国内外鱼和鱼制品的气调保鲜研究

气调保鲜包装能抑制微生物的生长和氧化反应,从而延长食品货架期。延长的能力取决于食品种类、脂肪含量、原细菌数、混合气体的组成、气体和食品的体积比,最重要的是储藏温度。鱼制品的货架期受微生物活性的限制,有些高脂鱼或超低温储藏的鱼制品受微生物作用的影响很小。另外,MAP制品的微生物安全是首要考虑。     

微冻复合保鲜技术在水产品中的应用研究进展

水产品在实际运输贮藏销售环节,易受到环境温度、微生物等因素影响而导致腐败变质,造成资源浪费、环境污染等问题。微冻保鲜能有效抑制微生物生长、维持食品原有风味。但是其温度控制严格,单一的微冻保鲜不能很好地延长水产品货架期,因此常采用微冻与其他技术结合的保鲜技术,以更好地发挥栅栏效应。该文综述了水产品腐败机理及品质变化、单一微冻保鲜应用,微冻与抗冻剂、气调、涂膜、静电场等联合对水产品保鲜的最新应用,并对微冻保鲜存在的问题作出总结与展望。旨在为微冻保鲜技术的进一步优化做铺垫,为水产品保鲜应用提供参考。     

稻谷低温储藏保鲜技术研究

在冬季干冷气候条件下,利用机械通风对储粮降温后用聚氯乙烯塑料泡沫板(或防虫磷药糠装袋)进行压盖试验,对稻谷在不同储藏方式下的储藏品质、菌落数、微生物区系等项目的变化进行对比分析,结果表明应用低温储粮技术储存稻谷等粮食能够起到保鲜作用,从而延缓粮食陈化,具有一定的可行性、实用性和良好的市场前景,进一步达到绿色储粮技术要求。     

稻谷低温储藏保鲜技术研究

通过冬季干冷天气利用机械通风时储粮降温后用聚氯乙烯塑料泡沫板(或防虫磷药糠装袋)选择有利时机实施压盖试验，稻谷在不同的储藏方式下的储藏品质、菌落数、微生物区系等项目的变化进行对比分析。应用低温储粮技术储存稻谷等粮食能够起到保鲜作用，从而延缓粮食陈化，具有一定的可行性、实用性和良好的市场前景，进一步达到绿色储粮技术要求。     

NTSPI涂膜对冷鲜草鱼块品质的影响

为了探讨草鱼块的冷藏保鲜技术,本文研究了新型复合物纳米二氧化钛/大豆分离蛋白(NTSPI)涂膜对鲜草鱼块低温贮藏过程中品质的影响。研究发现,NTSPI涂膜处理能有效抑制草鱼块低温贮藏期间硬度和L值的下降,延缓p H值的变化和硫化氢反应的产生。NTSPI涂膜还可显著抑制细菌生长繁殖,8 d时对照组细菌总数为7.6 lg(CFU/g),而NTSPI涂膜组仅为5.43 lg(CFU/g)。NTSPI涂膜处理组TVB-N和TBA值显著低于对照组,而其感官品质显著高于对照。其货架期比对照延长2~3 d。这些结果表明NTSPI涂膜处理在草鱼块保鲜方面具有潜在的应用价值。     

