冰藏中凡纳滨对虾的质构变化研究

采用质构仪的质地剖面（TPA）模式,对冰藏条件下的凡纳滨对虾（Penaeusvannamei）全虾和虾仁的硬度、弹性指数、咀嚼性和凝聚性等质构参数进行测定,同时对其品质进行了感官评定。测定周期为7d。结果显示,全虾和虾仁的总体评分、硬度、弹性指数、咀嚼性和凝聚性均随贮藏时间的延长而下降,表明其日感品质在贮藏中持续下降,显示感官评定与质构测量结果具有一致性;贮藏中虾仁的总体评分、硬度、咀嚼性和弹性指数的下降速率低于全虾,因此以虾仁的形式贮藏能更好地保存虾肉的质构品质。     

益生菌对凡纳滨对虾生长和全虾营养组成的影响

研究了芽孢杆菌制剂（Bacillus sp．，10^9CFU·g^-1）对凡纳滨对虾Litopenaeus vannamei（初始体重0．03g·尾^-1）生长性能、全虾营养成分和氨基酸的影响。7种试验饲料中芽孢杆菌制剂的添加量分别为0，0．5，1．0，1．5，2．0，2．5和3．0g·kg^-1饲料。芽孢杆菌制剂对凡纳滨对虾的成活率没有显著影响。摄食添加益生菌1．0和1．5g·kg^-1饲料的凡纳滨对虾的增重率高并且饲料系数低于对照组，特别是添加量为1．0g·kg^-1时，差异显著；然而，其它添加量并不存在显著性差异。添加益生菌对凡纳滨对虾全虾的水分、蛋白质和灰分含量的影响不显著；投喂添加益生菌1．0和1．5g·kg^-1饲料，脂肪含量高于对照组。饲料中添加益生菌可以改变凡纳滨对虾全虾中部分氨基酸的含量。     

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.     

溴苯酚对凡纳滨对虾海洋风味的贡献

测定了凡纳滨对虾(Penaeus vannamei)和中国明对虾(Penaeus chinensis)中5种溴苯酚物质2-溴苯酚(2-BP)、4-溴苯酚(4-BP)、2,4-溴苯酚(2,4-DBP)、2,6-二溴苯酚(2,6-DBP)和2,4,6-三溴苯酚(2,4,6-TBP)的含量,根据两种对虾的差异设计向凡纳滨对虾中添加不同浓度的溴苯酚,进一步研究溴苯酚对凡纳滨对虾风味的影响.结果表明,凡纳滨对虾和中国明对虾中溴苯酚含量差异显著,其含量范围分别是1.24～9.87 ng/g和1.66～20.88 ng/g.感官实验进一步证明溴苯酚影响凡纳滨对虾的海洋风味,其中2,4,6-TBP添加量在6～9 ng/g、2-BP在0.4～1.2 ng/g、2,6-DBP在1.5～4.5 ng/g、2,4-DBP在0.0～0.55 ng/g、4-BP在0.0 ng/g时凡纳滨对虾的气味最好,与中国明对虾最为接近,并且不会带来异味.     

中草药对凡纳滨对虾生长、免疫功能的影响

以凡纳滨对虾（Litopenaeus vannamei）为实验对象，基础饵料中分别添加不同水平的中草药（0％、1．0％、2．0％）,结果表明，添加不同剂量的中草药能显著提高凡纳滨对虾的增重率和增长率，显著地降低对虾的饵料系数，对凡纳滨对虾的成活率有极显著提高．能极显著提高对虾血清中溶菌酶和SOD活性，能显著提高ACP活性，极显著提高对虾对溶藻弧菌的免疫保护率。     

