两种烤房对烤烟烟叶化学成分和物理性状的影响

对两种烤房条件下的烤后烟叶进行常规化学成分和物理性状分析,结果表明:(1)在密集烤房烘烤的烟叶整体质量优于气流上升式烤房烘烤的烟叶,其总糖,还原糖,钾含量高于气流上升式烤房烘烤的烟叶,而总氮,烟碱含量低于在气流上升式烤房烘烤的烟叶;(2)密集烤房烘烤的烟叶的拉力、抗张强度、平衡含水率、填充值大于气流上升式烤房烘烤的烟叶,而厚度和叶质重则小于气流上升式烤房烘烤的烟叶。     

转谷氨酰胺酶对鲢鱼鱼丸品质特性的影响

为了探究转谷氨酰胺酶（TG酶）对鲢鱼鱼丸品质影响,本研究测定了TG酶添加量、温度、时间的变化对鲢鱼鱼丸持水性、色泽、质构特性、感官品质的影响。结果表明TG酶的添加可以明显提高鱼丸持水性、质构特性和感官品质,但对色泽无明显影响;随着温度升高,鱼丸持水性、色泽、质构特性、感官品质总分均呈先上升后下降的趋势;随着时间延长,鱼丸持水性、色泽、质构特性、感官品质总分均呈上升趋势,而后趋于平缓。TG酶对鲢鱼鱼丸品质有显著的改善作用。     

臭氧处理对贮藏后期库尔勒香梨贮藏品质的影响

以贮藏后期的新疆库尔勒香梨为试材,探究不同浓度臭氧(0(CK)、10.7、21.4、32.1 mg/m~3)处理对新疆库尔勒香梨贮藏品质调控的影响。结果表明,与CK组相比,10.7、21.4、32.1 mg/m~3臭氧处理组均能维持贮藏后期库尔勒香梨的可溶性固形物含量,提高果实的亮度,有利于抗坏血酸和可滴定酸的积累,抑制叶绿素的降解,同时抑制多酚氧化酶活性,增强过氧化物酶活性,其中10.7 mg/m~3臭氧处理组效果较好。     

臭氧处理对哈密瓜常温贮藏品质的影响

以"西州蜜25号"哈密瓜为原料,在常温下分别对其进行0 mg/m³(对照组)和10 mg/m³臭氧(处理组)处理4 h,并置于常温(22±2)℃下进行贮藏。通过观察哈密瓜果实的腐烂症状,测定腐烂指数、可溶性糖等指标,研究10 mg/m³臭氧处理对哈密瓜贮藏品质的影响。结果表明:与对照组相比,臭氧处理可降低果实腐烂指数,减轻腐烂症状,抑制果实呼吸作用,并延缓果实硬度和抗坏血酸含量的下降速度,较好地维持了果实可溶性固形物、可滴定酸、可溶性糖和可溶性蛋白含量,一定程度上保持了果实的贮藏品质。     

臭氧处理对不同成熟度金丝小枣贮藏品质的影响

以白熟期和脆熟期的山东金丝小枣为试材,采用微孔膜包装,在预冷24 h期间连续用0.5 m L/m3浓度的臭氧处理,并在-1~0℃条件下贮藏72 d期间以同浓度每周定期进行臭氧处理5 h,以相同成熟度的空白处理为对照,研究臭氧对不同成熟度金丝小枣果实贮藏品质的影响。结果表明,0.5 m L/m3浓度的臭氧能够有效抑制金丝小枣可溶性固形物和可滴定酸含量的下降,抑制酒化及水分含量的流失,保持果实硬度,减少腐烂,显著提高金丝小枣的贮藏保鲜效果。     

臭氧对甜瓜贮藏性能的影响研究

以"西州密25号"甜瓜为试材,将不同组甜瓜分别放于大小一致、密闭性较好的不同冷藏库中,采用臭氧间歇处理,每24 h对不同组甜瓜分别充臭氧0.5 h、1 h、1.5 h,连续处理3 d,在6-8℃贮藏条件下,研究不同臭氧处理方式对甜瓜果实腐烂率、可溶性固形物含量、失重率等的影响.结果表明:臭氧处理能够保持甜瓜果实较好的果肉硬度,有效延缓果实可溶性固形物含量的下降,降低果实的腐烂率,延长甜瓜的贮藏期,且每隔24 h充入0.5 h臭氧处理效果较好.     