低压静电场辅助低温对葡萄和无花果保鲜效果的影响

目的 探讨了低压静电场（low voltage electrostatic field,LVEF）处理对水果采后贮藏过程中腐烂程度、生理品质的影响。方法 以葡萄和无花果为试验材料,以纯低温组作为对照,探讨LVEF辅助低温环境下对两种水果感官品质、失重率、可溶性固形物含量、总酸含量、腐烂率等重要新鲜度指标的影响规律。结果 LVEF辅助低温能更好地保持葡萄和无花果的感官品质;随着贮藏时间的延长,LVEF处理能有效抑制葡萄、无花果果实失重率的上升,贮藏到12 d时,失重率仅为无LVEF处理组的5.45%和24.14%;可有效减缓葡萄、无花果腐烂率的升高,储藏过程中葡萄、无花果一直保持良好的感官性状,腐烂率仅1.76%、21.46%;可有效抑制葡萄、无花果果实可溶性固形物含量下降,为无LVEF处理组的1.01%和1.02%;处于LVEF的葡萄、无花果中总酸含量分别高于低温组39.47%、69.7%。结论 LVEF辅助低温保鲜效果明显优于低温保鲜,通过LVEF辅助低温保鲜方式有利于保持葡萄和无花果的生理品质,大大延长了贮藏时间。该研究可为葡萄、无花果的贮藏保鲜技术提供理论依据。     

冰温保鲜对鱼肉糜品质特性影响的研究

试验研究了鲤鱼鱼肉糜在冰温保鲜和冷藏两种储藏条件下,鱼肉糜品质特性的变化。测定了鱼肉糜的冰点,同时测定了在不同储藏条件下鱼肉糜的pH值、色差值(a*值)、硫代巴比妥酸值(TBARS值)和羰基含量等理化指标,并且对鱼肉糜进行感官评价。试验结果表明,鱼肉糜的冰点为-1.5℃,随着贮藏时间的延长,鱼肉糜的pH值、TBARS值以及羰基含量显著增大(p<0.05),而a*值随着贮藏时间的延长而显著降低(p<0.05);在整个贮藏过程中,冰温条件下鱼肉糜的各项感官评定指标均优于冷藏条件(p<0.05)。说明冰温保鲜技术对于改善鱼肉糜品质特性、延长保质期具有良好的效果。     

糙米储藏技术研究进展

概述了糙米的常温储藏、低温储藏、气调储藏和保鲜新技术等四种储藏方法,重点从低温储粮原理、实现方法、低温仓设计等三个方面介绍了糙米低温储藏技术的研究进展,分析认为:(1)我国不同水稻产区应当根据其气候特点与后续利用方式,选择适宜的糙米储藏方法;(2)对于高温湿热产区,建议探讨先稻谷储藏再糙米储藏的组合式储藏方法,以期降低储藏能耗,改善糙米品质;(3)进一步通过理论与试验研究,优化低温储藏方法,改善粮仓设计,降低储藏成本,从而突现糙米低温储藏的价值;(4)不断宣传糙米的营养价值.     

冷链流通过程中水产品低温保鲜技术研究进展

如何较好地维持水产品的鲜度和营养价值一直是研究的热点。目前的水产品流通过程中,低温保鲜仍是最常用的保鲜技术。本文介绍了影响冷链储运过程中水产品品质的因素,对冷藏、冷海水、冰温、微冻、冻藏等低温保鲜技术的原理、特点以及最新研究进展进行综述。指出了它们在冷链流通中存在的技术问题,并对未来低温保鲜的发展趋势作出展望。     

微冻保鲜方法对带鱼品质及组织结构的影响

以舟山东海带鱼为原料,分别于冷藏（4 ℃）、微冻贮藏（－3 ℃）和冻藏（－18 ℃）3 种低温条件下,研究贮藏30 d内带鱼的pH值、电导率、挥发性盐基氮（total volatile basic nitrogen,TVB-N）值、硫代巴比妥酸（thiobarbituric acid,TBA）、盐溶性蛋白含量、Ca2＋-ATPase活性等理化指标变化,结合带鱼感官评价,比较微冻保鲜方法与其他2 种不同低温保鲜方式对带鱼品质的影响,并观察其肌肉微观组织结构变化。结果表明：随着贮藏时间的延长,3 种低温保鲜方式下带鱼的pH值呈现先下降后上升的趋势;电导率、TBA值、TVB-N值都随贮藏时间的延长而逐渐升高;盐溶性蛋白含量、Ca2＋-ATPase活性和感官评分都随着贮藏时间的延长呈现下降趋势,其中冻藏方式下带鱼品质保持较好,其次为微冻保鲜,冷藏条件下带鱼品质下降最快。观察其肌肉微观组织发现,短期贮藏以微冻组样品细胞完整性最好,而长期贮藏时冻藏方法维持其结构完整效果最好。     

