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1.
Ethylene triggers the ripening process of tomato affecting the storage durability and shelf life (loss of quality) and inducing fruit decay. In this paper, an active packaging has been developed on the basis of the combination of modified atmosphere packaging (MAP) and the addition of granular-activated carbon (GAC) alone or impregnated with palladium as a catalyst (GAC-Pd). A steady-state atmosphere was 4 and 10 kPa for O2 and CO2 in control packages, while it was 8 and 7 kPa for O2 and CO2 in treated ones. The addition of GAC-Pd led to the lower ethylene accumulation inside packages, while the higher was obtained in controls. The parameters related to ripening showed that treated tomatoes exhibited a reduction in color evolution, softening, and weight loss, especially for GAC-Pd treatment. Moreover, these treatments were also effective in delaying tomato decay. After sensorial panel, tomatoes treated with GAC-Pd received the higher scores in terms of sweetness, firmness, juiciness, color, odor, and flavor. Results from the GC-MS analysis of the MAP headspace showed that 23 volatile compounds were identified in control packages, with these volatiles being significantly reduced in MAP-treated packages, which was correlated to the odor intensity detected by panelists after bag opening.  相似文献   

2.
Several natural antimicrobial compounds derived from essential oils of plants were investigated for their efficacies in inhibiting decay and extending the shelf life of strawberries (Fragaria x ananassas Duch.). The severity of decay in strawberries stored at 10 degrees C was significantly reduced by treatment with thymol. Treatments with menthol or eugenol also suppressed the fungal growth, but to a lesser extent. All of these three natural antimicrobial compounds extended shelf life of strawberries as compared to the control. Strawberries treated with thymol, menthol, or eugenol also maintained better fruit quality with higher levels of sugars, organic acids, phenolics, anthocyanins, flavonoids, and oxygen radical absorbance capacity than the untreated fruits. The free radical scavenging properties of strawberry fruit were evaluated against 2,2-diphenyl-1-picryhydrazyl (DPPH(.)), hydroxyl (HO(.)), and superoxide radicals (O2(.-)) using electron spin resonance measurements. Higher radical scavenging capacities were found against DPPH(.) and HO(.) in all treated fruit, particularly in berries treated with thymol, compared to those in the control groups. In addition, strawberry extracts were evaluated for their antiproliferative activities using HT-29 colon cancer cells. Extracts from all treated fruit exhibited significantly stronger inhibition on HT-29 cell proliferation than those from the control fruit. These data provide evidence that, in addition to possessing antimicrobial activity, the essential oils also increase free radical scavenging capacity and antiproliferative activity in fruit and, in turn, enhance the resistance of fruit tissues to deterioration and spoilage.  相似文献   

3.
Apiary trials on the use of three different treatments (Apilife Var, thymol solution in olive oil, and thymol solution in ethanol) for the control of Varroa destructor were conducted in Aragon (northeastern Spain). For the evaluation of the presence of residues of these treatments in honey an analytical method was developed. The method is applied to analyze honey samples before and after treatments with the acaricides mentioned. A solid-phase extraction on trifunctional silane SPE C18 cartridge and gas chromatography separation using a flame ionization detector allow reliable and precise determination of residues of thymol, menthol, eucalyptol, and camphor in honey. The results indicate that camphor is present in only low concentrations, residues of eucalyptol or menthol were not found at all, and only thymol left residues in high concentrations. Residues of thymol found in honey collected from the beehives ranged from 0.75 to 8.20 microg/g for Apilife Var, from 0.03 to 6.30 microg/g for thymol solution in olive oil, and from 0.05 to 6.20 microg/g for thymol solution in ethanol. Even so, natural treatments can be considered to be good alternatives for synthetic acaricides, especially because they do not represent a sanitary risk.  相似文献   

