平菇专用保鲜膜常温MAP保鲜试验

以3种特制抗菌膜、1种常规保鲜LDPE膜和1种普通LDPE膜为试材,研究平菇常温不同特性保鲜膜MAP保鲜效果,确定最佳平菇保鲜膜.结果表明,日本产保鲜膜和国家农产品保鲜中心研制的抗菌膜包装平菇后于常温下贮藏8天,基本保持平菇原有的品质,失重率小于2%.     

不同保鲜包装对高唐紫茄贮藏品质的影响

为研究不同保鲜包装对高唐紫茄品质的影响,以高唐紫茄聊育3号品种为试材,分别采用聚乙烯(PE)微孔保鲜膜和聚氯乙烯(PVC)保鲜膜两种自发气调包装(MAP)处理,于9℃冷库贮藏,测定茄子果实贮藏期间各生理生化指标的变化情况。结果表明:采用微孔膜和PVC膜包装均可明显延长聊育3号茄子果实的贮藏期,显著抑制果实硬度的下降和失重率的上升,有利于茄子果实贮藏期间可滴定酸(TA)和可溶性固形物(TSS)含量的保持,显著抑制茄子果实多酚氧化酶(PPO)活性的上升,PVC包装处理可较好地抑制果皮亮度及色泽的变化,微孔膜包装有利于果实中芦丁含量的保持。综合分析得出,高唐紫茄聊育3号品种宜采用PVC膜包装贮藏,推荐贮藏期为25 d。     

不同厚度聚乙烯薄膜对韭薹低温贮藏品质的影响

为建立冷藏条件下韭薹自发气调包装(MAP)保鲜方法,将新鲜预冷的韭薹(200±0.5)g密封包装于25 cm×60 cm的聚乙烯(Polyethylene,PE)薄膜包装袋内,薄膜厚度分别为10、20、25、30、45μm,于(0±0.5)℃下贮藏105 d,研究不同O₂和CO₂透过率的薄膜对韭薹贮藏过程中包装袋内O₂和CO₂体积分数及产品品质的影响。结果表明,不同O₂和CO₂透过率的聚乙烯薄膜包装处理都可以很好地抑制韭薹品质劣变;不同处理组之间袋内O₂和CO₂的体积分数均存在显著差异(P<0.05);45μm PE袋(O₂透过率(4 080±352)cm³·m^-2·d^-1·0.1 MPa^-1、CO₂透过率(16 566±1 415)cm³·m^-...     

不同保鲜膜不同保鲜剂处理对甜瓜贮藏品质的影响

为高品质甜瓜选择较适宜的包装保鲜膜和保鲜剂,提高其贮藏保鲜品质。本试验以西州密25号为试材,采用常规的PE和PVC保鲜膜包装,并用目前保鲜效果较好的1-MCP保鲜剂和壳聚糖进行保鲜处理,研究保鲜膜和保鲜剂处理对甜瓜贮藏品质的影响。结果表明,使用保鲜膜比不使用保鲜膜效果好,使用保鲜剂比不使用保鲜剂效果好,PE保鲜膜比PVC保鲜膜效果好,1-MCP保鲜剂和壳聚糖因其保鲜机理不一样,保鲜效果有差异,但两者对提高甜瓜贮藏品质均有很好的效果。因此PE保鲜膜包装结合1-MCP保鲜处理或壳聚糖涂膜是获取高品质甜瓜的有效手段之一。     

不同保鲜膜、保鲜剂处理对甜瓜贮藏品质的影响

为高品质甜瓜选择较适宜的包装保鲜膜和保鲜剂,提高其贮藏保鲜品质。本试验以‘西州密25号’为试材,采用常规的PE和PVC保鲜膜包装,并用目前保鲜效果较好的1-MCP保鲜剂和壳聚糖进行保鲜处理,研究保鲜膜和保鲜剂处理对甜瓜贮藏品质的影响。结果表明,使用保鲜膜比不使用保鲜膜效果好,使用保鲜剂比不使用保鲜剂效果好,PE保鲜膜比PVC保鲜膜效果好,1-MCP保鲜剂和壳聚糖因其保鲜机理不一样,保鲜效果有差异,但两者对提高甜瓜贮藏品质均有很好的效果。因此,PE保鲜膜包装结合1-MCP保鲜处理或壳聚糖涂膜是获取高品质甜瓜的有效手段之一。     

