不同聚乙烯薄膜包装对红椒贮藏品质的影响

目的探索适于采后红椒贮藏保鲜的包装方式。方法以"先红一号"红椒为试材,研究在常温((23±1)℃,80%~90%)条件下,5种不同厚度的聚乙烯薄膜包装(0.01,0.02,0.03,0.04,0.05 mm)对采后红椒贮藏品质的影响。结果与其余薄膜包装相比,0.01 mm厚的聚乙烯薄膜包装能显著延缓红椒硬度和可溶性固形物含量的降低,降低了质量损失率与腐烂率,维持组织较高的抗坏血酸过氧化物酶、过氧化物酶、过氧化氢酶和超氧化物歧化酶活性。0.01 mm厚的聚乙烯薄膜包装可有效维持红椒的综合感官品质,与其薄膜袋内形成的低O2(4.15%~9.49%)及高CO2(3.40%~7.10%)体积分数的微环境密切相关。结论 0.01 mm厚的聚乙烯薄膜包装能更好维持采后红椒的贮藏品质,适宜用作采后红椒的包装贮运材料。     

抗菌薄膜包装材料对马铃薯贮藏品质的影响

目的研究不同包装材料对马铃薯品质的影响,依据马铃薯品质指标变化,选取较优的包装与贮藏工艺,以延长其贮藏期。方法分别用聚乙烯(PE)、聚丁二酸丁二醇酯(PBS)及含有壳聚糖(CTS)、纳米氧化锌(Nano-Zn O)和山梨酸钾(Pto)的抗菌薄膜作为包装材料,以常规贮藏作为对照,贮存期为120 d,每隔30 d检测马铃薯块茎品质指标的变化情况,分别考察包装材料对马铃薯的呼吸强度、维生素C含量、葡萄糖含量、褐变度、丙二醛含量、干物质含量、发霉等指标的影响。结果所设计的抗菌薄膜对马铃薯包装处理后,可有效降低其贮藏过程中的发芽率、腐烂率以及营养物质的流失速度,有利于维持马铃薯的营养品质及感官品质。其中,抗菌薄膜PE/CTS/Pto作为马铃薯的包装材料时,可减弱马铃薯的呼吸作用,还原糖质量分数维持在0.63%,丙二醛含量为0.18μmol/g。结论用抗菌薄膜PE/CTS/Pto作为马铃薯的包装材料,可有效延长马铃薯的贮藏期。     

不同聚乙烯薄膜包装对雪青梨冷藏品质的影响

目的 研究0 ℃条件下不同聚乙烯薄膜包装雪青梨贮藏24周后对其品质的影响。方法 采用0.03 mm厚的PE膜、 0.06 mm厚的PE膜和微孔膜对雪青梨进行包装后, 测量在0 ℃贮藏24周的品质变化。结果 在 0 ℃条件下贮藏 24 周后, 微孔膜包装雪青梨的品质最好, 其感官评价为 7.0, 失重率为1.65%, 硬度为24.36 N, 维生素C含量为6.68 mg/100 g, 可溶性固形物、 可滴定酸、 可溶性糖质量分数分别为10.93%, 0.107%, 4.61%。结论 薄膜包装能够抑制雪青梨冷藏期间失重率的升高和延缓感官评价、 维生素C、 可溶性固形物、 可溶性糖和可滴定酸含量的降低, 微孔膜包装的雪青梨品质最好。     

不同薄膜包装对水蜜桃冷藏品质的影响

目的研究0℃冷藏温度下不同薄膜包装对水蜜桃品质的影响,得出更加适合水蜜桃贮藏保鲜的包装方式。方法采用0.035 mm防雾型流延聚丙烯膜、0.025 mm聚氯乙烯膜、0.03 mm微孔膜和0.03 mm聚乙烯膜包装水蜜桃,测定在0℃下贮藏48 d的品质变化。结果 0℃条件下贮藏48d后,流延性聚丙烯膜对水蜜桃的保鲜效果最好,其感官评分为6.83,失重率、硬度、相对电导率分别为2.16%,56.33 N,38.11%,可溶性固形物、可滴定酸、可溶性糖的质量分数分别为10.2%,0.16%,6.05%,100 g水蜜桃中含维生素C 8.11 mg。结论薄膜包装能显著抑制水蜜桃在冷藏期间失重率和相对电导率的升高,延缓可溶性固形物、可滴定酸、可溶性糖和维生素C含量的降低,保持较高的感官评分,防雾型流延聚丙烯膜包装的水蜜桃品质最好。     

