Effects of composite chemical pretreatment on maintaining quality in button mushrooms (Agaricus bisporus) during postharvest storage

This study evaluated the effects of composite chemical pretreatment on the quality of postharvest button mushrooms. Three different treatments, including (T1) control (water), (T2) 1 mmol L⁻¹ Na₂EDTA + 10 mmol L⁻¹ CaCl₂ and (T3) 1 mmol L⁻¹ Na₂EDTA + 2.5% CaCl₂ + 0.5% citric acid + 2.5% sorbitol were used for pretreatments. The results showed that T3-treated samples maintained good firmness and color and had less weight loss during the postharvest storage. Lower levels of H₂O₂, ⁻OH and low malondialdehyde content (MDA) were observed in T3 compared with T1 and T2 samples. Significantly higher soluble protein contents and higher activities in the antioxidant enzymes, i.e., superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) were observed in T3 compared with T1 and T2 at the end of the storage period (P < 0.05). These results suggest that the T3 treatment could be useful in preserving button mushrooms.     

Effects of ultrasound and high pressure argon on physico-chemical properties of white mushrooms (Agaricus bisporus) during postharvest storage

Effects of high pressure argon (H), ultrasound (U) and their combination treatments (UH) on physico-chemical characteristics of white mushrooms were studied during 9 d of postharvest storage at 4 °C. H treated samples exhibited the smallest weight loss and respiration rate compared to all other samples. Mass losses after 9 d of storage were 3.01%, 5.09%, 5.39% and 9.59% for H, UH, U and untreated mushrooms, respectively. Furthermore, U treated samples showed lower polyphenol oxidase activity (PPO, E.C. 1.14.18.1) during storage while UH treated samples showed a slight increase in antioxidant capacity during storage and also experienced reduced mass loss and respiration rate. In addition, treated samples were effective in retaining mushrooms colour changes compared to control. Physico-chemical properties of differently treated mushrooms (UH, H and U) stored at 4 °C were significantly different (p < 0.05) from control.     

Surface decontamination of fresh-cut apple by pulsed light: Effects on structure,colour and sensory properties

The effect of pulsed light at increasing fluence (17.5, 52.5, 105.0 and 157.5 kJ/m²) was studied with reference to germicidal efficiency and changes in fresh-like appearance of sliced apple. Independent of fluence, viable counts and inoculated bacteria were reduced by 1 and 3 logs respectively. Fluence significantly affected weight loss, colour and sensory attributes of apple slices during storage at 6 °C. Pulsed light at 17.5 kJ/m² resulted in apple slices comparable to the untreated samples, with limited quality changes. By contrast, at higher fluence, apple slices underwent dehydration and browning due to loss of cell integrity. Exposure to high fluence treatments was also associated with negative changes in the flavour profile of sliced apple during storage.     

Effect of alginate coating on physicochemical and sensory qualities of button mushrooms (Agaricus bisporus) under a high oxygen modified atmosphere

Button mushrooms (Agaricus bisporus) were dipped for 2 min in different concentrations (1%, 2% and 3%) of alginate, then placed in jars and ventilated continuously with 100% O₂ for up to 16 d at 4 °C. Mushroom respiration rate, weight loss, texture, color, percent open caps, chemical properties and activities of polyphenol oxidase (PPO), and peroxidase (POD) were measured. The results indicate that treatment with alginate coating (2%) + 100% O₂ maintained a high level of firmness, and delayed browning and cap opening. In addition, alginate coating (2%) + 100% O₂ also delayed changes in the soluble solids concentration, total sugars and ascorbic acid, and inhibited the activity of PPO and POD throughout storage. Our study suggests that the use of alginate coating under a high oxygen modified atmosphere has the potential to maintain button mushroom quality and extend its postharvest life to 16 d.     

