共查询到20条相似文献,搜索用时 93 毫秒
1.
结球白菜通风贮藏过程,采用不同大小的通风量,可导致贮藏环境的气体组成发生变化。乙烯气体的比重小于二氧化碳气体,所以较小的通风量(0.8L/h, 24h/d)即可使贮藏环境内乙烯清除,而二氧化碳却有一定积累。此处理外层叶片叶绿素和蛋白质含量下降最慢,生长点过氧化物酶活性最低,商品菜率最高。可望商业性白菜通风贮藏能够寻找一适宜的通风量。抑制生长点再生长和外层叶片的衰老,以进一步降低损耗,提高贮藏效果。 相似文献
2.
3.
不结球白菜体外抗氧化活性部位的筛选与研究 总被引:1,自引:0,他引:1
应用DPPH自由基清除法、羟自由基清除法、超氧阴离子自由基清除法、ABTS+·清除法四个抗氧化指标对不结球白菜的5个不同极性部位石油醚相、氯仿相、乙酸乙酯相、正丁醇相和水相的抗氧化能力进行评价,同时考察了总酚和总黄酮的含量与抗氧化能力的关系,并对活性最强部位进行了脂质抗氧化研究。结果表明,除水相外,不结球白菜其他4个极性部位均表现出一定的抗氧化能力。总酚和总黄酮的含量与各部位的抗氧化能力具有显著相关性。乙酸乙酯相清除DPPH自由基、羟自由基、超氧阴离子自由基、ABTS+·的EC50值分别为(0.64±0.05)、(1.17±0.12)、(1.02±0.15)、(0.78±0.07)mg/m L;乙酸乙酯相的抗氧化能力最高,其总酚的含量为(151.32±1.87)mg GAE/g DW,总黄酮含量为(32.97±0.56)mg rutin/g DW;10 mg/m L的乙酸乙酯相对H2O2诱导红细胞氧化的抑制率达到62.11%,对H2O2诱导小鼠肝脏脂质过氧化的抑制率为51.26%。实验结果表明,不结球白菜乙酸乙酯相具有较强的抗氧化活性,是天然抗氧化活性物质的良好来源。 相似文献
4.
应用DPPH自由基清除法、羟自由基清除法、超氧阴离子自由基清除法、ABTS+·清除法四个抗氧化指标对不结球白菜的5个不同极性部位石油醚相、氯仿相、乙酸乙酯相、正丁醇相和水相的抗氧化能力进行评价,同时考察了总酚和总黄酮的含量与抗氧化能力的关系,并对活性最强部位进行了脂质抗氧化研究。结果表明,除水相外,不结球白菜其他4个极性部位均表现出一定的抗氧化能力。总酚和总黄酮的含量与各部位的抗氧化能力具有显著相关性。乙酸乙酯相清除DPPH自由基、羟自由基、超氧阴离子自由基、ABTS+·的EC50值分别为(0.64±0.05)、(1.17±0.12)、(1.02±0.15)、(0.78±0.07)mg/m L;乙酸乙酯相的抗氧化能力最高,其总酚的含量为(151.32±1.87)mg GAE/g DW,总黄酮含量为(32.97±0.56)mg rutin/g DW;10 mg/m L的乙酸乙酯相对H2O2诱导红细胞氧化的抑制率达到62.11%,对H2O2诱导小鼠肝脏脂质过氧化的抑制率为51.26%。实验结果表明,不结球白菜乙酸乙酯相具有较强的抗氧化活性,是天然抗氧化活性物质的良好来源。 相似文献
5.
6.
以“妃子笑”荔枝为试验材料,用浓度0.4 mmol/L的褪黑素对采后荔枝进行浸泡处理,以蒸馏水处理为对照,探究外源褪黑素对荔枝采后品质的影响,在4℃下贮藏并定期测定荔枝生理指标的变化。结果表明,在贮藏16 d时,褪黑素处理组(0.4 mmol/L)的失重率、褐变指数、相对电导率、超氧阴离子产生速率、丙二醛含量和过氧化物酶活性分别比对照组降低27.65%、29.39%、20.28%、19.65%、15.59%和14.77%,而L*值、花青素含量、过氧化氢酶活性和超氧化物歧化酶活性则分别比对照组高8.24%、93.00%、44.42%和23.46%。此外,贮藏中期荔枝褪黑素处理组多酚氧化酶活性上升速率比对照组低。通过主成分分析得出,第1、2主成分的贡献率分别是67.431%、16.530%,累计总贡献率83.961%,其中失重率和过氧化氢酶活性则是评价荔枝生理品质的关键指标,褪黑素能显著延缓荔枝失重率上升和提高过氧化氢酶活性。 相似文献
7.
8.
本文主要研究了采前施肥对青菜蒌蔫和黄化的影响。研究表明:肥料浓度越高,青菜的失水百分率就越大,对照组由于含水量较高,因此失水率也较大,施肥0.2%MgSO4和0.12%CaCl2的青菜能够较好的保持绿色。 相似文献
9.
为探索外源补充对采后西兰花保鲜的作用效果,本文以清水为对照,分别采用200 mg/L赤霉素(GA)、200 mg/L赤霉素(GA)+无机盐营养液、50 mg/L 6-苄基腺嘌呤(6-BA)、无机盐营养液、50 mg/L 6-苄基腺嘌呤(6-BA)+无机盐营养液等5种处理,通过对西兰花贮藏期外观(色差)、营养物质(维生素C、可溶性固形物、叶绿素、水分活度)及其他生理生化指标(质量损失率、相对电导率、丙二醛含量)的比较分析,结果表明:与CK相比,西兰花采后外源补充可以有效抑制质量损失率、延缓相对电导率和丙二醛含量的上升,抑制叶绿素降解,有利于西兰花采后保持较高的水分、维生素C含量和可溶性固形物含量。200 mg/L赤霉素+无机盐营养液处理的西兰花,贮藏28 d时维持最高的TSS含量(7.27%)和Vc含量(27.53 mg/100 g Fw),较高的叶绿素含量
(5.57 mg/100g Fw),最低的MDA(15.31 nmol/g Fw),是5种外源补充中最好的西兰花采后保鲜方法。 相似文献
10.