低温气调协同臭氧间歇处理对柑橘贮藏品质的影响

以柑橘为试材,将其贮于3~5℃、相对湿度85%~90%的气调贮藏箱内,由气调箱每35 min自动对柑橘进行3 min的臭氧(浓度4.0 mg/m3)处理,研究低温气调协同臭氧间歇处理对柑橘贮藏品质的影响。结果表明,低温气调协同臭氧处理组可有效保持柑橘果实的水分、可溶性固形物、总酸、总糖和VC含量,有效控制柑橘果皮上的微生物数量。其中,以CO2含量5%~7%、O2含量3%~4%、N2含量89%~92%的气调处理贮藏效果最好。     

TG酶复合物对巴沙鱼鱼丸品质特性的影响

以巴沙鱼为主要原料,选择木薯淀粉、TG酶、食盐和大豆分离蛋白添加量为主要影响因素,以鱼丸的凝胶强度、持水性、感官评分为评价指标,通过计算评价指标的相关权重得到影响巴沙鱼鱼丸品质的综合评价得分。在单因素试验的基础上,通过响应面法优化巴沙鱼鱼丸最佳配方,并使用扫描电镜观察鱼丸的微观形貌。结果表明：100 g巴沙鱼鱼糜中添加木薯淀粉6%、TG酶0.4%、食盐2%、大豆分离蛋白0.3%,该条件下制得的鱼丸综合评价得分最高,为33.04分;扫描电镜图显示其纤维结构较为致密均匀,空洞较小,明显优于无添加物的对照组,证明了TG酶复合物的配方有助于改善巴沙鱼鱼丸的凝胶特性,为巴沙鱼鱼丸的生产加工提供了理论依据。     

贮藏温度对成熟百香果贮藏品质的影响

为了探明贮藏温度对成熟百香果贮藏品质的影响,为提高百香果采后贮藏品质提供参考。以‘台农一号’百香果为材料,分别把成熟果实放于4℃、8℃冰箱和室温下贮藏,每2天测定相关品质指标。结果表明,低温贮藏（4℃和8℃）均能显著延缓百香果果皮转色和皱缩,可以保持较高感观品质和延长货架期,低温贮藏TSS、TA和TSS/TA和感官品质都没有显著差异(P>0.05)。室温贮藏,4～6天TSS显著高于低温贮藏(P<0.05),14天时显著低于低温贮藏(P<0.05),10天后TA显著低于低温贮藏(P<0.05),6天后TSS/TA显著高于低温贮藏(P<0.05),2～6天感官品质显著高于低温贮藏(P<0.05),10天后显著低于低温贮藏(P<0.05)。失重率都是随着贮藏时间延长和贮藏温度升高而升高。总之,6天前室温贮藏果实品质优于低温贮藏,而低温贮藏可以保持较高的感观品质和延长货架期。     

不同贮藏条件对草莓贮藏品质的影响

为提高草莓的贮藏品质,寻求适合草莓的贮藏条件,将新鲜草莓分别置于常温阴凉（20℃）、冷藏库（0℃和-3℃）条件下贮藏7 d,每天测定草莓的可溶性固形物、可滴定酸、VC含量,同时监测失重率、腐烂指数和感官品质,研究不同贮藏条件对草莓品质的影响。结果表明：贮藏期间,冷藏库0℃贮藏草莓的可滴定酸和VC含量高于冷库-3℃和常温20℃贮藏的草莓,0℃贮藏7 d的草莓可滴定酸和VC含量分别为0.58%、29.8 mg/100 g;贮藏7 d时,-3℃贮藏草莓的可溶性固形物含量高于0℃和20℃处理,失重率和腐烂指数最低,分别为8.41%、8%、9.93;贮藏期间,0℃和-3℃贮藏草莓的感官品质均较好,优于20℃贮藏的草莓。综上可得,冷藏库0℃和-3℃贮藏草莓的品质优于常温20℃贮藏的草莓;冷藏库-3～0℃低温贮藏有利于保持草莓的品质,且避免草莓冻害。该研究可为草莓贮藏保鲜技术的研发提供参考。     

Application of low concentrations of ozone during the cold storage of table grapes

