脱涩方法对三种成熟度磨盘柿货架品质的影响

目的 为了探讨真空包装脱涩和干冰脱涩方法对不同成熟度磨盘柿的脱涩效果和货架品质的影响。方法 以北京房山3种成熟度（7成、8成、9成）磨盘柿为实验材料,在常温下采用真空脱涩和干冰脱涩等2种方法进行柿果脱涩,研究不同脱涩方法对3种磨盘柿可溶性单宁的影响和脱涩后货架期间果实营养品质、呼吸强度、硬度、色泽和挥发性成分的变化规律。结果 真空包装脱涩处理7成、8成、9成熟柿果的脱涩时间分别为144,72,60 h,而干冰处理7成、8成、9成熟柿果的脱涩时间分别为48,24,24 h。随着成熟度的增加,果实硬度、脱涩时间逐渐降低,但可溶性固形物含量逐渐升高。7成熟柿果的挥发性成分变化速率较8成、9成熟柿果变化快。另外,3种柿果脱涩前Vc含量均高于脱涩后,干冰脱涩时间较真空脱涩时间快,且有效延缓了脱涩后果实硬度的降低。8成熟柿果果实色泽鲜艳,果实硬度和可溶性固形物含量在货架期变化较小。结论 干冰脱涩8成熟柿果常温货架品质较优。     

不同温度对真空包装下鲜切胡萝卜贮藏品质的影响

目的 研究不同贮藏温度对真空包装下鲜切胡萝卜贮藏品质的影响。方法 将新鲜胡萝卜切片后采用真空包装，分别置于4、8和20℃下贮藏3、12和25 d。分析贮藏期间鲜切胡萝卜的感官品质、色差、气味、硬度、呼吸强度、菌落总数和总酚含量的变化并进行测定。结果 与8℃和20℃下贮藏相比，4℃低温贮藏显著抑了制微生物生长，降低了表面白化现象发生的概率，保持了鲜切胡萝卜的硬度。不同温度下短期贮藏的鲜切胡萝卜气味变化无明显差异，但长期贮藏后会导致甲基类、氮氧化合物、醇类和醛酮类等化合物的释放。4℃条件下样品的总酚含量显著低于8℃和20℃。结论 较短时间的高温贮藏可以促进酚类化合物的合成和积累，而低温结合真空包装可以保持鲜切胡萝卜的品质以及保证食用的安全性。     

包装方式对留胚米品质的影响

目的 研究在3种贮藏温度条件下,4种包装方式对留胚米品质的影响。方法 以实验室自制留胚米（留胚率为85%）为实验材料,选用同一种包装材料,分别采用普通包装、真空包装、充CO2包装和充N2包装等4种方式,并在3种不同温度（5,25,35 ℃）条件下贮藏,以感官品质、含水率和脂肪酸含量为评价指标,定期抽样测量各指标的变化规律。结果 各种包装方式下的留胚米感官品质均随贮藏时间的增加而降低,含水率随贮藏时间的增加呈现先增加后降低的规律,脂肪酸含量随贮藏时间的增加而增加。普通包装的留胚米在5,25,35 ℃下贮藏的保质期分别为45,30,15 d;真空包装的留胚米在5 ℃下贮藏的保质期大于120 d,在25 ℃和35 ℃下贮藏的保质期分别为105 d和90 d;充CO2包装的留胚米在5 ℃和25 ℃下贮藏的保质期为90 d,在35 ℃下贮藏的保质期为60 d;充N2包装的留胚米在5,25,35 ℃下贮藏的保质期分别为90,75,60 d。结论 真空包装为最适宜的包装方式,其次为充CO2包装和充N2包装,普通包装方式的留胚米保质期相对最短。     

GB／T 22445-2008《地理标志产品 房山磨盘柿》标准解读

磨盘柿又称盖柿、盒柿、腰带柿、帽儿柿、重台柿、箍箍柿或藕柿,为华北地区主要品种。磨盘柿是北京地区的主栽品种,北京市约60％的磨盘柿分布在房山区。目前,房山区磨盘柿栽培面积达到12．1万亩,年产量2300余万公斤,产量在我国磨盘柿生产中占有一定的比例。     

