基于主成分分析和聚类分析评价中华绒螯蟹蟹肉香气品质的研究

运用顶空固相微萃取-气-质联用技术,对采自阳澄湖的特级、1级、2级的雌性中华绒螯蟹体肉、钳肉和足肉中的香气成分进行了鉴定并以内标法对其定量。通过主成分分析法(PCA)和聚类分析法(CA)对不同蟹肉样品的香气品质进行评价。主成分分析结果显示:不同等级中华绒螯蟹钳肉和足肉的综合得分均大于零(2级-钳肉除外),香气品质较好,醇类、酮类、呋喃类、含氮类和芳香类五类成分对其贡献显著,是表征"高品质风味"的特征性香气成分;将部位因素统一考虑后,大闸蟹等级越高,蟹肉香气品质越好;将等级因素统一考虑后,大闸蟹足肉香气品质最佳,钳肉次之,体肉最差。经聚类分析发现:不同等级大闸蟹体肉及足肉样品香气轮廓可各自聚为一类。醇类、呋喃类、酮类、含氮类和芳香类5类香气成分可聚为一类。主成分分析和聚类分析结果存在一致性且可以相互补充,今后可利用两种方法建立不同大闸蟹蟹肉香气品质的评价模型。     

斑点叉尾鮰下脚料生产加工鱼糜的研究

以斑点叉尾鮰鱼片加工下脚料为原料加工鱼糜,分析其组成和肌肉成分,研究采肉与精滤工艺及其设备参数,结果表明:斑点叉尾鮰鱼片加工下脚料的肌肉特性适合鱼糜加工,总含肉率为39.6％;轴辊挤压结合采肉机是最适合斑点叉尾鮰下脚料的采肉方法,采肉得率可达35.7％,能有效地减少鱼骨和鱼刺混入鱼糜;网孔直径1.8 mm结合螺杆转速6...     

用于水酶法提油的油菜籽挤压预处理参数优化

为提高水酶法提菜籽油的得率,对油菜籽进行挤压预处理,以提油率为考察指标,研究套筒温度、喂料量、螺杆转速、物料加水量对提油效果的影响。在单因素试验的基础上进行正交优化试验,确定挤压辅助水酶法提取菜籽油的最佳挤压参数。结果表明：4个因素对提油率影响的大小顺序为：套筒温度>喂料量>物料加水量>螺杆转速;最佳挤压参数为套筒温度90 ℃、喂料量12 kg/h、螺杆转速210 r/min、物料加水量10%。经此挤压参数处理后的油菜籽,用水酶法提油时清油的提取率可达80.834%。     

发酵全脂大豆粉提取油和蛋白的研究

采用发酵工艺分别联合磨碎和挤压膨化前处理技术制取大豆油和蛋白,通过油和蛋白得率及其品质评估工艺的可行性。结果显示发酵全脂豆粉联合挤压膨化能够显著提高油和蛋白提取率,总油和总蛋白得率分别为95.1%和87.12%,与水酶法得率相近,显著高于磨碎前处理工艺。磨碎豆粉与膨化豆粉经发酵提取油的品质和脂肪酸组成相似,均优于溶剂浸提油;磨碎与膨化豆粉发酵所得分离蛋白(FE-SPI和FGSPI)分子质量主要分布在10 000 u以下,FE-SPI的功能性优于或接近于FG-SPI,二者的溶解性、持水性显著优于碱溶酸沉制取的分离蛋白(W-SPI),但疏水性、持油性、乳化性、发泡性能及黏度均低于W-SPI。研究证实发酵联合挤压膨化提取大豆油作为一项环境友好制油技术具有良好的应用前景。     

解冻方式对炝蟹食用品质的影响

为研究不同解冻方式对冻藏炝蟹食用品质的影响,筛选食用前的最佳解冻方式,对低温解冻、室温解冻、流水解冻、超声解冻和脉冲磁场辅助解冻5种方式的解冻曲线、感官评价、电子舌、蟹肉蛋白质及其降解产物和呈味核苷酸含量变化进行分析。结果表明：超声和脉冲磁场辅助解冻最具时效性（10.4、26.2 min）,低温解冻最耗时（312.6 min）。脉冲磁场辅助解冻蟹肉的色泽、质地和气味的评分最高,超声解冻的口感评分最好。电子舌结果表明,低温解冻、脉冲磁场辅助解冻和超声解冻蟹肉品质较接近,与流水解冻和室温解冻之间存在较大差异。超声解冻蟹肉的水分质量分数最高（84.37%）,脉冲磁场辅助解冻的蛋白降解指数最低（13.83%）,流水解冻的蟹肉水分质量分数最低（77.36%）,且蛋白降解指数最高（16.64%）。低温解冻蟹肉的总游离氨基酸含量最高（2 885.78 mg/100 g）,脉冲磁场辅助和超声解冻蟹肉中谷氨基酸、甘氨酸和丙氨酸的含量相近,分别为97.50、665.80 mg/100 g和487.20 mg/100 g及92.30、642.40 mg/100 g和490.50 mg/100 g,显著高于其...     