聚乙烯膜包装对磨盘柿贮藏品质的影响

以不同厚度(20、30、50μm)的聚乙烯(PE)保鲜膜和打孔聚乙烯膜(20μm)包装磨盘柿,以裸放柿子为对照,在(0±0.5)℃下对磨盘柿进行贮藏,通过测定柿果的VC含量、可溶性糖含量、丙二醛含量、果肉组织相对电导率和果肉硬度的变化和对外观品质的分析,研究自发气调包装对磨盘柿的保鲜效果。结果表明,自发气调包装可保持磨盘柿较高的VC和可溶性糖含量,显著抑制果肉丙二醛含量和果肉组织相对电导率的上升,减缓硬度下降速率,减少失水起皱和病斑的发生,抑制果肉、果皮色泽加深和褐变程度。自发气调包装对磨盘柿有显著的保鲜效果。50μm厚的聚乙烯保鲜膜包装袋内氧气含量为14%±1.1%,二氧化碳含量为5.5%±0.3%,袋内磨盘柿的VC含量、果肉硬度显著高于其他包装(P0.05),丙二醛含量显著低于其他包装(P0.05),果皮不起皱、无病斑、无褐变,但可溶性糖低于其他包装。因此,50μm厚的聚乙烯保鲜膜包装具有显著的自发气调保鲜效果。     

微孔鲜膜对鸭梨冷藏保鲜效果的影响

以普通PE膜包装和单果纸包装作为对照,研究冷藏条件下微孔保鲜膜对鸭梨果实贮藏效果的影响.结果表明,在整个冷藏期间,微孔包装袋内二氧化碳浓度在0～0.6%之间,而普通PE膜包装袋内二氧化碳浓度在1.1%～3.2%之间.采用微孔保鲜膜包装果实的果心果肉褐变指数明显低于普通PE膜包装,与纸包装相似.同时,微孔保鲜膜包装果实的失重率和果皮缩皱指数明显低于纸包装.除普通聚乙烯膜包装的果实内可滴定酸含量略偏高外,3个处理的可溶性固形物(TSS)和可滴定酸(TA)含量没有明显区别.与普通PE膜包装和单果纸包装相比,微孔保鲜膜包装在鸭梨的贮藏保鲜方面具有明显的优势.     

不同MAP包装内气体变化情况及其对山楂果实品质的影响

为延长山楂果实的保鲜期,提高果实贮藏品质,筛选适宜山楂果实长期低温贮藏的塑料薄膜包装。本研究采用4种不同薄膜包装(MAP),对‘大金星’山楂果实进行冷藏(0±0.5)℃试验,研究了不同MAP处理中O2、CO₂和乙烯气体体积分数的变化趋势,以及山楂果实生理和贮藏品质的变化。结果表明：在低温(0±0.5)℃条件下,厚度为30μm的PVC薄膜包装有利于减缓山楂果肉硬度和可滴定酸含量的下降,但加速了贮藏后期果实中MDA含量和果肉褐变率的上升;而厚度为15μm的高渗出CO₂保鲜袋,对抑制果实硬度下降和减缓果实可滴定酸降解效果不显著,但对减缓MDA含量和果肉褐变率的上升有积极作用。4种不同薄膜包装(MAP)处理中,厚度为15μm的高渗出CO₂保鲜袋贮藏效果最佳,适宜山楂果实长期保鲜。     

大米聚烯烃基薄膜MAP保鲜效应研究

以小站稻大米越选3#为试材,研究不同质地、不同厚度、不同规格聚烯烃基薄膜的保鲜效应.研究结果表明,常温条件下,大米MAP保鲜4个月(过夏),总酸、脂肪酸、还原糖和黏度变化与膜基材、厚度、包装量等因素密切相关,其中以0.05 mm PE保鲜膜的综合保鲜效果最佳,其次为0.03 mm PVC保鲜膜.     

微孔保鲜膜对鸭梨冷藏保鲜效果的影响

以普通PE膜包装和单果纸包装作为对照,研究冷藏条件下微孔保鲜膜对鸭梨果实贮藏效果的影响。结果表明,在整个冷藏期间,微孔包装袋内二氧化碳浓度在0～0．6％之间,而普通PE膜包装袋内二氧化碳浓度在1．1％-3．2％之间。采用微孔保鲜膜包装果实的果心果肉褐变指数明显低于普通PE膜包装,与纸包装相似。同时,微孔保鲜膜包装果实的失重率和果皮缩皱指数明显低于纸包装。除普通聚乙烯膜包装的果实内可滴定酸含量略偏高外,3个处理的可溶性固形物（TSS）和可滴定酸（TA）含量没有明显区别。与普通PE膜包装和单果纸包装相比,微孔保鲜膜包装在鸭梨的贮藏保鲜方面具有明显的优势。     