不同种植条件莲藕的真空包装品质综合评价

目的 研究真空包装及不同种植条件对莲藕贮藏和营养品质的影响,明确品质指标间的相关性,建立莲藕采后品质综合评价体系。方法 首先对比真空包装对莲藕失水率及色泽的影响。在此基础上以真空包装的莲藕为实验材料,研究露天和大棚2种种植方式及长、短种植周期对莲藕贮藏品质和营养成分的影响,利用品质指数(Lotus Quality Index,LQI)对莲藕营养品质进行评价。结果 低温下,真空包装能有效缓解莲藕水分散失及维持外观色泽,将货架期从2 d延长至10 d左右。大棚长周期种植的莲藕耐贮性最强,外观品质保持较好,而大棚短周期产品营养品质最佳。单位质量莲藕中可溶性固形物(Total Soluble Solids,TSS)、总糖、淀粉、可溶性蛋白、抗坏血酸(Vitamin C,Vc)和总酚经10 d贮藏后均增加。LQI表明真空包装有利于维持莲藕贮藏期间的营养价值。结论 大棚种植有效提升了莲藕的营养及贮藏品质,而种植周期要结合经济效益决定。     

不同处理对磨盘柿采后生理和货架品质的影响

目的 在常温条件下,研究1-MCP与高浓度CO2脱涩处理方式对柿果实采后生理和货架品质的影响。方法 以磨盘柿为实验材料,选用体积分数85%~90%的CO2对柿果脱涩24 h,1.0 μL/L浓度的1-甲基环丙烯（1-methylcyclopropene,1-MCP）处理,探究不同处理方式（CO2脱涩、1-MCP处理后CO2脱涩、1-MCP与CO2脱涩同时处理）对柿果呼吸强度、乙烯生成速率、颜色、质地、营养物质（TSS,TA,Vc）含量和挥发性气体成分的影响。结果 在货架期内,与CO2脱涩（CK）相比较,1-MCP处理后脱涩可以有效降低柿果呼吸强度,抑制乙烯生成速率,延缓柿果色泽的改变,延缓柿果在货架期间硬度和脆性的下降速率,使果实的营养物质（TSS、TA及Vc含量）维持在较高水平,有效减缓了挥发性香气成分的减弱。实验结果进一步表明,与CK组相比,1-MCP与CO2脱涩同时处理技术加速了果实的成熟软化,且贮藏后期差异显著（P < 0.05）。结论 柿果经1-MCP处理之后再进行高浓度CO2脱涩不仅可以如期脱涩,而且还具有较好的保脆、保鲜效果,延长了柿果的货架期,所以相较于其他2个处理组,1-MCP处理后再脱涩组果实的货架品质最佳。     

常温运输后甜樱桃不同温度贮藏品质变化研究

目的探明经物流运输后甜樱桃不同温度贮藏期间品质的损耗情况。方法以雷吉娜甜樱桃为实验材料,研究经常温运输以后甜樱桃在25,5,0℃下贮藏品质的变化情况。结果在25,5,0℃贮藏温度下,甜樱桃果实分别在贮藏5,15,35 d时保持腐烂率低于5%。5℃和0℃贮藏均可以保持较高的果柄拉力。0℃贮藏维持了甜樱桃果实较高的硬度、可溶性固形物和可滴定酸含量,延缓了果实VC含量的下降和花青素的积累。结论 25℃和5℃贮藏时,甜樱桃果实的贮藏期分别为5 d和15 d,甜樱桃在0℃贮藏35 d后仍具有较好的感官品质。     

不同包装方式对黑山羊冷鲜肉保鲜效果的比较

目的以新鲜的黑山羊肉为原料,研究真空和气调包装对山羊肉贮藏过程中感官质量、pH值、色泽、菌落总数、TVB-N值等主要技术指标变化的影响。方法将山羊屠宰后取其后腿,在-18℃下冷却到中心温度低于4℃后,去掉筋腱和脂肪,切分成约30 g的肉块,随机分成2组,装入已灭菌的包装袋内进行真空和气调包装,4℃贮藏,每隔3 d进行技术指标的测定。结果贮藏到16 d时,气调包装组的感官品质明显优于真空包装组;整个贮藏期,2组试样的pH值都低于6.6,即符合标准中对山羊肉pH值的要求;贮藏的前16 d,气调包装组的a*值高于真空包装组,表明气调包装较好地保持了羊肉的自然色泽;贮藏到16 d时,真空包装组的菌落总数为6.12,已超标,而气调包装组的试样属于次鲜肉;贮藏20 d,气调包装组的TVB-N值仍不超标,而真空包装组的TVB-N值为21.48,已超标。结论采用气调包装比真空包装好,能使山羊肉贮藏16~20 d。     

