)錄激活分析[J]. 核農(nóng)學(xué)報,2022,36(3):544-553.
LIU Lu,WANG Kang,HAN Yilu,YANG Minjie,CHEN Wei,CAO Shifeng,SHI Liyu. Functional identification of AcbHLH137 and its transcriptional activation of starch degradation gene AcBAM3 in kiwifruit[J]. Journal of Nuclear Agricultural Sciences,2022,36(3):544-553.
[45] 陳璐,高柱,毛積鵬,張小麗,盧玉鵬,林孟飛,公旭晨,王小玲. 不同溫度處理采后獼猴桃果實(shí)淀粉降解的轉(zhuǎn)錄組分析[J]. 江西農(nóng)業(yè)大學(xué)學(xué)報,2023,45(3):591-604.
CHEN Lu,GAO Zhu,MAO Jipeng,ZHANG Xiaoli,LU Yupeng,LIN Mengfei,GONG Xuchen,WANG Xiaoling. Transcriptome analysis of starch degradation in post-harvest kiwifruit treated at different temperatures[J]. Acta Agriculturae Universitatis Jiangxiensis,2023,45(3):591-604.
[46] 胡光明,黎純斌,楊斌,王周倩,申素云,李作洲,鐘彩虹. 宜昌市72份野生中華獼猴桃果實(shí)性狀多樣性分析與綜合評價[J]. 果樹學(xué)報,2022,39(9):1540-1552.
HU Guangming,LI Chunbin,YANG Bin,WANG Zhouqian,SHEN Suyun,LI Zuozhou,ZHONG Caihong. Analysis and comprehensive evaluation of fruit trait diversity of 72 Actinidia chinensis accessions in Yichang[J]. Journal of Fruit Science,2022,39(9):1540-1552.
[47] 鐘曼茜,翟舒嘉,劉偉,睢國祥,段玉權(quán),林瓊,陶鑫涼. 我國即食獼猴桃產(chǎn)業(yè)發(fā)展現(xiàn)狀、問題與對策[J]. 中國果樹,2023(2):122-127.
ZHONG Manxi,ZHAI Shujia,LIU Wei,SUI Guoxiang,DUAN Yuquan,LIN Qiong,TAO Xinliang. Current situation,problems and countermeasures of the development of ready-to-eat kiwifruit industry in China[J]. China Fruits,2023(2):122-127.