玫瑰香葡萄贮藏环境气体阈值和极值的研究

研究了不同气体组合条件，玫瑰香葡萄0℃下120天的贮藏效果。结果表明，气调有利于玫瑰葡萄贮藏，合适的气体环境能够明显防止玫瑰香葡萄腐烂和脱粒，保持果梗的绿色，葡萄果实中的乙醇含量升高不明显。玫瑰香葡萄最佳气体成分为10％O2＋8％CO2，CO2伤害极值为10％O2＋18％CO2条件下100天，10％O2＋15CO2条件下120天；低O2伤害症状不明显。     

Effect of modified atmosphere packaging on Quality Index Method (QIM) scores of farmed gilthead seabream (Sparus aurata L.) at low and abused temperatures

A Quality Index Method (QIM) scheme was developed for modified atmosphere packaging (MAP) packed gilthead seabream, and the effect of MAP gas mixtures (60% CO2 and 40% N2; 60% CO2, 30% O2, and 10% N2), temperature (2, 4, and 8 °C), and time of storage on QI scores was assessed. QI scores were crossed with sensory evaluation of cooked fish according to a modified Torry scheme to establish the rejection point. In order to reduce redundant parameters, a principal component analysis was applied on preliminary QIM parameters scores coming from the best performing MAP among those tested. The final QIM scheme consists of 13 parameters and a maximum demerit score of 25. The maximum storage time was found to be 13 d at 4 °C for MAP 60% CO2 and 40% N2. Storage at 2 °C do not substantially improved sensory parameters scores, while storage under temperature abuse (8 °C) accelerated drastically the rate of increase of QI scores and reduced the maximum storage time to 6 d.     

Internal Modified Atmospheres of Coated Fresh Fruits and Vegetables: Understanding Relative Humidity Effects

ABSTRACT: Internal atmosphere modification in fruits and vegetables by surface film coatings depends on film permeability, coating thickness, and fruit surface coverage. Research in this area has been mostly empirical, with unpredictable results and diverse conclusions. To reduce variability, it is necessary to have a better understanding of factors that may influence the response of coatings applied to fruits. One factor is relative humidity (RH), which is known to affect the permeability of biopolymer films. By using steady-state mathematical models as tools, we hypothesize that fruits coated with hydrophilic films will be largely influenced by the RH of storage conditions. For hydrophobic materials, RH would have less influence on coating performance.     

Pigment Changes in Parsley Leaves during Storage in Controlled or Ethylene Containing Atmosphere

Pigments were monitored in parsley leaves stored in air, air + 10 ppm C₂H₄, or 10% O₂+ 10% CO₂ controlled atmosphere (CA). Chlorophylls a and b, as determined with HPLC, decreased sharply in leaves held in air or air + 10 ppm C₂H₄. The decrease was less in leaves held in 10% O₂ and 10% CO₂ CA. The oxidized product of chlorophyll a, 10-hydroxychlorophyll a, did not accumulate and chlo-rophyllide accumulated minimally. Xanthophylls decreased but new pigments, suspected to be esterified xanthophylls, formed with yellowing of leaves. Neither the pathway of Chl degradation or xantho-phyll products were altered by C₂H₄ or CA.     

Combined effect of aqueous chlorine dioxide and modified atmosphere packaging on inhibiting Salmonella Typhimurium and Listeria monocytogenes in mungbean sprouts

