鱼鳞蛋白酶解物为基料的涂膜剂对鲫的保鲜效果

研究了鱼鳞蛋白酶解物为基料的复合涂膜剂对鲫4 ℃贮藏过程中其鲜度指标变化和保鲜效果的影响。实验将去鳞、去内脏并洗净后的鲫分别于4 ℃的鱼鳞蛋白酶解物溶液和添加了迷迭香的鱼鳞蛋白酶解物溶液中浸泡1.5 min,沥干后用保鲜膜包好于4 ℃条件下贮藏。通过测定鱼体贮藏过程中细菌总数、TBA值、TVB-N值、K值、重量损失、感官评分等鲜度指标的变化规律,评价了鱼鳞蛋白酶解物对鲫在4 ℃贮藏条件下保鲜作用效果。结果表明,涂有鱼鳞蛋白酶解物的鲫的细菌总数、TVB-N值、K值、TBA值、重量损失在10 d内显著(P<0.05)低于对照组,而感官品质显著(P<0.05)高于对照组,在4 ℃条件下能延长鲫贮藏期8 d左右;涂有添加了迷迭香提取物的鱼鳞蛋白酶解物的鲫的TVB-N值、K值、重量损失在4～6 d内显著(P<0.05)低于对照组,而感官品质显著(P<0.05)高于对照组,但不能有效延长鱼体的贮藏期。鱼鳞蛋白经过胃蛋白酶在一定条件下酶解后,其产物对鱼体具有较好的保鲜效果,是一种良好的鱼体生物保鲜涂膜材料,但不适宜与迷迭香提取物联合使用。     

竹叶抗氧化物浸泡结合乳清分离蛋白涂膜对冷藏富硒虹鳟食用品质的影响

为延长冷藏富硒虹鳟的货架期,实验以3种浓度的竹叶抗氧化物溶液(AOBS,质量浓度分别为0.5%、1.0%和1.5%)分别浸泡富硒虹鳟鱼块,再进行乳清分离蛋白溶液(WPIS)涂膜,(25±1)°C下鼓风吹干表面水后置于4°C冰箱贮藏1、4、7、10和13 d,测定鱼块的pH值、TVB-N值、K值、菌落总数和嗜冷菌数、结合水分含量和水分状态,分析涂膜对冷藏富硒虹鳟鱼块品质的影响。结果显示,随着冷藏时间的延长,鱼块的pH值、TVB-N值、K值、菌落总数和嗜冷菌数显著增加,水分含量显著降低,结合水和不易流动水向自由水迁移。其中,1.0%AOBS+WPIS组的pH值、TVB-N值、K值、菌落总数和嗜冷菌数的增加速率和水分含量的减少速率最慢,结合水与不易流动水的比例最高。1.0%竹叶抗氧化物浸泡结合乳清分离蛋白涂膜,提升了乳清分离蛋白涂膜的保鲜效果,可有效抑制富硒虹鳟冷藏过程中品质的劣变,延长货架期。根据TVB-N值、K值和菌落总数,1.0%AOBS+WPIS组可延长富硒虹鳟货架期3 d。本研究可以为富硒虹鳟的低温贮藏技术提供科学指导。     

冰温保鲜条件下牙鲆的鲜度及质构变化

研究牙鲆在冰温贮藏条件下鱼肉的鲜度指标(pH值、K值、TVB-N、细菌总数)和质构特征参数(感官评定、组织构造、破断强度等)的变化,并与冷藏样品的相应变化进行了比较分析.结果表明,随着贮藏时间的延长,菌落总数、K值和TVB-N上升,pH值则先下降后上升,冷藏后期样品pH值上升较快且很高;至货架期终点时破断强度呈减小趋势,组织结构逐渐劣化.与冷藏样品相比,冰温贮藏条件能更有效地抑制牙鲆鱼体内微生物的作用,延长牙鲆的贮藏期.     