4.
Ten different gaseous treatments were evaluated for their efficacy in the keeping quality of cv. Napoleon table grapes during 38 days of storage at 0 degrees C followed by 6 days of shelf life at 15 degrees C in air. These storage methods included modified atmosphere packaging (MAP) with and without SO(2) or natural fungicides (hexanal and hexenal), two controlled atmospheres (CA), and intermittent and continuous applications of O(3). As a control, air atmosphere during cold storage was used. Most of the treatments applied kept the postharvest quality of the grapes, although the best results were obtained by the use of a MAP with 5 kPa of O(2) plus 15 kPa of CO(2) plus 80 kPa of N(2). The total anthocyanin content at harvest was 170 +/- 19 microg/g of fresh weight (fw) of grapes, which declined in most of the treatments applied and was reflected in the loss of red color. Peonidin 3-glucoside was detected at all sampling times as the major anthocyanin (always >50% from the total content). Treatments applied kept or decreased the total flavonol content from that measured at harvest (17 +/- 1.4 microg/g of fw of berries). However, an increase of up to 2-fold in total stilbenoid content after shelf life for CA and O(3) treatments was observed. At all sampling times for almost every treatment piceid concentration remained unaltered or slightly changed, whereas large increases were observed after shelf life for resveratrol (1.2 +/- 0.6 microg/g of fw of grapes sampled at harvest), even up to 3- and 4-fold for O(3)-treated grapes and 2-fold for CA-treated ones. Therefore, improved techniques for the keeping quality of cv. Napoleon table grapes during long-term storage seem to maintain or enhance their antioxidant compound content.  相似文献   

5.
果蔬气调包装理论研究进展   总被引：19，自引：4，他引：15  
气调包装是一种可延长新鲜水果货架寿命的重要技术。气调包装的质量主要取决于包装内气体成分、温湿度的调节。建立气调包装的理论模型是保证气调包装质量、进行气调包装系统设计的关键。该文综述了国内外这方面的研究成果,着重论述了果蔬呼吸模型、呼吸速率的测定方法、包装内外气体交换模型、包装内温度与湿度变化数学模型,并分析了目前研究存在的不足,为果蔬气调包装的深入研究提供参考。  相似文献   

6.
涂膜和热处理对葡萄能量和贮藏生理及品质的影响   总被引：3，自引：2，他引：1  
研究不同处理对欧亚种"维多利亚"葡萄组织能量水平和生理品质的影响。采后葡萄经钙联合涂膜和热处理,即在质量分数为0.2%Ca Cl2和1%壳聚糖中浸泡20 min,45℃的0.2%Ca Cl2溶液中浸泡20 min,晾干后(4±0.5)℃贮藏,每10d测定果实的呼吸强度、褐变指数(browning index,BI)、腐烂率、硬度、丙二醛(malondialdehyde,MDA)含量、三磷酸腺苷(adenosine triphosphate,ATP)、二磷酸腺苷(adenosine diphosphate,ADP)、单磷酸腺苷(adenosine monophosphate,AMP)的含量,多酚氧化酶(polyphenol oxidase,PPO)、过氧化物酶(peroxidase,POD)、脂氧合酶(lipoxygenase,LOX)和超氧化物歧化酶(soperoxide dismutase,SOD)活性变化,以未处理为对照。结果显示对照组葡萄组织中能量物质处于亏损状态,呼吸强度减弱,细胞膜氧化增加,膜透性、BI、腐烂率增加,PPO、POD和LOX活性增加,SOD降低,果实软化。钙联合热和涂膜处理较好维持了果实的能量水平和生理品质,且涂膜优于热处理。ATP与硬度、SOD显著正相关(r=0.938,0.930,P0.01),与MDA、膜透性、LOX显著负相关(r=-0.896,-0.932,-0.940,P0.01);能荷(energy charge,EC)值与膜透性、LOX负相关(P0.05),与呼吸强度和SOD活性正相关(P0.05)。随贮藏时间的延长,葡萄组织的能量水平处于亏损状态,能量水平显著影响生理品质。经适当的采后处理可延缓能量亏损,涂膜优于热处理。  相似文献   

