复合生物保鲜剂结合冰温贮藏对南美白对虾的保鲜效果

目的：研究复合保鲜剂结合冰温贮藏对南美白对虾的保鲜作用,避免其腐败变质,从而延长其货架期。方法：将复合生物保鲜剂处理过的南美白对虾贮藏在不同温度（4 ℃和－2.2～－1 ℃）条件下,通过pH值、感官评分、菌落总数、挥发性盐基氮含量、Ca2+-ATP酶比活力和硫代巴比妥酸含量指标的测定,对实验结果进行方差分析,确定最佳保鲜贮藏组合。结果：复合生物保鲜剂结合冰温贮藏延长了南美白对虾的货架期。结论：复合生物保鲜剂结合冰温贮藏对南美白对虾保鲜效果更佳,能使南美白对虾货架期达到21 d。     

南美白对虾冰温气调保鲜效果评价

将鲜南美白对虾进行空气包装(AP)、真空包装(VP)、气调包装(MAP,75% CO2/25% N2),分别冰温(－2.3～0℃)贮藏和冰藏,通过研究样品贮藏过程中多酚氧化酶(PPO)活力、总挥发性盐基氮(TVB-N)、菌落总数(TPC)、汁液流失率(DL)的变化,结合感官指标评价冰温气调保鲜的效果。结果表明：南美白对虾的PPO活力变化与腐败变质同步;冰温结合MAP能有效防止褐变,货架期可达10d,比冰藏结合AP延长了约3倍,此时样品色泽良好,TPC、TVB-N、DL分别为5.4(lg(CFU/g))、25.6mg/100g、3.13%,而其他包装样品已腐败。VP也能较好的保持色泽,但贮藏后期汁液流失相对严重,影响外观。     

复合生物保鲜剂在南美白对虾保鲜中的应用

近年来南美白对虾深受国内外消费者的喜爱,但是由于货架期较短,影响了食用性,使其不能发挥应有的商品价值.复合生物保鲜剂能较好的抑制南美白对虾的腐败变质和黑变,成为了水产品保鲜的研究热点.该文详细介绍了几种常见生物保鲜剂(壳聚糖、茶多酚、溶菌酶、乳酸链球菌素)的保鲜机理和应用现状,并对这几种天然物质与其它保鲜剂的复合使用进...     

冰温技术结合保鲜剂对南美白对虾品质的影响

研究冰温技术结合4- 己基间苯二酚(4-hexylresorcinol,4-HR)等保鲜剂对延缓虾类黑变和保持品质方面的效果。通过正交试验确定保鲜剂的配方(M),以冻结试验确定冰温贮藏温度,测定贮藏设备的温控范围,通过评定南美白对虾的黑变感官得分,测定多酚氧化酶(PPO)活力、挥发性盐基氮(TVB-N)、pH 值和菌落总数(TBC)等鲜度指标评价保鲜效果差异。结果表明：南美白对虾的冰温带为－ 2.2～0℃,贮藏设备温度波动满足冰温技术要求,M 保鲜剂配方为0.01% 4- 己基间苯二酚+1.5% 柠檬酸+1% 抗坏血酸,冰温能显著减缓TVB-N 值、pH 值和TBC值增加速度,M 配方保鲜剂能有效抑制虾的多酚氧化酶活性和黑变,冰温技术结合M 配方保鲜剂保藏南美白对虾能互补二者优缺点,能显著减低黑变感官得分,PPO 活性、TVB-N、pH 值和TBC 的增长速度。比(4 ± 1)℃冷藏的货架期延长近1 倍。冰温技术结合保鲜剂能有效防止虾类黑变和延长品质货架期。     