The control by ozone of postharvest decay of table grapes, caused by Botrytis cinerea and other pathogens, was evaluated in chambers and commercial storage facilities. Ozone at 0.100 μL/L or higher inhibited the spread of gray mold among stored grapes. Ozone diffusion into many types of commercial packaging was measured. Boxes made of uncoated paper corrugate inhibited diffusion more than those composed of coated paper corrugate, plastic corrugate, hard plastic, or expanded polystyrene. Internal packaging of hard plastic clamshell containers inhibited diffusion less than low density polyethylene cluster bags. Atmospheres of 0.100 μL/L ozone in the day and 0.300 μL/L at night reduced the natural incidence of gray mold by approximately 65% after 5–8 weeks of storage. Its effectiveness to control postharvest decay was compared to sulfur dioxide fumigation. After 68 days at 1 °C the incidence of gray mold among grapes stored in air, ozone, or with weekly sulfur dioxide fumigation was 38.8%, 2.1%, and 0.1%, respectively. However, decay by other fungi, such as Alternaria spp. and Penicillium spp., was controlled by sulfur dioxide, but not by ozone. In some tests, rachis appearance was moderately harmed by ozone. The combination of ozone use in storage following a single initial sulfur dioxide fumigation, or its use in between biweekly sulfur dioxide fumigations, controlled both gray mold and other pathogens and matched the commercial practice of initial and weekly sulfur dioxide fumigation. The use of both gases in this way reduced sulfur dioxide use greatly. Differences in flavor of grapes treated with ozone were not detectable compared to those stored in air, and grapes treated with ozone were preferred over those treated with sulfur dioxide.     

几种贮藏方式对新疆厚皮甜瓜采后生理及贮藏品质的影响

为研究贮藏方式对厚皮甜瓜采后生理及贮藏品质的影响,以期得出比较理想的贮藏方式。本实验以新疆厚皮甜瓜“金凤凰”为试材,分别进行了冷藏、冷藏结合臭氧间隙处理、O2 4%~6%、CO2 0.2% ~ 0.5% 气调三种贮藏方式的比较研究。结果表明,在6℃贮藏条件下,气调贮藏显著抑制了甜瓜的呼吸强度,延缓了果实的衰老,并有效抑制了果肉硬度、可溶性固形物、Vc和还原糖含量的下降,降低了果实的腐烂指数,保持了甜瓜较好的品质和风味。试验同时得出采用冷藏结合臭氧间隙处理模式,效果好于冷藏,但不及气调贮藏的效果。     

气调冷藏对龙眼保鲜品质的影响

以提高龙眼果实保鲜质量为目的,采用可控气体成分调节方法,温度、湿度和气体成分全自动控制,以普通冷藏为对照对龙眼进行气调保鲜。研究了气调冷藏对龙眼果实保鲜效果、果实营养成分及理化指标的影响。结果表明,通过降低贮藏环境中的O2含量,提高CO2浓度,可有效抑制龙眼果实的呼吸作用,延缓了果实的衰老与变质,保鲜效果好,商品率高。     

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.     

1-MCP处理对黄瓜冷藏期间保鲜效果的影响

以“叶三”黄瓜果实为材料,采用10 ppm1-MCP处理24 h后,与对照(CK)同时转入0℃低温冷藏,并对低温贮藏过程中的黄瓜感官品质、组织相对电导率、可滴定酸(TA)、Vc含量和失重率的变化进行了研究,结果表明,1-MCP处理可抑制低温贮藏中黄瓜相对电导率的上升,减缓黄瓜果实冷害症状的发展,同时延缓Vc和可滴定酸的下降速率,维持黄瓜较好品质。     

Effect of prolonged cold storage on the sensory quality of peach and nectarine

To maintain peach and nectarine quality after harvest, low temperature storage is used. Low temperatures induce physiological disorders in peach, but the effect of cold storage on the sensory quality of the fruit before it is damaged by chilling injury syndrome remains unclear. To evaluate the cold storage effect on the sensory quality two peach cultivars (’Royal Glory’ and ‘Elegant Lady’) and two nectarines (’Ruby Diamond’ and ‘Venus’) were harvested at a standardized firmness level and subjected to quality evaluations and sensory analysis at harvest and after storage at 0 °C for 35 d. For both time points, a supplementary ripening followed such that homogeneous flesh firmness and suitability for consumption was achieved.The fruit segregation through the Durofel firmness (DF), evaluated using a non-destructively method (Durofel device), allowed the formation of a uniform group of fruit in terms of flesh firmness (FF), showing scores between 45.1 and 55.9 N. The average FF in fruit ripened immediately after harvest was 22.9 N and 25.6 N in fruit ripened after cold storage for 35 d.The “acceptability” of fruit is highly correlated with “aroma”, “sweetness”, “juiciness”, “texture” and “flavor”. Only the “acid taste” parameter had no significant correlation with “acceptability” or with the other parameters evaluated.It is possible to conclude that the sensory quality and acceptability of peach and nectarine are characteristic of each cultivar and change, depending on the time elapsed after harvest. In general, it was confirmed that nectarine cultivars have a more consistent quality than peach cultivars.     