一氧化氮对双孢蘑菇采后生理及贮藏品质的影响

以硝普钠（SNP）为一氧化氮供体,研究了不同浓度NO在常温（25±1℃）和低温（4±1℃）条件下对双孢蘑菇‘F56’贮藏过程中相关品质（失重率、开伞率、可溶性固形物、维生素C（Vc）、游离氨基酸含量）以及过氧化氢酶（CAT）、过氧化物酶（POD）和多酚氧化酶（PPO）活性的影响。结果表明,0.09 mmol/L SNP释放的NO显著抑制了双孢蘑菇采后失重率和游离氨基酸含量的上升,减缓了可溶性固形物含量的增加、延缓Vc的降解,抑制了开伞率的增大;使CAT、POD的活性显著增强,同时降低PPO活性。因此,0.09mmol/L SNP处理显著提高了常温和低温下双胞蘑菇‘F56’ 贮藏期间的CAT、POD活性,抑制了PPO活性的升高,延缓了菇体品质的下降。     

真空预冷压力对双孢菇贮藏效果的研究

以双孢菇为试材,研究其在0℃经不同真空预冷终压(0.1、0.3、0.5 k Pa)预冷后,在常压(0.1 MPa)(0±1)℃下的贮藏效果。结果表明,预冷压力对双孢菇预冷后的失重率有显著影响,随着预冷压力的降低失重率升高;与未预冷组相比,真空预冷可有效抑制双孢菇的褐变、萎蔫和细胞膜渗透率的增长,但预冷压力对细胞膜渗透率和褐变影响不明显;真空预冷和预冷压力对开伞度无明显影响;真空预冷和预冷压力对双孢菇呼吸强度和萎蔫程度影响显著,0.3 k Pa组双孢菇样品的呼吸高峰较其他组均延迟,且贮藏结束时的萎蔫程度远小于0.1 k Pa组样品。综合分析得出,双孢菇的最佳预冷压力为0.3 k Pa,此结论为双孢菇的贮藏应用提供了一定的理论参考。     

Biodegradation of Lantana camara and waste-paper to cultivate Agaricus bisporus (Lange) singer

This paper deals with a new substrate, Lantana straw and waste-paper, for button mushroom cultivation. The substrate was first biodegraded by Pleurotus ostreatus (Jacq.) Fr. and then the sterilized substrate was used for button mushroom cultivation. Thus both the mushrooms (P. ostreatus and Agaricus bisporus) can be grown economically on the same substrate in succession.     

不同培养料的双孢蘑菇多酚氧化酶活性抑制研究

为解决双孢蘑菇保鲜和加工中的褐变问题,以邻苯二酚(C6H602)为底物,分析了不同培养料栽培的双孢蘑菇中多酚氧化酶(PPO)的动力学特性。结果表明,蘑菇PPO活力最低的条件为：pH2．0,温度40℃,褐变抑制剂VC浓度0．09％。用均匀设计回归分析程序拟合的不同培养料蘑菇PPO活力与pH值、温度和褐变抑制剂VC浓度间关系的数学方程,置信水平大于95％。     

Effect of ultraviolet-C light on quality and microbial population of fresh-cut watermelon

The influence of ultraviolet (UV-C) light (1.4–13.7 kJ m⁻² at 254 nm) on the quality and microbial populations of fresh-cut watermelon [Citrulus lanatus (Thunb.) Matsum. and Nakai] was investigated and compared to that of common sanitizing solutions used for fresh-cut produce. Dipping cubes in chlorine (40 μL L⁻¹) and ozone (0.4 μL L⁻¹) was not effective in reducing microbial populations and quality was lower in cubes receiving these aqueous treatments compared to UV-irradiated cubes or control. In commercial trials, exposing packaged watermelons cubes to UV-C light at 4.1 kJ m⁻² produced >1 log reduction in microbial populations by the end of the product's shelf life without affecting juice leakage, color and, overall visual quality. In further experimentation, lower UV-C dose (1.4 kJ m⁻²) reduced microbial populations to a lower degree and only when complete surface exposure was ensured. Higher UV-C doses did not show any difference in microbial populations (6.3 kJ m⁻²) or result in quality deterioration (13.7 kJ m⁻²). Spray applications of hydrogen peroxide (2%) and chlorine (40 μL L⁻¹), without subsequent removal of excess water, failed to further decrease microbial load of cubes exposed to UV-C light at 4.1 kJ m⁻². When properly utilized, UV-C light is the only method tested in this study that could potentially be used for sanitizing fresh-cut watermelon.     