包装材料对大豆贮藏品质影响的研究

目的研究大豆在贮藏过程中包装材料对其品质变化的影响。方法采用3种包装材料(PE,PA/PE,BOPP/PA/PE)对大豆进行真空保鲜包装,监测常规储藏和不同材料包装大豆存储期间品质指标的变化,研究包装材料对大豆保鲜效果的影响。结果用薄膜包装大豆的重要品质指标均明显优于对照组,储藏至18个月时,3种包装大豆的脂肪酸值分别为20.2 mg/100 g,15.5 mg/100 g,13.7mg/100 g,而对照组大豆的脂肪酸值达到28.6 mg/100 g,已开始陈化;3种薄膜包装大豆的蛋白质溶解比率分别为71%,75.8%,74.2%,对照组的大豆蛋白质溶解比率为61.8%,高于国家规定不易存储的临界值。结论包装材料能够明显改善大豆的储藏品质,其中材料的阻隔性对大豆保鲜效果影响最显著,3种薄膜中BOPP/PA/PE的保鲜效果最优。     

壳聚糖/柠檬酸复合涂膜对胡萝卜的保鲜效果

目的研究壳聚糖和柠檬酸复合涂膜对胡萝卜保鲜效果的影响,为胡萝卜采后保鲜贮藏提供新途径。方法以胡萝卜为实验材料,采用壳聚糖(质量分数为1%)涂膜、壳聚糖(质量分数为1%)/柠檬酸(质量分数为1%)复合涂膜处理胡萝卜,以未涂膜处理的胡萝卜为空白对照,研究贮藏期间不同处理组胡萝卜的主要品质指标和生理活性随贮藏时间的变化情况。结果贮藏90 d后,复合涂膜处理组胡萝卜的呼吸强度为3.02 mg/(kg·h),质量损失率为3.32%,Vc含量为0.1704 mg/g,可溶性糖质量分数为2.08%,胡萝卜素含量为0.0549mg/g,POD活性为0.53U/g,PAL活性为65.87U/g,复合涂膜较单一涂膜更好地延缓了贮藏期间Vc含量、可溶性糖含量和胡萝卜素含量的下降,较好地保持了POD和PAL酶的活性。结论壳聚糖涂膜和壳聚糖/柠檬酸复合涂膜处理能够有效提高胡萝卜的贮藏品质,维持其生理活性,延缓衰老进程,其中,壳聚糖/柠檬酸复合涂膜处理的综合保鲜效果要优于单一壳聚糖涂膜处理。     

黄芩提取物对百香果采后贮藏品质的影响

目的 为研究不同质量浓度黄芩提取物处理对百香果采后贮藏保鲜品质的效果,以期延长百香果贮藏时间。方法 以百香果为原料,黄芩提取物为保鲜剂,蒸馏水浸泡为对照,使用不同质量浓度黄芩提取物对百香果进行浸泡处理并置于室温贮藏(温度为18~23 ℃)。检测不同质量浓度黄芩提取物对百香果果实品质指标的影响,总结黄芩提取物最佳保鲜质量浓度以及贮藏保鲜效果。结果 在室温条件下,与对照处理相比,不同质量浓度黄芩提取物处理均能起到贮藏保鲜的效果。CK组的百香果在贮藏17 d后质量损失率为24.67%,硬度为6.31 kg/cm²,可溶性固形物含量为10.45 mg/g,而黄芩提取物处理B组(12.5 mg/mL)的百香果在贮藏17 d后质量损失率为17.60%、硬度为8.29 kg/cm²、可溶性固形物含量为12.84 mg/g,CK组与黄芩提取物处理B组(12.5 mg/mL)之间各指标呈显著性差异(P<0.05)。B组(12.5 mg/mL)黄芩提取物在保持百香果果实硬度、质量损失率、可溶性蛋白质、可溶性糖和维生素C等外在及内在品质指标的稳定均不同程度优于CK组和其他质量浓度黄芩提取物处理组。结论 在百香果室温贮藏保鲜中,采用质量浓度为12.5 mg/mL的黄芩提取物处理可以减少果实营养物质消耗,保持较好的果实品质。     

