共查询到18条相似文献,搜索用时 355 毫秒
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为选出高压电场调控番茄后熟衰老贮藏的有效条件,以“朝研219”番茄为试材,以果实硬度和颜色转化及腐烂指数为评价指标,研究不同电场处理方式对番茄贮藏效果的影响,从而筛选出电场处理提高番茄贮藏效果的有效条件。结果表明:经- 200kV/m、2h/d 的间歇稳恒电场和- 200~200kV/m 波动场强、2h 的交变电场一次预处理方式能够显著延缓番茄果实硬度的下降和颜色的转化,并降低腐烂指数(P < 0.05);而稳恒电场和交变电场持续作用于果实时,可促进果实成熟。筛选出的电场处理方式均可延缓番茄的后熟衰老,延长果实贮藏期。 相似文献
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研究浸钙结合静电场处理对草莓采后生理的影响,为高压电场处理技术应用于果实贮藏提供理论依据.以“长虹2号”草莓果实为试材,研究浸钙( 1% CaCl2,20 min)结合静电场(-200 kV/m,2h/d)处理对冷藏草莓(贮藏温度0℃,相对湿度85%~90%)果肉最大破断应力、呼吸强度、乙烯释放量及细胞膜透性的影响.结果表明:浸钙结合电场处理较对照(单纯浸钙和浸水)明显抑制了草莓果实的乙烯释放,降低了果实的呼吸强度,保持贮藏期间果实最大破断应力,延缓果肉细胞相对电导率的上升,从而有效地抑制采后草莓果实的衰老过程.而单纯浸钙仅显著抑制了果实最大破断应力的上升,对草莓采后生理无显著影响.浸钙结合高压静电场处理草莓,贮藏效果较佳,且节能特点非常突出. 相似文献
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以香蕉果实为试验材料,在(20±1)℃试验冷库中贮藏21d,贮藏期间用-100kV/m和-200kV/m的高压静电场连续处理并测定果实的呼吸强度、乙烯释放量、硬度、果皮颜色变化以及果肉淀粉和可溶性糖含量的变化。结果表明:连续高压静电场处理可以使香蕉果实的呼吸跃变和乙烯释放高峰提前,淀粉转化为糖的速度快而且比对照早,果皮叶绿素含量明显低于对照,同时处理后的果肉硬度下降,低于对照;并且-200kV/m处理组的效果要优于-100kV/m处理组。说明高压静电场连续处理促进了香蕉果实的成熟,尤以-200kV/m处理组比对照提前成熟4d。 相似文献
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以‘中椒4号’青椒为试材,研完了不同高压电场间歇处理青椒果实的保鲜试验。结果表明:-200kV/m,2h/d的间歇静电场处理可降低青椒贮藏期间的呼吸强度,减少水分散失,降低果实细胞相对电导率,抑制丙二醛的积累,使处理青椒比对照在40d内保持较高的好果率,而波动场强-200-200kV/m、2h/d的间歇交变电场处理方式却对青椒保鲜没有影响。 相似文献
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以"西州蜜25号"哈密瓜为原料,在常温下浸泡于10、15、20 mmol/L(添加0.5 ml/L吐温-20)3个浓度的草酸溶液中10 min,以常温蒸馏水浸泡(添加0.5 ml/L吐温-20)10 min为对照,待其表面水分完全晾干后,置于3℃~5℃的冷库中进行贮藏42 d。观察和测定贮藏期间哈密瓜果实冷害指数及品质指标等。试验结果表明,与对照相比,草酸处理抑制整个贮期果实硬度和维生素C含量的下降,提高贮藏前期(0~21 d)哈密瓜果实可溶性固形物含量(P0.05),其中15 mmol/L的草酸处理效果较显著。15 mmol/L草酸处理降低呼吸速率和细胞膜渗透率及冷害指数(P0.05),20 mmol/L草酸处理提高果实的冷害指数和细胞膜透性,但减缓叶绿素含量下降速度。结果表明,15 mmol/L草酸是降低哈密瓜冷害,延长果实低温冷藏品质较为有效的处理方法。 相似文献
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ABSTRACT: Pulsed electric field (PEF) inactivation models for tomato juice lipoxygenase (LOX) were studied. Tomato juice was treated by PEF with the combinations of electric field strength (0, 10, 15, 20, 30, 35 kV/cm), PEF treatment time (20, 30, 50, 60, 70 μs), and PEF treatment temperature (10, 20, 30, 40, 50 °C). The first-order inactivation models, Hulsheger's model, Fermi's model, and the 2nd-order polynomial equation adequately described the LOX inactivation. Calculated D values were 161.0, 112.9, 101.0, and 74.8 μs at 15, 20, 30, and 35 kV/cm, respectively, at 30 °C. The activation energy for the inactivation of LOX by PEF was 35.7 kJ/mol. Applied electric field strength was the primary variable for the inactivation of LOX. 相似文献
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In recent years, outbreaks of infections associated with raw and minimally processed fruits and vegetables have been reported. The objective of this study was to analyse the growth/survival of Salmonella Enteritidis at spot-inoculated or stem-injected cherry tomatoes during passive modified atmosphere packaging (MAP), controlled atmosphere (CA) and to compare the results with those of air storage at 7 and 22 degrees C. During MAP, the gas composition equilibrated to 6% O2/4% CO2. CO2 level was maintained as 5% through the term of CA storage at 7 and 22 degrees C. The results demonstrate that S. Enteritidis can survive and/or grow during the storage of tomatoes depending on the location site of the pathogen on fruit, suspension cell density and storage temperature. During MAP, CA and air storage, S. Enteritidis with initial population of 7.0 log10 cfu/tomato survived on tomato surfaces with an approximate decrease of 4.0-5.0 log10 cfu/tomato in population within the storage period; however, in the case of initial population of 3.0 log10 cfu/tomato, cells died completely on day 4 during MAP storage and on day 6 during both CA and air storage. The death rate of S. Enteritidis on the surfaces of tomatoes that were stored in MAP was faster than that of stored in air and in CA. Storage temperature was effective on the survival of S. Enteritidis for the samples stored at ambient atmosphere; cells died completely on day 6 at 7 degrees