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黄瓜Cucumis sativus在中国各地普遍栽培, 是夏季主要菜蔬之一, 常用冷藏法保鲜。黄瓜储藏难度较大, 当在低于7~10 ℃下储藏或流通时极易发生冷害[1], 症状为表面出现水渍状溃烂、暗斑和腐烂斑, 从而影响其食用品质和商业价值。有报道称外源一氧化氮(NO)[2], 茉莉酸甲酯(MeJA)[3], 壳聚糖-g-水杨酸[4]和6-苄基腺嘌呤(6-BA)[5]均能减轻黄瓜冷害的发生, 但对环境或人体健康存在潜在威胁。采后热处理也是果蔬储藏中广泛使用的物理保鲜技术, 可有效减轻番茄Lycopersicon esculentum[6], 番木瓜Carica papaya[7]和哈密瓜Cucumis melo var.saccharinus[8]的储藏冷害。也有报道认为热处理会对果蔬品质造成一定的不良作用, 如果肉变红和絮败[9], 总酚含量降低等[10]。低剂量短波紫外线(UV-C)处理是一种无化学污染的物理处理方法, 广泛用于果蔬采后处理, 能够控制果蔬的采后腐烂, 延缓衰老和延长果蔬保鲜期[11-14]。目前, 未见将热处理和UV-C处理两者联合来抑制冷害的研究。本研究以黄瓜为试验材料, 筛选UV-C处理抑制黄瓜冷害的适宜剂量, 研究UV-C与热处理结合对低温下黄瓜冷害发生、抗氧化代谢和食用品质的影响以及UV-C联合热处理延缓黄瓜冷害发生的协同互补机制, 期望为减缓黄瓜储运冷害提供理论依据。
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如图 2所示:T0和T2处理组的黄瓜在储藏4 d表现出轻微冷害症状, 此后冷害程度继续加剧。4 d后T0组处理黄瓜的冷害指数显著高于T1, T2, T3处理的黄瓜(P<0.05)。8 d后T0处理黄瓜的冷害指数已经显著高于T1和T2处理的黄瓜(P<0.05)。16 d时T0和T2处理黄瓜的冷害指数分别达到3.13和2.85, 冷害程度严重, 而T3处理对冷害发生表现出更有效的抑制作用, 16 d时冷害指数分别为T0, T2和T1处理的48%, 53%和80%。表明UV-C和热处理能够协同抑制黄瓜冷害的发生。
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如图 3所示:黄瓜果实的相对电导率和丙二醛质量摩尔浓度随着冷藏进程不断上升, T2或T1处理均能抑制黄瓜相对电导率和丙二醛质量摩尔浓度的增加(图 3)。就单独比较而言, 热处理对相对电导率和丙二醛的抑制效应强于UV-C处理。冷藏16 d后T3处理黄瓜的相对电导率和丙二醛质量摩尔浓度均低于T0处理, 表明两者结合处理能更有效地抑制黄瓜相对电导率和丙二醛的增加(P<0.05)。
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如图 4所示:对照组黄瓜SOD, CAT, APX和GR的活性在储藏期间基本呈现为先上升后下降, 说明冷藏开始抗氧化酶活性有一应激升高的过程, 这可能是储藏果蔬的一种保护性反应; 当低温胁迫持续时, 冷敏果蔬抗氧化保护系统的活性会下降或紊乱, 过量的活性氧将在果实组织内积累而发生脂质过氧化, 从而导致膜的完整性受到破坏, 组织内生理代谢紊乱, 最终引起冷害的发生。本研究发现:与对照相比, T1, T2和T3在储藏初期均能诱导黄瓜抗氧化酶活性短暂上升, 其中SOD和APX活性在储藏第4天达到最大值, CAT和GR在第8天达到最大值, 然后逐渐下降; 但T3处理下, 黄瓜SOD, CAT, APX和GR活性均显著高于T0, T1和T2处理(P<0.05)。
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如图 5所示:在黄瓜储藏期间对照果实的总酚质量分数和总抗氧化能力先上升后下降, T1, T2和T3处理黄瓜的总酚和总抗氧化能力在第4天达到高峰, 然后逐渐下降。但T3处理黄瓜的总酚和总抗氧化能力始终高于其他3个处理。
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果实硬度, 可溶性固形物(TSS), 叶绿素和抗坏血酸质量分数是表示果蔬储藏品质的主要指标。如表 1所示:经过16 d冷藏, 黄瓜果实的4个品质指标呈下降趋势。T2和T1处理均能抑制硬度、可溶性固形物以及叶绿素和抗坏血酸质量分数的降低, 经过T3处理的黄瓜叶绿素和抗坏血酸质量分数显著高于其他处理(P<0.05), 但硬度和可溶性固形物含量与T1和T2处理无显著差异(P>0.05)。
表 1 UV-C结合热处理对黄瓜储藏过程中品质变化的影响
Table 1. Effects of combined UV-C and heat treatment on quality parameters of cucumber fruit during storage at 4 ℃ for 16 days