不同保鲜剂处理对圆青椒贮藏品质的影响

目的 探究不同保鲜剂对圆青椒货架期间品质的影响。方法 实验采用SO2保鲜剂、1-MCP、乙烯吸收剂,在贮藏温度为(9±0.5)℃下分别对青椒进行处理,并分析贮藏期间圆青椒的腐败率、转红率、质量损失率、可溶性固形物含量、可滴定酸含量、丙二醛含量、Vc含量、叶绿素含量,以及抗坏血酸过氧化物酶（ascorbate peroxidase, APX）活性。结果1-MCP处理组的腐败率、转红率、质量损失率均在贮藏8 d后加快上升,而在贮藏到20 d时1-MCP处理组的可溶性固形、可滴定酸质量分数分别下降到0.041%,3.87%,Vc和叶绿素含量分别下降到59.95 mg/100 g,0.073 mg/g,丙二醛质量摩尔浓度上升至1.1 μmol/g,抗坏血酸过氧化物酶（APX）活性下降至20.38 U/(min?g),相较于其他组可减少圆青椒的腐败率、转红率、质量损失率,减缓可溶性固形物、可滴定酸、Vc、叶绿素等含量的下降,抑制丙二醛含量的升高,显著提高了抗坏血酸过氧化物酶（APX）活性。结论 1-MCP可保持圆青椒贮藏期间的品质,并延长货架期。     

永定红柿最适贮藏温度研究

柿果在常温贮藏过程中容易软化、褐变和腐烂,食用品质受到很大影响。因此本文主要研究了柿子的最适贮藏温度,旨在探明低温贮藏对柿子食用品质的影响。研究结果如下,以柿果感观品质、呼吸强度、可溶性糖含量、Vc含量、失重率、可滴定酸含量为考核指标,探讨了贮藏温度与柿果贮藏品质的关系。结果表明：在0℃-2℃下贮藏的柿子能够保持良好的色泽和较高硬度,呼吸强度、失重率较低,可溶性糖含量、Vc含量、可滴定酸等营养成分保持得较好。     

壳聚糖涂膜对荔枝生物热的影响

采用不同脱乙酰度的壳聚糖涂膜保鲜荔枝,研究了在贮藏过程中,壳聚糖涂膜对荔枝生物热产生和传递的影响。结果表明,在贮藏期内,荔枝的生物热主要由呼吸作用所产生,环境温度越高,呼吸速率越大,产生的生物热越多。随着脱乙酰度(D D)的增大,壳聚糖膜的透水汽率变大,单位时间单位面积传递的水汽量和热量增大。壳聚糖的透水汽率越大,其生物热传递性能越好。中脱乙酰度的壳聚糖涂膜荔枝与未涂膜的荔枝比较,前者呼吸速率变化平稳,贮藏期为7d,未涂膜的荔枝贮藏期仅为3d。     

Effects of Packaging Liners on Cooling Rate and Quality Attributes of Table Grape (cv. Regal Seedless)

Table grapes are commonly packed in multi‐layered packages consisting of cardboard carton, plastic liners and carry bag/pouch to maintain product quality along the cold chain. Each liner is characterized by the number and the size of perforations, which influence the environmental conditions around the produce inside the package. This study investigated the effects of different carton liners on the cooling rate and quality attributes of ‘Regal Seedless’ table grapes. Fruit quality attributes measured include weight loss, stem dehydration and browning, SO₂ injury, decay, berry firmness and colour. Non‐perforated liners maintained relative humidity (RH) close to 100% during cold storage and during a 7 day shelf life period, which resulted in delaying the loss of stem quality but significantly (p ≤ 0.05) increasing the incidence of SO₂ injury and berry drop during storage, as compared with perforated liners. Perforated liners improved fruit cooling rates but significantly (p ≤ 0.05) reduced RH. Low RH in perforated liners resulted in significant (p ≤ 0.05) increase in stem dehydration and browning as compared with non‐perforated liners. Berry firmness decreased by 78% after 42 days of storage at ?0.5°C. Significant (p ≤ 0.05) differences in berry firmness between the different packages were observed only during the first 7 days of storage. Berry colour changed from greenish‐yellow to yellowish‐green in all types of plastic liner during the storage period. Fruit decay occurred in all packages after a 7 day shelf life, with the highest incidence of decay occurring in liners with less perforation. Copyright © 2011 John Wiley & Sons, Ltd.     

