预制菜包装技术的发展概况及趋势

目的 综述预制菜包装材料和技术的应用,为进一步开发预制菜包装提供研究基础。方法 根据国内外预制菜包装的研究进展,介绍预制菜包装主要的材料和技术,及可用于预制菜包装的新型包装技术。结果 目前使用的预制菜包装技术有真空包装和气调包装等,需要加快对预制菜包装技术的研究和新型包装材料的应用,促进预制菜产业的发展和升级。结论 随着预制菜的迅速发展,预制菜的包装受到消费者的更多关注,新型的食品包装技术在预制菜领域具有广阔的发展空间。     

Several melanosis-inhibiting formulas to enhance the quality of deepwater pink shrimp (Parapenaeus longirostris)

The aim of this work was to assess the effect of several melanosis-inhibiting formulations on quality of deepwater pink shrimp (Parapenaeus longirostris) during storage. The formulations tested were as follows: one containing 4-hexylresorcinol (0.1%) in combination with organic acids (citric, ascorbic and acetic) and chelating agents (ethylenediaminetetraacetic acid [EDTA] and di-sodium di-hydrogen pyrophosphate [PPi]); a commercial formula based on sulphites (3%), and another formulation containing a mixture of chitosan (0.3%) and commercial sulphites. Non-treated shrimp were used as control. The 4-hexylresorcinol-based formulation was more effective than 3% of commercial sulphite solutions in preventing melanosis. This treatment prolonged the sensory acceptability of shrimp by up to six days in ice storage. During chilled storage, the treatment with the 4-hexylresorcinol-based formula inhibited the growth of microorganisms by 1.5–2 log cycles as compared to commercial sulphites, especially H₂S-producers and pseudomonads. At the end of the experimental period, TVB-N levels were slightly higher in the lot treated with 4-hexylresorcinol (33 mg/100 mg) and reflected greater endogenous enzymatic activity, since the counts of the spoiler microorganisms remained around log 5 cfu/g or even lower. In general, the incorporation of chitosan to sulphites did not improve or produce a marked effect on shrimps during storage. During the sensory analysis, the panellists rated all the lots very similar, although the 4-hexylresorcinol formulation was the only one with a neutral odour at the end of the period. The 4-hexylresorcinol-based formulation induced yellow-green colorations to some extent in the cephalothorax, possibly due to the effect of organic acids and chelants, while the rest of the lots presented greyish/blackish colorations. Therefore, the formulation based on 4-hexylresorcinol may safely substitute traditional sulphites to improve the quality of fresh shrimp and prolong their shelf life during storage.     

发酵工程实验“研究型+趣味”教学方式探索

微生物发酵工程实验是生物技术、生物工程专业的主干实验课程,为激发学生学习兴趣、提升教学质量,本文作者在生物技术专业(生物制药方向)本科生的该课程教学中,以抗生素发酵上下游工程为主线,在教学大纲设计、课堂教学与多种形式课外科技实践的结合以及课程考核内容与评价方式等方面尝试了研究型、趣味性教学方式的运用,取得了较好的效果。     

罗非鱼蛋白-大豆蛋白共沉淀物的乳化性

为研究罗非鱼蛋白-大豆蛋白共沉淀物的乳化性,以罗非鱼肉和脱脂豆粕为原料,按照不同质量比(1∶0、1∶1、2∶1、3∶1、0∶1)混合,采用碱溶酸沉法制备鱼分离蛋白(FPI)、罗非鱼蛋白-大豆蛋白共沉淀物(Co-p)和大豆分离蛋白(SPI),并探讨了p H、盐浓度、多糖对其乳化活性(EAI)和乳化稳定性(ESI)的影响。结果表明:FPI、Co-p(1∶1)、Co-p(2∶1)、Co-p(3∶1)和SPI的得率分别为62.21%、39.10%、29.58%、18.45%、32.10%(P0.05);p H 3.0时,FPI、Co-p和SPI的乳化活性依次减小,而p H 4.0~10.0时,Co-p(2∶1)和Co-p(3∶1)的乳化活性最好(P0.05);在0%~0.4%Na Cl体系中,Co-p的乳化活性明显强于FPI或SPI;p H 3.0~7.0时,添加0.2%~0.3%的瓜尔豆胶和黄原胶能显著提高蛋白乳化体系的EAI值(P0.05),且Co-p的乳化性较FPI或SPI有明显提高。比较而言,罗非鱼蛋白-大豆蛋白共沉淀物较FPI或SPI有更好的乳化性。     

金鲳鱼鱼糜制品加工工艺优化

以金鲳鱼鱼糜凝胶为研究对象,利用部分因子试验从漂洗时间、漂洗次数、擂溃方式、加热时间1、加热温度1、加热时间2、加热温度2七因素中筛选出5个对金鲳鱼鱼糜制品的凝胶强度和白度影响显著的因素,即漂洗时间、漂洗次数、擂溃时间、加热时间1及加热时间2。通过最陡爬坡试验逼近该5个因素的最大响应区域,最后利用中心复合设计响应面试验优化显著的因素,结果表明:漂洗时间3min,漂洗5次,擂溃21min,第1次加热10min,第2次加热10min,所得鱼糜凝胶强度为10 728.16g·mm;漂洗时间4min,漂洗6次,擂溃22min,第1次加热11min,第2次加热10min,优化后白度为70.91。     

