预温处理对草莓贮藏保鲜效果的影响

本试验从草莓果实贮藏期间的腐烂率入手,研究了不同贮前预温处理对草莓果实采后贮藏保鲜效果的影响。结果表明:预热处理后,无论是冷藏或室温贮藏,均以贮前50℃30min 处理的果实腐烂率最低;预冷处理后,室温贮藏条件下,以5℃30min处理的果实腐烂率最低;预冷处理和预热处理均能明显抑制果实 Vc 含量的下降。     

流态冰预冷处理对西兰花品质及生理的影响

本实验为了探究流态冰预冷处理对西兰花贮藏品质的影响,以西兰花为实验材料,将其用流态冰预冷处理后,待温度降至0±1℃后于货架温度(20±1℃)贮藏。测定贮藏期间西兰花的黄化指数、感官评分、叶绿素、硫代葡萄糖苷、抗氧化酶活性等生理指标,探究流态冰预冷处理对西兰花货架期品质的影响。结果表明:流态冰预冷技术可以快速将西兰花降温至0.4℃,降温时间缩短至4 h;在贮藏第3 d,经过流态冰处理的西兰花,叶绿素和维生素C(Vc)含量高于CK组2倍,丙二醛(MDA)含量高于CK组1倍,可溶性固形物(TSS)和硫代葡萄糖苷含量均处于较高水平,保持了西兰花的营养品质;贮藏第3 d,过氧化氢酶(CAT)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)的活性,分别提高了32%、23%和64%,增强了其抗氧化酶活性。故流态冰预冷处理可有效维持西兰花的贮藏品质。     

不同预冷方式结合1-MCP处理对蟠桃冷藏品质的影响

针对新疆蟠桃不耐贮藏，贮藏品质差等问题，分别采用蓄冷周转箱、原位压差、冷库直冷式预冷并结合1μL/L 1-MCP对蟠桃果实进行熏蒸及纳米聚乙烯微孔保鲜膜包装的预处理措施，以无预冷及熏蒸处理为CK，通过测定果实腐烂率、硬度、呼吸强度、SSC、MDA、总酚含量、CAT和POD等指标，分析蟠桃在贮藏过程中冷藏品质变化的规律及作用机理。结果表明，1-MCP结合3种预冷方式均可减少蟠桃果实的腐烂率，延缓蟠桃的硬度、总酚、SSC含量的下降速度；推迟呼吸高峰的出现，抑制MDA在果实体内的积累，提高果实的POD、CAT活性，延长果实新鲜品质的保质期。其中以1-MCP结合原位压差预冷处理的效果最优，在贮藏第36 d，处理组果实的腐烂率、呼吸强度和MDA较CK组分别降低33.33%,33.33%,27.78%，硬度、SSC、CAT和POD较CK组分别提高60%,42.86%,60%,66.67%，促进蟠桃的正常后熟，最大限度地保持果实的新鲜品质。研究为蟠桃规模化贮运保鲜提供技术借鉴。     

中药提取物对‘红地球’葡萄保鲜效果的影响

以黄连、黄芩、大黄、大青叶、艾叶五种中药材的乙醇提取物浸渍处理‘红地球’葡萄,以无菌水为CK1、2 g·L^-1的亚硫酸钠溶液为CK2,在4℃下贮藏65 d,比较不同中药提取物处理的‘红地球’葡萄果实腐烂率、总酚和抗坏血酸含量、可溶性固形物及相关抗氧化酶活性的差异,旨在明确中药提取物在葡萄贮藏保鲜方面的应用潜力。结果显示,大青叶处理组的葡萄果实多酚、抗坏血酸、可溶性固形物含量下降速度均较慢,烂果率较低,抑菌效果较优,多酚氧化酶(PPO)活性较低;艾叶处理组烂果率较低,抑菌效果最优,超氧化物歧化酶(SOD)、过氧化物酶(POD)活性较高,多酚氧化酶(PPO)活性较低;黄芩处理组SOD、POD酶活性显著高于CK1、CK2,抗坏血酸、可溶性固形物含量下降速度较慢。大青叶、艾叶和黄芩提取物对‘红地球’果实的贮藏保鲜具有一定效果,其中黄芩处理能使葡萄果实维持较高的抗氧化保护酶活性,以保持果实的品质;而大青叶和艾叶处理能较好地抑制葡萄表面杂菌生长,延缓葡萄果实的腐烂来保持果实品质。综合比较,大青叶对葡萄贮藏品质的综合保鲜效果较佳。     

