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硫化氢作为植物体内的一种气体信号分子,可以调节植物的代谢,影响采后果蔬贮藏期间的生理活动及营养品质。硫化氢能够参与调控果蔬的成熟衰老,激发防御基因的表达,诱导植物的病伤害反应、抗性的形成,延缓其采后衰老,延长货架寿命。本文综述了国内外关于硫化氢在采后果蔬贮藏保鲜中的研究进展,从采后生理学角度出发,对硫化氢在果蔬的代谢过程中的作用进行阐述,主要对感官品质、能量代谢、呼吸强度、乙烯生成、褐变和病害6个方面进行探讨,以期为今后硫化氢在果蔬保鲜上的研究及应用提供参考依据。 相似文献
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水杨酸(salicylic acid)是植物体内普遍存在的一种酚类化合物,是植物应对生物胁迫的重要信号分子。水杨酸参与调控植物体内的许多生理生化过程,如细胞生长、呼吸作用、气孔开闭、衰老、种子萌发、幼苗发育等,在植物对生物及非生物胁迫中起到重要作用,诱导植物产生抗性。近年来,水杨酸作为一种植物生长调节剂和重要的信号分子被广泛应用于植物和果实的抗性诱导。本文综述了水杨酸的生物合成途径及其作为信号分子在诱导果蔬抗机械伤害及抗病性,调控果蔬生理活动方面的作用,讨论了水杨酸对鲜切果蔬的防御反应、抗氧化反应、品质及果蔬成熟衰老的影响,并对水杨酸与其他信号分子综合调控果蔬的生理代谢及防御系统响应的研究进行了展望,为鲜切果蔬的贮藏保鲜的实验研究及其发展提供依据。 相似文献
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褪黑素是广泛存在于生物体内的一种吲哚类色胺,具有调控果蔬衰老、清除活性氧自由基、防止抗氧化酶钝化等作用。最新研究发现褪黑素可以显著延缓果蔬采后由呼吸作用、乙烯释放、蒸腾作用、自由基代谢等代谢活动导致的品质劣变。本文从果蔬采后品质劣变角度综述了褪黑素对果蔬采后生理的调节作用,从导致品质劣变的关键生理活动包括呼吸作用、乙烯合成、蒸腾作用、酶促褐变、膜脂氧化、抗性激活等方面阐述了外源褪黑素的调控机制,系统阐述了外源褪黑素对果蔬品质的影响,包括感官品质、糖酸代谢、风味变化等,以期为褪黑素在保持果蔬采后品质及相关贮藏保鲜新技术的应用奠定一定的理论基础和技术支持。 相似文献
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褪黑素是一种广泛存在于生物体中的吲哚胺类化合物,已经被证实广泛分布在高等植物的组织和器官中,具有调节植物种子萌发、生长发育、抗逆性以及成熟衰老等重要作用。最新研究表明褪黑素在延缓果蔬采后衰老和品质劣变中具有显著的调控作用。本文首先简述植物中褪黑素合成途径、部分果蔬中褪黑素的含量及其影响因素,重点综述褪黑素对果蔬采后生理(呼吸作用、乙烯生成、抗氧化酶活力)和品质(色泽、生物活性物质、抗氧化活性)的调控作用,并对其可能的调控机制进行详细解析,最后归纳褪黑素在果蔬采后保鲜研究中存在的问题和将来的研究重点,为今后褪黑素在果蔬采后保鲜中的研究和应用提供参考。 相似文献
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果蔬采后活性氧(reactive oxygen species,ROS)代谢失衡造成氧化胁迫,加速品质劣变,破坏其商业价值。文章以ROS代谢与果蔬贮藏品质的关系为切入点,探讨低温诱导抗氧化酶活性延缓果蔬采后品质劣变的作用;同时,从转录调控角度综述bHLH、WRKY及NAC等低温响应转录因子参与果蔬采后抗氧化作用,进而揭示低温延缓果蔬品质劣变的抗氧化转录调控作用的可能机制,旨在为开展果蔬采后品质生理生化及分子生物学等基础研究及进一步阐明果蔬采后成熟衰老和品质劣变机制提供新的理论依据。 相似文献
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能量状态在果蔬采后衰老中的作用及其调控研究进展 总被引:1,自引:0,他引:1
能量是采后果蔬维持正常生理代谢活动的基础。近年来的研究表明,能量亏缺是导致采后果蔬衰老的重要因素。本文从采后果蔬的呼吸代谢、活性氧和细胞膜完整性与能量状态的关系等方面阐述能量状态在果蔬采后衰老中的作用,并对采后果蔬能量状态的调控措施以及调控机制等方面的研究进展进行综述。此外,从能量合成、转运、耗散和感知相关基因在转录和蛋白水平的表达与调控,采后果蔬衰老的起始因子,能量亏缺的应激反应等方面进行展望,旨在为从能量角度探究采后果蔬衰老的机制和研发果蔬采后保鲜新技术提供参考。 相似文献
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茉莉酸甲酯(methyl jasmonate, MeJA)是一种广泛存在于植物中的天然植物激素,参与植物的许多代谢过程包括生长、发育、成熟、衰老、抵御生物和非生物胁迫等。由病原真菌侵染引起的果蔬采后病害是导致果蔬贮藏和运输过程中品质劣变和腐烂的原因之一,不仅对生产者和消费者造成巨大经济损失,还会在组织体内产生危害人体健康的有毒次生代谢产物。因此,开发绿色安全的果蔬采后病害控制技术具有重要意义。本文总结了采前和采后MeJA单独或与其他物理、生物方法复合处理对果蔬采后主要真菌性病害的控制作用,并从活性氧代谢、病程相关蛋白的积累、苯丙烷代谢、多胺代谢、能量代谢、细胞壁物质代谢、转录调控等方面详细阐述了其诱导抗性机制,以期为MeJA广泛用于控制果蔬采后病害提供实践参考和理论依据。 相似文献
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M. C. Galindo M. S. Campos J. A. Garcia F. Lisbona 《Molecular nutrition & food research》1991,35(6):577-580
We studied the influence of the Na+-K+ pump inhibitor ouabain on water and electrolyte transport in the rabbit distal ileum and proximal colon in vitro and in vivo. Under in vitro conditions, ouabain markedly reduced the absorption of water, sodium, chloride and bicarbonate, and reduced potassium secretion in both the ileum and the colon. In vivo results were similar but less marked than those obtained in vitro, with significant differences only at the level of the distal ileum. 相似文献
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目的 建立超高效液相色谱-串联质谱法同时测定蔬菜和鸡蛋中氟虫腈及其代谢物(氟甲腈、氟虫腈砜和氟虫腈亚砜), 并对深圳市售的蔬菜和鸡蛋中氟虫腈及其代谢物残留状况进行抽样检测。方法 采用QuEChERS前处理方法, 以C18色谱柱为分离柱, 以乙腈和10 mmol甲酸+6 mmol甲酸铵水溶液为流动相进行梯度洗脱, 用超高效液相色谱-串联质谱(ultra performance liquid chromatography-mass spectrometry/mass spectrometry, UPLC-MS/MS), 电喷雾电离(electrospray ionization, ESI), 多反应监测(multiple reaction monitoring, MRM)模式检测, 外标法同时定量测定氟虫腈及其代谢物。结果 方法的线性范围为0.1~2.0 μg/L, 线性相关系数均大于0.9994, 检出限0.0005 mg/kg, 定量限0.001 mg/kg; 蔬菜中3个水平的平均加标回收率88.0%~101.2%, 相对标准偏差(relative standard deviation, RSD)均小于8.5%; 鸡蛋中3个水平的平均加标回收率86.1%~104.8%, 相对标准偏差(RSD)均小于9.2%。结论 该方法具有操作简单、干扰少、快速、准确可靠等特点, 可适用于蔬菜鸡蛋中氟虫腈及其代谢物的检测。 相似文献