Modified atmosphere packaging alleviates chilling injury in cucumbers

Cucumbers (Cucumis sativus L.) packaged in perforated or sealed 31.75 μm (1.25 mil) low density polyethylene (LDPE) bags were found to have less severe chilling injury than nonwrapped fruit in storage at 5 °C and 90–95% relative humidity. The onset of chilling injury was also delayed by the LDPE packaging compared to the nonpackaged control. The concentrations of CO₂ increased to 3% while O₂ levels decreased to 16% in the sealed bags. Fruit in the sealed bags had the least decay. The O₂ and CO₂ concentrations inside the perforated bags changed very little from the ambient atmosphere. However, there was a marked difference in the weight loss between nonwrapped cucumbers and fruit from perforated or sealed bags. The weight loss of nonwrapped fruit reached 9% in 18 days while perforated and sealed samples lost less than 1% during the same period. Chilling stress induced increases in putrescine levels in all treatments but the sealed fruit had the highest levels of putrescine. Sealed fruit and perforated fruit also had higher content of spermidine than non-wrapped fruit. These high levels of polyamines may have contributed to the increase of chilling tolerance in fruit from perforated and sealed packages.     

Influence of modified atmosphere packaging on sensory quality of shiitake mushrooms

Shiitake mushrooms (Lentinus edodes) were packaged under air in two macroperforated packages (A—9.0 × 10³ perforations/m², 0.1 mm² surface and B—17 perforations/m², 0.1 mm² surface) and under two gas mixtures (15% and 25% O₂) in polyethylene packages, and stored at 5 °C for 18 d. The sensory quality of the mushrooms was evaluated using a trained assessors panel.

Mushrooms packaged in macroperforated packages A showed the smallest deterioration rate. However, weight loss after 6 d of storage reached 15%, which is unacceptable. Besides, shelf life of shiitake mushrooms in active modified atmosphere was limited by off-odour development. Mushrooms in these packages developed off-odour after 12 d of storage due to the fact that O₂ concentrations fall bellow 5%.

On the other hand, the shelf life of mushrooms packaged in macroperforated packages B was limited by their sensory deterioration, particularly by changes in the colour and uniformity of their gills. In this film, mushrooms could be stored for approximately 10 d with a weight loss lower than 2%.

Results from the present work suggest that during the first 6 d of storage all the evaluated packaging conditions were useful for reducing mushroom deterioration rate.     

Physio-pathological responses of cabbage stored under controlled atmospheres

The response of cabbage to controlled atmospheres (CA) of 1–3% O₂ and 1–10% CO₂; 3% O₂ and 5% CO₂ was studied in relation to the incidence of physiological and pathological disorders. Fungal infections, pepper spot, low oxygen injury, weight loss, colour, odour, flavour and ethanol were evaluated. The findings show that CA did not reduce Botrytis cinerea rot in comparison to low temperature storage in air. PVC film and CA, on the other hand, reduced pepper spot by over 50% with respect to the air control. In particular, pepper spot was eliminated by high CO₂ (10%) levels. Low O₂ (1% O₂ and 1% CO₂) atmospheres caused 33 and 50% injury respectively after 89 and 109 days of storage. CA and PVC film reduced weight loss to 1%, as compared with 11% in the heads in air, which had shrivelled. The combination of 3% O₂/5% CO₂ and PVC film delayed yellowing with respect to air control. Concentrations of 1–3% O₂ and 10% CO₂ resulted in off odours and flavours after 74 days of storage. This result was confirmed by a considerable increase in ethanol concentrations. The most effective concentration tested was 3%O₂/5%CO₂ although, in general, infection by B. cinerea limited the storage life.     

延长低温牛肉制品货架期方法的研究

低温牛肉西红柿肠用可食性壳聚糖和Nisin作为涂膜保鲜液处理后,结合真空包装,分别置于常温(20℃左右)和冷藏(0￣4℃)两种不同温度下贮藏,测定不同贮藏期细菌总数、大肠杆菌、TVB-N和H2S等指标及进行感官评定。结果表明,经处理贮藏的牛肉西红柿肠的货架期均优于对照组;在20℃时,各处理组的货架期分别为30,30和60d;在4℃条件下,各处理组的货架期分别为60,60和120d以上。     

丝瓜伤流液对食用菌的保鲜效果

以质脆、颜色鲜艳的榆黄蘑为试材,研究了丝瓜伤流液对食用菌的保鲜效果。结果表明：丝瓜伤流液能有效延长食用菌的贮藏期,有利于保持商品质量。75%的有棱丝瓜伤流液保鲜效果最好,榆黄蘑菌盖开裂、变色、腐败变味等变质性状的出现比对照推迟4d～6d,10 0C下贮藏到12d时,失重仅为水对照的54.17%,极显著低于对照及其它处理。     