短波紫外线、热空气和丁香酚处理对“晚秋红心桃”采后病害的抑制作用及果实品质的影响

该研究以晚熟桃“晚秋红心桃”为原料,分别进行短波紫外线、热空气和丁香酚处理,随后于20℃贮藏8 d,期间每2 d取样,测定果实的发病率、病斑直径、颜色、硬度、失重率、可溶性固形物含量和可滴定酸含量。结果表明,3种处理均能有效抑制采后病害的发生,其中热空气处理效果最佳。经热空气处理(40℃,4 h)后,桃果实病害发生率和病斑直径显著低于对照(P<0.05),贮藏第8天时,桃果实病害发生率为20.00%,病斑直径为15.98 mm。此外,热空气处理能够显著抑制采后桃果实失重率的上升和硬度的下降,维持采后果皮色泽(P<0.05)。主成分分析结果进一步证明,热空气处理能维持桃果实采后贮藏期间的品质。综上所述,热空气处理对“晚秋红心桃”采后病害具有良好的抑制效果,并且对桃果实保鲜具有一定的增效作用。     

葡萄糖酸钙采前处理对鲜枣果实低温贮藏品质及活性氧代谢的影响

以鲜枣(Zizyphus jujube cv.Fengmiguan)为材料,用0.1 mol/L葡萄糖酸钙在白露时节开始每7 d喷洒1次果实,根据喷洒次数预设处理1、处理2、处理3和CK(未处理),果实着色面积达到50%～70%时采摘,0±0.5℃下贮藏,每10 d取样并测定相关指标。结果表明,与CK相比,不同处理组都能抑制果实的失重率、维生素C、叶绿素和多酚含量的下降,阻止H_2O_2、相对电导率和MDA含量的上升,CK处理1处理2处理3,且差异显著(P0.05);采前钙处理能降低腐烂率、O~-_2·的含量、提高硬度和可溶性蛋白,但处理次数对腐烂率的影响不显著(P0.05),硬度、O~-_2·、可溶性蛋白的变化未表现出规律性。     

高压静电场对早艳桃贮藏品质的影响

以早艳桃果实为原料，研究了-100kV／m高压静电场处理对果实失重率、褐变率、腐烂率、果肉硬度、呼吸强度以及相对电导率变化的影响。试验结果表明，高压静电场处理能够有效保持桃果实的采后品质，明显降低早艳桃贮藏过程中的失重率、褐变率和腐烂率，对桃果实的呼吸强度有一定的抑制作用，减缓果实硬度的下降过程，同时使果实果皮相对电导率上升缓慢。     

臭氧处理对哈密瓜采后腐烂与细胞壁代谢影响

为研究臭氧处理对哈密瓜采后腐烂与细胞壁代谢关系,以“西州蜜25 号”哈密瓜为材料,在常温（22.0±0.5）℃下分别对哈密瓜进行0 mg/m3（对照组）和10 mg/m3（臭氧处理组）臭氧处理4 h,置于常温下贮藏,观察记录哈密瓜贮藏期间腐烂症状,测定腐烂指数、腐烂率及细胞壁代谢相关指标。结果表明,与对照组相比,臭氧处理不仅抑制哈密瓜果实采后腐烂指数和腐烂率的上升,减轻腐烂症状,并且抑制果实多聚半乳糖醛酸酶、β-葡萄糖苷酶和β-半乳糖苷酶活性,降低纤维素酶活性,从而延缓原果胶的降解以及可溶性果胶含量的增加,较好保持哈密瓜果实硬度,延缓果实软化、降低果实腐烂、延长果实贮藏期。因此,臭氧能够在一定程度上抑制细胞壁降解酶对果胶的降解,从而维持细胞壁坚挺,达到延缓软化以及果实腐烂的目的。     

