王 遠(yuǎn),宋江峰*,劉春泉3,李大婧3
(1.南京農(nóng)業(yè)大學(xué)食品科學(xué)技術(shù)學(xué)院,江蘇 南京 210095;2. 江蘇省農(nóng)業(yè)科學(xué)院農(nóng)產(chǎn)品加工研究所,江蘇 南京 210014;3.南京市(明天)農(nóng)產(chǎn)品加 工技術(shù)研究中心,江蘇 南京 210014)
不同貯藏溫度條件下菜用大豆蔗糖代謝與相關(guān)酶活性變化
王 遠(yuǎn)1,2,宋江峰2,*,劉春泉2,3,李大婧2,3
(1.南京農(nóng)業(yè)大學(xué)食品科學(xué)技術(shù)學(xué)院,江蘇 南京 210095;2. 江蘇省農(nóng)業(yè)科學(xué)院農(nóng)產(chǎn)品加工研究所,江蘇 南京 210014;3.南京市(明天)農(nóng)產(chǎn)品加 工技術(shù)研究中心,江蘇 南京 210014)
以‘新大粒1號(hào)’菜用大豆為試材,研究不同貯藏溫度(1、5、10、20 ℃)條件下菜用大豆蔗糖代謝及相關(guān)酶活性的變化情況。結(jié)果表明,貯藏期間菜用大豆蔗糖、果糖及葡萄糖含量均呈整體下降趨勢(shì),1 ℃有效控制了蔗糖降解;酸性轉(zhuǎn)化酶(AI)活性在第1天達(dá)到峰值后逐漸下降,不受貯藏溫度影響;20 ℃條件下中性轉(zhuǎn)化酶(NI)活性持續(xù)增加,至第4天達(dá)到最大值,其他溫度組變化差異不顯著(P>0.05);蔗糖合成酶(SS)活性略有降低后快速升高,至第4天達(dá)到峰值后逐漸下降;蔗糖磷酸合成酶(SPS)活性呈整體下降趨勢(shì),與蔗糖含量呈極顯著正相關(guān)(P<0.01),與果糖含量呈顯著正相關(guān)(P <0.05),其他酶活性與糖含量之間均無(wú)顯著相關(guān)性(P>0.05)。這表明SPS可能與‘新大粒1號(hào)’菜用大豆中蔗糖降解密切相關(guān)。
菜用大豆;貯藏溫度;蔗糖代謝;蔗糖磷酸合成酶
菜用大豆(Glycine max [L.] Merr.)由于采收時(shí)溫度較高,極易衰老、黃化和營(yíng)養(yǎng)耗竭,嚴(yán)重影響其食味品質(zhì)。甜味作為菜用大豆重要的食味品質(zhì)指標(biāo),主要依賴于蔗糖、葡萄糖和果糖含量以及蔗糖代謝相關(guān)酶活性的調(diào)控[1]。與蔗糖代謝相關(guān)的酶主要包括酸性轉(zhuǎn)化酶(acid invertase,AI)、中性轉(zhuǎn)化酶(neutral invertase,NI)、蔗糖合成酶(sucrose synthase,SS)和蔗糖磷酸合成酶(sucrose phosphate synthase,SPS),其中轉(zhuǎn)化酶主要負(fù)
責(zé)蔗糖降解,AI在快速生長(zhǎng)的組織活性較高,例如根尖和未成熟的莖;NI在貯藏組織中含量較高,但主要存在于細(xì)胞質(zhì)中,常被認(rèn)為當(dāng)AI活性較低或蔗糖合成受限時(shí)才發(fā)揮降解作用[2]。SS和SPS催化蔗糖合成和降解,與果實(shí)品質(zhì)形成和成熟衰老密切相關(guān)[3]。果蔬采后蔗糖代謝的研究在西蘭花[4]、甘蔗[5]等中都已有報(bào)道,其關(guān)鍵調(diào)節(jié)酶及作用機(jī)制差異顯著。目前菜用大豆蔗糖代謝的研究主要集中在生長(zhǎng)發(fā)育階段,張古文等[6]報(bào)道稱菜用大豆發(fā)育過(guò)程中蔗糖含量約為可溶性糖的70%,蔗糖代謝相關(guān)酶凈活性是調(diào)控蔗糖積累的主要因素;Kassinee等[7]認(rèn)為發(fā)育過(guò)程中‘Ajigen’品種的AI是調(diào)節(jié)其蔗糖代謝的關(guān)鍵酶,與蔗糖含量呈顯著負(fù)相關(guān);而‘Fuuki’品種中SS和SPS對(duì)其蔗糖代謝 起關(guān)鍵調(diào)節(jié)作用,與蔗糖含量均呈顯著正相關(guān)。