南美白对虾复合生物保鲜剂的优选

为解决南美白对虾易腐败以及化学保鲜剂可能引起的食品安全等问题,通过正交试验,将壳聚糖、茶多酚、乳酸链球菌素(Nisin)进行复配,优选出一种复合生物保鲜剂,并验证了其在南美白对虾防腐保鲜中的效果。结果表明：复合生物保鲜剂的优化质量分数配比为壳聚糖1.5%、茶多酚0.1%、Nisin 0.02%;经该复合生物保鲜剂处理后的南美白对虾在(4 ± 1)℃贮藏过程中挥发性盐基氮(TVB-N)在第8 天还未达到30mg/100g,细菌总数在第9天才达到5 × 105 个/g,保持了较好的感官品质,货架期由4d 延长到了7～8d。处理1kg 对虾新增成本为0.17 元,具有较好的应用价值。     

南美白对虾保鲜剂研究进展

介绍常用的几种南美白对虾保鲜剂,对溶菌酶、乳酸链球菌素、植酸及壳聚糖这几种生物保鲜剂在南美白对虾保鲜中的研究进展进行较为详尽的阐述。其中,生物保鲜剂因其具有安全、高效的作用而在南美白对虾保鲜方面具有较大的发展前景。     

纳米TiO_2/壳聚糖复合保鲜剂在南美白对虾保鲜中的应用

为解决南美白对虾易腐易黑变问题,延长其货架期,利用不同质量分数的纳米TiO2/壳聚糖保鲜剂处理南美白对虾,并贮藏在(4±1)℃条件下。通过对虾体进行pH值、挥发性盐基氮、菌落总数指标的测定,结合感官评定,表明了纳米TiO2/壳聚糖保鲜剂能够有效地保持南美白对虾的品质,使南美白对虾货架期由原来的4 d延长至7 d,为南美白对虾保鲜技术的推广提供一定的技术支持。     

不同生物保鲜剂对冷藏南美白对虾的保鲜效果

为提高冷藏南美白对虾的贮藏品质,分别采用0.05%溶菌酶、0.1%植酸、0.5%柠檬酸、0.15%抗坏血酸、0.5%L-半胱氨酸和1.5%壳聚糖保鲜对虾,通过感官评价、pH、细菌总数、挥发性盐基氮和多酚氧化酶相对酶活力的测定评价保鲜效果。研究结果表明,1.5%壳聚糖能有效减缓新鲜对虾感官品质的下降,并抑制微生物生长,0.5%柠檬酸对挥发性盐基氮抑制效果最好,并有较强的抑制多酚氧化酶作用,0.5%L-半胱氨酸能有效抑制多酚氧化酶和黑变,而0.05%溶菌酶、0.1%植酸和0.15%抗坏血酸对南美白对虾的品质改善不明显。     

不同生物保鲜剂对冷藏南美白对虾的保鲜效果

为提高冷藏南美白对虾的贮藏品质,分别采用0.05%溶菌酶、0.1%植酸、0.5%柠檬酸、0.15%抗坏血酸、0.5%L-半胱氨酸和1.5%壳聚糖保鲜对虾,通过感官评价、pH、细菌总数、挥发性盐基氮和多酚氧化酶相对酶活力的测定评价保鲜效果。研究结果表明,1.5%壳聚糖能有效减缓新鲜对虾感官品质的下降,并抑制微生物生长,0.5%柠檬酸对挥发性盐基氮抑制效果最好,并有较强的抑制多酚氧化酶作用,0.5%L-半胱氨酸能有效抑制多酚氧化酶和黑变,而0.05%溶菌酶、0.1%植酸和0.15%抗坏血酸对南美白对虾的品质改善不明显。      