高压静电场结合冰温气调保鲜技术对罗非鱼鱼片品质的影响

文章研究了高压静电场结合冰温气调保鲜技术对罗非鱼鱼片的保鲜效果,通过罗非鱼片贮藏过程中肉汁渗出率、菌落总数、感官品质、色差值、总挥发性盐基氮(TVB-N)、脂质氧化(TBA)、p H等指标的变化情况,分析比较3.8 kV、1.8 kV、0 V高压静电下罗非鱼肉品质指标的变化。结果表明,高压静电场能够显著改善鱼肉的品质,贮藏至第30天,样品无异味,感官品质良好,可显著抑制肉汁渗出;可有效抑制微生物的生长和挥发性盐基氮的增加,在一定程度上抑制了鱼肉内脂肪氧化,具有较好的保鲜效果。总体上3.8 kV高压静电对鱼肉的保鲜效果优于1.8 kV高压静电,可延长肉片的保质期至30 d。     

鲤鱼片真空包装与盐腌处理在冷藏过程中的品质变化规律研究

为了科学地了解鲤鱼(Cyprinuscarpio)鱼片贮藏过程中的品质变化规律,帮助建立高效的品质控制技术,研究了鲤鱼片生鲜真空包装及1.5%盐腌普通包装在4℃冷藏条件下,挥发性盐基氮(TVB-N)、p H、电导率、汁液损失和K值的变化情况。结果显示,在整个贮藏过程中,TVB-N、电导率、汁液损失和K值均随贮藏时间的延长而上升。其中,真空包装生鲜鲤鱼片的TVB-N在贮藏过程中上升较缓慢,与生鲜鱼片相比,盐腌鱼片的TVB-N在贮藏过程中上升较慢,但汁液损失和电导率明显偏高;真空包装能有效抑制鱼片K值的上升,但盐腌无明显抑制效果;p H在贮藏过程中呈"V"形变化,贮藏后期真空包装和腌制处理均能抑制p H的升高。研究表明,鲤鱼片生鲜真空包装和1.5%盐腌普通包装在冷藏期间均能保持较好的鱼肉品质,具有良好的应用前景。     

冷藏与微冻贮藏过程中鲟鱼肉品质变化

为了比较鲟鱼(Acipenser sinensis)肉在4℃冷藏与?3℃微冻过程中的品质变化，提供一种提高鲟鱼新鲜品质的贮藏方式，通过感官评分、菌落总数(TVC)、pH值、挥发性盐基氮值(TVB-N)、硫代巴比妥酸值(TBA)、质构、挥发性风味物质、水分分布状态与肌纤维微观结构等指标的测定，评价了2种温度贮藏对鲟鱼肉品质的影响。结果显示，随着贮藏时间的延长，2种低温保鲜方式下鲟鱼肉的自由水与结合水的比例、TVB-N、TBA和菌落总数均呈现上升趋势；质构指标硬度和弹性及感官评分均呈降低趋势；观察其微观结构发现，随着贮藏时间的延长，肌纤维之间出现黏连，肌节逐渐由清晰变为模糊，?3℃贮藏后期表现尤为明显。综合各指标的变化规律，确定了4℃冷藏和?3℃微冻条件下，鲟鱼肉的货架期分别为6 d和18 d。与冷藏相比，微冻可较好地保持鲟鱼肉品质，微生物对鲟鱼肉的腐败进程影响较小，而质构指标则是影响贮藏末期感官评分的最主要因素。     