針對(duì)菜用大豆采后蔗糖代謝的研究鮮有報(bào)道。因此,本研究擬考察不同貯藏溫度條件下‘新大粒1號(hào)’菜用大豆蔗糖代謝及相關(guān)酶活性變化規(guī)律,以期明確采后蔗糖代謝關(guān)鍵調(diào)節(jié)酶及其調(diào)控機(jī)制。
1.1 材料與試劑
供試菜用大豆品種為‘新大粒1號(hào)’,于2013年10月16日采自江蘇省農(nóng)業(yè)科學(xué)院六合基地,采收當(dāng)天運(yùn)至實(shí)驗(yàn)室。(4±1)℃預(yù)冷0.5 h,選取大小均一,成熟度基本一致,籽粒飽滿,無(wú)銹斑、病蟲害及機(jī)械損傷的豆莢,0.02 mm聚乙烯保鮮袋分裝,每袋約500 g,橡皮筋封口。分別置于溫度為(1±1)、(5±1)、(10±1)、(20±1)℃,相對(duì)濕度為85%~90%恒溫恒濕箱中,貯藏7 d。分批取樣,進(jìn)行相關(guān)指標(biāo)測(cè)定。
尿苷二磷酸葡萄糖(uridine diphosphate glucose,UDPG)、果糖-6-磷酸(fructose 6-phosphate,6-P-F)(均為生化試劑) 美國(guó)Sigma公司。
1.2 儀器與設(shè)備
配有1260示差檢測(cè)器的1200液相色譜儀 美國(guó)安捷倫科技有限公司;HPX-160BSH-III恒溫恒濕箱 上海滬粵明科學(xué)儀器有限公司;AR224CN電子天平 賽多利斯科學(xué)儀器(北京)有限公司;TU-1810紫外-可見(jiàn)分光光度計(jì) 北京普析通用儀器有限公司;H-2050R冷凍離心機(jī) 長(zhǎng)沙湘儀離心機(jī)有限公司。
1.3 方法
1.3.1 蔗糖、果糖、葡萄糖的提取及含量測(cè)定
參照Giannoccaro等[8]的方法,略加改動(dòng)。取菜用大豆約1 g,液氮研磨后,加5 mL水混勻,50 ℃水浴15 min,4 ℃條件下12 000 r/min離心20 min,取上清液,殘?jiān)铀畯?fù)提,合并上清液加入等體積乙腈,0.45 μm過(guò)濾器過(guò)濾,用于液相色譜分析。
色譜條件為:C a r b o h y d r a t e色譜柱(150 mm×4.6 mm,5 μm),示差檢測(cè)器檢測(cè),流動(dòng)相:乙腈-水(75∶25,V/V),流速1.00 mL/min,檢測(cè)器溫度30 ℃,柱溫箱溫度30 ℃。
糖標(biāo)準(zhǔn)溶液配制:準(zhǔn)確稱取蔗糖、果糖、葡萄糖各3.0 g(精確到0.000 1 g),轉(zhuǎn)移到100 mL容量瓶,高純水定容至100 mL,得到30 mg/mL的混標(biāo)溶液,分別稀釋到10、8、6、4、2 mg/mL。進(jìn)樣前經(jīng)0.45 μm微孔濾膜過(guò)濾。每個(gè)樣品重復(fù)3 次。
1.3.2 粗酶提取液制備
參照Nielsen等[9]的方法,略加改動(dòng)。取菜用大豆約1 g,液氮研磨,加入6 mL預(yù)冷提取液混勻,4 ℃條件下12 000 r/min離心20 min,上清液備用。提取液組成為:50 mmol/L 4-羥乙基哌嗪乙磺酸(4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid,HEPES)-NaOH(pH 7.5),10 mmol/L MgCl2,1 mmol/L乙二胺四乙酸(ethylene diamine tetraacetic acid,EDTA),2.5 mmol/L二硫蘇糖醇(DL-dithiothreitol),10 mmol/L VC,0.1 g/100 mL牛血清白蛋白(bovine serum albumin,BSA),0.5 g/100 mL交聯(lián)聚乙烯吡咯烷酮(crosslinking polyvingypyrrolidone,PVPP)。