臭氧联合二氧化氯处理对草鱼鱼糕保质期及品质的影响

制备草鱼鱼糕,采用0.65 mg/L臭氧水溶液和10 mg/L二氧化氯（ClO2）联合对鱼糕进行预处理,研究该处 理方式对鱼糕冷藏（4 ℃）保质期及品质的影响。结果表明：臭氧-ClO2处理能够有效延长草鱼鱼糕的保质期（与 对照组相比延长10 d）,4 ℃冷藏25 d后草鱼鱼糕的挥发性盐基氮含量、菌落总数等指标均未超过国家相应限量标 准;十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析表明,臭氧-ClO2处理可通过抑制内源酶活性来抑制蛋白质降解,从 而提高鱼糕的持水力,使草鱼鱼糕在贮藏过程中维持原有的白度和质构特性。     

不同贮藏温度下草鱼内脏鱼油品质变化

为探究草鱼内脏鱼油在不同贮藏温度下的品质变化,以草鱼内脏为原料,采用酶法提取鱼油,将草鱼内脏鱼油分别置于冷藏（4 ℃）、常温（25 ℃）和37 ℃条件下贮藏60 d,定期测定其酸价和过氧化值,并运用指纹特征分析、主成分分析（PCA）、线性判别分析（LDA）和载荷分析等电子鼻技术定期分析其挥发性成分的变化。结果表明:在贮藏期内,低温贮藏时（4 ℃ ）的草鱼内脏粗鱼油酸价、过氧化值和挥发性气味成分变化均不明显;在常温（25 ℃）及37 ℃贮藏温度下草鱼内脏粗鱼油的酸价、过氧化值均明显升高,挥发性气味成分变化较大,尤其37 ℃时变化显著;以酸价和过氧化值作为鱼油是否变质的评判标准,4 ℃时保质期约为55 d,25 ℃时保质期约为40 d,37 ℃时保质期约为30 d;鱼油贮藏过程中的挥发性成分主要为氮氧化合物、硫化物和芳香成分等物质。本研究为草鱼内脏的有效利用提供了理论基础。     

APPLICATION OF CHITOSAN TO MAINTAIN THE QUALITY OF KAMABOKO GELS MADE FROM GRASS CARP (CTENOPHARYNGODON IDELLUS) DURING STORAGE

Chitosan was added to kamaboko gels made from grass carp ( Ctenopharyngodon idellus ), and the effects on preservation quality were determined by biochemical (pH, total volatile basic nitrogen [TVBN], thiobarbituric acid [TBA], peroxide value) and microbiological (total bacterial count) determinations during storage at 4C. Application of chitosan, at a level of 1% (w/w), exhibited a beneficial effect on inhibiting lipid oxidation and bacterial growth in the gels. The preservative function was related to the molecular weight of chitosans. Relative low molecular weight chitosan showed a higher antioxidant capacity than high molecular weight chitosan. However, mixture of 300 and 10 kDa chitosans exhibited the highest antibacterial activity. Increases of pH, TVBN, TBA and peroxide values in gels during storage were significantly reduced when chitosan was applied. The present study provides a possible application of chitosan as a food additive for surimi-based foods.

PRACTICAL APPLICATIONS

Surimi-based product processing is an effective way to utilize freshwater fish with low commercial value, but the shelf life of surimi products is quite limited. Therefore, preservatives are commonly added to surimi products to extend the shelf life. This research has investigated the effect of chitosan, a natural preservative and antioxidant, on maintaining the quality of grass carp gels during storage at 4C. Results showed that chitosan could inhibit the growth of microorganism and prevent lipid oxidation, which was related to the molecular weight of chitosans. The present study should provide a possible application of chitosan as a natural food additive for surimi foods.     