Effect of ovenproof plastic films on the quality of spotted rose snapper (lutjanus guttatus) fillets during frozen storage

Spotted rose snapper (Lutjanus guttatus) fillets packed in two polymer films, polyamide 6,6 (PA66) and polyethylene terephthalate (PET), were stored at ?20°C for a period of 120 days. Films were tested for melting temperature (PA66 253–257°C and PET 252–255°C), oxygen transmission rate [PA66 51.8 ± 12.9cm³/(m²·24h·atm) and PET 152.7 ± 0.2cm³/(m²·24h·atm)] and water vapor transmission rate [PA66 17.8 ± 1.7g/(m²·24h) and PET 6.5 ± 0.2g/(m²·24h)]. Sensory analyses (firmness, flavour and appearance) were performed at 0, 30, 60, 90 and 120 days of storage after baking the fillets in the same storage bags. For raw fillets, their water‐holding capacity (WHC), total aerobic counts (TAC), pH, trimethylamine (TMA) and shear‐force resistance were measured at the same periods. Sensory analyses after baking showed no differences between the fillets packaged in the two films. The WHC, TAC, pH and TMA values in both products were kept within accepted limits. The fillets packed in PET showed a significant increase in firmness (shear‐force resistance) during the first 60 days of storage and then a decrease at 90 days due to dehydration through the film seals. Over the same period, the fillets packed in PA66 showed no significant changes in firmness. In this study, it was demonstrated that it is possible to develop a ready‐to‐bake fish fillet product by using ovenproof films for packaging during storage. Copyright © 2006 John Wiley & Sons, Ltd.     

The effect of ethanol and oxygen absorption on the shelf-life of packed sliced rye bread

The effect of ethanol emitters, 1% (v/v) ethanol-containing gases and oxygen absorbers on the shelf-life of whole grain rye bread was investigated in two 6 week storage experiments. The bread slices (215 g) were packed in 500 ml plastic containers with headspace volumes of 240 ml. The biggest ethanol emitters (2 and 3 G) extended the microbial shelf-life of rye bread from 8–12 to 26–27 days in the two experiments, and oxygen absorbers correspondingly to the end of the storage period (42 days). Small ethanol emitters (0.6 and 1 G) and 1% (v/v) ethanol-containing gases had no influence on the microbial shelf-life. Ethanol and oxygen absorbers had no effect on changes in texture and moisture during storage. The overall sensory quality of the samples without microbial growth was evaluated as rather good at the end of the storage period. The flavour of ethanol was discovered not to prevent the use of ethanol for the preservation of bread, since ethanol was detected only a few times in the panellist sensory evaluation     

壳聚糖结合脱氢乙酸钠涂膜对槟榔品质的影响

目的以槟榔为实验材料,基于气调贮藏(O2和CO2的体积分数均为4%)技术,探究壳聚糖结合脱氢乙酸钠涂膜对槟榔的保鲜效果。方法采用不同质量分数壳聚糖溶液(0,0.5%,1.0%,1.5%)结合质量浓度为50 mg/L的脱氢乙酸钠对槟榔进行涂膜,测定其在气调贮藏期间对槟榔感官品质、腐烂率、营养品质的影响。结果涂膜后的槟榔各项品质显著优于未涂膜槟榔。结论经壳聚糖(0.5%)/脱氢乙酸钠(50 mg/L)涂膜后的槟榔在贮藏期30 d内能保持良好的品质,能延缓果皮变黄。     

Effect of Storage in a Low Oxygen Gas Atmosphere on Colour and Sensory Properties of Pork Loins

The objective of this study was to examine the quality characteristics of packaging materials and packaging units, and the viability and acceptability of the colour and sensorial properties of fresh pork meat during storage in low oxygen and high carbon dioxide modified atmosphere packaging up to 16 days at two temperatures (0°C and 4°C), as well as the sensorial properties of cooked meat. Packaging materials had good mechanical and barrier properties and were suitable for packaging in selected atmosphere. The concentration of oxygen during the whole storage period was less than 0.5% at both temperatures. The proportion of red colour (a*) was successfully maintained although the colour was slightly darker (L*) and the sensory value was lower when evaluated at the end of the storage period. Based on the obtained results and discussion, it can be concluded that samples packaged in a modified atmosphere with 40% CO₂ and 60% N₂ can be stored at 0°C for 15 days and at 4°C for 10 days. Samples had a good sensory quality until the 16th day, with the best results achieved on the 7th day. Copyright © 2013 John Wiley & Sons, Ltd.     

