生物保鲜剂结合气调包装对冷藏蟹棒保鲜品质的影响

鱼糜是鲜鱼肉经脱骨绞碎制成的,可进一步加工成为鱼糜制品,鱼糜制品低温下易储藏、食用方便、营养价值高,是目前水产品深加工的重要途径.蟹棒是中国传统的鱼糜制品,在常温下极易变质,而传统的冷冻贮藏方式会影响口感和风味,且能耗高.所以改进蟹棒的贮藏工艺,保持其口感和风味、延长其保鲜期、降低能耗具有重要低碳经济意义和广阔的发展前景.     

臭氧杀菌结合气调包装对缢蛏的保鲜效果

以缢蛏为研究对象,通过臭氧杀菌及不同气调包装处理,测定其在(0±0.5) ℃冷藏过程中的菌落总数、理化和感官等指标的变化,评价臭氧杀菌结合气调包装的保鲜效果。臭氧处理浓度为1 mg/L,包装条件分别为低氧气调包装(60% CO₂+30% N₂+10% O₂)、无氧气调包装(60% CO₂+40% N₂)、空气包装(对照)、低氧气调包装(60% CO₂+30% N₂+10% O₂)与臭氧处理复合、无氧气调包装(60% CO₂+40% N₂)与臭氧处理复合、臭氧处理包装。结果显示:0 ℃下缢蛏在空气包装下贮藏4 d和臭氧处理包装下贮藏8 d后菌落总数分别达到1.76×10⁷ cfu/g和1.14×10⁷ cfu/g,在有氧气调包装条件下和无氧气调包装调节下贮藏10 d后菌落总数分别达到1.87×10⁷ cfu/g和1.03×10⁷ cfu/g,超过规定的卫生标准;而有氧气调包装结合臭氧处理可使缢蛏的货架期达到12 d(9.33×10⁶ cfu/g),无氧气调包装结合臭氧处理可使缢蛏货架期延长至14 d(8.74×10⁶ cfu/g)以上。各处理组的TVB-N、K值、感官评分、pH变化也均与贮藏时间相关(P<0.05),并且气调包装结合臭氧处理组样品在冷藏期间的TVB-N、pH、K值和感官等指标均优于单独的气调包装或臭氧处理。相对于其它实验组,臭氧处理结合无氧气调包装组保鲜效果最好,样品在货架期末(14 d)TVB-N达到14.952 mgN/100 g,K值达到55%,感官评分达到5分,仍处于中等新鲜水平或可接受程度。总体结果表明,臭氧处理结合气调包装能有效延长冷藏缢蛏的货架期。     

气体比例对气调包装罗非鱼片货架期的影响研究

研究了气调包装中CO2浓度对罗非鱼片产品货架期的影响。分别采用100％CO2（Ⅰ）、70％CO2／30％N2（Ⅱ）、50％CO2／50％N2（Ⅲ）和30％CO2／70％N2（Ⅳ）的气体比例作为变量,主要通过感官评分并结合液汁流失率与色差值、微生物数量和总挥发性盐基氮（TVB-N）3个关键指标分别评定罗非鱼片的货架期。试验结果表明,4种不同气体比例气调包装感官评定的货架期分别为19、22、17和13d,4组样品货架期差异均明显（P〈0．05）;微生物指标评定的货架期分别为26、25、20和15d,Ⅰ和Ⅱ组差异不明显（P〉0．05）,但相对Ⅲ和Ⅳ组差异明显（P〈0．05）;TVB—N评定的货架期分别为25、23、18和13d,4组样品货架期差异均明显（P〈0．05）。但高浓度的CO2会加速液汁的渗出,因此,使用70％CO2的气调包装能够更好地延长货架期与保持产品良好外观。     