Development of a moisture absorber for packaging of fresh mushrooms (Agaricus bisporous)

Polymeric films used in fruit and vegetable packaging have lower water vapour transmission rates relative to the transpiration rates of fresh products. Therefore, high humidity conditions prevail in the packages, causing moisture condensation, microbial growth and decay of the product. A possible solution to control humidity is to use moisture absorbers. However, existing moisture absorbers either have low absorption capacity and/or absorb moisture quickly, making them unsuitable for mushrooms. This study was undertaken in order to develop a moisture absorber with high moisture holding capacity and slower rate of moisture absorption for packaging of fresh mushrooms. Fast absorbing moisture absorbers such as CaCl₂, KCl and sorbitol were mixed with a slow absorbing desiccant such as bentonite in different proportions. The best combination was found to be with bentonite, sorbitol and CaCl₂ in proportions of 0.55, 0.25 and 0.2 g g⁻¹ desiccant, respectively. It showed a moisture holding capacity of 0.9 g water g⁻¹ mixed desiccant that remained in powder form during 120 h of storage at 10 °C. Further study was conducted to evaluate the kinetics of moisture absorption of this mixed desiccant at 4, 10 and 16 °C and at different humidity levels of 76, 86 and 96%. The change in moisture content of the mixed desiccant with respect to storage time was fitted to a Weibull distribution model. The moisture holding capacity was found to be dependent on the relative humidity; it increased from 0.51 to 0.94 g water g⁻¹ desiccant when relative humidity was increased from 76 to 96%. The kinetic parameter of the Weibull distribution function was found to be dependent on both temperature and relative humidity. Overall appearance of mushrooms improved when 5 g of mixed desiccant was packed in 250 g of mushroom punnet compared to those packed without desiccant.     

双孢菇饼干的生产工艺研究

以感官评价为指标,选择双孢菇粉、糖粉和黄油添加量为单因素进行梯度试验,并在此基础上进行正交试验优化双孢菇饼干的制作工艺。结果表明,最佳工艺参数为以低筋面粉量为烘焙百分比100%,双孢菇粉10%,白砂糖35%,黄油70%,全蛋液15%,奶粉5%,面火180℃,底火190℃下焙烤15 min得到的双孢菇饼干感官品质最佳。     

双孢蘑菇涂膜保鲜技术研究

以提高贮藏质量延长保鲜期为目的,探讨了双孢蘑菇的最适贮温,采用海藻酸钠、琼脂和魔芋涂膜液等对双孢蘑菇进行涂膜及优化。结果表明:双孢蘑菇的最适贮温0~3℃,采用涂膜法可延缓褐变进程,保鲜质量好;在相同条件下,双孢蘑菇采用海藻酸钠涂膜的保鲜效果最好。海藻酸钠涂膜双孢蘑菇的最佳条件为海藻酸钠用量0.8g/100g水、蔗糖酯用量0.7g/100g水、涂膜时间4min。     

Surface decontamination of fresh-cut apple by UV-C light exposure: Effects on structure,colour and sensory properties

The effect of UV-C light treatments at 1.2, 6.0, 12.0 and 24.0 kJ/m² was studied with reference to germicidal efficiency and changes in fresh-like appearance of fresh-cut apple. Independently of UV-C light fluence, all treatments imparted the same germicidal effect with 1–2 log reduction in total viable counts. Treatments at a fluence exceeding 1.2 kJ/m² caused the loss of compartmentalisation of surface apple cells, activating dehydration and oxidative phenomena. By contrast, mild treatments resulted in apple slices much more stable than the untreated control in terms of microbial growth and development of browning and off-flavours. These effects were attributed not only to the direct inactivation of spoilage microrganisms and enzymes by UV-C light, but also to the formation of a thin, dried film on the surface of the product. This edible protective film inhibited microbial growth and hindered dehydration during storage but was too thin to be perceived by consumers. UV-C light exposure was demonstrated to be an effective non-visible technology for food surface decontamination, but only if applied at mild intensity.     