不同涂膜处理对水蜜桃常温贮藏品质的影响

以水蜜桃为试验材料,研究壳聚糖、海藻酸钠、普鲁兰多糖浸泡涂膜处理对水蜜桃采后常温下(28℃)贮藏品质的影响,定期测定各项生理指标。结果表明,与对照组相比,3种涂膜处理均能在不同程度上抑制水蜜桃果实的腐烂过程,维持贮藏期果实的品质。海藻酸钠涂膜处理果实能够显著降低果实的腐烂率(比对照组降低40%),同时维持果实硬度、延缓丙二醛含量的上升;壳聚糖涂膜处理在控制果实失重、抑制多酚氧化酶活性方面则优于海藻酸钠和普鲁兰多糖;3种涂膜处理在维持可溶性固形物含量、抑制呼吸方面无显著差异。1%海藻酸钠涂膜处理由于能够显著抑制果实腐烂,延长果实的货架期,保鲜效果相对最佳。     

控制桃果实采后病害拮抗酵母的筛选及其固体制剂的制备

通过体内实验筛选对桃果实采后软腐病具有控制作用的拮抗酵母菌,并考察其对桃果实自然腐烂的控制效果及对桃果实品质的影响。通过单因素试验优化喷雾干燥法制备拮抗酵母固体制剂的条件,并考察保存90 d的固体制剂对桃果实采后软腐病的控制效果。结果表明,膜醭毕赤酵母(Pichia membranaefaciens)处理的桃果实贮藏72 h后,软腐病造成的腐烂率(26.23%)显著低于对照(95.70%)。该拮抗酵母还可显著降低桃果实采后自然腐烂,且对其品质无显著不良影响。制备固体制剂的优化条件为:保护剂阿拉伯胶与海藻糖的质量比1∶1、保护剂质量浓度100 g/L、雾化器压强200 kPa、进风温度100℃、进料速率15 mL/min。制备的固体制剂在25℃和4℃保存90 d后,酵母存活率分别为66.97%和82.91%。4℃保存90 d的固体制剂处理的桃果实软腐病腐烂率(37.04%)与新鲜制备的拮抗酵母处理的桃果实腐烂率(31.48%)虽有显著性差异,但控制效果仍然非常明显。     

1-MCP和预贮对深州蜜桃采后生理和品质的影响

为保持深州蜜桃冷藏期间良好的品质, 延长贮藏时间, 采用1 . 0 μ L / L 1 - 甲基环丙烯
（1-methylcyclopropene,1-MCP）熏蒸和预贮（8 ℃、5 d转入0 ℃）的方法对采后深州蜜桃进行处理,测定0 ℃冷
藏期间果实呼吸速率、乙烯释放速率和品质的变化。结果表明,1-MCP处理能够明显抑制桃果实冷藏期间的呼吸速
率和乙烯释放速率,推迟呼吸高峰期的出现;同时延缓了果实软化,抑制可溶性固形物含量上升,降低了果实的褐
变指数和腐烂指数;预贮促进了果实后熟,但预贮和1-MCP处理均明显降低了贮藏期果实褐变度和酚类物质含量,
二者结合处理对抑制果实褐变效果最佳。     

The effect of impact and fruit properties on the bruising of peach

Peach fruit quality is adversely affected by bruise damage. In order to reduce this damage, it is necessary to know the influence of fruit properties on bruise susceptibility. Two bruise prediction models were constructed for the damage susceptibility of peach fruit (measured by bruise volume) using multiple linear regression analyses. In the first model, peak contact force and three fruit properties (acoustic stiffness, fruit temperature and radius of curvature) were used as independent variables. In the second model, peak contact force was replaced by the impact energy. Peaches were subjected to dynamic loading by means of a pendulum at three levels of impact. Significant effects of acoustic stiffness, temperature and the radius of curvature and some interactions on bruising were obtained at 5% probability level with the coefficient of determination of 0.97 and 0.98 for models 1 and 2, respectively. It was concluded that lowering the temperature and increasing the radius of curvature and acoustic stiffness will reduce the bruise damage of the peach fruit.     