壳聚糖复合涂膜对杏鲍菇保鲜效果的研究

【研究目的】杏鲍菇在采后易失水褐化等原因降低食用及商品价值,为延长其货架期,需筛选出适于杏鲍菇的壳聚糖复合涂膜。【方法】该实验以杏鲍菇（Pleurotus eryngii）为研究材料,在室温（22±2℃）条件下,以去离子水浸涂杏鲍菇为对照,采用不同的壳聚糖复合涂膜处理进行保鲜实验,通过L9（33）正交试验筛选杏鲍菇保鲜的最佳复合涂膜配方,并研究其生理效应。【结果】结果表明,与对照相比,筛选出的最佳壳聚糖复合涂膜液能够有效降低杏鲍菇的褐变程度与含水率,延缓游离氨基酸含量、可溶性蛋白含量、可溶性总糖等各指标的变化幅度,保鲜效果达到显著水平（P＜0.05）。【结论】适于杏鲍菇的壳聚糖复合涂膜的配比为1.5%的壳聚糖+1.0%的乙酸+0.03%的吐温20+3.0%的甘油,该涂膜起到延缓杏鲍菇采后衰老,保持较好的营养价值和加工风味,达到保鲜目的。     

Effects of new packaging solutions on physico-chemical,nutritional and aromatic characteristics of red raspberries (Rubus idaeus L.) in postharvest storage

Postharvest life of raspberries (Rubus idaeus L.) is limited due to their high respiration rate, loss of firmness and freshness and susceptibility to fruit rot. The aim of this research was to evaluate the effects of various packaging solutions on physico-chemical, nutritional and aromatic properties of raspberries during storage at +4 °C up to 7 days. Plastic materials with low (LDPE) and high (LDPE/EVOH/LDPE) gas barrier, a biopolymeric film (PLA) with medium gas barrier and micro perforated stretch film (PVC) were used. The packaging material modified the composition of the atmosphere in the package, which depended on the combined action of the respiration activity of the fruit and the permeability of the material. Results showed that the most sensitive parameters for the assessment of raspberry decay were percentage of damaged berries, weight loss, fruit softening and the aromatic profile development, evaluated by an electronic nose; these parameters showed significant changes during storage and were influenced by the packing material. All samples showed a clear loss of firmness after 4 days of storage, which was maximally reduced in the case of LDPE/EVOH/LDPE and PLA packages. Raspberries stored in PVC packaging material had an aromatic development similar to the control, whereas berries stored in the medium and high barrier materials showed important changes in the aromatic profile, reflecting anaerobic metabolism of fruit. Soluble solids, pH, total phenolics and ascorbic acid did not change significantly; changes in colour and total anthocyanins were observed, with differences depending on the kind of packaging.     

不同采后处理对‘水晶蜜柚’果实品质的影响

为探究不同采后处理对水晶蜜柚品质的影响,对成熟采收的柚子进行撞击、套袋、保鲜和贮藏4个因素的试验,研究不同采后处理对‘水晶蜜柚’贮藏期间果实品质的动态变化,并对果实感官品质进行评分,探讨不同处理下柚子内在品质与感官品质的关系。结果表明,果实失重随试验时间延长而加剧,失重率1.7%~35.7%,相对于撞击处理和清水浸果处理,非撞击和咪鲜胺浸果处理可减少柚子损坏率,0.01 mm聚乙烯膜套袋处理和冷库低温贮藏可降低柚子失重。随贮藏时间推移,果实内在指标变化趋势总体一致,表现为可溶性固形物先略微增加再降低,可滴定酸先降低再增加再降低,Vc逐渐降低,木质素含量先降低再增加,且不同处理柚子可溶性固形物在19~40天达最大、木质素含量达最低。套袋和保鲜较未套袋和清水浸果处理分别增加柚子可溶性固形物133.8%和72.3%;撞击和冷库贮藏柚子可滴定酸含量较未撞击和常温贮藏处理分别增加82.4%和86.3%;套袋和冷库贮藏Vc含量分别增加17.6%和15.9%;撞击方式处理木质素含量增加85.0%,套袋、咪鲜胺保鲜和冷库贮藏处理分别降低柚子木质素34.3%、33.3%和51.7%。不同处理柚子果实感官评分随着试验时间延长呈先增加后降低的趋势,撞击加速柚子感官品质降低,较未撞击处理增加12.9%,套袋、咪鲜胺保鲜和冷库贮藏减缓柚子感官品质的降低,较未套袋、清水浸果保鲜和常温贮藏增加2.5%、7.7%和10.5%。柚子感官评价与果实内在品质存在高度一致性,随着贮藏时间的推延柚子感官评价和内在品质均呈现先增加后降低的趋势,采后1个月左右柚子品质最佳。综合而言,采取轻拿轻放、0.01 mm聚乙烯膜、咪鲜胺浸果和冷库贮藏组合处理(T1)可保持柚子的新鲜品质,并延长货架期。