t/d 处理 硬度/N 可溶性固形物/D w叶绿素/(mg·kg-1) w抗坏血酸/(mg·kg-1) 0 22.84 ± 1.95 3.41 ± 0.12 41.12 ± 1.28 124.05 ± 3.61 16 T0 14.26 ± 1.11b 2.56 ± 0.15 b 28.38 ± 1.24 c 95.46 ± 1.61 c T1 19.10 ± 1.58 a 3.12 ± 0.17 a 32.04 ± 1.18 b 104.38 ± 2.42 b T2 15.74 ± 1.68 b 2.94 ± 0.11 a 31.58 ± 1.12 b 98.42 ± 1.76 b T3 19.79 ± 1.23 a 3.21 ± 0.13 a 35.68 ± 1.64 a 116.48 ± 2.58 a 说明:硬度为10次测定的平均值±标准差。可溶性固形物, 叶绿素和抗坏血酸均重复3次测定。处理间不同小写字母表示差异显著(P<0.05)
Chilling injury and antioxidative metabolism in cucumber with combined UV-C and heat treatment
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摘要: 为了减轻黄瓜Cucumis sativus采后储运过程中的冷害发生,以黄瓜'戴多星''Deltasta'为试验材料,研究了短波紫外线(UV-C)和热空气单独或结合处理对4 ℃储藏条件下黄瓜冷害以及膜透性,丙二醛(MDA),抗坏血酸,总酚,总抗氧化能力和抗氧化酶活性等的影响。结果表明:与对照、UV-C和热空气单独处理相比,5.0 kJ·m-2的UV-C照射结合37 ℃热处理能够诱导低温下黄瓜组织中抗氧化酶保持较高的活性,维持较高的总酚和抗坏血酸质量分数以及总抗氧化能力,从而延缓低温胁迫下活性氧积累造成的膜质过氧化,阻止了黄瓜相对电导率的增加和丙二醛的积累,从而显著降低低温下黄瓜的冷害发生程度。同时,UV-C结合热处理也较好地保持了黄瓜的硬度、可溶性固形物和叶绿素质量分数,在抑制黄瓜冷害的作用中存在协同效应。为减少黄瓜在低温储运过程中的冷害发生和保持品质提供数据支持。Abstract: To reduce the incidence of chilling injury for cucumber during storage and transportation, the effects of ultraviolet (UV)-C and heat treatment alone or in combination on chilling injury, membrane permeability, malondialdehyde, ascorbic acid, total phenol, total antioxidant capacity, and antioxidant enzyme activities of a cucumber variety called 'Deltastar' stored at 4℃ were studied. Results showed that compared with the control, UV-C and heat treatment alone, 5.0 kJ·m-2 UV-C combined with heat at 37℃ could induce higher antioxidant enzyme activities, such as superoxide dismutase (SOD), catalase activities (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) in cucumber. Higher total phenolics, ascorbic acid content, and total antioxidant capacity were also realized; thereby, delaying membrane oxidation caused by the accumulation of reactive oxygen species with low temperature stress. So, the combined treatments prevented an increase in the relative leakage rate and the accumulation of malondialdehyde; thus reducing the occurrence of chilling injury. At the same time, UV-C combined with the heat treatment also maintained a better hardness, more soluble solids, and greater chlorophyll content. Overall, UV-C and heat treatment inhibited the chilling injury of cucumber synergistically making this study beneficial for reduction of chilling injury and maintenance of cucumber during storage and transportation at low temperatures.