鲜切草鱼鱼腩保鲜剂筛选与货架期

以鲜切草鱼鱼腩为原料,选取17 种平皿体系条件下对假单胞菌抑菌效果好的保鲜剂对草鱼鱼腩进行保鲜处理,通过感官初筛选出对产品色泽、味道、组织形态、组织弹性影响小的保鲜剂;研究不同初筛得到的保鲜剂处理后冷鲜草鱼肉贮藏期间品质变化,并根据微生物生长曲线构建微生物生长一级模型,通过模型参数的变化定量反映抑菌剂对微生物生长的抑制作用,综合考虑保鲜剂对冷鲜鱼腩品质以及抑菌特性影响,选出草鱼鱼腩处理的最佳保鲜剂;并结合气调包装（50% CO2＋50% N2）研究保鲜处理后草鱼鱼腩的货架期。结果表明：没食子酸、柠檬酸、鞣酸、磷酸三钾、ε-聚赖氨酸、植酸处理后鱼腩颜色正常,保持原有鱼香味,组织形态和弹性无不好影响;ε-聚赖氨酸处理后品质优于其他组,并在草鱼鱼腩基质上有较好抑菌特性,确定ε-聚赖氨酸为草鱼鱼腩最佳保鲜剂;经ε-聚赖氨酸处理的鲜切鱼腩结合气调包装后置于4 ℃贮藏时的货架期可达13 d,能较长时间保持鲜切草鱼鱼腩的品质。     

Effect of Slaughter Method on Postmortem Changes of Grass Carp (Ctenopharyngodon idella) Stored in Icesti

ABSTRACT: The effect of 2 slaughter methods (immersion in ice-water slurry and electrical stunning followed by ice slurry asphyxiation) on the quality of grass carp ( Ctenopharyngodon idella ) stored in ice for 20 d was evaluated using sensory and chemical analysis. Electricity immediately stunned the fish and did not induce blood spots in the flesh. Fish killed by electricity showed a faster initial rate of ATP degradation and entered into rigor mortis earlier, but did not show significant differences in the sensory score when compared with fish killed by immersion in ice-water slurry. Thus, no differences were observed in the shelf life of carps between the 2 slaughter methods evaluated. The limit for acceptability of grass carp stored in ice was around 13 to 16 d. Grass carp accumulated more inosine than hypoxanthine. K, Ki, P , Fr, and H values were highly correlated with storage time and with the TFRU sensory scores in both groups; these could be used to assess the freshness quality of grass carp.     

低温贮藏下草鱼肉优势腐败菌鉴定及其消长规律

通过稀释平板法对4℃条件贮藏6 d的草鱼肉的腐败菌进行分离,再以微生物鉴定系统对优势腐败菌进行鉴定,并分析了其消长规律。结果表明,草鱼肉冷藏过程中的优势腐败菌主要为乡间布丘氏菌(Buttiauxella gaviniae)、草莓假单胞菌(Pseudomonas fragi)、热杀索丝菌(Brochothrix thermosphacta)、静止嗜冷杆菌(Psychrobacter immobilis)。而且在整个冷藏过程中,除静止嗜冷杆菌数量一直增长外,其余3种腐败菌都需经过一定的适应期后才开始缓慢增长。     

Spoilage and shelf‐life extension of fresh fish and shellfish

Fresh fish and shellfish are highly perishable products due to their biological composition. Under normal refrigerated storage conditions, the shelf life of these products is limited by enzymatic and microbiological spoilage. However, with increasing consumer demands for fresh products with extended shelf life and increasing energy costs associated with freezing and frozen storage, the fish‐processing industry is actively seeking alternative methods of shelf life preservation and marketability of fresh, refrigerated fish and at the same time economizing on energy costs. Additional methods that could fulfill these objectives include chemical decontamination, low‐dose irradiation, ultra‐high pressure, and modified atmosphere packaging (MAP). This review focuses on the biochemical and microbiological composition of fresh fish/shellfish, the spoilage patterns in these products, factors influencing spoilage, and the combination treatments that can be used in conjunction with refrigeration to extend the shelf life and keeping quality of fresh fish/shellfish. The safety concerns of minimally processed/MAP fish, specifically with respect to the growth of Clostridium botulinum type E, is also addressed.     