不同培养料配方对双孢菇产量的影响

为充分利用农业秸秆资源,在双孢蘑菇隧道培养料传统麦草配方的基础上,分别添加菇渣和玉米秸秆,对培养料堆制过程中的含水量、pH、含氮量、碳氮比等指标变化趋势进行监测,并对双孢蘑菇产量及农艺学性状进行统计。结果表明,培养料建堆至二次发酵结束均以添加玉米秸秆的配方含水量最高,以传统麦草配方含氮量最高,3个处理的pH差异不大。传统麦草鸡粪配方的产量为18.31 kg/m²,添加菇渣的处理产量为11.43 kg/m²,添加玉米秸秆的处理产量为14.48 kg/m²,添加玉米秸秆还可以显著提高头潮菇所占产量的比重。此外,二次发酵结束后的培养料碳氮比与产量有一定的相关性。     

Low oxygen levels and light exposure affect quality of fresh-cut Romaine lettuce

Modified atmosphere packaging (MAP) has the potential to extend the shelf-life of fresh-cut lettuce mainly by limiting the oxidation processes. However, exposure to light conditions has been described as causing browning and quality loss. The influence of O₂ partial pressures (pO₂) and light exposure during storage on the shelf-life of fresh-cut Romaine lettuce was studied. Fresh-cut lettuce was exposed daily during storage to different light conditions: light (24 h), darkness (24 h) and photoperiod (12 h light + 12 h darkness). Changes in respiration rate, headspace gas composition, sensory quality, colour, electrolyte leakage, stomatal opening, water loss, texture and compositional constituents related to browning such as vitamin C and individual and total phenolic compounds were evaluated. Different weight samples (75–275 g), packaged with an initial pO₂ of 0.5–2.0 kPa balanced with N₂, reached pO₂ from 0.1 to 1.5 at the steady-state. Atmospheres with low pO₂ (0.2–0.5) at the steady-state preserved lettuce quality by the control of browning and the prevention of off-odours and off-flavours. Light exposure during storage positively influenced the number of open stomata (74% in light vs 24% in darkness) which contributed slightly to weight loss. Consumption of O₂ in samples exposed to light differed significantly from those stored in photoperiod or darkness (10.6 ± 7.0, 18.3 ± 3.5 and 25.8 ± 8.6 nmol O₂ kg^?1 s^?1, respectively). Packages exposed to light showed higher pO₂ compared with packages stored in darkness while those exposed to photoperiod had intermediate values. Moreover, location of the packages in the shelves affected package headspace gas composition and thus, packages near the front of the shelves showed higher pO₂ than those at the back. The different light conditions did not influence the content of vitamin C or the individual and total phenolic compounds. This study shows that under light conditions respiration activity was compensated by photosynthesis resulting in a higher pO₂. Thus, browning of fresh-cut Romaine lettuce can be promoted by light exposure during storage as it increases headspace pO₂.     

双孢蘑菇袋式菌丝培养适宜配方研究

为探讨不同基质配方对双胞蘑菇生长的影响,开展了5个不同配方基质的试验研究。结果表明:配方玉米芯(粉碎)100kg、干牛粪100kg、尿素1kg、过磷酸钙3kg、石膏1kg、石灰3kg种植双孢蘑菇单产最高,达16.1kg/m2,净产值最高,为95.7元/m2,产投比较高,为3.55。     