Effect of tea polyphenols on the physical and chemical characteristics of dried-seasoned squid (Dosidicus gigas) during storage

The effects of tea polyphenols (TP) dip treatment on the physical and chemical characteristics of dried-seasoned squid (Dosidicus gigas) during storage at 25 °C were assessed. After the storage, the b* value increased significantly, while the free amino acids (FAA) including Ser, Gly, Arg, Tyr and Lys, and the dominant reducing sugar (RS), lactose, decreased remarkably, which revealed the occurrence of browning reaction in dried-seasoned squid. The progressive conversion of trimethylamine oxide (TMAO) and production of thiobarbituric acid (TBA) and total volatile basic nitrogen (TVB-N) were found during the entire period of storage. Furthermore, the advantages of reducing moisture loss, inhibiting oxidation of lipids, depressing TMAO breakdown and TVB-N accumulation were observed, while the browning reaction exhibited no significant decrease for the TP samples. These results indicated that the addition of TP could maintain quality of dried-seasoned squid.     

预冷温度对冰温罗非鱼片品质的影响

通过设置不同预处理温度(-18,-30,-60℃)对罗非鱼片进行预冷处理,使鱼片中心温度降至-1℃后置于-2℃环境中贮藏。以pH、色泽、质构特性、挥发性盐基氮(TVB-N)、菌落总数、硫代巴比妥酸值(TBA)、钙离子酶活(Ca~(2+)-ATPase)作为考察指标,进行不同时间间隔下的系列跟踪测试与分析。结果表明:预冷温度对鱼片的TVB-N值、菌落总数、TBA、Ca~(2+)-ATPase有较大影响,经过预冷处理鱼片的TVB-N值、菌落总数增长趋势有所减缓,并且预冷温度越低,鱼片细菌生长速率和鱼肉腐败的进程越慢,同时鱼片脂肪氧化和蛋白质变性的程度也相对较小,其中-30,-60℃预冷处理能更好地维持鱼肉的品质;贮藏期间各处理组鱼片的pH值整体表现出先下降后上升的趋势,预冷处理可显著抑制鱼片pH的回升。预冷处理组与对照组鱼片的硬度、咀嚼性和胶黏性均随贮藏时间推移呈下降趋势。-30,-60℃预冷处理鱼片的货架期为17d,比对照组延长了6d。综上可知,预冷处理能够进一步抑制鱼片微生物繁殖和腐败变质,改善冰温罗非鱼片的品质。     

Purification and characterization of a novel bacteriocin CAMT2 produced by Bacillus amyloliquefaciens isolated from marine fish Epinephelus areolatus

A novel bacteriocin named CAMT2 was produced by strain ZJHD3-06 which was isolated from the marine fish Epinephelus areolatus and identified as Bacillus amyloliquefaciens, Bacteriocin CAMT2 inhibits important food spoilage and food-borne pathogens such as Listeria monocytogenes, Staphylococcus aureus, Escherichia coli and Vibrio parahaemolyticus. Bacteriocin CAMT2 was purified by ammonium sulfate precipitation, gel filtration chromatography on Sephadex G-50 and reversed phase chromatography on a C₁₈ column. The molecular mass of the purified bacteriocin CAMT2 was about 20.0 kDa and N-terminal sequencing of the peptides revealed low similarity with existing antimicrobial peptides, as determined by an LC–MS/MS system. Bacteriocin CAMT2 was resistant for up to 100 °C and pH ranging 2–10, but lost its activity when treated with protease K. The bacteriocin also showed significant antimicrobial activity against L. monocytogenes in a meat model system. These obtained results suggest that bacteriocin CAMT2 has potential for use as a food biopreservative.     

凡纳滨对虾肌肉中组织蛋白酶L提取工艺优化及分离纯化

优化凡纳滨对虾肌肉中组织蛋白酶L提取工艺,分离纯化组织蛋白酶L并验证其对肌原纤维蛋白的降解作用.以凡纳滨对虾肌肉为原料,采用单因素试验、Plackett-Burman试验和双因素等重复试验对肌肉中组织蛋白酶L的提取工艺进行了优化.采用Tris-HCl缓冲液浸提、硫酸铵沉淀、Q-Seharose F.F阴离子交换层析、S...     

典型冷链温度下南美白对虾品质劣变规律及 相关性分析

目的探究典型冷链贮藏温度下南美白对虾品质劣变规律及相关性。方法采用感官评价、仪器分析和理化分析的方法对南美白对虾在-23、0、5℃贮藏温度下的感官、色差、挥发性盐基总氮(total volatile basic nitrogen,TVB-N)含量进行分析与检测,并采用Pearson线性回归分析三者之间的相关性。结果 3种典型冷链贮藏温度下南美白对虾的感官品质变化差异显著,-23℃条件下感官评分一直处于8.0左右;0℃下感官评分在前3 d基本维持在7.0以上,之后快速下降,至第5 d时下降至4.0以下,失去商品价值;5℃条件仅在第1 d维持在7.0以上,第2 d时开始迅速下降。亮度值自贮藏第2 d起不同冷链温度下都有显著性差异(P0.05)。TVB-N值在-23℃条件下第9 d仍在20 mg/100 g以下,而0℃第3 d即发生显著升高(P0.05)。Pearson相关系数表明,TVB-N值与感官评分及亮度变化存在显著相关性。结论与理化检验法相比,感官评价结合色差测定的方法可准确、快速反映对虾鲜度,预测产品货架期。