1.3.3 AI和NI活性測(cè)定
參照Nielsen等[9]的方法,略加改動(dòng)。540 nm波長(zhǎng)處測(cè)定吸光度,轉(zhuǎn)化酶活性單位為μmol/(h·g),以葡萄糖計(jì)。
1.3.4 SS和SPS活性測(cè)定
參照Giannoccaro等[8]的方法,略加改動(dòng)。620 nm波長(zhǎng)處測(cè)定吸光度,合成酶活性單位為μmol/(h·g),以蔗糖計(jì)。
1.4 數(shù)據(jù)處理與分析
采用Excel 2003和SAS V8統(tǒng)計(jì)分析軟件對(duì)實(shí)驗(yàn)數(shù)據(jù)進(jìn)行顯著性檢驗(yàn)和相關(guān)性分析,所有數(shù)值均為3 次重復(fù)平均值。
2.1 不同貯藏溫度條件下菜用大豆主要糖含量變化
由圖1可以看出,菜用大豆采后蔗糖、葡萄糖、果糖含量均呈整體下降趨勢(shì),但不同貯藏溫度對(duì)糖含量影響不同。貯藏第1天,蔗糖和果糖含量在20 ℃條件下急劇下降,但1 ℃貯藏明顯延緩了其下降趨勢(shì);葡萄糖含量下降較快,不同貯藏溫度對(duì)其無(wú)顯著影響(P>0.05)。貯藏第4天,各溫度條件下蔗糖含量差異顯著(P<0.05),隨著貯藏溫度的升高,蔗糖含量下降。果糖含量在1 ℃條件下顯著高于其他貯藏溫度組(P<0.05),而葡萄糖的含量隨著貯藏溫度升高略有增加。貯藏第7天,蔗糖、葡
萄糖和果糖含量均隨溫度的升高而減少,低溫減少了貯藏期間可溶性糖含量的損失,且1 ℃條件下貯藏時(shí)大豆的蔗糖含量顯著高于其他貯藏溫度組(P<0.05),果糖含量在1 ℃與5 ℃組無(wú)顯著性差異,但顯著高于10 ℃和20 ℃組(P<0.05)。
圖1 菜用大豆采后蔗糖(a)、葡萄糖(b)、果糖(c)含量的變化Fig.1 Changes in the contents of sucrose (a), glucose (b) and fructose (c) in postharvest vegetable soybean
2.2 不同貯藏溫度條件下菜用大豆的酶活性變化
2.2.1 AI活性
圖2 菜用大豆采后AI活性的變化Fig.2 Change in acid invertase activity in postharvest vegetable soybean
圖2表明,菜用大豆采后AI活性呈先上升后下降趨勢(shì),不同貯藏溫度對(duì)AI活性變化趨勢(shì)基本無(wú)影響。貯藏第1天,AI活性達(dá)到峰值,20 ℃條件下AI活性與10 ℃組無(wú)顯著性差異(P>0.05),但顯著高于1 ℃和5 ℃組(P<0.05);隨著貯藏時(shí)間的延長(zhǎng)AI活性逐漸下降,但5 ℃條件下大豆的AI活性下降最為緩慢,且在第7天顯著高于其他貯藏溫度組(P<0.05)。
2.2.2 NI活性
圖3 菜用大豆采后NI活性的變化Fig.3 Change in neutral invertase activity in postharvest vegetable soybean
圖3表明,菜用大豆采后NI活性總體表現(xiàn)為先升高后降低再增加的趨勢(shì)。1、5 ℃和10 ℃條件下NI活性均在貯藏第1天達(dá)到峰值,但1 ℃峰值并不明顯,而20 ℃條件下NI活性持續(xù)增加,在第4天達(dá)到最大值,其他溫度組NI活性均在第4天出現(xiàn)不同程度的下降,且顯著低于20 ℃組(P<0.05)。貯藏至第7天,1、5 ℃和10 ℃條件下NI活性均增加,而20 ℃條件下NI活性降低,但均高于初始值。