饲料中添加桑叶黄酮对凡纳滨对虾生长性能、抗氧化指标及抗胁迫能力的影响

为了探讨桑叶黄酮对凡纳滨对虾（Litopenaeus vannamei）生长性能、体成分、血清生化和抗氧化指标的影响，选用初始体重为（1.32±0.01）g的凡纳滨对虾960尾，随机分为6组（每组4个重复，每个重复40尾），分别投喂在基础饲料中添加0、10 mg/kg、50 mg/kg、100 mg/kg、150 mg/kg和300 mg/kg桑叶黄酮的实验饲料，饲养50 d后测定成活率、生长相关指标、血清生化指标、抗氧化指标及抗低氧胁迫能力。结果显示，饲料中添加桑叶黄酮对凡纳滨对虾成活率、增重率、特定生长率、饲料系数等无显著影响（P>0.05）。饲料中添加桑叶黄酮对凡纳滨对虾体成分无显著性影响（P>0.05）。添加150 mg/kg和300 mg/kg桑叶黄酮可显著提高凡纳滨对虾血清谷丙转氨酶和谷草转氨酶活性（P<0.05）。添加10~300 mg/kg桑叶黄酮可显著提高血清和肝脏总抗氧化能力，显著降低肝胰腺丙二醛和脂质过氧化物的含量，添加50 mg/kg桑叶黄酮可提高血清谷胱甘肽过氧化物酶的活性（P<0.05）。低氧胁迫2 h时，10 mg/kg、50 mg/kg组的累计死亡率显著低于对照组（P<0.05）；在低氧胁迫4 h时，10 mg/kg、50 mg/kg、100 mg/kg组的累计死亡率显著低于对照组（P<0.05）。结果表明，以血清总抗氧化能力为评价指标进行回归分析得出，桑叶黄酮在凡纳滨对虾饲料中的适宜添加量为56.18 mg/kg，添加10~100 mg/kg桑叶黄酮可提高凡纳滨对虾抗低氧胁迫能力。     

不同环境条件对溶藻弧菌粘附大黄鱼肠粘液的影响

在低盐度5~6和水温25~29℃条件下,分别投喂1种对照饲料和7种添加二甲基-β-丙酸噻亭(DMPT)(添加量分别为100、2003、00、400、5006、00和700mg.kg-1)的试验饲料,饲养初始体重约每尾0.77g的凡纳滨对虾56d,观察DMPT对凡纳滨对虾的生长、蜕壳和渗透压调节的影响。实验结果表明,添加DMPT的各组凡纳滨对虾增重率随着DMPT添加量的增加,呈现先升后降的趋势,在400mg.kg-1凡纳滨对虾增重率达到最高,显著高于对照组;与对照组相比,各试验组凡纳滨对虾的饲料系数均不同程度降低,500mg.kg-1DMPT组凡纳滨对虾的饲料系数降低达到显著水平。添加DMPT对凡纳滨对虾的蜕壳次数无显著影响。除100mg.kg-1DMPT组外,DMPT组凡纳滨对虾的渗透压均明显低于对照组,其中,添加300和500mg.kg-1组凡纳滨对虾的渗透压降低呈现显著性差异。凡纳滨对虾肌肉粗蛋白和粗脂肪含量随着DMPT水平增加呈现出先上升后下降的趋势。粗蛋白含量在DMPT添加量为400mg.kg-1时达到最高,粗脂肪含量在DMPT添加量为600mg.kg-1时达到最高,均显著高于对照组。以增重率为判定指标,DMPT在凡纳滨对虾饲料中的适宜添加量为383mg.kg-1。     

饲料中添加盐对低盐养殖凡纳滨对虾肌肉常规营养成分及质构的影响

以初始体重为2.70&#177;0.16g的凡纳滨对虾Litopenaeus vannamei为研究对象,在基础饲料中分别添加0（对照组）、1%、2%和4%的食盐,配制成4种实验饲料,在低盐养殖水体中饲养40d,探讨饲料中添加盐对低盐养殖凡纳滨对虾肌肉营养成分及质构的影响。结果表明,随着食盐添加量的升高,凡纳滨对虾虾体蛋白质和灰分含量有增加的趋势,而虾体水分、脂肪有降低的趋势。其中,盐添加量为4%组的蛋白质含量增加极显著（P〈0.01）,而水分降低亦显著（P〈0.05）。在肌肉质构方面,随着饲料中盐添加量的增加,除粘性下降外,其他质构参数都逐渐升高。而且添加4%盐组对虾的硬度、弹性、胶粘性、耐咀性和回复性显著优于其他组（P〈0.05）,但各组的内聚性无显著差异（P〉0.05）。结果表明,饲料中添加盐可以改善低盐养殖凡纳滨对虾肌肉的质构,且当添加量为4%时效果最佳。     

凡纳滨对虾在不同冷藏条件下的品质变化研究

通过感官评估、生化分析及蛋白质指纹图谱比较研究了4 ℃和0 ℃冷藏条件下凡纳滨对虾的品质变化,并对评价指标的有效性进行了分析.试验结果表明,0 ℃冷藏能延缓虾的腐败,比4 ℃更有利于凡纳滨对虾的保藏.虾肌肉的挥发性盐基氮(TVB-N)含量随贮藏时间的延长而增加,但在0 ℃条件下无法准确反映虾的品质变化.K值也随贮藏时间的延长而增加,且与感官评价之间存在良好的相关性,能反映凡纳滨对虾在冷藏初期的品质变化.而肌浆蛋白和肌纤蛋白的指纹图谱则能标记冷藏后期凡纳滨对虾肌肉蛋白发生的降解.     