7.
The effects of post-harvest and packaging treatments on glucoraphanin (4-methylsulfinylbutyl glucosinolate), the glucosinolate precursor of anticancer isothiocyanate sulforaphane [4-methylsulfinylbutyl isothiocyanate], were examined in broccoli (Brassica oleracea var. italica) during storage times. The results showed that at 20 degrees C, 55% loss of glucoraphanin concentration occurred in broccoli stored in open boxes during the first 3 days of the treatment and 56% loss was found in broccoli stored in plastic bags by day 7. Under both air and controlled atmosphere (CA) storage, glucoraphanin concentration appeared to fluctuate slightly during 25 days of storage and the concentrations under CA was significantly higher than those stored under air treatment. In modified atmosphere packaging (MAP) treatments, glucoraphanin concentration in air control packaging decreased significantly whereas there were no significant changes in glucoraphanin concentration in MAP with no holes at 4 degrees C and two microholes at 20 degrees C for up to 10 days. Decreases in glucoraphanin concentration occurred when the broccoli heads deteriorated. In the present study, the best method for preserving glucoraphanin concentration in broccoli heads after harvest was storage of broccoli in MAP and refrigeration at 4 degrees C. This condition maintained the glucoraphanin concentration for at least 10 days and also maintained the visual quality of the broccoli heads.  相似文献   

8.
Table grape quality and firmness are key parameters for Chile's export, given distances from the main markets. As a consequence, calcium (Ca) fertilization has become a standard practice in the country, although its effects have not been fully evaluated. The objectives in this study were to investigate the effects of calcium fertilization on table grape nutrition and quality. A two-year field trial was conducted in central Chile, using grapevines (Vitis vinifera) cv. ‘Thompson seedless’, grown on an overhead trellis system. Calcium (CaCl2) application treatments included foliar, soil, foliar plus soil, and a control without Ca fertilization. Calcium and other nutrients concentration were determined afterwards in soil, leaves, and berries. Also, yield and some fruit quality parameters were evaluated. Calcium application method did not have an effect on soil, leaf or fruit Ca content, neither on yield and berry sugar concentration, with levels being similar to the control treatment. Additionally, in treatments where CaCl2 was applied to soil, chlorides concentration in soil, leaves, and berries were higher. Also, berries were larger, more turgent, with lower dry matter and larger cells. In the second season, in these same treatments, berry firmness at harvest was higher, but this effect disappeared after the storage simulation period. These results question the validity that Ca applications might improve table grape postharvest quality for growing conditions similar to the ones in this experiment. The temporal changes in berry quality parameters were attributed to higher Cl soil content and the associated plant osmoregulatory mechanisms.  相似文献   

9.
冰温结合不同比例氧气气调对冷却肉的保鲜效果   总被引：4，自引：1，他引：3  
试验研究了在冰温基础上结合不同含氧比例气调对冷却猪肉保鲜的影响,试验设置冰温、冷藏（4℃）、真空包装+冰温、20%CO2+80%O2（高氧）+冰温、20%CO2+20%O2+60%N2（低氧）+冰温、20%CO2+80%N2（无氧）+冰温6个试验组,测定菌落总数、挥发性盐基氮、汁液流失率、保水能力和色差。结果表明：冰温条件下高氧和低氧的菌落总数24 d还未超过冷却肉卫生标准,且两组之间无显著差异（P＞0.05）;在整个贮藏期内高氧气调和低氧气调可以维持冷却肉的色泽在一个小的范围内变化;高氧气调和低氧气调8 d后汁液流失率显著高于单纯冰温和无氧气调（P＜0.05）,高氧气调12 d后汁液流失率显著高于低氧气调（P＜0.05）,同时高氧气调8 d后持水能力显著大于低氧气调（P＜0.05）。在冰温条件下,80%O2和20%O2都能长时间维护冷却肉的色泽,均能较好抑制微生物的增殖,但在汁液流失率、保水能力方面各有优势。  相似文献   