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Key words:
- botany /
- cucumber /
- chilling injury /
- UV-C /
- heat treatment /
- antioxidative metabolism
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表 1 UV-C结合热处理对黄瓜储藏过程中品质变化的影响
Table 1. Effects of combined UV-C and heat treatment on quality parameters of cucumber fruit during storage at 4 ℃ for 16 days
t/d 处理 硬度/N 可溶性固形物/D w叶绿素/(mg·kg-1) w抗坏血酸/(mg·kg-1) 0 22.84 ± 1.95 3.41 ± 0.12 41.12 ± 1.28 124.05 ± 3.61 16 T0 14.26 ± 1.11b 2.56 ± 0.15 b 28.38 ± 1.24 c 95.46 ± 1.61 c T1 19.10 ± 1.58 a 3.12 ± 0.17 a 32.04 ± 1.18 b 104.38 ± 2.42 b T2 15.74 ± 1.68 b 2.94 ± 0.11 a 31.58 ± 1.12 b 98.42 ± 1.76 b T3 19.79 ± 1.23 a 3.21 ± 0.13 a 35.68 ± 1.64 a 116.48 ± 2.58 a 说明:硬度为10次测定的平均值±标准差。可溶性固形物, 叶绿素和抗坏血酸均重复3次测定。处理间不同小写字母表示差异显著(P<0.05) -
[1] HAKIM A, PURVIS A C, MULLINIX B G. Differences in chilling sensitivity of cucumber varieties depend on storage temperature and the physiological dysfunction evaluated[J]. Postharvest Biol Technol, 1999, 17(2):97-104. [2] YANG Huiqing, WU Fenghua, CHENG Jiyu. Reduced chilling injury in cucumber by nitric oxide and the antioxidant response[J]. Food Chem, 2011, 127(3):1237-1242. [3] 韩晋, 田世平.外源茉莉酸甲酯对黄瓜采后冷害及生理生化的影响[J].园艺学报, 2006, 33(2):289-293. HAN Jin, TIAN Shiping. Effects of exogenous methyl jasmonate on chilling injury and physiology and biochemistry in postharvest cucumber[J]. Acta Hortic Sin, 2006, 33(2):289-293. [4] ZHANG Youzuo, ZHANG Meiling, YANG Huqing. Postharvest chitosan-g-salicylic acid application alleviates chilling injury and preserves cucumber fruit quality during cold storage[J]. Food Chem, 2015, 174(1):558-563. [5] CHEN Binxia, YANG Huqing. 6-Benzylaminopurine alleviates chilling injury of postharvest cucumber fruit through modulating antioxidant system and energy status[J]. J Sci Food Agric, 2013, 93(8):1915-1921. [6] IMAHORI Y, BAI Jinhe, BALDWIN E. Antioxidative responses of ripe tomato fruit to postharvest chillingand heating treatments[J]. Sci Hortic, 2016, 198(75):398-406. [7] SHADMANI N, AHMAD S H, SAARI N, et al. Chilling injury incidence and antioxidant enzyme activities of Carica papaya L. 'Frangi' as influenced by postharvest hot water treatmentand storage temperature[J]. Postharv Biol Technol, 2015, 99(1):114-119. [8] 王静, 茅林春, 李学文, 等.热处理降低哈密瓜果实活性氧代谢减轻冷害[J].农业工程学报, 2016, 32(2):280-286. WANG Jing, MAO Linchun, LI Xuewen, et al. Reduction of active oxygen metabolism and mitigation of chilling injury in Hami melon fruit as influenced by postharvest hot water treatment[J]. Trans Chin Soc Agric Eng, 2016, 32(2):280-286. [9] JIN Peng, ZHENG Yonghua, TANG Shuangshuang, et al. A combination of hot air and methyl jasmonate vapor treatment alleviates chilling injury of peach fruit[J]. Postharv Biol Technol, 2009, 52(1):24-29. [10] LEMOINE M L, CIVELLO P, CHAVES A, et al. Hot air treatment delays senescence and maintains quality of minimally processed broccoli florets during refrigerated storage[J]. LWT Food Sci Technol, 2009, 42(6):1076-1081. [11] GONZÁLEZ-AGUILAR G A, VILLA-RODRIGUEZ J A, AYALA-ZAVALA J F, et al. Improvement of the antioxidant atatus of tropical fruits as a secondary response to some postharvest treatments[J]. Trends Food Sci Technol, 2010, 21(10):475-482. [12] PONGPRASERT N, SEKOZAWA Y, SUGAYA S, et al. A novel postharvest UV-C treatment to reduce chilling injury (membrane damage, browning and chlorophyll degradation) in banana peel[J]. Sci Hortic, 2011, 130(1):73-77. [13] ZENG Fangfang, JIANG Tianjia, WANG Yansheng, et al. Effect of UV-C treatment on modulating antioxidative system and proline metabolism of bamboo shoots subjected to chilling stress[J]. Acta Physiol Plant, 2015, 37(11):244. doi:10.1007/S11738.015-1995-4. [14] LEMOINE M L, CIVELLO P M, CHAVES A R, et al. Influence of a combined hot air and UV-C treatment on quality parameters of fresh-cut broccoli florets at 0℃[J]. Int J Food Sci Technol, 2010, 45(6):1212-1218. [15] 尹建云. UV-C结合热处理调控黄瓜冷害机理研究[D]. 