不同贮藏温度下大菱鲆品质变化及货架期预测模型的建立

为探究大菱鲆(Scophthalmus maximus)在不同贮藏温度下品质特性与货架期的关系,将大菱鲆贮藏在-3℃、0℃、4℃、10℃和15℃温度下,测定其感官品质、挥发性盐基总氮(TVB-N)、菌落总数、硫代巴比妥酸值(TBA)、电导率的变化,并且观测肌肉的微观结构;采用低场核磁共振技术(Low-field nuclear magnetic resonance, LF-NMR)分析鱼肉中水分迁移状况,并且建立了TVB-N及菌落总数与贮藏时间和温度的动力学模型。研究发现,随着贮藏时间的延长,5种不同贮藏温度下鱼肉中不易流动水均减少,货架期终点各贮藏温度下的样品相对于新鲜鱼肉,其肌纤维结构均由紧密变得疏松;TVB-N和菌落总数变化预测模型中的活化能和指前因子分别为79.50、75.07 kJ/mol和1.3×10~(14)、7.62×10~(12)。选用10℃进行验证性试验,结果显示实测值与预测值相对误差在10%以内。因此,可根据TVB-N值及菌落总数对大菱鲆贮藏在-3℃～15℃的货架期进行实时预测。     

壳聚糖-柑橘精油微胶囊制备工艺优化及其在凡纳滨对虾保鲜中的应用

本研究分别以壳聚糖浓度、乳化剂用量和三聚磷酸钠用量为指标进行单因素试验，以粒径、PDI和Zeta电位为指标进行分析，制备壳聚糖?柑橘精油微胶囊。以挥发性盐基氮(TVB-N)值、SDS-PAGE电泳、硫代巴比妥酸值(TBA)和菌落总数(TVC)为指标分析壳聚糖?柑橘精油微胶囊在 凡纳滨对虾(Litopenaeus vannamei) 4℃贮藏过程中对其品质的影响。结果显示，与对照组相比，壳聚糖?柑橘精油微胶囊处理组可以明显抑制TVB-N值、TBA值和TVC值增长(P<0.05)；SDS-PAGE图谱也显示实验组的肌球蛋白重链分解更慢。说明在4℃冷藏条件下，壳聚糖?柑橘精油微胶囊能够有效地抑制蛋白质的变性、脂肪的酸败和微生物的增长，从而延缓凡纳滨对虾腐败变质，延长凡纳滨对虾货架期3~4 d。     

冷藏和微冻条件下鲤鱼品质变化的研究

为了了解淡水养殖鲤鱼在冷藏和微冻贮藏条件下的品质变化情况,本研究将经前处理后的鲜活鲤鱼分别贮藏于4℃和-3℃冰箱中,测定了菌落总数(TVC)、挥发性盐基氮(TVB-N)、硫代巴比妥酸值(TBA)以及K值等指标的变化。结果显示:冷藏第12天鲤鱼的菌落总数为5.67 logcfu/g,微冻第40天为5.72 logcfu/g;冷藏第8天时TVB-N值为10.55 mg/100 g,微冻第30天TVB-N值为18.85 mg/100 g;冷藏条件下TBA值在贮藏的第14天为0.52 mg/kg,微冻第40天为1.06 mg/kg,均未超过2.00 mg/kg;冷藏第8天K值为55.96%,微冻第30天K值为53.99%。综合各指标变化,4℃和-3℃贮藏鲤鱼的贮藏期分别为8 d和30d,-3℃的微冻贮藏较4℃贮藏鲤鱼贮藏期延长了2.75倍。     

低盐低糖处理鲟鱼片冷藏过程中品质变化规律

文章通过测定感官分值、菌落总数(TAC)、挥发性盐基氮(TVB-N)、ATP关联物、生物胺等指标,研究了低浓度盐和糖处理对鲟(Acipenser sinensis)鱼片4℃冷藏过程中品质变化的影响。结果显示,T1(1.8%食盐干腌)和T2(1.8%食盐+1.0%绵白糖干腌)组鱼片感官可接受时间均比空白组延长了5 d;空白组菌落总数第6天达到7.34 log CFU·g-1,而T1和T2组在第16和第12天分别达到6.76 log CFU·g-1和6.78 log CFU·g-1;空白组TVB-N的增长速率也显著高于T1和T2组(P0.05);和空白组相比,T1和T2组HxR的含量显著高于空白组(P0.05),但K值及ATP、AMP、IMP含量差异不显著(P0.05);腐胺、酪胺和精胺的含量随贮藏时间的延长升高,T1和T2组腐胺含量显著低于空白组(P0.05)。结果表明,盐和糖的加入,明显改善了鲟鱼片冷藏过程中的品质变化。     