BioSuee膜对葡萄品质的影响及其降解性能研究

目的 探究BioSuee可降解膜对鲜食葡萄采后的保鲜作用,以及在贮藏过程中的降解性能,筛选出保鲜及降解效果较好的BioSuee膜材料。方法 以新疆无核白葡萄为实验材料,采用3种不同厚度的BioSuee膜(B4、B5、B6)及PE保鲜膜进行包装,在(15±1)℃条件下贮藏14 d;将膜分别放置在自然条件和土壤中140 d进行观察。通过分析葡萄的生理品质、包装膜内的气体成分和降解情况,探讨BioSuee膜对葡萄贮藏品质的影响,以及其自身的降解情况。结果 采用BioSuee膜处理均可较好地保持果实的采后品质,且具有较好的降解效果,B4膜的降解率为84.7%,B5膜的降解率为81.22%,B6膜的降解率为92.8%。在贮藏结束时,B6膜处理组葡萄果实的质量损失率为7.62%,腐烂率为8.8%,分别为PE贮藏组果实的75.37%和28.33%;无核白葡萄果实的可溶性固形物含量为18.8%,硬度为4.94 N,与PE贮藏组相比分别提高了20.44%和10.46%。在贮藏中后期,B6膜包装中CO2的体积分数为3.5%~4%,O2的体积分数在16.6%~16.7%间波动。在降解结束时,土壤环境中B6膜的质量损失率和断裂伸长率分别为12.64%和6.84%,表面形态和微观结构均出现了明显的破碎和崩裂。结论 与其他处理组相比,采用B6膜能较好地保持无核白葡萄的贮藏品质,且具有较好的降解效果。     

茉莉酸甲酯处理对石榴贮藏品质及相关酶活性的影响

目的研究茉莉酸甲酯对石榴贮藏品质的影响,为延长石榴货架期提供依据。方法以临潼“净皮甜”石榴为实验材料,采用不同浓度茉莉酸甲酯(0.01,0.05,0.1 mmol/L)对石榴果实进行熏蒸处理,然后转入(4±0.5)℃冷库贮藏56 d。结果在整个贮藏期间内,茉莉酸甲酯处理可延缓石榴硬度、可溶性固形物含量、总糖含量、可滴定酸含量、感官品质的下降,抑制石榴果皮褐变指数和质量损失率的上升,并能提高CAT,POD,PAL,GLU等的酶活性。实验得出,当茉莉酸甲酯浓度为0.05 mmol/L时处理效果最好。结论茉莉酸甲酯处理是一种有效保持石榴贮藏品质、延长货架期的方法。     

红提葡萄SO2脉冲式防腐保鲜技术

目的针对红提葡萄保鲜时存在的药害、失水、落粒和腐烂等问题,研究SO_2脉冲式熏蒸防腐的最佳浓度、时间参数。方法以新疆红提葡萄为实验材料,采用脉冲式防腐设备精准定量控制,研究不同脉冲防腐方式对红提葡萄贮藏期可滴定酸、电导率、质量损失率、多酚氧化酶活性等理化指标的影响。结果首先用SO_2(体积分数1%)循环熏蒸30min,之后每间隔15d采用SO_2(体积分数0.2%)循环熏蒸30 min,可有效抑制有机酸的消耗,保持细胞膜的完整性,抑制代谢,防止腐烂和落粒,保鲜期延长至180 d,漂白指数仅为0.3,果粒SO_2残留量仅为3.1 mg/kg。结论脉冲式防腐显著延长了红提葡萄的贮藏期,保证了较佳的贮藏品质,解决了传统保鲜纸SO_2释放不均衡、果粒漂白和残留量偏高等产业难题。     

Effect of Antimicrobial Starch Edible Coating on Shelf‐Life of Fresh Strawberries

Strawberry is a very sensitive fruit and presents a short post‐harvest shelf‐life. Among the factors responsible for strawberries' quality loss are high metabolic activities and mold decay. To increase product shelf‐life, cassava starch–based edible coatings (3%), added or not with potassium sorbate (0.05%), were applied on minimally processed strawberries. Uncoated minimally processed strawberries were used as control samples. Physical and chemical properties, respiration rate and sensorial acceptance of uncoated and coated strawberries stored up to 15 days at 5°C were monitored. The results showed that coatings had no significant effect on soluble solids, titrable acidity, pH and colour of strawberries. Besides reducing the respiration rate of samples, cassava starch edible coatings were efficient in delaying weight and firmness loss of strawberries during storage. In the studied conditions, potassium sorbate was not efficient in controlling microbial growth. Strawberries coated with cassava starch without the antimicrobial agent showed good conditions for consumption and good sensorial acceptance up to 12 days of storage, whereas the control samples and the samples treated with the coating containing potassium sorbate achieved a shelf‐life of 9 days because of microbial spoilage. Copyright © 2011 John Wiley & Sons, Ltd.