2.2.3 SS活性
圖4 菜用大豆采后SS活性的變化Fig.4 Change in sucrose synthase activity in postharvest vegetable soybean
圖4表明,菜用大豆采后SS活性略有降低后快速升高再減少,不同貯藏溫度對(duì)SS活性變化趨勢(shì)基本無(wú)影響。但貯藏第1天,20 ℃組顯著降低了SS活性(P<0.05);貯藏第4天,SS活性達(dá)到峰值,不同溫度條件下菜用大豆的SS活性無(wú)顯著差異(P<0.05);貯藏第7天,SS活性急劇下降,1 ℃條件下SS活性顯著高于其他溫度組(P<0.05),但相對(duì)于初始值SS活性僅略有下降。
2.2.4 SPS活性
圖5表明,菜用大豆采后SPS活性呈整體下降趨勢(shì),但不同溫度條件下SPS活性差異顯著。貯藏第1天,10 ℃和20 ℃組SPS活性急劇下降,1 ℃和5 ℃組SPS活性僅略有降低。隨著貯藏期的延長(zhǎng),至第4天SPS活性明顯隨著
貯藏溫度的升高而降低,且在第7天,1 ℃組SPS活性與其他溫度組差異達(dá)到顯著性水平(P<0.05),其他貯藏溫度條件下均無(wú)顯著差異(P>0.05)。
圖5 菜用大豆采后SPS活性的變化Fig.5 Change in sucrose phosphate synthase activity in postharvest vegetable soybean
2.3 采后菜用大豆的主要糖含量與酶活性相關(guān)性分析
表1 菜用大豆蔗糖代謝相關(guān)酶活性與糖含量相關(guān)系數(shù)Table 1 Correlation coefficient between sucrose-metabolizing enzyme activity and sugar concentration in vegetable soybean
由表1可以看出,菜用大豆采后SPS活性與蔗糖含量呈極顯著正相關(guān)(P<0.01),與果糖含量呈顯著正相關(guān)(P<0.05)。其他酶活性與蔗糖、葡萄糖、果糖含量?jī)H有微弱的正或負(fù)相關(guān)性,且均不顯著(P>0.05)。
蔗糖與之代謝相關(guān)的果糖、葡萄糖等糖類物質(zhì)不僅與菜用大豆甜味品質(zhì)密切相關(guān),也是其代謝中間物質(zhì)和風(fēng)味物質(zhì)形成的關(guān)鍵[10]。本研究表明,菜用大豆采后蔗糖、果糖和葡萄糖含量均呈整體下降趨勢(shì),這與Glew[11]、Sugimoto[12]等研究結(jié)果一致。但低溫明顯延緩了蔗糖含量下降,貯藏末期1 ℃顯著減少了蔗糖含量的下降(P<0.05)。5 ℃組與與10、20 ℃無(wú)顯著差異(P>0.05),說(shuō)明較低的溫度更有利于維持可溶性碳水化合物含量[13-14]。
蔗糖濃度由AI、NI、SS、SPS活性共同決定[15],不同溫度條件下蔗糖代謝差異,也體現(xiàn)了溫度對(duì)酶活性的調(diào)節(jié)作用。本研究表明,貯藏第1天AI和NI活性顯著增加,SS和SPS活性降低,蔗糖含量急劇下降,這與王君等[16]研究結(jié)果一致??赡苤饕糜诤粑饔?,轉(zhuǎn)化為有機(jī)酸或者代謝中間物質(zhì)[17]。蔗糖降解有利于葡萄糖、果糖含量增加,更多的己糖用于呼吸作用也進(jìn)一步促進(jìn)蔗糖了的降解[18]。本研究中果糖和葡萄糖含量整體均有所下降,可能主要由于其初始量較低,在貯藏過(guò)程中進(jìn)一步通過(guò)呼吸作用消耗所致。