凡纳滨对虾营养生理研究进展

凡纳滨对虾（Penaeus vannamei）俗称南美白对虾、太平洋白虾等,原产于美洲太平洋海域,目前是世界上最重要的海水经济虾之一。自上世纪90年代开始,凡纳滨对虾逐渐成为我国最重要的对虾养殖品种,目前其养殖量占我国对虾养殖量的70％以上。本文就近年来国内外学者关于凡纳滨对虾营养研究结果进行综述,以期为凡纳滨对虾营养生理、饲料配制以及今后的相关研究提供科学参考。     

基于卵黄蛋白原基因表达的水丝蚓促熟南美白对虾研究

针对传统海产亲虾饵料易感染或携带与对虾共患病毒,给育种和苗种繁育工作带来巨大生物安全隐患的问题,以淡水品种水丝蚓作为替代饵料进行南美白对虾亲虾催熟试验,并以卵黄蛋白原基因的表达水平变化验证饵料的催熟效果。设水丝蚓、水丝蚓组合饵料、商业亲虾饲料及传统沙蚕组合饵料等4个饵料组合,分别投喂南美白对虾后备亲虾,测定繁殖性能相关参数,并通过荧光定量PCR技术对各亲虾肝胰腺和卵巢中VTG的表达水平的变化进行了追踪研究。结果显示,水丝蚓组的性腺增重最高,达1 475%,连续产卵率最大,平均为72.08%,与传统沙蚕组合饵料组无显著差异性(P0.05)。南美白对虾肝胰腺和卵巢组织中均存在VTG mRNA,在肝胰腺和卵巢中均呈先上升后下降的表达模式;VTG mRNA的表达量能够一定程度上反映对虾的繁殖性能,有希望发展成为亲虾繁殖性能选育指标;水丝蚓在促进亲虾性腺发育方面效果较传统沙蚕饵料组合好,在改善亲虾产卵效果方面基本与沙蚕组合相当,可作为沙蚕替代饵料用于南美白对虾的亲虾强化培育和催熟。     

Effect of Heat Treatment at Different Stages of Rigor on the Quality of Pacific White Shrimp (Litopenaeus vannamei)

Effect of blanching and cooking on the quality of Pacific white shrimp with skeletal muscle severed (by beheading and peeling) at different stages of rigor was evaluated. Peeling and beheading shrimp in post-rigor stage resulted in higher yields compared to shrimp in in-rigor and pre-rigor stages. Weight loss due to blanching/cooking was highest when skeletal muscle was severed in in-rigor stage followed by post- and pre-rigor stages. Highest crude and sarcoplasmic protein contents were found in the shrimp blanched or cooked while in in-rigor stage followed by pre-rigor and post-rigor stages. Hardness, springiness, and chewiness were found to be better in the shrimp blanched in pre-rigor stage. Highest sensory scores for color, appearance, succulence, and odor were found for shrimp blanched or cooked in pre-rigor followed by in-rigor stage. Instrumental analysis of color and texture confirmed the sensory scores.     

Effects of Different Treatments on Fishy Odor of Fish Soups

The odor-active substances in a fish soup cooked with scallions, ginger, and cooking wine were extracted by solid-phase micro-extraction and analyzed by gas chromatography–olfactometry–mass spectrometry. The results of sensory evaluation indicate that the three seasonings—scallions, ginger, and cooking wine—reduced the fishy odor. Further, the effect of cooking wine or scallions was better than ginger. The main odorants of scallions, ginger, and cooking wine that reduced the fishy odor by masking the odor were detected. The main odorants in the scallions-treated sample were isovaleraldehyde, nonanal, alloaromadendrene, and dipropyl disulfide. The main odorants in the ginger-treated sample were sesquiterpenes, olefins, aldehydes, alcohols, and ketones. The main odorants in the cooking wine-treated sample were (E)-2-heptenal, decanal, copaene, and terpinen-4-ol.     