不同包装材料对‘紫秋’葡萄贮藏理化指标的影响

目的研究双向拉伸聚丙烯(BOPP)和聚乙烯(PE)等2种不同薄膜包装材料对葡萄低温贮藏期间理化指标的影响,以期为延长葡萄保鲜期提供依据。方法以‘紫秋’葡萄为实验材料,采用厚度为0.03mm的BOPP和PE薄膜袋进行单穗包装,在(0±0.5)℃冷库中贮藏,以不包装为对照,每隔10 d测定其生理生化指标,对不同包装材料的低温贮藏保鲜效果进行探讨。结果采用BOPP和PE包装处理可以减少果实的质量损失和落粒的发生,并降低果梗的褐变程度和维生素C的氧化速度,在贮藏前30d可以延缓果实可溶性固形物和可滴定酸的降解,相较于PE包装,BOPP包装能更大程度地降低果实腐烂、脱粒的发生,减少质量损失,延缓TSS、TA、花色苷和维生素C含量的下降。结论 BOPP包装贮藏保鲜效果最好,能更好地保持‘紫秋’葡萄果实的外观和内在营养品质,减缓其衰老进程,延长其贮藏期。     

甜玉米微孔自发气调包装应用研究

目的确定甜玉米的微孔包装参数及其保鲜效果。方法在40μm厚的聚乙烯(PE)保鲜袋(35 cm×55 cm)上制备不同数量的微孔,孔径为(0.18±0.005)mm,孔的数量分别为2,3,6,9,20,50个。采用微孔袋对甜玉米进行包装,检测在0℃下贮藏时不同时间袋内的气体浓度,抽样分析甜玉米的营养指标、乙醇含量及感官品质。结果甜玉米贮藏前期呼吸旺盛,后期呼吸强度下降,呼吸强度的变化会引起包装袋内氧气和二氧化碳浓度的波动;低氧或高二氧化碳有利于保持甜玉米中可溶性固形物、Vc含量和可溶性糖含量,但易造成乙醇的积累和异味的产生。结论在40μm厚的PE保鲜袋上制备6个直径为(0.18±0.005)mm的微孔,对甜玉米的保鲜效果最佳,贮藏14 d,能保持良好的品质。     

臭氧处理对美人指葡萄保鲜效果的影响

目的研究不同臭氧浓度对美人指葡萄的保鲜效果。方法以美人指葡萄为实验材料,设置0,6.72,12.84,19.26 mg/m3等4种臭氧浓度对果实进行处理,通过测定贮藏期间美人指葡萄的果柄耐拉力、可溶性固形物、硬度、色差、还原糖含量和多酚氧化酶活性等指标来研究美人指葡萄在贮藏过程中品质的变化。结果结果表明,3组臭氧处理组对美人指葡萄均有一定的保鲜效果,其中19.26 mg/m~3处理组的效果要优于6.72和12.84 mg/m~3处理组。在整个贮藏过程中,19.26 mg/m~3处理组果实的果柄耐拉力、可溶性固形物含量、硬度和还原糖的含量分别下降了2.71 N,1.58%,2.76 N,5.51%,果皮的L*值提高了4.22,同时多酚氧化酶(polyphenol oxidase, PPO)的活性降低了0.072 U/(min·g)。结论采用19.26 mg/m~3臭氧浓度能够有效保持美人指葡萄采后果实的品质,减缓了美人指葡萄果柄耐拉力的降低进程,以及还原糖含量的减小趋势,保持了果实的硬度、可溶性固形物含量和果皮色泽,同时抑制了多酚氧化酶活性,延缓了果实褐变的进程。     

Prediction of plastic film thickness based on gas permeability and validation with ‘Kyoho’ table grapes for optimal modified atmosphere packaging

Modified atmosphere packaging (MAP) storage has become a useful technique for extending the shelf life of fruit and vegetables. However, the success of MAP depends on many factors, including types of fresh products, storage conditions, and the characteristics of the packaging films. To achieve the optimal gas composition in the package headspace and improve the postharvest quality of fresh produce, the packaging film with appropriate barrier properties needs to be selected. This study aimed to predict the film thickness by applying produce respiration rate and package film permeability data measured in given product weight and storage conditions. An available film (eg, 25‐μm‐thick low‐density polyethylene) was used to pack fresh produce, and the respiration rate of fresh produce and in‐package O₂ and CO₂ concentrations at steady state were measured. Permeability of the film was calculated based on mass balance, and the thickness of the film could be predicted if the recommended target O₂ and CO₂ concentration was obtained from the literature. To validate the predicted thickness value, an experiment was conducted by packaging fresh table grapes in bags of the predicted thickness. The effect of packaging with different film thicknesses on the quality of the fruit was determined. The results showed good agreement between the predicted and the experimental in‐bag O₂ and CO₂ concentrations, and the MAP with predicted thickness (90 μm) film was more effective in maintaining postharvest quality of grapes during low‐temperature storage than the thinner films (30 and 60 μm) and the control.     