Effects of Chitosan Coatings Enriched with Different Antioxidants on Preservation of Grass Carp (Ctenopharyngodon idellus) During Cold Storage

To investigate the effects of chitosan composite coatings for maintaining the quality of grass carp portions, indictors of microbiology (total bacteria count, TBC), chemistry (pH; total volatile basic nitrogen, TVB-N; 2-thiobarbituric acid, TBA; K-value), and sensory characteristics were analyzed periodically. The results showed that chitosan (1.5%, w/v) + acetic acid (1.0%, v/v) + tea polyphenol (TP, 0.5%, w/v) coating significantly (p ≤ 0.05) reduced growth of microorganisms as reflected in TBC, lipid oxidation as displayed in TBA, chemical spoilage as reflected in pH, TVB-N, K-value, and sensory characteristic scores compared to the control samples. The effect of chitosan (1.5%, w/v) + acetic acid (1.0%, v/v) + vitamin C (VC, 0.5%, w/v) coating was better than chitosan (1.5%, w/v) + acetic acid (1.0%, v/v) coating. Chitosan together with acetic acid and TP can be used as a type of preservative coating for grass carp portions under chilled storage.     

Effect of Chitosan and Garlic Essential Oil on Microbiological and Biochemical Changes that Affect Quality in Grass Carp (Ctenopharyngodon idellus) Fillets During Storage at 4°C

Solutions of chitosan (2%, w/v), garlic essential oil (5%, v/v), and their combination (2%, w/v chitosan +5%, v/v garlic essential oil) were applied to the surface of grass carp fillets. Subsequently, sensory, microbiological analyses (total viable count (TVC), Pseudomonas spp., Aeromonas spp., and H₂S-producing bacteria), and physicochemical changes (total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and centrifugation loss) of grass carp fillets were evaluated over a 16-day storage at 4 ± 1°C. The treated samples resulted in significantly (p < 0.05) higher overall acceptance scores than the control from day 8. The TVC of grass carp fillets was reduced from the initial level (4.0 log CFU/g) to 2–3 log CFU/g when the fillets were treated with either garlic essential oil or chitosan solution. After 4 days of storage, the Pseudomonas spp. counts in the chitosan-treated samples were significantly lower (p < 0.05) than the counts in control and samples treated with garlic essential oil. A lag phase of 6 days for the counts of H₂S-producing bacteria of fish fillets that were treated with chitosan or the combination solution was observed. The combination of chitosan with garlic essential oil did not show synergistic effects, although it displayed a higher degree of antimicrobial efficacy with respect to the spoiled bacteria. However, the combination of chitosan with garlic essential oil was the most effective at inhibiting the formation of TVB-N. Samples that were treated with garlic essential oil displayed the highest TBARS levels on days 4 and 6 (p < 0.05).     

Microbiological and Physicochemical Quality of Carp sausage Enriched With Propolis Natural Extract during Chilled Storage

This study aimed to determine the effect of propolis extract on quality of liquid smoked carp (Cyprinus carpio) sausage stored at 2°C for 9 weeks. Carp sausages were separated into three groups: control group, without propolis extract; second group, with 1% (w/w) propolis extract added; and third group, with 2% (w/w) propolis extract added. Propolis extract added carp sausages showed lower total volatile basic nitrogen (TVB-N) value, peroxide value (PV), and free fatty acid (FFA) content compared to control during the storage period. During 9 weeks of storage, propolis extract added carp sausages showed significantly lower total aerobic mesophilic bacteria (TAMB) and psychrophilic bacteria count (PBC) than those of control samples (p < .05). Yeast and mold were not detected in all fish sausages throughout the storage period.     