臭氧结合1-MCP对桃子货架期品质的影响

为研究臭氧结合1-MCP对桃子货架期品质的效果,以"红桃"桃子为试验材料,采用3种不同地处理(臭氧、1-MCP、臭氧+1-MCP)及对照(CK)对桃子进行货架期贮藏(20±0.5℃)保鲜,研究不同处理对桃子货架期间品质的变化。结果表明,与对照组比较,3种处理均能够推迟桃子的生理代谢水平,保持桃子的货架期品质。其中,臭氧结合1-MCP对桃子的保鲜效果更好,能够显著抑制桃子腐烂指数、呼吸强度及乙烯生成速率的上升,推迟桃子硬度和可溶性固形物含量的降低,保持桃子过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、过氧化物酶(POD)和脂氧合酶(LOX)的活性。因此,臭氧结合1-MCP处理对桃子的保鲜效果最好,能够更好地保持桃子的货架期品质。     

Forced‐air precooling treatment enhanced antioxidant capacities of apricots

Effects of forced‐air precooling on fruit quality and antioxidant system of apricot were evaluated in this study. Apricots were forced‐air precooled for 24 hr at 0°C, and then stored at 0°C for up to 20 days. Results showed that precooling treatment slowed down a decrease of titratable acidity (TA) and total soluble solids (TSS) during storage period, whereas it had no effect on pH and L* value. On the 15th day of storage, associated with higher flavonoids content, precooled fruit had 73.6% higher DPPH and 183% higher ABTS radical‐scavenging activities than the control. In addition, the peak of ascorbate peroxidase (APX) was earlier, and H₂O₂ content was reduced by precooling treatment with respect to control. These results indicate that precooling treatment could maintain the quality of apricot by enhancing antioxidant activity.

Practical applications

Fruit with high antioxidants implies high nutritional value. In this study, we found forced air precooling induced an increase of antioxidant activity of apricots. Precooling treatment should be used to enhance the quality and nutritional value of apricots.     

不同包装及延时预冷处理对模拟冷链贮运及货架期期间桃果实品质的影响

对不同包装和延时预冷的“八月脆”桃在－ 0.5～0℃低温条件下贮藏15d,随后回温3d,通过测定硬度、可溶性固形物、果实颜色、失重率和腐烂率等品质指标,以探求桃果实满足冷链贮运和货价期要求的最佳预冷和包装条件。结果表明,采用包装纸+ 纸箱(X1)和网套+ 礼品盒(X2)的果实在冷藏15d 后均能保持较高的硬度,SSC 变化不明显,X1 果实腐烂率显著高于其他两组,未包装(X3)果实失重率最高。在回温3d 后,X2 果实的硬度(11.45N)和SSC(9.99%)显著高于X1,腐烂率和失重率最低,果实表面着色充分,果肉未出现褐变;采后6h 入库预冷的果实在冷藏15d 和回温3d 后的硬度均显著高于采后12h 和18h 入库果实,腐烂率和失重率均显著低于对照组,果实表面色泽呈微红色,果心处无褐变。综合评定采后6h 入库预冷和采用网套+ 礼品盒包装果实的贮运性和货架期的商品率较高。     

不同挥发性物质对桃果实品质及抗氧化活性影响的多变量分析

采用单因素方差分析、主成分分析、相关性分析、偏最小二乘回归分析、通径分析5种数据分析方法考察1-甲基环丙烯(1-MCP)、二氧化氯、百里酚和乙醇处理对桃果实品质及抗氧化活性的作用效果。结果表明：乙醇处理可显著抑制常温贮藏4d后桃果实侵染性病害的发生,其他处理与空白对照无显著性差异;1- MCP 处理延缓了桃果皮b*值的升高,乙醇处理提高果皮L*值的同时降低了果皮a*值;与空白对照相比,乙醇、1-MCP及二氧化氯处理对总黄酮含量、总抗氧化能力、清除DPPH自由基能力、清除·OH能力4个指标的影响较为显著。结合相关性分析与回归分析可知,腐烂率仅与可溶性固形物含量(SSC)呈显著负相关;对果皮L*值、果皮a*值、果皮b*值的直接效应最为强烈的参数分别是总黄酮含量、清除DPPH自由基能力、SSC;总酚含量与清除DPPH自由基能力具有显著正相关性;总黄酮含量与总抗氧化能力、清除DPPH自由基及·OH能力也存在显著或极显著相关性效应。     

Effect of yeast antagonist in combination with heat treatment on postharvest blue mold decay and Rhizopus decay of peaches