工厂化双孢蘑菇栽培环境与产量分析

通过对工厂化生产双孢菇的菇房环境因子变化的观察和记录,形成以环境因子为衡量双孢菇产量的曲线图,以期为增加双孢菇产量提供依据。笔者以麦草、鸡粪为培养料进行隧道发酵,空调菇房栽培双孢菇,对4个菇房的环境和产量进行了1个生产周期的测定,结果表明：菇房环境总体上符合双孢菇生长要求。播种后至降温期间,室温保持在16~21℃之间,各层料温差异明显,上层高于下层;采菇期室温保持在16~18℃之间,料温18~20℃之间,各层料温差异不明显。采收期湿度及CO₂浓度都保持在较好水平,子实体生长正常。品种A15产量高于192,2个品种在栽培管理相同的情况下,栽培面积为600 m²的菇房产量都达到了12 t以上,最高14.6 t,折合21~24.3 kg/m²。     

复配杀菌剂对双孢蘑菇疣孢霉病的防治研究

为了解决单一药剂的长期使用使致病菌产生抗药性及复配剂对双孢蘑菇疣孢霉病的防治问题,以双孢蘑菇疣孢霉为检测菌,对21种复配杀菌剂进行了实验室平板药效检测试验,并筛选对疣孢霉抑制力强的药剂组合进行菇床应用验证。结果显示,对疣孢霉病的防治效果和对双孢蘑菇生长的影响,不同复配杀菌剂存在很大差异,其中用4000倍与4800倍的复配杀菌剂（25%腐霉·福美双可湿性粉剂＋70%百菌清可湿性粉剂,体积比1:1）和4000倍的复配杀菌剂（40%多·福可湿性粉剂＋70%百菌清可湿性粉剂,体积比1:1）处理覆土材料,对防治疣孢霉病均有较好的实效,且对蘑菇的菌丝生长与子实体发育无不良影响,生产上值得推广。     

Recent approaches using chemical treatments to preserve quality of fresh-cut fruit: A review

This review covers some recent advances for the maintenance of fresh-cut fruit quality with respect to the use of chemical compounds, including plant natural antimicrobials and antioxidants, as well as calcium salts for maintaining texture. It focuses especially on the use of natural preservatives, which are of increasing interest because of toxicity and/or allergenicity of some traditional food preservatives. The difficulties in the application of these substances on fresh-cut fruit without adversely affecting sensory characteristics of the product are reviewed. Edible coatings are presented as an excellent way to carry additives since they are shown to maintain high concentrations of preservatives on the food surfaces, reducing the impact of such chemicals on overall consumer acceptability of fresh-cut fruit.     

双孢蘑菇HMG转录因子鉴定及在采后贮藏中的表达模式分析

双孢蘑菇（Agaricus bisporus）采后贮藏期间极易发生表皮褐变,其中涉及的分子机制尚不明确。为探索双孢蘑菇采后褐变涉及的分子机制,基于全基因组数据对双孢蘑菇HMG转录因子进行鉴定,并对AbHMG蛋白特性,以及AbHMG基因在双孢蘑菇采后贮藏期间的表达模式进行了分析。结果表明：基于PFAM注释结果在双孢蘑菇中鉴定到13个AbHMG转录因子,编码序列长度425～1 881 bp,编码141～626个氨基酸,相对分子质量15 996～69 651,等电点5.12～11.13,α螺旋和无规则卷曲为AbHMG蛋白的主要结构元件,所有AbHMG蛋白均为定位于细胞核的不稳定蛋白。双孢蘑菇贮藏期间表皮L*值呈逐渐下降趋势,表现为表皮褐变程度加深,同时双孢蘑菇子实体相对电导率和呼吸强度呈现逐渐上升趋势;荧光定量PCR分析结果表明,AbHMG7、AbHMG9和AbHMG13基因在双孢蘑菇贮藏后期的表皮样品中显著上调表达。双孢蘑菇中共鉴定到13个HMG转录因子,其中AbHMG7、AbHMG9和AbHMG13转录因子可能参与了双孢蘑菇采后褐变相关的转录调控进程。