C and on day 8 at 22 degrees C. Stem scars provided protective environments for Salmonella; an approximate increase of 1.0 log10 cfu/tomato in stem-scar population was observed during MAP, CA and air storage at 22 degrees C within the period of 20 days. Cells survived with no significant change in number at 7 degrees C. During the research, the effect of ozone treatment (5-30 mg/l ozone gas for 0-20 min) was also considered for surface sanitation before storage. Gaseous ozone treatment has bactericidal effect on S. Enteritidis, inoculated on the surface of the tomatoes and can be used for surface sanitation of S. Enteritidis on tomatoes before storage at different conditions. Ten mg/l ozone gas treatment with different time intervals of 5 and 15 min was found to be effective respectively on low and high dose inoculum levels of S. Enteritidis attached for 1 h. Another variable considered during ozone treatment was the 4 h attachment time. 相似文献
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Ingrid Aguiló-Aguayo Robert Soliva-Fortuny Olga Martín-Belloso 《European Food Research and Technology》2008,227(2):599-606
The effects of high intensity pulsed electric fields (HIPEF) processing (35 kV/cm for 1,500 μs using bipolar 4-μs pulses at
100 Hz) on color parameters and viscosity, as well as peroxidase (POD), pectin methylesterase (PME) and polygalacturonase
(PG), were evaluated during 77 days of storage at 4 °C and compared to thermal treatments at 90 °C for 1 min or 30 s for unprocessed
tomato juice. HIPEF-treated tomato juice showed higher values of lightness than the thermally processed and the untreated
juice throughout storage time (P < 0.05). Viscosity of HIPEF-treated tomato juice was also greater than both thermally treated and untreated for the first
35 days of storage. POD of HIPEF-treated tomato juice was inactivated by 97% whereas in the case of the thermally treated,
90 and 79% inactivation was achieved after 1 min and 30 s, respectively. The highest PME inactivation in tomato juice was
obtained by PEF (82%) and heat treatment at 90 °C for 1 min (96%). PG of PEF-treated tomato juice was inactivated by 12% whereas
thermal treatments at 90 °C for 1 min or 30 s achieved 44 and 22%, respectively. Despite the low rates of PG inactivation
obtained, the pattern followed in the residual activity along the storage time was similar in the tomato juice treated by
HIPEF than the thermally processed. 相似文献
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Effect of high-voltage electrostatic field pretreatment on the antioxidant system in stored green mature tomatoes 总被引:1,自引:0,他引:1
BACKGROUND: High‐voltage electrostatic field (HVEF), as a feasible and non‐chemical technique, applied to food preservation is a new area of study. Our previous research suggested HVEF could maintain the quality of tomato in storage. The present article intensively investigated the effect of HVEF pretreatment on antioxidant system of green mature tomato in storage. RESULTS: Green mature tomatoes were exposed to negative (or positive) HVEF for 2 h at 20 °C and then stored for 24 days at 13 ± 1 °C, 85–90% relative humidity. The results indicated HVEF significantly reduced contents of O2? and H2O2 of tomato fruits during storage compared to the control. HVEF treatment also enhanced the activities of antioxidant enzymes including catalase, superoxide dismutase, ascorbate peroxidase and peroxidase. The contents of non‐enzyme antioxidant components including reduced glutathione, phenols and ascorbic acid also were increased by HVEF treatment. However, HVEF treatment did not increase the content of lycopene in tomato fruit. CONCLUSION: HVEF treatment could promote the antioxidant capacity of tomato fruits in storage. Further research is be highly recommended to understand the mechanisms improving the antioxidant capacity of tomato fruits by HVEF. Copyright © 2011 Society of Chemical Industry 相似文献