SS在第4天有明顯的活性高峰,可能主要起了催化蔗糖降解的作用,且在缺氧條件下作用更明顯[19]。不同溫度條件下AI、NI和SS活性差異不顯著(P>0.05),且與可溶性糖含量均無(wú)顯著相關(guān)性(P>0.05)。說(shuō)明它們未對(duì)‘新大粒1號(hào)’菜用大豆采后蔗糖降解起關(guān)鍵調(diào)節(jié)作用。有研究[20]報(bào)道,菜用大豆‘Huuki’品種的AI與其蔗糖降解密切相關(guān),其活性與蔗糖、果糖、葡萄糖含量均呈顯著負(fù)相關(guān)(P<0.05),可能與品種、貯藏初期可溶性糖濃度[5],非生物因素如水、缺氧等相關(guān)[4]。而NI在細(xì)胞的分布區(qū)域以及其新的生理功能的研究表明,NI在糖類物質(zhì)卸載或者果實(shí)成熟時(shí)起才起關(guān)鍵調(diào)節(jié)作用[21]。SPS活性呈整體下降趨勢(shì),這與Batta[22]、Moriguchi[23]等研究結(jié)果一致,可能與光反應(yīng)終止導(dǎo)致蔗糖合成底物減少有關(guān)[24]。SPS調(diào)節(jié)光合產(chǎn)物的分配,較高的活性有利于蔗糖/淀粉比例增加,促進(jìn)蔗糖積累[25]。菜用大豆貯藏期間低溫有效抑制了SPS活性下降,而對(duì)其他酶活性并無(wú)顯著影響。此外,菜用大豆貯藏期SPS活性與蔗糖含量呈極顯著正相關(guān)(P<0.01)。因此推測(cè)SPS可能是‘新大粒1號(hào)’菜用大豆采后蔗糖代謝中的關(guān)鍵調(diào)節(jié)酶,這與蘋果[26]、梨[27]等研究一致。SPS活性反映了蔗糖合成的能力,低溫有利于延緩貯藏期SPS活性下降或調(diào)節(jié)其活性增加,保持蔗糖較高的合成速率,減少貯藏期蔗糖含量下降。
‘新大粒1號(hào)’菜用大豆貯藏期間蔗糖、果糖、葡萄糖含量不斷下降,但不同溫度條件下糖含量差異顯著。AI、NI和SS活性受溫度調(diào)節(jié)作用不明顯,但1 ℃顯著抑制了SPS活性在整個(gè)貯藏期的下降,減少了蔗糖降解;且SPS活性與蔗糖含量呈極顯著正相關(guān)(P<0.01),與果糖含量呈顯著正相關(guān)(P<0.05),而其他酶活性與糖含量均無(wú)顯著相關(guān)性(P>0.05)。因此,SPS可能在菜用大豆采后蔗糖代謝中起關(guān)鍵調(diào)節(jié)作用。
[1] SONG J Y, AN G H, KIM C J. Color, texture, nutrient contents, and sensory values of vegetable soybeans [Glycine max(L.) Merrill] as affected by blanching[J]. Food Chemistry, 2003, 83(1): 69-74.
[2] WINTER H, HUBER S C. Regulation of sucrose metabolism in higher plants: localization and regulation of activity of key enzymes[J]. Critical Reviews in Plant Sciences, 2000, 19(1): 31-67.
[3] GROF C P L, ALBERTSON P L, BURSLE J, et al. Sucrose-phosphate synthase, a biochemical marker of high sucrose accumulation in sugarcane[J]. Crop Science, 2007, 47(4): 1530-1539.