Quality and Sensory Characteristics of Volutharpa ampullacea perryi (False Abalone) Meat during the Boiling Cooking

Volutharpa ampullacea perryi (false abalone) meats were water cooked at 75–100°C for 5–60 min, and the changes in weight loss, pH, color, in vitro digestibility, texture, microstructure, and sensory characteristics were investigated. The weight rapidly decreased in the initial cooking and decreased slightly with the extension of both heating temperature and time. Obvious differences in color were found compared between the raw and cooked meats with respect to ΔL*, Δa*, and Δb* values. Digestibility was significantly improved with the thermal treatments. Textual properties, such as hardness, springiness, chewiness, and resilience, improved with the increasing of thermal intensity, but reduced with overcooking, and the variations were further confirmed by the scanning electron microscopy analysis. The samples boiled at 90–95°C for 10–15 min and 100°C for 5–10 min acquired better acceptance in the sensory evaluation. The complex relationship among cooking conditions and physicochemical and histological characteristics of meat as well as the consumer perceptions was illuminated by the principal components regression analysis. These results could provide useful information for quality control in V. a. perryi meat cooking.     

Chemical, physical and sensory changes of small abalone meat during cooking

ABSTRACT:   Small abalone meats were heated at 80°C and 98°C for 0–120 min and the differences in chemical, physical and sensory changes of the cooked meats were investigated. The decrease in moisture and weight and the increase in browning and Hunter's b -value were relatively higher for cooking at 98°C than at 80°C. After cooking for 20–120 min, the total amount of adenosine triphosphate and its related compounds on a dry weight basis decreased by 17–27% at 80°C and by 30–39% at 98°C; the total amount of free amino acids on a dry weight basis changed insignificantly at 80°C but decreased by 22–35% after cooking at 98°C. The meats cooked at 80°C were higher in cutting force whereas the levels in the samples cooked at 98°C did not decrease until samples had been cooked for 60 min. The hydroxyproline content showed little change during cooking except for in samples cooked at 98°C for 120 min, in which the content was found to be low. The extended cooking at 80°C improved the acceptability of small abalone meat, whereas only the acceptability score of aroma increased significantly for cooking at 98°C.     

Effect of Different Thawing Methods and Multiple Freeze-Thaw Cycles on the Quality of Common Carp (Cyprinus carpio)

The effect of different thawing methods—running water, microwave, slack water (25°C), air (25°C), and refrigerator (4°C)—and multiple freeze-thaw cycles (0, 1, 3, and 5) on the quality of common carp were investigated. Microwave thawing showed the lowest score for sensory assessment and the highest cooking loss (p < 0.05), while 4°C refrigerator thawing showed less thawing loss and cooking loss but required the longest thawing time. Ca²⁺-ATPase activity and sulfhydryl content of air thawing were lower (p < 0.05), while no significant differences were observed among other thawing methods. Water loss and the thiobarbituric acid reactive substances (TBARS) value increased (p < 0.05) when freeze-thaw cycles increased. The sensory scores and hardness decreased significantly when the freeze-thaw cycles increased (p < 0.05). A significant decrease (p < 0.05) was observed in salt-extractable protein content after five freeze-thaw cycles. Different thawing methods affected the quality of common carp. Frozen common carp subjected to freeze-thaw cycles resulted in accelerated lipid and protein oxidation and caused mechanical damage to muscle tissues.     

上海市售扇贝冻品品质评价模型构建及关键影响因素分析.

为分析上海销售端扇贝冻品的品质状况及存在的问题,探究市售扇贝冻品的品质评价方法以及冻藏过程中导致其品质劣变的关键因素,本研究依据冰柜温度、冻藏时间、产品形式、包装方式和摆放位置共5种常见影响因素,对上海市售的11种扇贝冻品商品进行采样,测定白度、解冻损失、蒸煮损失、持水力、回复性、内聚性、弹性、咀嚼性、硬度和感官评分共10项品质指标,利用因子分析构建扇贝冻品品质评价模型,并结合多元线性回归分析确定影响扇贝冻品品质劣变的关键因素。结果显示,扇贝冻品10项品质指标之间存在一定相关性,通过因子分析提取了3个因子成分,累计方差贡献率为73.33%,可以代替原有指标来综合评价扇贝冻品的品质,建立了市售扇贝冻品的品质评价模型：f=0.467f1+0.302f2+0.231f3,其中,f1公因子包括弹性、回复性、内聚性、蒸煮损失和持水力,f2公因子包括硬度、白度和咀嚼度,f3公因子包括解冻损失和感官评分;进一步由多元线性回归分析得出,冻藏时间、冰柜温度和产品形式是影响扇贝冻品品质的关键因素,其他2种因素无显著影响。研究表明,基于因子分析和多元线性回归的方法能够较好地进行扇贝冻品的品质评价并分析导致其品质劣变的影响因素。     