充气比率对罗非鱼片冰温气调贮藏期间品质的影响

采用不同的充气体积（V）与鱼片质量（m）比率包装鲜罗非鱼片,在冰温下贮藏,通过微生物、挥发性盐基氮（TVB—N）和脂质氧化（TBA）等指标考察充气比率对鱼片品质的影响。结果表明,充气比率≥3：1能抑制产品微生物的增长（P〈0．05）,贮藏第25天微生物数量仍小于可接受的限（10^6cfu·g^-1）;气调包装样品的肉汁渗出率均高于对照产品,充气比率越大对肉汁渗出率影响越明显;贮藏期间,对照组的TVB—N第4天开始明显高于充气比率≥3：1的样品,第19天时充气比率≥3：1的TVB—N仍在安全限内,约19．30mg·100g^-1;充气比率对产品pH的影响不明显;贮藏期间TBA缓慢上升,气调包装样品之间差异不明显,但与对照组差异显著（P〈0．05）。总而言之,充气比率为3：1～4：1的气调包装样品在贮藏期间品质差异不明显,能明显延长鲜罗非鱼片的货架期。     

不同气调包装方式对池沼公鱼保鲜品质的影响

鱼类是极易腐败变质的食品,而且一旦鲜度变差其价值下降很多,甚至可能完全丧失其食用价值并造成重大的经济损失。气调包装（Modified Atmosphere Packaging, MAP）是采用人工混合气体代替包装袋内的空气,改变食品贮藏环境,延长食品保鲜期的一种包装方法。     

TG酶制剂对鱼糜凝胶强度的影响

本文研究了TG-K、TG-B、TG-AK三种酶制剂在不同的添加量、凝胶化时间下对冷冻蛇鲻鱼糜凝胶强度的影响。结果表明:三种酶制剂都有增强冷冻蛇鲻鱼糜凝胶强度的作用,以 0.15％的 TG-AK酶制剂,30℃时凝胶化 30分钟凝胶强度增强效果最好,此方案应用于鱼丸的生产,产品的凝胶强度弹性明显增强。     

黄肚金线鱼(Nemipterus bathybius Snyder)冷冻鱼糜制品生产工艺的研究

本项研究通过引进国外先进设备,运用科学、先进的加工方法和工艺配方,采用黄肚金线鱼等低值水产品试验研制出适销对路的鱼丸等鱼糜制品,并在漂洗、漂白、脱水、擂溃、添加剂等方面有所创新,能有效地提高产品成品率和质量。应用本项研究成果后,每吨鱼丸的生产成本由1.51万元降至1.32万元,节约了0.91万元/t;每吨鱼丸价格由1.65万元上升至1.71万元,提高了600元/t。     

淡水鱼鱼糜制品加工特性及品质影响因素

以罗非鱼 (Oreochromis niloticus×O. areus) 鱼糜为原料,通过向鱼糜中添加不同剂量的羧甲基琼胶 (Carboxymethyl agar, CMA),并测定鱼糜凝胶的强度、持水性、质构特性、色泽、蛋白化学组成和微观结构等指标,研究了CMA对鱼糜凝胶性能的影响。结果表明,添加量为0.5%~2.0%时,CMA可显著提高鱼糜的凝胶强度 (P<0.05),最高达70.7%;1.5%~2.5%的CMA可显著提高凝胶持水性 (P<0.05);添加量为1.5%~2.0%时,CMA对鱼糜凝胶的质构特性具有良好的改善效果;添加量为0.5%时,CMA对鱼糜凝胶具有显著的增白效果 (P<0.05);CMA对鱼糜蛋白化学作用力具有显著影响 (P<0.05),适量添加可以破坏离子键,促进氢键、疏水键和二硫键的形成,促使鱼糜发生胶凝化;SDS-PAGE电泳和扫描电镜分析结果显示,CMA促使了肌球蛋白重链 (Myosin heavy chain, MHC) 之间的交联,添加1.5%的CMA可使鱼糜凝胶形成均匀、致密的网络结构。总之,罗非鱼鱼糜中添加1.0%~1.5%的CMA,改变了鱼糜的持水性、化学作用力和蛋白质的聚集性,增强了蛋白质的交联作用,改进了鱼糜凝胶的网络结构,从而提升了鱼糜的凝胶性能。     