保鲜剂与保鲜膜在芒果贮藏保鲜中的应用试验

芒果(MangiferaindicaL.)是典型热带水果,七八成熟的果实采后在常温下5～7d,即可完全成熟,而后稍不加控制马上会迅速腐烂。分析其原因有两个:一是果实发生生理病变,如营养失调,过度失水,有毒代谢产物过多积累等,导致果实组织中毒,扰乱果品正常生理;二是病原真菌和细菌浸染,引起果实组织败坏崩解而腐烂。其中后者产生的作用更为严重。急需加强采后保鲜技术研究。笔者试验的目的是研究贵妃芒、台农芒的采后生理及保鲜措施,为芒果保鲜提供技术服务。     

Effect of non-conventional atmospheres and bio-based packaging on the quality and safety of Listeria monocytogenes-inoculated fresh-cut celery (Apium graveolens L.) during storage

The increased consumption of fresh-cut celery has led to the need to explore packaging alternatives for fresh-cut celery that can meet consumer, market, and industry needs. In this study, the effect of bio-based packaging and non-conventional atmospheres on the quality and safety of chlorine-sanitized celery sticks stored at 7 °C was investigated. Two materials differing in permeability [a bio-based polyester (polylactic acid (PLA)) and a petroleum-based polyolefin (polypropylene/low density polyethylene (PP/PE)] and four initial gas compositions [air (A-PLA or A-PP/PE), 95 kPa O₂ + 5 kPa N₂ (O₂-PLA), 99 kPa N₂ + 1 kPa O₂ (N₂-PLA), and 6 kPa O₂ + 12 kPa CO₂ + 82 kPa N₂ (CO₂-PLA)] were evaluated. Changes in headspace composition, weight loss, surface and cut end color, texture, ethanol content, appearance, and growth of Listeria monocytogenes on inoculated celery sticks were assessed during 21 d of storage. Active MAP (CO₂-PLA) out-performed passive MAP (A-PLA) in maintaining celery stick quality but not safety. Conventional active MAP (CO₂-PLA) out-performed non-conventional active MAPs (O₂-PLA and N₂-PLA) in maintaining celery stick quality throughout storage, but O₂-PLA suppressed L. monocytogenes growth while CO₂-PLA promoted growth during the first 10 d of storage. PLA and PP/PE materials affected celery stick quality but not Listeria growth. This study shows that the initial gas composition and packaging material both impact the quality and safety of celery sticks. Overall, the combination PLA and 95 kPa O₂ proved most beneficial in maximizing both the safety and quality of celery sticks during one week of storage at 7 °C.     

Effect of hyperbaric pressure and temperature on respiration rates and quality attributes of tomato

Previous work with hyperbaric treatment of tomato focused on application at lower temperature (13 °C). In this work, hyperbaric treatment at varying pressure levels (i.e., 0.1, 0.3, 0.5, 0.7 and 0.9 MPa) at ambient temperature (20 °C) was tested as a potential alternative to conventional refrigerated storage (0.1 MPa at 13 °C) to preserve tomato quality. The experiments were divided into 3 phases: (1) 4 day of hyperbaric treatment, (2) 5 day of post-treatment ripening, and (3) 10 day of post-treatment ripening. Respiration rate (RR) of the tomatoes was continuously monitored during the course of the hyperbaric treatments. Quality attributes were assessed immediately after removal from the hyperbaric treatments and after 5 and 10 day ripening at 20 °C after removal from the treatments. Hyperbaric treatments at ≥0.3 MPa resulted in RR equal or higher than the RR in control fruit (0.1 MPa at 20 °C). The lowest RR was obtained from tomato stored at 0.1 MPa at 13 °C. Hyperbaric treatment at 0.5, 0.7 and 0.9 MPa significantly reduced weight loss, retained color, firmness, total soluble solid (TSS), titratable acidity (TA) and TSS:TA ratio at similar levels as the tomato treated at 13 °C and 0.1 MPa. Firmness after treatment was highest for fruit from 0.1 MPa at 13 °C and from 0.5, 0.7 and 0.9 MPa at 20 °C. The higher firmness advantage declined by 5 day of ripening after treatment, with higher firmness only being retained for fruit from the 0.9 MPa at 20 °C and the 0.1 MPa at 13 °C treatments. After 10 day ripening, firmness was similar for all treatments. Lightness (L*) and hue angle were greater for all treatments compared with the 0.1 MPa at 20 °C treatment. However, only the greater hue angle difference was maintained after 5 day of ripening. After 10 day ripening, no significant differences were found in color attributes. Only 0.1 MPa at 13 °C retained higher soluble solids, lower titratable acidity and higher TSS:TA ratios after treatment and after 5 day ripening. At 10 day of ripening none of the quality attribute differences noted were retained for any of the treatments. These results show that the only consistent effect of hyperbaric treatment at 0.5, 0.7 and 0.9 MPa was to reduce weight loss and enhance firmness retention up to 5 day ripening after treatment.     

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.