不同保藏方式南美白对虾的电子鼻分析

基于Alpha MOS公司生产的FOX4000型电子鼻,对不同贮藏条件下和不同贮藏时间的南美白对虾样品进行分析,并结合感官评定与微生物计数培养分析,旨在建立一种基于电子鼻对虾质量评价的方法,并对不同保藏方法的南美白对虾的气味进行研究。三种保藏方法是:组1:直接放入4℃冰箱中,即非气调保藏;组2:经40%CO2+60%N2气调包装,4℃冰箱保藏;组3:经60%CO2+15%N2+25%O2气调包装,4℃冰箱保藏。结果显示,三组对虾样品感官得分逐渐下降;pH先下降后上升;细菌总数逐渐增多。三种不同保藏方式的对虾不同保藏时间气味有很大的差别;随着贮藏时间的延长,传感器的响应强度逐渐增强,且不同贮藏时间的样品可以相互区分;组3条件下气调气味变化最为缓慢;并且气调保藏约延长货架期6d。电子鼻可以用于不同保藏方式南美白对虾气味的检测。      

Effect of pyrophosphate and 4-hexylresorcinol pretreatment on quality of refrigerated white shrimp (Litopenaeus vannamei) kept under modified atmosphere packaging

ABSTRACT:  The effect of pretreatment with pyrophosphate and 4-hexylresorcinol in combination with modified atmosphere packaging (MAP) (80% CO₂, 10% O₂, 10% N₂, or 80% CO₂, 20% N₂) on the quality of white shrimp during storage at 4 °C was investigated. Shrimp pretreated with 2% pyrophosphate and 0.25% 4-hexylresorcinol and stored under MAP showed the lower microbiological and chemical deteriorations as evidenced by delayed microbial growth as well as lower trimethylamine (TMA) and total volatile base nitrogen (TVB) production ( P < 0.05). Additionally, the growth of coliforms was inhibited effectively. White shrimp pretreated with 4-hexylresorcinol had the lower melanosis throughout the storage compared with those without treatment ( P < 0.05). This was associated with the lowered polyphenol oxidase (PPO) activity in shrimp treated with 4-hexylresorcinol. Therefore, the effective retardation of microbiological and chemical deterioration of white shrimp stored under MAP with the decrease in melanosis could be achieved by pretreatment of the shrimp with pyrophosphate and 4-hexylresorcinol. Furthermore, decapitation could be another means to lower the microbial load and melanosis in white shrimp, particularly those stored under MAP.     

牛肉冰温气调保鲜技术的研究

研究了以不同组合比例的CO2、O2、N2的气调包装,结合冰温（-1．5±1℃）贮藏的牛肉保鲜技术。以空气包装为对照,以牛肉的色差值、菌落总数、失水率、挥发性盐基氮、PH值为衡量指标,综合评价冰温气调保鲜牛肉的效果。研究结果表明,最佳的气调包装组分为10％O2,70％CO2和20％N2,在此条件下可以保鲜达28天;保鲜牛肉的PH值为6．09,挥发性盐基氮值为14．634mg／100g,菌落总数为3．7×10^4efu／g,色泽紫红,无异味。     

冰温结合气调贮藏对树莓保鲜效果的影响

实验采用不同厚度的PE袋包装树莓,贮藏于冰温条件下,研究冰温结合气调贮藏对树莓品质的影响。结果表明,冰温结合气调处理使树莓贮藏期延至20d,并有效延缓了果实可滴定酸、可溶性固形物(TSS)含量的下降,对照组15d时的可滴定酸、TSS含量分别降至1.47%、9.2%,而0.04mm气调处理组20d时的可滴定酸、TSS降至了1.58%、9.7%。但抑制呼吸强度、乙烯生成速率的差异不明显。同时,气调处理提高了树莓过氧化物酶(POD)、过氧化氢酶(CAT)的活性,降低了多酚氧化酶(PPO)活性,延缓了丙二醛(MDA)含量的升高,延缓了树莓的衰老。其中,0.04mm PE保鲜袋中树莓的品质最好。这说明适当的气调结合冰温贮藏更有利于树莓的贮藏。      

Autolysis of Pacific white shrimp (Litopenaeus vannamei) meat: characterization and the effects of protein additives