The Relationship Between Electric Impedance and Quality Parameters of Ungutted and Gutted Common Carp (Cyprinus carpio) Stored at 4°C

In order to understand the relationship between electric conductivity and quality parameters of common carp during storage, the electric impedances in the frequencies ranging from 1 to 20 kHz, total viable count (TVC), total volatile basic nitrogen (TVB-N), and K values of gutted and ungutted common carp were determined during 4°C storage. The result showed that the change ratio of electric impedance (Q value) of both gutted and ungutted common carp decreased with increasing storage time, while TVC, TVB-N, and K values increased gradually. There was a good correlation between Q values and TVC, TVB-N, and K values of gutted and ungutted common carp, and their correlation coefficients were 0.952, 0.965, 0.928, and 0.956, 0.975, and 0.938, respectively. This result demonstrated that Q value is valid to predict some quality parameters of common carp during 4°C storage.     

Assessment of the Antibacterial Effect of Chitosan Coated with Heracleum persicum Oil on Rainbow Trout Quality

Today, due to the rapid spoilage of fish, the use of natural preservatives is a priority over those of synthetic varieties. Also, the natural antimicrobial effects of essential oils can help to increase shelf life. There are very few studies concerning the use of essential oils in this regard. In the present study, the antibacterial effect of chitosan coated with Heracleum persicum oil was investigated on the quality of rainbow trout. The control and the coated fish samples were analyzed periodically by generalized estimating equation (GEE) for total viable count (TVC), psychrophilic bacteria, total volatile base nitrogen (TVB-N), polyunsaturated fatty acids (PUFA), texture, taste, odor, and overall acceptance parameters. The results showed that by increasing the amount of chitosan, TVC, psychrophilic bacteria, and TVB-N decreased while PUFA, texture, taste, odor, and overall acceptance parameters increased.     

The Effects of Chitosan Coating on Biogenic Amines Inhibition and Microbial Succession of Refrigerated Grass Carp (Ctenopharyngodon idellus) Fillets

Chitosan coating and plastic wrap coating were investigated for their effects on the quality of grass carp fillets stored at 4 ± 1ºC for a period of 20 days. The fillets were divided into groups of untreated (Control), wrapped with sterile preservative film (PE), and chitosan-treated (1, 2, and 2.5% w/v corresponding to CH1, CH2, and CH2.5, respectively). The final result demonstrated that chitosan coating has positive effects on the microbial inhibition of total volatile count (TVC), lactic acid bacteria (LAB), Enterobacteriaceae, Pseudomonas, H₂S-producing bacteria (including Shewanella putrefaciens), and Staphylococcus. With regard to the results of biogenic amines (BAs), putrescine (PUT) and histamine (HIS) were the major amines, and their concentration was significantly (p < 0.05) higher in Control and PE than in chitosan-coated fillets at the end of storage. The final concentration in Control, PE, CH1, CH2, and CH2.5 was 143.7, 160.1, 83.0, 59.4, and 44.2 mg/kg for PUT and 228.0, 57.1, 4.1 3.2, and 2.9 for HIS, respectively. Chitosan coating was found to inhibit the increase of total volatile base nitrogen (TVB-N), microbial population, and total BAs and prolong the shelf life of grass carp fillets. However, sterile plastic wrap coating had little positive effect on maintaining the quality of grass carp fillets during refrigerated storage.     

气调包装结合臭氧预处理保鲜鲟鱼片

本文研究了气调包装(MAP,50%CO2+10%O2+40%N2)结合臭氧处理用于鲟鱼片保鲜的效果。通过以未经过臭氧预处理的MAP做对照组,试验分别研究了臭氧预处理10min、20min和30min对鲟鱼片MAP保鲜期的影响。结果表明:臭氧预处理能有效减少鲟鱼片原始的带菌数,减缓贮藏期间细菌总数和TVB-N值的增加速度,以及减缓感官品质的下降。综合分析臭氧预处理时间对鲟鱼片贮藏期间感官品质、细菌总数、TVB-N值和肌肉持水力的影响,确定以臭氧预处理20min效果最好,与对照组比较,贮藏货架期延长3～5d。     