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Determination of nitrite and nitrate in some horticultural and meat products and in samples of soil 总被引:1,自引:0,他引:1
This study of quantitative determination of nitrite and nitrate contents is based on spectrophotometric measurement of the red colour formed when sulphanilic acid is diazotised by the nitrite to be determined and coupled to 1-naphthylamine-7-sulphonic acid (Cleve's acid 1-7). Nitrate is first reduced to nitrite in a cadmium reducing column. Good results have been obtained with some horticultural and meat products and samples of soil. 相似文献
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The work presents the content and composition of free lipids and carotenoids in spring and winter classes of wheat flour. It discusses genetical and physiological aspects of their synthesis and accumulation in wheat kernels and also indicates how methodological differences explain differences in results presented in the literature. It has been reported that spring wheat flours are richer in free lipids, especially in the non-polar fraction. The content of glycolipids ranged from 134 to 215 mg/100 g flour and was more stable within the winter wheat class. The percentages of the two main fractions, namely DGDG and MGDG, were similar in both wheat classes and reached ca. 77%. Phospholipids constituted the smallest fraction of the flour free lipids in both wheat classes; however, spring wheat flours were richer in these compounds, which is likely associated with a greater content of spherosomes in the endosperm of this wheat class. The free lipids of spring wheat flour contained more oleic and slightly less linoleic and linolenic acids. Spring wheat flour was also richer in carotenoids, although there were varieties in both classes that deviated from this. The main carotenoid was lutein, whose total percentage in the form of different isomers ranged from 71.3% to 83.3% and was slightly lower for spring wheat flour. Lutein, in the form of a trans-isomer, constituted about 62% and 70% of all carotenoids in spring and winter wheat flours, respectively. 相似文献
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We studied the influence of the Na(+)-K+ pump inhibitor ouabain on water and electrolyte transport in the rabbit distal ileum and proximal colon in vitro and in vivo. Under in vitro conditions, ouabain markedly reduced the absorption of water, sodium, chloride and bicarbonate, and reduced potassium secretion in both the ileum and the colon. In vivo results were similar but less marked than those obtained in vitro, with significant differences only at the level of the distal ileum. 相似文献
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Capacities of limestones of differing particle size to neutralize acid in vitro and to modify pH and utilization of feedstuffs in vivo were compared. Acid neutralization during pH-stat titrations was faster for fine than for coarse limestone, and mixed microbial cultures were more resistant to pH change when they contained fine calcium carbonate. Diets containing 25:75 corn silage to concentrates and .95% calcium from either coarse or fine limestone were fed to rumen-fistulated heifers. Total ruminal volatile fatty acid concentrations were higher for the fine limestone treatment. Ruminal volumes, dry matter disappearance, and ruminal fluid pH and dilution rate did not differ between fine and coarse limestone treatments. Ruminal fluid volume, osmolality, ratios of acetate to propionate, and concentrations of total volatile fatty acids were unaffected in rumen-fistulated Holstein cows fed 60:40 corn silage to concentrates and either .5% calcium (control) or 1.0% calcium from either coarse or fine limestone. Ruminal pH increased .07 to .10 units with limestone supplementation. Ruminal fluid dilution and particulate turnover rates were slower for the coarse limestone than the control treatment. Differences between coarse and fine limestones in vitro were observed under some conditions in vivo, but they were not consistent. 相似文献