10.
Postharvest treatment of seedless white table grapes (var. 'Superior') with different gas ozone concentrations (3.88 and 1.67 g/h) for 1, 3, and 5 h induced an increase in stilbenoid biosynthesis [trans-resveratrol, piceatannol, and viniferinas (resveratrol dehydrodimers and dehydrotrimers)] during storage at 22 degrees C and 95% relative humidity. The maximal resveratrol concentration was reached after 2 days of storage, and this amount was similar to that induced by optimized UV-C treatments (1 min, 510 W, 40 cm). Although similar resveratrol concentrations accumulated in grapes after both UV-C and O3 treatments (maximum ozone production and time), the ozone treatment was more efficient in inducing viniferins accumulation in grape berries. A sequence in the biosynthesis of stilbenoids was observed, starting with the resveratrol monomer, continuing with the resveratrol dehydrodimers epsilon-viniferin and delta-viniferin, and ending with four different resveratrol dehydrotrimers. These trimers were different from alpha-viniferin, a trimer previously reported to be induced in grapes after biotic and abiotic stresses. Two alpha-viniferin isomers were also detected in the ozone-treated grapes, although at very low concentrations that prevented their quantification.  相似文献   

11.
挖掘运输过程中环境因子和生鲜果蔬感官品质之间的关系,实现基于环境因子的感官品质评估和预测,对于保持生鲜果蔬物流品质具有重要意义。该研究以鲜食葡萄为研究对象,通过对实际运输过程的跟踪监测,在实验室开展了鲜食葡萄运输模拟试验和感官试验,构建了鲜食葡萄运输感官品质数据集。在建模方法层面,该研究提出了一种基于多输出支持向量回归（Multiple Output Support Vector Regression,MSVR）模型的运输环境因子（温度、相对湿度）与感官品质（外观、香气、质地和风味品质）的预测模型,并利用粒子群（Particle Swarm Optimization,PSO）算法和遗传算法（Genetic Algorithm,GA）对模型进行优化（PSOGA-MSVR）。结果表明,PSOGA联合优化算法有效提高了MSVR模型的调参效率,且在常温运输、保冷运输和冷链运输3种不同的运输模式下,PSOGA-MSVR模型的预测效果均更优,决定系数R2高于0.98且各项误差指标低于其他模型;研究结果为运输过程中合理调控环境因子减缓生鲜水果感官品质的下降提供参考。  相似文献   

12.
White table grapes, var. Superior, were treated with UV-C light after harvest to increase stilbenes concentration, especially trans-resveratrol (RES), because this may be of relevance to the health-promoting properties assigned to these compounds. However, irradiated grapes also developed some browning on the surface on the third day of storage at 22 degrees C, with the subsequent detriment in the sensorial quality of the fruit. Possible causes for browning development during storage were investigated. The phenolic-related oxidative enzymes, polyphenol oxidase (PPO) and peroxidase (POD), were not specifically activated, and no new isoforms appeared upon UV-C treatment. UV-treated grapes had lower content of chlorophyll b than control grapes on the fourth day of storage, concomitant with the increase of pheophytins (chlorophyll degradation derived compounds). Microscopy data showed lower fluorescence emission in chloroplasts from the UV-treated samples, which may explain the decrease of chlorophylls content in the corresponding grape berries extracts. In addition, microscopy images showed cell wall thickening in the skin tissue of UV-treated grapes which could be considered as a general wound response in plant tissues. These results suggest that the development of browning in Superior white grapes after UV-C treatment is not closely related with the evolution of oxidative enzymes during storage and may be mainly due to the decrease of chlorophylls content.  相似文献   

13.
薄膜气调包装对枇杷果实冷藏期间呼吸和品质性状的影响   总被引：3，自引：4，他引：3  
通过对呼吸速率、总可溶性固形物、可滴定酸、pH值、果肉硬度、维生素C、失重率和品质及感官指标的变化进行分析，研究了薄膜气调包装对枇杷(Eriobotrya japonica Lindl.，品种：解放钟）果实冷藏期间呼吸和品质特性的影响，气调包装用的薄膜为低密度聚乙烯薄膜(LDPE，厚度20 μm)，以打孔的低密度聚乙烯薄膜包装为对照。结果表明，低密度聚乙烯薄膜包装枇杷果实后，3～4 d后可维持一个相对稳定的适宜枇杷贮藏的O2和CO2的气体浓度，即CO2(4.8±0.67)%，O2(11.5±0.85)%；薄膜气调包装结合低温可明显地降低枇杷果实的呼吸速率；薄膜气调包装可以最大限度地减小冷藏期间的枇杷果实的失重率、果肉硬度、维生素C、总可溶性固形物、可滴定酸和固酸比的变化，维持枇杷的新鲜品质，延长货架期。因此，低密度聚乙烯薄膜（LDPE，厚度20 μm）气调包装可用于枇杷的贮藏保鲜。  相似文献   