Physicochemical,microbiological, and sensory attributes of chitosan-coated grass carp (Ctenopharyngodon idellus) fillets stored at 4°C

This study investigated the effect of chitosan coating (1 and 2%) on the quality of grass carp fillets stored at 4°C for 20 days. During storage, the physicochemical properties (pH, thiobarbituric acid value, total volatile basic nitrogen value, trimethylamine nitrogen value, K-value, water loss, and instrumental texture), microbiology (total viable count and psychrotrophic count), and sensory properties were evaluated. The results showed that chitosan coating could effectively inhibit bacterial growth, improve physicochemical and sensory qualities, and it reduced the deterioration of the quality of grass carp fillets. Compared with fillets without chitosan coating, the shelf life of fillets with 1 and 2% chitosan coating was extended by ~3 and 6–7 days, respectively.     

淡水鱼鱼糕加工适性和微冻特性的研究

测定了草鱼、鲢鱼、鲫鱼、鲈鱼、鲑鱼、黑鱼、鳊鱼、鲶鱼、鳙鱼等9种淡水鱼的采肉率和成本,比较不同淡水鱼鱼糕的营养特性和品质差异,测定鱼糕微冻贮藏过程中细菌总数、挥发性盐基氮(TVB-N)和硫代巴比妥酸还原值(TBARS)的变化。试验结果表明,鲶鱼采肉率最高,所需成本最低。不同淡水鱼鱼糕总蛋白含量有显著差异(p<0.05),而含水量、脂肪和灰分含量差异不显著(p>0.05)。草鱼鱼糕的硬度适中,弹性和凝聚性均优于其他种类淡水鱼鱼糕,咀嚼性和凝胶强度仅次于鲑鱼鱼糕,最适合作为淡水鱼鱼糜制品的加工原料。微冻与真空包装结合能明显延长鱼糕的货架期。草鱼鱼糕、鲢鱼鱼糕、黑鱼鱼糕和鳙鱼鱼糕的微冻保鲜期在56d以上。     

Quality changes and storage life of common carp (Cyprinus carpio) at various storage temperatures

The shelf life and freshness changes in pond-grown common carp (Cyprinus carpio L) during storage at 0–2°C, 5–6°C and room temperature (26–29°C) were investigated by sensory, microbiological, physical and chemical analyses. The effect of gutting on the shelf life during storage at 0–2°C was examined. Iodine/starch and potassium sorbate were examined for their effects on shelf life of whole fish stored at 0–2°C and 5–6°C. Sensory results indicated that the whole fish had a maximum shelf life of 24 to 25 days at 0– 2°C. The life of the fish to the point beyond which it would be unsuitable for sale (commercial shelf life) was 17 days at 0–2°C. Storage at 5–6°C shortened shelf life 2- to 2.5-fold. At room temperature (26–29°C), spoilage was evident after 13 h. Gutting the carp shortened its storage potential at 0–2°C. Iodine treatment of this species stored at 0–2°C and at 5–6°C did not extend shelf life. The maximum shelf life of sorbate-treated fish at 0–2°C and 5–6°C was extended by 1–2 days, commercial shelf life by 3–4 days. Total volatile basic nitrogen, pH and penetrometer analyses were not reliable indicators of changes in freshness during shelf life. Thiobarbituric acid values were not useful as rancid odours or flavours were not detected during storage.