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Ingrid Aguiló‐Aguayo Robert Soliva‐Fortuny Olga Martín‐Belloso 《Journal of the science of food and agriculture》2010,90(10):1597-1604
BACKGROUND: The effects of high‐intensity pulsed electric field (HIPEF) processing (35 kV cm?1 for 1500 µs, using 4 µs bipolar pulses at 100 Hz) on the production of volatile compounds and flavour‐related enzymes in tomato juice were investigated and compared with those of thermal processing (90 °C for 30 or 60 s). RESULTS: Tomato juice treated by HIPEF showed lower residual lipoxygenase (LOX) activity (70.2%) than juice heated at 90 °C for 60 s (80.1%) or 30 s (93.2%). In contrast, hydroperoxide lyase (HPL) was almost completely inactivated when the juice was subjected to 90 °C for 60 s, whereas roughly 50% of the control tomato juice was depleted after HIPEF treatment or thermal processing at 90 °C for 30 s. A slight decrease was observed in the initial LOX activity of treated and untreated samples during storage, whereas initial HPL activity was strongly affected over time. CONCLUSION: HIPEF‐treated juice exhibited higher levels of compounds contributing to tomato aroma than untreated and heat‐treated juices throughout storage. Thus HIPEF processing can preserve flavour quality and stability of tomato juice compared with conventional thermal treatments. Copyright © 2010 Society of Chemical Industry 相似文献
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BACKGROUND: High electrostatic field, as a feasible and non‐chemical technique, applied to food preservation is a new area of study. The present article intensively investigated this new preservation method, together with its effects on post‐harvest physiology and quality of tomato. RESULTS: Green mature tomatoes were exposed to negative (or positive) high electrostatic field for 2 h at 20 °C and then stored for 30 days at 13 ± 1 °C, 85–90% RH. Our results indicated that negative high electrostatic field (?2 kV cm?1) could delay the decline of firmness and the change in color, total soluble sugar and titratable acidity of tomato fruit during storage. The peak of respiration and ethylene production of tomato fruit during storage were delayed by negative high electrostatic field treatment for 6 days and 3 days, respectively. Increases of malondialdehyde content and electrical conductivity in tomato fruit were inhibited significantly by negative high electrostatic field treatment during storage (P < 0.05). CONCLUSION: A high electrostatic field of ? 2 kV cm?1 can be used to keep the qualities and extend the shelf‐life of tomato fruit. Further research should be highly recommended to understand the mechanisms improving the storability of tomato fruit by negative high electrostatic field. Copyright © 2007 Society of Chemical Industry 相似文献
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Pedro Javier Zapata Fabián Guillén Domingo Martínez‐Romero Salvador Castillo Daniel Valero María Serrano 《Journal of the science of food and agriculture》2008,88(7):1287-1293
BACKGROUND: Edible coatings could be effective tools for delaying the ripening process of fruits. Alginate or zein as edible coatings were assayed in tomato in order to maintain parameters related to quality during postharvest storage. RESULTS: Coated tomatoes showed lower respiration rate and ethylene production than control ones, with a twofold lower concentration of ethylene precursor. In addition, the evolution of parameters related to tomato quality losses, such as softening, colour evolution and weight loss, was significantly delayed (4–6 days on average) in coated tomatoes as compared to controls. Thereafter, sugars, organic acids (and especially ascorbic acid) and scores from sensory analysis remained at much higher levels at the end of storage in treated than in control tomatoes. CONCLUSIONS: Coatings based on alginate or zein could be effective tools for delaying the tomato‐ripening process during postharvest storage, and in turn maintaining tomato quality and its acceptability by consumers. Copyright © 2008 Society of Chemical Industry 相似文献