[4] PRAMANIK B K, MATSUI T, SUZUKI H, et al. Changes in acid invertase activity and sugar distribution during postharvest senescence in broccoli[J]. Pakistan Journal Biological Sciences, 2004, 7(5): 679-684.
[5] LONTOM W, KOSITTRAKUM M, LINGLE S E. Relationship of acid invertase activities to sugar content in sugarcane internodes during ripening and after harvest[J]. Thai Journal of Agricultural Sciences, 2008, 41(3): 143-151.
[6] 張古文, 胡齊贊, 徐盛春, 等. 菜用大豆籽粒發(fā)育過(guò)程中蔗糖積累及相關(guān)酶活性的研究[J]. 浙江農(nóng)業(yè)學(xué)報(bào), 2012, 24(6): 1015-1020.
[7] KASSINEE S, TOSHIYUKI M, TOSHIYUKI M, et al. Changes in carbohydrate content and the activities of acid invertase, sucrose synthase[J]. Asian Journal of Plant Sciences, 2005, 4(6): 684-690.
[8] GIANNOCCARO E, WANG Y J, CHEN P. Effects of solvent, temperature, time, solvent-to-sample ratio, sample size, and defatting on the extraction of soluble sugars in soybean[J]. Journal of Food Science, 2006, 71(1): C59-C64.
[9] NIELSEN T H, SKAERBAEK H C, KARLSEN P. Carbohydrate metabolism during fruit development in sweet pepper (Capsicum annuum) plants[J]. Physiologia Plantarum, 1991, 82(2): 311-319.
[10] 王丹英, 汪自強(qiáng), 方勇, 等. 菜用大豆食味品質(zhì)及其與內(nèi)含物關(guān)系研究[J]. 金華職業(yè)技術(shù)學(xué)院學(xué)報(bào), 2002, 2(3): 15-17.
[11] GLEW R H, AYAZ F A, SANZ C, et al. Effect of postharvest period on sugars, organic acids and fatty acids composition in commercially sold medlar (Mespilus germanica ‘Dutch’) fruit[J]. European Food Research and Technology, 2003, 216(5): 390-394.
[12] SUGIMOTO M, GOTO H, OTOMO K, et al. Metabolomic profiles and sensory attributes of edamame under various storage duration and temperature conditions[J]. Journal of Agricultural and Food Chemistry, 2010, 58(14): 8418-8425.
[13] WANG K, SHAO X, GONG Y, et al. The metabolism of soluble carbohydrates related to chilling injury in peach fruit exposed to cold stress[J]. Postharvest Biology and Technology, 2013, 86: 53-61.
[14] AGOPIAN D, GHEDINI R, PERONI-OKITA F H G, et al. Low temperature induced changes in activity and protein levels of the enzymes associated to conversion of starch to sucrose in banana fruit[J]. Postharvest Biology and Technology, 2011, 62(2): 133-140.
[15] HATCH M D, GLASZIOU K T. Sugar accumulation cycle in sugar cane. Ⅱ. Relationship of invertase activity to sugar content & growth rate in storage tissue of plants grown in controlled environments[J]. Plant Physiology, 1963, 38(3): 344-348.
[16] 王君, 李磊, 謝冰, 等. 采后黃冠梨果實(shí)糖代謝及相關(guān)酶活性變化規(guī)律[J]. 食品科學(xué), 2010, 31(18): 390-393.
[17] MAO L, LIU W. Study on postharvest physiological changes and storage techniques of sugarcane[J]. Scientia Agricultura Sinica, 2000, 33(5): 41-45.
[18] ZANOR M I, OSORIO S, NUNES N A, et al. RNA interference of LIN5 in tomato confirms its role in controlling Brix content, uncovers the influence of sugars on the levels of fruit hormones, and demonstrates the importance of sucrose cleavage for normal fruit development and fertility[J]. Plant Physiology, 2009, 150(3): 1204-1218.
[19] GEIGENBERGER P. Response of plant metabolism to too little oxygen[J]. Current Opinion in Plant Biology, 2003, 6(3): 247-256.