Quality Evaluation of Grass Carp (Ctenopharyngodon idella) Protein Concentrate Supplemented Noodles

ABSTRACT

The aim of the present study was to evaluate the quality of wheat flour noodles supplemented with 0%, 10%, 20% and 30% grass carp protein concentrate (GCPC). Proximate composition, color analyses, cooking properties (cooking time, cooking loss, swelling index and water absorption index), texture profile analyses (TPA), and sensory evaluations were performed. Significant (p ≤ 0.05) increases in the crude protein (18.94–35.19%), crude fat (0.88–1.06%), and ash (0.89–1.02%) were recorded for GCPC supplemented cooked noodles. Brightness (L*), redness (a*) and yellowness (b*) of GCPC 10–30% fortified cooked noodles was recorded as 77.00–69.97, 1.50–2.81 and 19.08–22.25, respectively. Cooking loss (CL) and optimal cooking time were significantly (p ≤ 0.05) increased with increased level of GCPC from 0%-30%, with readings of 6.13% ?8.90% and 7.53–11.77 min, respectively. Swelling and water absorption indices showed a decreasing trend at 2.33–1.77 and 102.6–78.49%, respectively. A significant (p ≤ 0.05) decreasing trend in hardness (24.50–19.03N) was observed for cooked noodles with increased level of GCPC, while the remaining TPA parameters were significantly different at p> .05. Sensory analyses showed higher preference for control noodles and noodles fortified with 10% GCPC.     

熟制与贮藏对凡纳滨对虾挥发性成分的影响

为研究熟制与贮藏对凡纳滨对虾挥发性成分的影响,采用电子鼻及固相微萃取—气相色谱—质谱联用技术分析虾肉的挥发性成分,并采用相对气味活度值和感官评定法评价虾肉风味的变化。结果显示,熟制与贮藏对虾肉中的挥发性成分影响显著。凡纳滨对虾生虾、熟虾、熟虾冷却、熟虾冷却过夜及二次熟制虾分别被检出50、68、63、49和41种挥发性成分。二次熟制后,虾肉中的挥发性成分有所减少,感官上虾的特征鲜香气也略微减弱;一次熟制对虾肉的风味影响不大。生虾肉中检测出的挥发性成分如壬醛和癸醛等对风味有显著性影响;熟虾肉中检测出壬醛、癸醛和十四醛等;二次熟制的虾肉中检测出对风味影响较大的挥发性成分主要是十八醛、二丁基羟基甲苯等。熟虾经过夜(4°C)放置后,其中检测出的挥发性成分种类和总量均减少,但总量差异不显著。研究表明,熟制可显著增加挥发性风味成分种类和总量,二次熟制与一次熟制相比,凡纳滨对虾的关键风味物质种类和含量显著降低;熟虾冷却后4°C贮藏12 h风味差异不显著。     

Changes in taste and textural properties of the foot of the Japanese cockle (Fulvia mutica) by cooking and during storage

Physicochemical changes of Japanese cockle foot parts occurring during cooking and cold storage at 4°C for 10 days were examined. Raw samples decreased in weight by 27% during cooking at 85°C for 15 s. Both raw and cooked samples decreased in weight to the same extent of 22–23% during the 10-day cold storage. The levels of ATP and related compounds, as well as those of free amino acids, were higher in raw than in cooked samples, although the former were found by sensory evaluation to have a stronger fishy odor. Raw samples started to decrease in ATP content after 5 days of cold storage, showing K' values of 18 and 42% after 5 and 7 days, respectively. The L* value in the Hunter scale color evaluation increased during the cold storage of raw samples, revealing a gradual disappearance of its original purple–gray color. Meanwhile, the L* value of cooked samples remained constant during the cold storage. The tensile strength of cooked samples was significantly higher than those of both raw samples before and after the cold storage, indicating increased toughness by cooking.