水溶性壳聚糖对鱼糜制品保鲜效果的影响

研究了添加不同质量分数的水溶性壳聚糖对鱼糜制品冷藏保鲜效果的影响。以感官评分、菌落总数、挥发性盐基氮（TVB-N）、硫代巴比妥酸（TBA）和pH为指标,考察鱼糜制品在4℃冷藏过程中的品质变化。结果表明,水溶性壳聚糖能够明显抑制细菌的生长与繁殖,阻止感官品质的下降,延缓TVB-N和TBA的上升。其中,添加2.0%的水溶性壳聚糖保鲜效果最佳,与空白组相比,能将鱼糜制品的冷藏保鲜期从9 d延长至13～14 d。     

谷氨酰胺转胺酶对鱼糜品质的影响

为了综合利用小杂鱼资源,以冻杂鱼浆为原料,探讨了谷氨酰胺转氨酶(简称TGase)的添加量、作用时间、作用温度对鱼糜制品的弹性和凝聚性的影响。单因素试验和L9(34)正交试验结果表明,TGase的最佳工艺参数水平组合为TGae的用量为0.10%,TGase的作用温度为35℃,作用时间为1.5 h。     

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。 

     

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。     

Different Packaging Conditions to Improve Shelf Life of Filleted Gilt-Head Sea Bream (Sparus aurata)

Abstract

Shelf life of cultured gilt-head sea bream fillets (Sparus aurata) in over-wrap, vacuum and gas mixture packages stored during 27 days at 1±1°C was compared. The gas mixtures used contained CO₂, O₂, and N₂ at different percentages (0% O₂ + 50% CO₂ + 50% N₂; 10% O₂ +50%CO₂ +40%N₂;20%O₂ +50%CO₂ +30%N₂;30%O₂ +50% CO₂ + 20% N₂).

The evolution of the freshness degree of the packaged fillets was carried out by measurements of total volatile bases (TVB), trimethylamine (TMA), Tiobarbituric Acid Reactives Substances (TBARS), K _i and H values, psychrotrophic bacterial counts and sensory evaluation (color, odor, flavor).

Fish fillets were obtained 3 hours after harvesting with the best handling practices. As a consequence of this, the initial bacterial load was very low. The inhibitory effect of CO₂ on bacterial growth was very effective, keeping very low counts throughout all the storage period. Gas packages without O₂ and vacuum packages presented very low oxidation, whereas TBARS values in over-wrap and 10%, 20% and 30% O₂packaged fillets increased according to the oxygen content in the package. K_i value and specially H value differentiated very well among aero-bically stored fillets, vacuum and modified atmosphere packaging. TVB and TMA productions were poor freshness indicators, since no differences were found among treatments. Sensory quality of fillets deteriorated faster in over-wrap than in vacuum and gas packages. Modified atmospheres containing 20 and 30% O₂ were given lower sensory scores than vacuum packages, since they gave rise to yellowness of the fillets and off-odors and off-flavors.

In summary, modified atmosphere packaging of filleted gilt-head sea breams with a gas mixture consisted of 50% CO₂ + 50% N₂ gave rise to an important extension of shelf life compared to over-wrap packaging, vacuum and modified atmosphere packaging with gas mixtures containing O₂. This was due to the very low oxidation levels produced during the storage, the lower H value as a consequence of a minor production of Hx and the great inhibition on microbial growth.     

Effects of Modified Atmospheric Packaging Conditions on the Quality Changes of Pasteurized Oyster (Crassostrea belcheri) Meat during Chilled Storage

ABSTRACT

The effects of different atmospheric conditions on the quality and the shelf life of pasteurized oyster meat in chilled storage were investigated. The alternatives tested for pasteurized oyster meat were normal air (Control), 75% CO₂/25% N₂ (MAP-1), 75% CO₂/25% O₂ (MAP-2), 75% CO₂/5% O₂/20% N₂ (MAP-3), and vacuum packing (VP). The various observations of microbiological (total viable count (TVC), Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria (LAB), and hydrogen sulfide–producing bacteria), physical (color coordinates L*, a*, and b*, and cutting strength), chemical (moisture, pH, total volatile basic nitrogen (TVB-N), peroxide value (PV), and thiobarbituric acid reactive substances (TBARS)) and sensory properties were performed every 3 days over a total of 27 days. During storage across all the treatments, L*, a*, cutting strength, pH, moisture content, and sensory scores decreased; whereas, b*, TVB-N, PV, TBARS, and microorganisms increased. However, among the various alternatives, MAP-1 had the best retention of oyster quality during storage. Based on sensory and microbiological qualities, the shelf lives in chilled storage were 9 days for control, 15 days for VP, 21 days for MAP-2 and MAP-3, and 24 days for MAP-1-treated cases.     