ABSTRACT:  Autolytic activity of Pacific white shrimp ( Litopenaeus vannamei ) mince in the absence and in the presence of 2.5%NaCl was investigated. Pacific white shrimp mince exhibited the maximum autolytic activity at 35 and 40 °C in the absence and in the presence of 2.5%NaCl, respectively, as evidenced by the highest TCA-soluble peptide content and the greatest disappearance of myosin heavy chain (MHC). The autolysis was more pronounced in the acidic pH values, followed by alkaline pH ranges. Pepstatin A showed the highest inhibition toward autolysis in the acidic condition, revealing that aspartic proteinase was dominant in shrimp muscle. Nevertheless, soybean trypsin inhibitor effectively inhibited the autolysis at neutral and alkaline pH values, suggesting that serine proteinase was present in shrimp mince but contributed to autolysis at a lower extent in shrimp meat. Autolysis in shrimp meat could be inhibited partially by all protein additives, including bovine plasma protein (BPP), egg white (EW), and whey protein concentrate (WPC). The inhibition of autolysis increased when the level of protein additives increased with the concomitant increase in band intensity of MHC retained. WPC and BPP in the range of 2% to 3% exhibited the highest inhibition toward autolysis of shrimp mince.     

Retardation of quality changes of Pacific white shrimp by green tea extract treatment and modified atmosphere packaging during refrigerated storage

The effect of modified atmosphere packaging (MAP) on the quality changes of Pacific white shrimp (Litopenaeus vannamei) treated with or without green tea extract (1 g/L; GTE) in combination with or without ascorbic acid (0.05 g/L; AA) during refrigerated storage of 10 days was investigated. Shrimp without treatment stored under MAP had lowered psychrotrophic bacteria, enterobacteriaceae and H₂S-producing bacteria count (P < 0.05) but similar lactic acid bacteria count (P > 0.05), in comparison with shrimp stored in air (control). The coincidental lowered rate of increase in pH, total volatile base (TVB) content and thiobarbituric acid reactive substances (TBARS) were obtained in shrimp stored under MAP (P < 0.05). However, MAP slightly lowered melanosis formation and improved likeness score to some extent. When shrimp were treated with GTE and stored under MAP, the lower microbiological and chemical changes as well as the lowest melanosis formation were observed, compared to shrimp kept under MAP without treatment and the control (P < 0.05). GTE treatment in combination with MAP could retard chemical changes and melanosis formation, regardless of AA incorporation (P > 0.05). Nevertheless, GTE in combination with AA had higher inhibition on microbial growth and yielded the shrimp with higher likeness, compared with the other treatments (P < 0.05). Therefore, shrimp treated with GTE in combination with AA prior to MAP had the lowest losses in quality during refrigerated storage.     

复合保鲜剂结合MAP对鲜切茄子贮藏品质的影响

为延长鲜切茄子的保鲜时间,研究单一气调包装(2%CO2+5%O2+93%N2)和保鲜液(1.5%壳聚糖+1%抗坏血酸+1%氯化钙+2%柠檬酸)结合气调包装对鲜切茄子品质的影响。以感官评分、褐变度、硬度、多酚氧化酶(PPO)活性和细菌总数为指标,分析鲜切茄子于(10±1)℃下贮藏8d内的品质变化。结果表明:贮藏8d后,对照组样品的L*值、硬度、PPO酶活性和细菌总数分别为75.66、7.41kg/cm2、68.77U/(min·g)和5.52lg CFU/g,而经保鲜液结合气调包装的鲜切茄子各指标分别为82.51、10.05kg/cm2、23.70U/(min·g)和2.87lg CFU/g。气调包装能够抑制鲜切茄子的褐变、萎蔫等感官品质的下降,并抑制PPO活性的增加和细菌的生长繁殖,尤其在结合保鲜液处理后效果更加明显,贮藏8d仍保持较好的品质。     

Effect of cinnamaldehyde on melanosis and spoilage of Pacific white shrimp (Litopenaeus vannamei) during storage