[20] KASSINEE S, MATSUI T, OKUDA N. Changes in acid invertase activity and sugar distribution during postharvest senescence in vegetable soybean[J]. Asian Journal of Plant Sciences, 2004, 3(4): 433-438.
[21] SZARKA A, HOREMANS N, PASSARELLA S, et al. Demonstration of an intramitochondrial invertase activity and the corresponding sugar transporters of the inner mitochondrial membrane in Jerusalem artichoke (Helianthus tuberosus L.) tubers[J]. Planta, 2008, 228(5): 765-775.
[22] BATTA S K, THIND K S, SINGH P, et al. Variability in activities of sucrose metabolizing enzymes in relation to sucrose accumulation among parents and their progenies of sugarcane[J]. Sugar Tech, 2011, 13(2): 114-122.
[23] MORIGUCHI T, ABE K, TANAKA K, et al. Polyuronides changes in japanese and Chinese pear fruits during ripening on the tree[J]. Journal of the Japanese Society for Horticultural Science, 1998, 67: 375-377.
[24] MAO L, QUE F, WANG G. Sugar metabolism and involvement of enzymes in sugarcane (Saccharum officinarum L.) stems during storage[J]. Food Chemistry, 2006, 98(2): 338-342.
[25] WORRELL A C, BRUNEAU J M, SUMMERFELT K, et al. Expression of a maize sucrose phosphate synthase in tomato alters leaf carbohydrate partitioning[J]. The Plant Cell Online, 1991, 3(10): 1121-1130.
[26] ZHU Z, LIU R, LI B, et al. Characterization of genes encoding key enzymes involved in sugar metabolism of apple fruit in controlled atmosphere storage[J]. Food Chemistry, 2013, 141(4): 3323-3328.
[27] 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.
Changes of Sucrose Metabolism and Related Enzyme Activities in Vegetable Soybean at Different Storage Temperatures
WANG Yuan1,2, SONG Jiang-feng2,*, LIU Chun-quan2,3, LI Da-jing2,3
(1. College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; 2. Institute of Farm Product Processing, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; 3. Nanjing (Tomorrow) Engineering Research Center for Agricultural Products Processing, Nanjing 210014, China)
Xindali No. 1 vegetable soybean was used as materials to investigate the changes of sucrose metabolism and related enzyme activities during storage at different temperatures (1, 5, 10, and 20 ℃). Results demonstrated that the contents of sucrose, fructose and glucose in vegetable soybean showed an overall downward trend, while storage at 1 ℃inhibited the degradation of sucrose significantly. The activity of acid invertase (AI) re ached the peak level on the first day, and then decreased gradually. It was not affected by various temperatures. The activity of neutral invertase (NI) increased until the fourth day at 20 ℃, while no significant difference was found among other storage temperature groups (P > 0.05). The activity of sucrose synthase (SS) increased rapidly with a slight decrease at first, and reached the peak level on the fourth day, and then decreased gradually. Furthermore, the activity of sucrose phosphate synthase (SPS) showed a decreasing trend. It had a significantly positive correlation with sucrose content (P < 0.01), and a positive correlation with the content of fructose (P < 0.05). However, no positive correlation was found between other enzymes and sugar content (P > 0.05). Therefore, SPS might play an important role in the sucrose degradation of Xindali No. 1 vegetable soybean.
vegetable soybean; storage temperature; sucrose metabolism; sucrose phosphate synthase (SPS)
TS255.3
A
1002-6630(2014)18-0185-05
10.7506/spkx1002-6630-201418036
2014-01-21
國(guó)家自然科學(xué)基金青年科學(xué)基金項(xiàng)目(31301534);南通市重大科技創(chuàng)新專項(xiàng)(XA2013012)
王遠(yuǎn)(1989—),男,碩士研究生,研究方向?yàn)檗r(nóng)產(chǎn)品加工與貯藏。E-mail:wangyuan2013@126.com
*通信作者:宋江峰(1981—),男,助理研究員,博士,研究方向?yàn)楣卟珊笃焚|(zhì)與加工過(guò)程控制。
E-mail:songjiangfeng102@163.com