This study was conducted to investigate the effect of chlorine dioxide (ClO2) combined with modified atmosphere packaging (MAP) on inhibiting total mesophilic microorganisms, Salmonella Typhimurium, and Listeria monocytogenes in mungbean sprouts during refrigerated storage. Mungbean sprouts were packaged using 4 different methods (air, vacuum, CO2 gas, and N2 gas) following treatment with water or 100 ppm ClO2 for 5 min and stored at 5 +/- 2 degrees C. The population of total mesophilic microorganisms in mungbean sprouts was about 8.4-log(10) CFU/g and this level was not significantly reduced by treatment with water or ClO2 (P > 0.05). However, when samples were packaged under vacuum, N2 gas, or CO2 gas following treatment with ClO2, the populations of total mesophilic microorganisms were significantly reduced during storage (P < 0.05). Levels of S. Typhimurium and L. monocytogenes in mungbean sprouts following inoculation were 4.6- and 5.6-log(10) CFU/g and treatment with water followed by different packaging conditions (air, vacuum, N2 gas, and CO2 gas) had no significant effect on population reduction (P > 0.05). However, treatment with ClO2 significantly reduced populations of S. Typhimurium and L. monocytogenes by 3.0- and 1.5-log CFU/g, respectively (P < 0.05), and these reduced cell levels were maintained or decreased in samples packaged under vacuum or in N2 or CO2 gas during storage. These results suggest that the combination of ClO2 treatment and MAP such as CO2 gas packaging may be useful for inhibiting microbial contamination and maintaining quality in mungbean sprouts during storage.     

硅窗气调包装保鲜贮藏茶树菇呼吸特性与贮藏品质的研究

以乙醇作为厌氧呼吸的指标，评估气调包装贮藏茶树菇时厌氧呼吸产生的条件，探讨硅窗对茶树菇的呼吸特性与贮藏品质变化的影响。结果表明：与普通气调相比较，硅窗气调能明显改善茶树菇贮藏的气体环境。贮藏温度为3℃，硅窗面积0．9cm。以上和贮藏温度为7℃，硅窗面积1．2cm。以上，都能避免厌氧呼吸的发生，茶树菇有更好的贮藏品质。     

Effects of controlled atmosphere (CA) storage on pectinmethylesterase (PME) activity and texture of ‘Rocha’ pears

Firmness and pectinmethylesterase (PME) activity were evaluated in pears (cv Rocha) after 9 months of storage in controlled atmosphere (CA) followed by various periods of exposure to air at room temperature. The free calcium content was also evaluated in tissues. Fruit firmness decreased with increasing time of air exposure for all four different CA storage conditions tested. After 9 days of air exposure, fruits stored in 2% O₂ + 1.5% CO₂ were less firm than control fruits (stored in air) and showed higher PME activity. In spite of normal textural changes being observed with increasing time of exposure to air at room temperature, the underlying metabolism might have been affected by CA storage. © 2001 Society of Chemical Industry     

硅窗袋保鲜芹菜的研究

研究了不同温度以及硅窗袋内不同初始气体浓度比例对芹菜贮藏效果的影响,测定了芹菜贮藏过程中失重率、黄化率、腐烂率、呼吸强度、袋内O2、CO2含量、细胞膜透性、粗纤维含量等指标的变化,结果表明:温度对芹菜贮藏效果影响显著,但15℃与5℃环境下芹菜贮藏效果相差不大。硅窗袋充气气调包装可以延缓采后芹菜的衰老,延长芹菜的货架寿命,15℃环境下芹菜贮藏15d后仍具有较好的商品价值。其中初始气体比例为5%CO2/5%O2/90%N2的包装袋芹菜贮藏结束后品质最佳。     

低氧贮藏对采后果实风味的影响研究进展

低氧是传统气调贮藏技术中采用的主要措施之一,可显著延长果实的贮藏期和缓解其采后生理紊乱症状。在气调贮藏期间,低氧环境可降低果实呼吸作用,减少乙烯的生物合成,延缓果实的成熟和衰老,更好地维持果实硬度、可溶性固形物、可滴定酸度、抗坏血酸含量等品质指标水平。然而,一般认为低氧会对果实的风味品质造成一定程度的负面影响。本文综述果实气调贮藏过程中低氧对其主要糖分、有机酸和挥发性香气组分生物合成的影响,并对其生化和分子机制进行了阐述,以期为改善气调贮藏果实的风味品质提供理论参考。