14.
荔枝果实采后商品化处理和贮藏技术   总被引：8，自引：4，他引：8  
荔枝是我国南方著名的主要亚热带果树，但其果实成熟于高温季节，采后由于果皮褐变(即失去红色)和果实腐烂而使果实迅速劣变，常温下的采后寿命少于3 d，这种短的采后寿命严格限制荔枝的长距离贮运、销售和消费。因此，荔枝采后技术研究成为荔枝生产的关键问题。该文全面地介绍了荔枝果实采后腐烂和损失的原因（即荔枝果实的结构特性、生理和病理原因），荔枝果实采后商品化处理和贮藏技术，包括不同品种的耐贮运性、采收成熟度和采收方法、选别和分级、杀菌剂浸泡、减少失水处理、减少果皮褐变和保持果实红色处理（如熏硫处理、酸浸或塑料包装）、检疫杀虫处理、预冷、包装、贮藏（常温贮藏、低温贮藏、气调贮藏、自发气调贮藏）、运输和销售。  相似文献   

15.
该文主要考察25℃下气调和真空包装对腌制海鳗货架期的影响.4个样品分别是M1:空气包装(对照),M2:真空包装,M3:CO2/N2,40%/60%,M4:100%CO2,以挥发性盐基氮,三甲胺,pH值,硫代巴比妥酸值,菌落总数和感官为指标.结果表明,气调包装的货架期为20 d,真空包装为19 d,对照为16 d.对照组细菌增加很快,而M4增加最慢.挥发性盐基氮和三甲胺都随着储存时间延长而增加,在气调包装下的感官质量明显好于对照组.气调和真空包装,特别是100%CO2包装是保藏腌制海鳗的最有效方法.  相似文献   

16.
Extensive research has been done in recent years to reduce the heavy dependence on chemical fungicides to control postharvest diseases and disorders of horticultural crops. Alternative strategies were based on improved cultural practices, biological control, plant-defense promoters, and physical treatments such as UV illumination, radiofrequency treatment, heat therapy, and storage technologies. Among these, postharvest heat treatments such as hot water dips, short hot water rinsing and brushing, and hot air conditioning have reduced rot development and enhanced fruit resistance to chilling injury in sensitive cultivars while retaining fruit quality during cold storage and shelf life. Additive or synergistic increases in effectiveness were observed by integrating heat therapy with various chemical compounds, thus leading to significant reductions in the application of active ingredients to protect produce from decay. This paper highlights the knowledge on this topic with emphasis on heat therapy effects and factors affecting the uptake, persistence, and performance of fungicide residues when they are applied in combination with hot water.  相似文献   

17.
Fresh strawberries and grapes grown in Michigan and Indiana were surveyed for residues of captan and folpet, 2 fungicides commonly used on these crops. The fungicides were reportedly applied to the crops by overhead irrigation, tractor sprayer, or aerial spraying, in amounts ranging from 0.5 to 6 lb formulation/acre for captan and from 1 to 4 lb formulation/acre for folpet. Reported dates of last application ranged from just 2 days to nearly 5 months before samples were collected. Twenty-eight strawberry samples and 24 grape samples were collected of crops field-treated with one or both of these fungicides. Samples were analyzed by previously described methodology. Captan residues were found in all strawberry samples, ranging from less than 0.01 to 1.5 ppm. Folpet was found in only one strawberry sample at 0.041 ppm. Captan residues were found in only 6 grape samples, ranging from less than 0.01 to 0.082 ppm. Folpet residues were found in 12 grape samples, ranging from less than 0.01 to 0.50 ppm. All residues were well below the current tolerances of 25 ppm for both captan and folpet in strawberries and 50 ppm for captan and 25 ppm for folpet in grapes. Residue levels of these surface-applied, nonsystemic fungicides were inconsistent with amounts and dates of application, most likely because of variations in weather conditions, especially rainfall. Residues were quite stable in frozen sample homogenates, declining only 5-10% after 2 months.  相似文献   