杭州: 浙江农林大学, 2013. YIN Jianyun. The Mechanism Study of Short Wave Ultraviolet (UV-C) Combined with Heat Treatment in the Chilling Injury of Cucumber[D]. Hangzhou: Zhejiang A&F University, 2013. [16] 杨虎清, 赵晓飞, 黄程前, 等.不同处理方式对甘薯冷害和抗氧化代谢影响分析[J].核农学报, 2014, 28(8):1407-1412. YANG Huqing, ZHAO Xiaofei, HUANG Chengqian, et al. Effects of different treatments on chilling injury and antioxidative metabolism in sweet potato[J]. J Nucl Agric Sci, 2014, 28(8):1407-1412. [17] 吴玲艳, 申燕飞, 赵晓飞, 等.不同汽蒸工艺对甘薯薯块口感和抗氧化能力的影响[J].食品科学, 2016, 37(9):66-70. WU Lingyan, SHEN Yanfei, ZHAO Xiaofei, et al. Effect of steaming process on taste quality and antioxidant properties of sweetpotato[J]. Food Sci, 2016, 37(9):66-70. [18] BRADFORD M M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding[J]. Anal Chem, 1976, 72(s 1/2), 248-254. [19] SUNDAR D, CHAITANYA K V, JUTUR P P, et al. Low temperature-induced changes in antioxidative metabolism in rubber-producing shrub, guayule (Parthenium argentatum Gray)[J]. Plant Growth Regul, 2004, 44(2):175-181. [20] BOLWELL G P, WOJTASZEK P. Mechanisms for the generation of reactive oxygen species in plant defense:a broad perspective[J]. Acta Physiol Mol Plant Pathol, 1997, 51(6):347-366. [21] LYONS J M. Chilling injury in plants[J]. Ann Rev Plant Physiol, 1973, 24(1):445-466. [22] BOWLER C, van MONTAGU M, INZE D. Superoxide dismutase and stress tolerance[J]. Ann Rev Plant Physiol Mol Biol, 1992, 43:83-116. [23] GUO Zhenfei, OU Weichao, LÜ Shaoyun, et al. Differential responses of antioxidative system to chilling and drought in four rice cultivars differing in sensitivity[J]. Plant Physiol Biochem, 2006, 44(11/12):828-836. [24] CAO Shifeng, HU Zhichao, WANG Haiou. Effect of salicylic acid on the activities of anti-oxidant enzymes and phenylalanine ammonia-lyase in cucumber fruit in relation to chilling injury[J]. J Hortic Sci Biotechnol, 2009, 84(2):125-130. [25] JOUVE L, ENGELMANN F, NOIROT M, et al. Evaluation of biochemical markers (sugar, proline, malondialdehyde and ethylene) for cold sensitivity in microcuttings of two coffee species[J]. Plant Sci, 1993, 91(1):109-116. [26] LEMOINE M L, CHAVES A R, MARTÍNEZ G A. Influence of combined hot air and UV-C treatment on the antioxidant system of minimally processed broccoli (Brassica oleracea L. var. Italica)[J]. LWT-Food Sci Technol, 2010, 43(9):1313-1319. [27] PINTO E P, PERIN E C, SCHOTT I B, et al. The effect of postharvest application of UV-C radiation on the phenolic compounds of conventional and organic grapes (Vitis labrusca 'Concord')[J]. Postharv Biol Technol, 2016, 120(10):84-91. [28] 梁敏华, 雷建敏, 邵佳蓉, 等. UV-C处理对桃果实酚类物质代谢和贮藏品质的影响[J].核农学报, 2015, 29(6):1088-1093. LIANG Minhua, LEI Jianmin, SHAO Jiarong, et al. Effect of UV-C treatment on phenolic metabolism and quality of postharvest peach fruit[J]. J Nucl Agric Sci, 2015, 29(6):1088-1093. -
链接本文:
https://zlxb.zafu.edu.cn/article/doi/10.11833/j.issn.2095-0756.2018.03.011