Quality preservation of salted,vacuum packaged and refrigerated mahi sefid (Rutilus frisii kutum) fillets using an onion (Allium cepa) extract

The combined effect of light salting, vacuum packaging and onion extract on the shelf life of mahi sefid (Rutilus frisii kutum) fillets under refrigeration was assessed using chemical, microbiological and sensory methods. The shelf life of control, air‐packaged, salted (APS), vacuum‐packaged, salted (VPS) and vacuum‐packaged, salted with onion extract (VPSOE) samples was determined to be up to 6, 9, 15 and 18 days respectively. The values of total volatile basic nitrogen, free fatty acid and thiobarbituric acid increased progressively during the storage period for all the treatments. However, the preservative methods applied led to an extended shelf life of fillets based on chemical indices and sensory attributes in the following order: VPSOE>VPS>APS>control group. The assay of the total viable count (TVC) revealed that 2% and 4%VPSOE produced a decrease in TVC throughout the storage period. According to the results obtained, the best method to preserve the mahi sefid fillet was by 4%VPSOE treatment.     

The Combined Efficacy of Superchilling and High CO2 Modified Atmosphere Packaging on Shelf Life and Quality of Swimming Crab (Portunus trituberculatus)

The combined effect of superchilling and modi?ed atmosphere packaging (MAP) treatment on the quality of swimming crab during storage was investigated. As a result, signi?cantly (p < 0.05) higher inhibitor effects on total aerobic plate counts (TPCs) were observed in MAP treatments than in control (air package). Additionally, chemical analysis results showed that MAP treatments with 40–80% carbon dioxide (CO₂) were highly effective in maintaining lower total volatile basic-nitrogen (TVB-N), trimethylamine-nitrogen (TMA-N), pH, and thiobarbituric acid reactive substances (TBARS) values in swimming crab (p < 0.05). On the other hand, the brightness (L*) results also con?rmed that this combined treatment showed a positive effect on the stability of color during storage. Results also indicated that the combination of superchilling and 60% CO₂ MAP treatment prolonged the shelf life of swimming crab to 15–20 days. However, 100% CO₂ MAP treatment showed a negative effect on the drip loss and overall acceptability, indicating CO₂ content should be considered as a critical factor in this promising technology.     

Effect of CO2 on Chemical and Microbial Changes of Pacific White Shrimp During Modified Atmosphere Packaging

ABSTRACT

This study monitored the physical, chemical, and sensory quality of raw Pacific white shrimp (Litopenaeus vannamei) and the evolution of microbial flora under modified atmosphere packaging (MAP) with varying concentrations of CO₂ (95% CO₂/5% O₂; 80% CO₂/15% N₂/5% O₂; 65% CO₂/30% N₂/5% O₂) at 4°C during 10-day storage. Plate counts on selective agars indicated that MAP had a strong inhibitory effect on psychrotrophic bacteria, mesophilic bacteria, Enterobacteriaceae, and H₂S-producing bacteria. Analyses with molecular techniques (denaturing gradient gel electrophoresis, DGGE) by extracting bacterial DNA from shrimp samples showed that Vibrio spp. and Aeromonas spp. were predominant in fresh MAP samples. Shewanella putrefaciens, which dominated in samples stored in air, were found sporadically in MAP samples. Interestingly, lactic acid bacteria were not predominant in MAP samples, whose pH values were high (6.66 to 8.14) during storage. The content of total volatile basic nitrogen in MAP samples was about 10 mg N/g lower than the control at the end of storage. Higher lightness values and sensory scores were also observed in samples under MAP. However, MAP with CO₂ concentrations higher than 80% did not enhance the inhibitory effect on bacterial growth but induced more severe reddening and sensory quality loss.