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了解开封市畜禽肉中沙门菌的污染状况及血清学分布,为沙门菌引起的食源性疾病的防控提供依据。方法 依据GB 4789.4—2010《中华人民共和国国家标准食品卫生微生物学检验方法》和2011年国家食源性疾病监测网监测方案,定期对开封市畜禽养殖场和屠宰场进行随机采样监测。结果 在691份样品中,沙门菌检出率为35.9%(248/691);分离出沙门菌253株,有17个血清型。结论 开封市生鸡肉和生猪肉不同程度受到沙门菌的污染,以生鸡肉污染最严重。应加强禽畜类养殖、屠宰加工等过程的卫生监管,减少食源性疾病的发生。 相似文献
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Mammary uptake of insulin from blood was quantified near parturition in nine dairy cows, some of which were milked prepartum to induce prepartum lactogenesis. Milk samples were immunoassayed for concentrations of insulin, insulin-like growth factor I, and insulin-like growth factor II. Cows milked prepartum, but in which prepartum lactogenesis did not occur (denoted as unsuccessful group), had higher arterial concentrations and greater mammary uptake of insulin during several days immediately preceding parturition than did those with prepartum lactogenesis. Although mammary uptake of insulin was measurable before parturition, estimated uptake on postpartum d 4 through 6 was negligible. Colostrum and milk contained very substantial quantities of insulin, insulin-like growth factor I, and insulin-like growth factor II. Cows in which prepartum lactogenesis was induced (denoted as successful group) had lower concentrations of both forms of insulin-like growth factor in prepartum samples of milk. Cows of the successful group also had a decreasing prepartum profile of milk insulin, but the unsuccessful group had an increasing trend until parturition. Milk concentrations of insulin and both forms of insulin-like growth factor declined rapidly after parturition and completion of lactogenesis. 相似文献
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Desirrê Morais Dias Neuza Maria Brunoro Costa Marilia Regini Nutti Elad Tako Hércia Stampini Duarte Martino 《Critical reviews in food science and nutrition》2018,58(13):2136-2146
ABSTRACTBiofortification aims to improve the micronutrient concentration of staple food crops through the best practices of breeding and modern biotechnology. However, increased zinc and iron concentrations in food crops may not always translate into proportional increases in absorbed zinc (Zn) and iron (Fe). Therefore, assessing iron and zinc bioavailability in biofortified crops is imperative to evaluate the efficacy of breeding programs. This review aimed to investigate the advantages and limitations of in vitro and in vivo methods of iron and zinc bioavailability evaluation in the assessment of biofortification program effectiveness. In vitro, animal and isotopic human studies have shown high iron and zinc bioavailability in biofortified staple food crops. Human studies provide direct knowledge regarding the effectiveness of biofortification, however, human studies are time consuming and are more expensive than in vitro and animal studies. Moreover, in vitro studies may be a useful preliminary screening method to identify promising plant cultivars, however, these studies cannot provide data that are directly applicable to humans. None of these methods provides complete information regarding mineral bioavailability, thus, a combination of these methods should be the most appropriate strategy to investigate the effectiveness of zinc and iron biofortification programs. 相似文献