18.
The effect of concentration, temperature, and length of treatment with imazalil (IMZ) and thiabendazole (TBZ) was studied with application to citrus fruit. The amount of residues retained by fruit after "home" washing was also monitored. IMZ uptake in citrus fruit was related to treatment duration, whereas TBZ residues was not. Residues of IMZ or TBZ fungicides were significantly correlated with dip temperature (r = 0.943 for IMZ; r = 0.911 for TBZ). Treatment at 50 degrees C produced a deposition approximately 8 and approximately 2.5 times higher than when treatments were carried out at 20 degrees C in IMZ and TBZ, respectively. No significant differences in terms of IMZ deposition were detected after treatments carried out alone or in combination. Uptake of the two fungicides was associated with their physicochemical characteristics as well as different formulation types. IMZ residues showed a great persistence during storage when applied separately, and >83% of active ingredient was present after 9 weeks of storage. IMZ residues increased with dip length, doubling when dip time increased from 0.5 to 3 min. In contrast, TBZ residues did not change with the different dip times. Following postharvest dip treatments of citrus fruit at 20 or 50 degrees C, home washing removed approximately 50% of the IMZ and approximately 90% of the TBZ.  相似文献   

19.
Since quality requirements for table grapes are mainly related to their physico-chemical and mechanical features, the aim of this work was to provide useful data for grape producers and consumers concerning the quality characteristics of table grapes of five new Vitis vinifera L. cultivars created in Romania and tending to spread within the temperate climate vineyards. During grape maturation, sugar content increased in a lesser extent than the reducing of total acidity, a balanced taste of grapes was given by the decrease in total acidity rather than sugar accumulation. Grapes of analysed cultivars showed lower concentrations of ascorbic acid and a higher content of organic nitrogenous compound. Berries with higher weight and volume (Transilvania cv.) incurred a higher mechanical deformation, while long berries (Gelu cv.) showed higher resistance to detachment from the pedicel, indicating higher resistance of grapes to packing, transport and storage. Antioxidant activity of mature grapes was high, but involvement of nonflavonoids in increasing the antioxidant capacity was statistically non-significant. Seeded table grapes of new Vitis vinifera L. cultivars showed superior physico-chemical and mechanical characteristics, indicating their high quality in the conditions of temperate continental climate, and promoting the studied cultivars as important grapevine germplasm resources.  相似文献   

20.
Treatments to inhibit browning and decay and prolong shelf life of fresh-cut mangoes were investigated. Combinations of antibrowning agents and modified atmosphere packaging (MAP) resulted in a reduction of browning and deterioration of fresh-cut mangoes stored at 10 degrees C. Combinations of several browning inhibitors were more effective than those applied individually. Among these treatments, solutions containing 4-hexylresorcinol (0.001 M) (HR) plus potassium sorbate (0.05 M) (KS) and HR plus KS plus D-isoascorbic acid (0.5 M) (ER) reduced changes in color (L, a, and b) and microbial growth and did not affect sensory characteristics of fresh-cut mangoes. In general, these treatments did not affect significantly the changes in organic acids and sugar content of slices during the 14 days of storage at 10 degrees C. High humidity created in the in-package atmosphere alleviated tissue dryness and was an important factor in the ability of the antibrowning solutions to prevent browning and decay. It appears that the maintenance of quality of fresh-cut mangoes is more related to particular combinations of the antibrowning agents used rather than the modified atmosphere created inside the package. HR + ER + KS treatment in combination with MAP could be used to inhibit browning, decay, and deterioration of fresh-cut mangoes.  相似文献   

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