BACKGROUND: Shrimp is a very perishable product and postmortem changes occur rapidly. Sulfiting agents were once and are still widely used as a preservative in the shrimp industry. However, the application of sulfite in shrimp may pose a risk to human health. Thus development of a natural preservative as a sulfite alternative to extend the shelf life of Pacific white shrimp is urgently needed. RESULTS: The effects of cinnamaldehyde essential oil (1 and 5 g kg^?1) on the shelf life of Pacific white shrimp stored at 4 °C were investigated. As the concentration of cinnamaldehyde increased, residual polyphenoloxidase (PPO) enzyme activity decreased. Kinetic analysis showed that cinnamaldehyde was a noncompetitive inhibitor for the oxidation of L ‐DOPA (L ‐3,4‐dihydroxyphenylalanine) by PPO of Pacific white shrimp. Based on this study, shrimp treated with 5 g kg^?1 cinnamaldehyde possessed the lowest aerobic plate count, total volatile basic nitrogen, and pH values in all treatments after 10 days of storage. According to the results of L*, cinnamaldehyde showed inhibitory activity toward the formation of melanosis. CONCLUSION: Treatment with cinnamaldehyde could improve the sensory properties and extend the shelf life of Pacific white shrimp to 8 days. Therefore, cinnamaldehyde could be used as a promising natural preservative for inhibiting melanosis and preventing the growth of microbes during the chilled storage of Pacific white shrimp. Copyright © 2012 Society of Chemical Industry     

生物保鲜剂处理结合气调包装对冷鲜滩羊肉贮藏品质的影响

目的 研究生物保鲜剂结合气调包装在4±1℃下对冷鲜滩羊肉贮藏品质的影响,探究复合保鲜技术的可行性。方法 以冷鲜滩羊肉的菌落总数为指标,通过响应面优化实验得到二次多项回归模型Y菌落总数和响应面回归方差分析表,并通过验证实验验证复合保鲜剂的合适配比。结果 复合保鲜剂最佳质量配比为：壳聚糖：1.5%、茶多酚：1.2%、Nisin：0.04%;联合保鲜使得样品在0、4、8、12、16、20、24 d在4℃±1℃下的菌数总数、pH、硫代巴比妥酸(thiobarbituric acid reactive substances,TBARS)、挥发性盐基氮(total volatile basic nitrogen,TVB-N)、色泽、蒸煮损失率、硬度、弹性、黏聚性、回复性均随着贮藏时间的延长有不同程度的增加。4±1℃条件下,贮藏后期菌落总数变化速率高于贮藏初期(P<0.05),且实验组的pH、TBARS、TVB-N、蒸煮损失率均高于对照组。贮藏至第16 d时实验组相比对照组菌落总数值相差2.01 lg(CFU/g)、pH相差0.69、TBARS相差0.56 mg/kg、TVB-N相差0.92 mg/100 g、蒸煮损失率相差1.7%,同时实验组肉贮藏期间a*优于对照组,肉的硬度、弹性、回复性均下降缓慢。结论 生物保鲜剂联合气调包装(75% O2+20% CO2+5% N2)可以维持冷鲜滩羊肉贮藏期间的良好品质且根据冷鲜肉微生物标准可以延长货架期约4~6 d。     

不同气调包装对醉虾贮藏品质的影响

研究了40%CO2+60%N2和100%CO2的气调包装以及真空和空气包装4种包装方式对贮藏醉虾菌落总数、理化指标和感官指标的影响。结果表明:相对于真空和空气包装组,100%CO2或40%CO2+60%N2的气体包装,对醉虾的保鲜效果较好,其样品的菌落总数和挥发性盐基氮含量较低,质地和色泽变化较小,感官评分较高。但由于100%CO2包装随着贮藏时间的延长,气体收缩较明显导致产品包装外观不理想,40%CO2+60%N2的混合气体包装更适合于醉虾的贮藏。