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。     

薄膜包装材料在采后果蔬保鲜中的应用

目的为薄膜包装材料在果蔬采后保鲜中的应用提供理论依据。方法综述国内外常见的3种薄膜包装材料的概念、优势以及在果蔬采后保鲜中的应用,并对目前薄膜材料存在的问题进行分析总结。结果薄膜包装材料一般具有安全无毒、绿色环保的性能,现已广泛应用于食品、医疗、环境、生物等领域,这里主要介绍了纳米薄膜、可食性薄膜和功能性薄膜包装在果蔬采后保鲜中的应用。结论薄膜保鲜在果蔬保鲜中的研究目前处于起步阶段,还有很多问题待解决。方便快捷、无毒无害的保鲜技术将会成为未来我国采后果蔬保鲜技术的发展趋势。     

聚乙烯醇柠檬酸改性薄膜对鲜切苹果保鲜性能的影响

目的研究聚乙烯醇柠檬酸改性薄膜对鲜切苹果保鲜性能的影响。方法以市售红富士苹果为材料,进行鲜切处理,分别采用不同浓度柠檬酸改性的聚乙烯醇薄膜密封包装。以不含柠檬酸的聚乙烯薄膜包装为对照,在室温下贮藏6 d,研究添加柠檬酸的聚乙烯醇薄膜对鲜切苹果保鲜效果各指标的影响。结果贮藏到第6天时,C处理组的各项指标均优于对照组和其他处理组,可较好地保持果实硬度,对维持果实可溶性固形物含量、维生素C及感官评定有明显作用。结论质量分数为2%的柠檬酸改性的薄膜具有较好的保鲜效果。     

两种包装材料结合氩气保鲜对香菇品质的影响

目的 研究2种不同的包装材料结合不同比例氩气气调方法对香菇品质的影响。方法 把新鲜采摘的香菇清洗干净后晾干, 装入LDPE材料封口袋及PE材料封口袋中,充入不同比例的氩气,观察并测定各组香菇的呼吸强度、多酚氧化酶活性、褐变度、水分活度、总酚及抗坏血酸含量的变化。结果 选择LDPE为适宜的氩气气调包装材料,O2,Ar,N2的体积分数分别为10%,60%~90%,0~30%,此时对香菇的保鲜效果最好。结论 实验表明LDPE为最佳包装材料。在气调保鲜的过程中充入氩气,可以延缓香菇褐变的速度,降低多酚氧化酶活性的提升速率,同时使香菇抗坏血酸及总酚含量得以降低,也能延缓香菇呼吸速率的提升,使香菇的品质得以保证。     

Quality of Fresh Cut Zucchini as Affected by Cultivar,Maturity at Processing and Packaging

Appropriate plant material at processing and film packaging selection has a strong influence on product quality preservation. This is the first report studying the feasibility for minimal processing of four zucchini cultivars at two maturity stages, immature (MS1) and mature, stored at 6 °C during 10 days under different packaging conditions. The treatments consisted a 4 × 2 × 2 × 3 factorial combination of variety, maturity at processing, film packaging and storage time, including correlation studies between quality parameters. Negative effect on final quality after processing at MS1 was observed as a result of a higher respiration rate (between 15.91 and 20.12% than at mature), CO₂ production and soluble solid consumption contributing to loss of firmness, slice discolouration and less overall quality. After 10 days under 25 µm film, cv. ‘Cronos’ showed the highest values in total chlorophylls (9.03 mg/100 g FW), while slices at MS1 suffered a noticeable oxidative stress increasing the total phenolic content (cv. ‘Parador’ > ‘Amalthée’ > ‘Cronos’ > ‘Cassiope’). At the end of storage, the highest vitamin C content was observed in trays sealed with 25 µm film (more evident in cv. ‘Cronos’ at MS1). In conclusion, processing more mature zucchini and 25 µm film packaging were the most effective combination for preserving quality. Copyright © 2016 John Wiley & Sons, Ltd.     