The potential of using heat treatment alone or in combination with an antagonistic yeast for the control of blue mold decay and Rhizopus decay of peaches caused by Penicillium expansum and Rhizopus stolonifer respectively, and in reducing natural decay development of peach fruits, as well as its effects on postharvest quality of fruit was investigated. In vitro tests, spore germination of pathogens in PDB was greatly controlled by the heat treatment of 37 degrees C for 2 d. In vivo test to control blue mold decay of peaches, heat treatment and antagonist yeast, as stand-alone treatments, were capable of reducing the percentage of infected wounds from 92.5% to 52.5% and 62.5%, respectively, when peach fruits stored at 25 degrees C for 6 d. However, in fruit treated with combination of heat treatment and Cryptococcus laurentii, the percentage of infected wounds of blue mold decay was only 22.5%. The test of using heat treatment alone or in combination with C. laurentii to control Rhizopus decay of peaches gave a similar result. The application of heat treatment and C. laurentii resulted in low average natural decay incidences on peaches after storage at 4 degrees C for 30 days and 20 degrees C for 7 days ranging from 40% to 30%, compared with 20% in the control fruit. The combination of heat treatment and C. laurentii was the most effective treatment, and the percentage of decayed fruits was 20%. Heat treatment in combination with C. laurentii had no significant effect on firmness, TSS, ascorbic acid or titratable acidity compared to control fruit. Thus, the combination of heat treatment and C. laurentii could be an alternative to chemicals for the control of postharvest decay on peach fruits.     

不同保鲜剂处理对水蜜桃贮藏效果的研究

研究不同保鲜处理剂(消毒液、植酸、脱氢醋酸钠)对水蜜桃生理生化变化的影响.在自然条件下,以普通贮藏为对照,对水蜜桃失重率、呼吸强度、硬度、多酚、多酚氧化酶、总酸、可溶性固形物、VC含量进行分析测定,结果表明,经过处理能抑制水蜜桃的呼吸强度,延缓硬度、多酚、总酸、可溶性固形物和VC含量的下降速度,抑制失重率和多酚氧化酶的活性,有利于水蜜桃的保鲜.     

预冷方式对长枣保鲜效果的影响

为了探究不同预冷方式对长枣保鲜效果的影响,本实验采用真空、压差和冷库预冷处理长枣,分析（1±1）℃贮藏期间长枣品质及抗氧化酶活力的变化。结果表明,与未预冷相比,3 种预冷处理均抑制了长枣的质量损失和软化,维持了可溶性固形物含量、可滴定酸质量分数及抗坏血酸含量,延缓了丙二醛积累和细胞膜透性增加。同时,预冷处理通过提高抗坏血酸过氧化物酶、超氧化物歧化酶和过氧化氢酶活力增强了细胞抗氧化能力,延缓了果实的氧化褐变和衰老。其中,压差预冷与其他处理组相比,能更显著抑制丙二醛积累和细胞膜透性增加,抑制细胞膜脂质过氧化保护细胞结构,同时维持较高的抗氧化酶活力,抵御氧化胁迫,抑制褐变,从而维持较高的贮藏品质,保鲜效果更佳。主成分分析结果进一步证明,压差预冷处理长枣贮藏稳定性更高,保鲜效果优于真空预冷和冷库预冷。综上所述,压差预冷能够有效维持长枣贮藏品质,延缓成熟和衰老进程。     

PERFORMANCE OF AN INSTRUMENT DESIGNED FOR,AND EVALUATION OF METHODS TO ASSESS,PEACH FRUIT IMPACT BRUISE SUSCEPTIBILITY1

A simple, inexpensive device was fabricated for imposing drop impact loads on fruit and tested using a 0.5 J load on peach [(Prunus persica (L.) Batsch] fruit harvested at two maturity stages. The device consists of an electromagnet to secure a metallic mass above the fruit, a height adjustment for positioning the mass, a foot pedal switch for interrupting current to the electromagnet, allowing the mass to strike the fruit, and a thick aluminum base to prevent fruit movement upon impact. Following impact, fruit were stored at 2C for one week (to simulate impact damage during harvest and packing, prior to short term cold storage). Impact bruise susceptibility was assessed after storage by bruise occurrence (without regard to bruise size), and by bruise severity (measured as bruise depth, bruise width and bruise discoloration). Maturity at harvest had no effect on bruise occurrence, but did significantly effect bruise severity. Bruise depth was more sensitive than bruise width or discoloration to differences between cultivars. Cultivar ranking for bruise susceptibility differed, depending on the parameter used to obtain the ranking.