短时间微流水处理对池塘养殖草鱼鱼肉品质的提升作用

以池塘养殖草鱼为对象,采用室内微流水系统处理草鱼,研究处理时间(0、1、4、7和10 d)对草鱼鱼肉基本营养组成、滋味特征和滋味成分、气味特征和气味成分、感官评分的影响,以评价短时间微流水处理对草鱼鱼肉品质的提升作用。结果显示,微流水处理对草鱼鱼肉的基本营养成分、滋味成分、气味成分和感官评分均有显著影响。随着微流水处理时间延长,草鱼鱼肉中脂肪和总糖含量显著下降、灰分含量显著增加,但鱼肉中蛋白质含量无明显差异。滋味分析仪(电子舌)和气味分析仪(电子鼻)检测结果表明,微流水处理能显著改变草鱼鱼肉的滋味特征和气味特征。处理后的草鱼鱼肉中IMP、鲜味氨基酸(天冬氨酸和谷氨酸)、甜味氨基酸(丝氨酸和丙氨酸)、苦味氨基酸(亮氨酸和异亮氨酸)含量显著增加,而其总挥发性盐基氮(TVB-N)、二十二碳六烯酸(DHA)等含量显著减少。微流水处理4 d的草鱼鱼肉气味评分、滋味评分和色泽评分显著高于处理0和1 d的草鱼样品,而与处理7和10 d的草鱼样品无差异。研究表明,短时间微流水处理能有效提升草鱼鱼肉品质,适宜处理时间为4 d,处理后的草鱼鱼肉腥味明显减弱、鲜味明显增强。     

反复冷冻-解冻对鲢品质的影响

研究鲢(Hypophthalmichthys molitrix)在冷冻-解冻过程中的品质变化规律。鲢于–18℃条件下冻藏10 d,流水解冻后再贮藏于–18℃条件下,5 d后解冻,共反复冷冻-解冻5次。在解冻1、3、5次后随机取3条鲢测定其解冻损失、蒸煮损失、硬度、咀嚼性、恢复性、硫代巴比妥酸(TBA)值、L*值、b*值、盐溶性蛋白(SSP)含量、Ca2+-ATP酶活性、总巯基含量、表面疏水性和感官值等指标,评价反复冷冻-解冻对鲢品质的影响。结果表明,在第1次冷冻-解冻时,硬度、咀嚼性、恢复性、盐溶性蛋白(SSP)含量和Ca2+-ATP酶活性与鲢初始值相比显著降低(P<0.05),b*值和表面疏水性显著升高(P<0.05);解冻损失、L*值和TBA值在第3次冷冻-解冻时显著上升(P<0.05);总巯基含量在第5次冷冻-解冻时显著下降(P<0.05);而蒸煮损失在冷冻-解冻过程中没有显著变化(P>0.05);感官值在第5次冷冻-解冻时为47,感官品质已不可接受。各指标变化表明,鲢品质会随着反复冷冻-解冻次数增加而下降,在运输、贮藏和销售过程中要防止温度波动,避免反复冻融对鲢品质造成不利影响。     

电子鼻在对虾新鲜度评价中的应用

以凡纳滨对虾Litopenaeus vanmamei为实验对象,研究电子鼻对不同保藏时间的凡纳滨对虾虾头和虾肉的气味响应,并与感官指标、挥发性盐基氮(TVB-N)和菌落总数进行对比分析,建立一种基于电子鼻技术的对虾新鲜度评价方法.结果表明,随着保藏时间的延长,对虾的鲜度和气味发生变化；电子鼻能将不同保藏时间的对虾区分开来,而且与感官评定、TVB-N和菌落总数检测结果一致.负荷加载分析(Loadings)显示,不同传感器对主成分的贡献率不同；采用线性判别分析(LDA)所得的总贡献率高于主成分分析(PCA)所得的总贡献率.电子鼻对虾头和虾肉的气味均有较好的响应,因此虾头和虾肉都可以用于电子鼻评价对虾的新鲜度.