低压静电场结合包装对采后樱桃番茄品质的影响

目的 研究常温环境下低压静电场(Low Voltage Electrostatic Filed,LVEF)结合不同商业包装处理对樱桃番茄果实贮藏品质的影响,探索基于LVEF处理的樱桃番茄采后常温货架期间适宜的商业包装方式。方法 待测樱桃番茄随机分为LVEF处理组、LVEF+PP组、LVEF+PET组和无任何处理的对照组,在温度为(23±1)℃和相对湿度为75%的同一培养箱中储存16 d,LVEF处理在整个储存期内持续进行,定期测定樱桃番茄在贮藏期间的品质变化。结果 LVEF处理能抑制质量损失率和丙二醛含量的上升,同时减缓亮度、硬度、可溶性固形物、可滴定酸、抗坏血酸和番茄红素含量的下降。在LVEF贮藏环境下,PET包装在采后樱桃番茄的质量、硬度、色度、可溶性固形物和抗坏血酸等质量指标方面优于PP包装和未包装的樱桃番茄。结论 LVEF处理对采后樱桃番茄有一定保鲜效果,且在LVEF贮藏环境下,PET包装樱桃番茄比PP包装的保鲜效果更好。     

Development of multilayer films with improved aroma barrier properties for durian packaging application

The symmetrical A/B/A structure of multilayer blown films was fabricated in this study. The immiscible low‐density polyethylene/polylactic acid (LDPE/PLA) blend was set as a core (B) layer and LDPE was used as skin (A) layers. The compositions of PLA in the core layer were varied from 20 to 50 wt%. The thickness of each layer was 10 μm (total film thickness of ~ 30 μm). In a blown film co‐extrusion process, the morphology of the fiber/ribbon‐like structures of LDPE/PLA blend was developed. Such structures had interesting effects on gas permeability and aroma barrier properties of the films. For instance, multilayer LDPE films containing 40 and 50 wt% PLA (P40 and P50) showed the reduction of oxygen permeability (PO₂) approximately 20% and 43%, respectively, compared with the neat LDPE film. A long tortuous path for gas and aroma transportation through film thickness was created from the developed ribbon‐like structures of the PLA minor phase. For durian packaging application, fresh‐cut durian of 300 g was packed in the developed multilayer films, LDPE, and HDPE (Control), stored at 4°C for 7 days. Results demonstrated that the steady‐state condition of 10% to 13% O₂ and 8% to 10% CO₂ was achieved in all packages except in the HDPE. Moreover, the P40 and P50 films exhibited an outstanding aroma barrier property for three major durian volatiles : diethyl sulfide, ethyl propanoate, and 2‐ethyl‐1‐hexanol. Overall results clearly indicated that the multilayer LDPE films containing PLA exhibited a significantly improved aroma barrier performance with optimum gas permeability desirable for modified atmosphere packaging to retain quality of fresh‐cut durian throughout the storage period.     

Comparison of Various Packaging Films for Mango Export

This study compared the effects of the use of various types of packaging films in maintaining quality, preserving bioactive compounds and extending shelf life of the ‘Nam Dok Mai’ mango. The principal techniques for maintaining the quality of mangoes are based on modified atmosphere packaging using highly gas‐permeable films and an ethylene‐removing mechanism. The films studied were non‐perforated highly gas‐permeable film, non‐perforated ethylene‐absorbing highly gas‐permeable film (HNPE), micro‐perforated highly gas‐permeable films (HMP) and common non‐perforated polyethylene film (LNP). These films were compared with non‐packaging treatment, which served as a control (C). Gas composition (O₂, CO₂ and C₂H₄) in the package headspace was monitored during storage at 12°C. The quality of mangoes were assessed by weight loss, colour (L* a* b*), texture, total soluble solids, titratable acidity, total phenolics, total flavonoids, ethanol concentration and sensory quality. Equilibrium‐modified atmospheres of 5 kPaO₂ + 5 kPaCO₂ and 4 kPaO₂ + 5 kPaCO₂ were achieved in the non‐perforated highly gas‐permeable film and HNPE packs, respectively. Carbon dioxide accumulation was observed in the HMP and LNP packs where CO₂ reached 17 and 10 kPa, respectively, after storage for 10 days. The shelf life of mangoes was extended to 40 days with HNPE, 35 days with HNP, and 30 days with HMP, as compared with 20 days with control and 5 days with LNP. HNPE, the film incorporated with fine particles of mordenite framework inverted‐type zeolite with ethylene‐absorbing ability, could further extend the shelf life of mangoes in addition to modified atmosphere packaging alone. Copyright © 2011 John Wiley & Sons, Ltd.