11.
12.
菜心采后贮藏保鲜技术研究进展 总被引:1,自引:0,他引:1
菜心是中国特色蔬菜之一,在出口创汇中起着重要的作用。菜心品质柔嫩、风味可口,能周年栽培,但采后不耐贮藏,常温下会使菜心失水严重,叶片变黄,微生物浸染会加快变质;低温较常温能延长贮藏期,但会出现木质化,导致口感变韧等现象。因此,如何有效维持菜心的品质和延长其货架期是菜心保鲜技术的关键。本文介绍了菜心采后生理特性,阐述了目前国内外菜心采后贮运保鲜情况,总结了目前主要的保鲜技术,包括物理保鲜技术(真空预冷及低温、气调、辐射、薄膜、臭氧)、化学保鲜技术(保鲜剂、褪黑素、二甲基二碳酸盐)和生物保鲜技术(壳聚糖涂膜、基因工程),并对未来菜心保鲜技术的发展方向进行了展望,以期为采后菜心贮藏保鲜提供理论参考。 相似文献
13.
Interaction between nitric oxide and hydrogen peroxide in postharvest tomato resistance response to Rhizopus nigricans 总被引:1,自引:0,他引:1
Bei Fan Lin Shen Kailang Liu Danying Zhao Mengmeng Yu Jiping Sheng 《Journal of the science of food and agriculture》2008,88(7):1238-1244
BACKGROUND: Nitric oxide (NO) and hydrogen peroxide (H2O2) are signal molecules involved in the disease response of plants, and there is a close relationship between them. To investigate the interaction of NO and H2O2 during disease resistance response in postharvest fruits and vegetables, tomato (Lycopersicon esculentum cv. Lichun) fruits were treated after harvest by vacuum infiltration with NO donor and H2O2 scavenger. RESULTS: The resistance of tomato fruits to Rhizopus nigricans Ehrenb. invasion and the activities of defensive enzymes phenylalanine ammonia‐lyase, chitinase and glutathione S‐transferase were enhanced by NO. However, these effects of NO on resistance were weakened by H2O2 scavenger, which showed that H2O2 was required in NO‐mediated disease resistance in harvested tomato. Meanwhile, the endogenous H2O2 level was dual‐regulated by NO. During the earlier period of storage the H2O2 peak was advanced by NO, but during the later period of storage, when the concentration of H2O2 was relatively higher, H2O2 accumulation was delayed by NO. The activities of superoxide dismutase, ascorbate peroxidase and catalase were involved in this regulation. CONCLUSION: The results imply that application of exogenous NO can enhance the disease resistance of postharvest tomato; NO may interact with H2O2 and exert its effect by modulating the endogenous H2O2 level. This result is useful for the further investigation and application of NO in postharvest disease control. Copyright © 2008 Society of Chemical Industry 相似文献
14.
15.
Young Bae Chung Hyeyeon Song Kyungae Jo Hyung Joo Suh 《Food science and biotechnology》2021,30(2):227
Changes in color, browning indices, enzyme activity, and physical and chemical quality during the storage period were investigated to assess the effectiveness of storage period extension along with the addition of ascorbic acid (AA) and citric acid (CA) to salted Chinese cabbage. After 16 days of storage, the change in chromaticity value showed treatment with 0.5% CA showed the lowest change in the brown index during the storage period. The control showed the highest residual activity of polyphenol oxidase among control, AA, and CA-treated salted cabbage. AA and CA treatment effectively inhibited the initial populations of microorganisms including total aerobic bacteria, lactic acid bacteria, and yeast and molds in salted Chinese cabbage during storage. Further, the texture, i.e., hardness, chewability, and elasticity, tended to decrease with increasing storage. These results suggest that treatment with AA could help maintain the quality of salted Chinese cabbage during the storage period. 相似文献
16.
17.
为了探明微酸性电解水(Slightly acidic electrolyzed water,SAEW)对采后娃娃菜货架品质的影响,本文分析了在低温流通(4±1) ℃及货架条件(25±1) ℃下,不同浓度(0、50、100和150 mg/L)SAEW超声雾化熏蒸处理对娃娃菜采后保鲜效果的影响。结果显示,较对照和其它浓度(50和150 mg/L)SAEW处理相比,100 mg/L SAEW超声雾化熏蒸处理在货架第6和第9 d时显著抑制了娃娃菜丙二醛含量的升高及总硫苷含量的下降(
18.
19.
20.
为了探讨高压二氧化碳处理对双孢蘑菇贮藏品质的影响,分别采用不同高压二氧化碳对双孢蘑菇进行瞬时处理,然后于4℃条件下贮藏8d,测定失重率、硬度、颜色、总酚和抗坏血酸含量以及PPO、PAL和POD活性的变化。结果表明:0.3 MPa高压二氧化碳瞬时处理对双孢蘑菇贮藏保鲜效果最佳,该处理能较好保持双孢蘑菇的硬度、降低其失重率和抑制其褐变,同时还能促进双孢蘑菇多酚和抗坏血酸的积累、降低PPO和POD的活性以及提高PAL的活性。因此,0.3 MPa二氧化碳处理可以较好保持双孢蘑菇的贮藏品质。 相似文献