高水分组织化复合蛋白的挤压制备及品质特性研究

以大豆分离蛋白、谷朊粉和豌豆蛋白为原料,采用高水分挤压技术制备组织化蛋白产品,研究了挤压参数对产品品质特性的影响,分别优化出以大豆分离蛋白和豌豆蛋白为主料的两种产品的配方及挤压参数。结果表明,水分添加量对产品品质特性影响显著;螺杆转速在280r/min,挤压温度在160℃时制备的产品具有较好的质构特性和拉丝效果;当大豆分离蛋白添加量40%,谷朊粉添加量35%,豌豆蛋白添加量25%,水分添加量14.0kg/h时,制得的组织化蛋白产品表面光滑,成型性好,可作为鸡肉仿肉制品;当豌豆蛋白添加量45%,谷朊粉添加量35%,大豆分离蛋白添加量20%,水分添加量13.5kg/h时,制得的组织化蛋白产品拉丝状态明显,质构特性指标与牛肉相似。     

中华绒螯蟹蟹肉挥发性风味成分分析

采用顶空固相微萃取(HS-SPME)方法提取中华绒螯蟹蟹肉中的挥发性风味成分,利用气相色谱-质谱法(GC-MS)对提取的风味成分进行分离鉴别。结果表明,萃取温度60℃、时间50min、NaCl添加量0.16g/ml的条件下,挥发性风味成分的吸附效果最好。中华绒螯蟹的蟹肉中鉴别出40种挥发性成分,其中醛类8种、酮类3种、醇类3种、酯类1种、烷烃类13种、芳香类化合物4种、含氮化合物4种、其他化合物4种。中华绒螯蟹的蟹肉中,三甲胺(TMA)、壬醛和十四烷的含量较高,其含量分别达到挥发性成分总含量的20%、18%和10%左右。     

玩转广式面点（清新蟹点）

蟹是餐馆里最受食客欢迎的食材之一。在制作蟹菜式时,常会有蟹只的个头不理想,或蟹脚受损、肢体不完整等情况,卖相差,则一般不能直接使用整只蟹,通常做法是拆肉后再入菜。但这些快要变“废”的食材,在点心师的手中,却能创制出缤纷美味的点心,蟹肉、蟹黄、蟹黄汤,再加点心思,可令点心变得生动起来。尤其是蟹壳,经烤制后再煮成汤,是一款百搭的汤品,可做成汤粉、汤面,还可加入到馅料中,增加点心的鲜味,有提味、醒味的作用。     

面包蟹中重金属镉的监测及健康风险评估

目的根据欧洲进口面包蟹中重金属镉的监测结果,对比面包蟹各个部位重金属镉的含量,对面包蟹中镉进行健康风险评估。方法采用电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)对534批面包蟹全蟹和面包蟹各部位的重金属镉分别进行测定,根据国家食品安全风险评估中心的风险矩阵方法对面包蟹中镉进行健康风险等级评价。结果面包蟹中镉的平均含量为2.62 mg/kg,测得值在ND~23.4 mg/kg之间,面包蟹各部位中镉含量:肝胰腺蟹黄和蟹腮蟹身肉蟹钳肉和蟹腿肉,面包蟹镉的健康风险等级为中风险。结论欧洲部分海域面包蟹重金属镉污染严重,其中肝胰腺、蟹黄和蟹腮中镉含量最高,根据风险矩阵方法初步判断面包蟹中镉的健康风险等级为中风险。     

不同解冻方式对早熟中华绒螯蟹品质和滋味的影响

采用4℃低温解冻、15℃自然解冻、15℃流水解冻(水流流速100 m L/s)、微波解冻(功率150 MHz)四种方式对冻藏早熟蟹进行解冻,通过测定蒸煮损失率、p H、TBA值、TVB-N值、肌原纤维蛋白特性和游离氨基酸含量,评价解冻方式对蟹肉品质和滋味的影响。结果表明:低温解冻时间最长为675 min,微波解冻时间最短为5 min,自然解冻和流水解冻时间分别为135、52 min。微波解冻后蟹肉的解冻损失率、TBA值和表面疏水性最高,分别为2.89%、0.29 mg/100 g和53.54μg,总巯基和活性巯基含量最低分别为69.09、64.16 nmol/mg;自然解冻后蟹肉蒸煮损失率最高为50.99%;低温解冻后蟹肉pH、TVB-N值最高,分别为7.23和11.71;流水解冻后蟹肉pH、TVB-N值和表面疏水性最低,分别为6.95、10.60和35.29μg,蟹肉中呈味氨基酸和游离氨基酸含量分别为7.158、10.645 mg/g,明显高于其它三种解冻方式,蟹肉品质和滋味较好。因此,流水解冻最适宜作为冻藏早熟蟹的解冻方式。     

Nutritional quality and safety of cooked edible crab (Cancer pagurus)

Edible crab (Cancer pagurus) is one of the most important crustaceans consumed in Southern European countries, either as boiled or steamed cooked product. So far, the majority of studies assessing health benefits and risks associated to seafood consumption have been carried out in raw products, despite being generally cooked before consumption, and mostly in muscle tissue. Therefore, the aim of this study was to assess the effect of steaming and boiling on the chemical safety and nutritional value of C. pagurus caught in spring and summer. Generally, chemical and elemental composition of brown meat (tissue in the body cavity comprising mainly gonads and hepatopancreas) differed significantly from muscle (white meat in claws and legs). Additionally, the same tissue revealed differences in chemical and elemental composition of raw and cooked C. pagurus, likely due to water leaching. In contrast, few variations between seasons were observed. The results revealed that the consumption of cooked edible crab muscle should be promoted, whereas brown meat ingestion should be done parsimoniously.     

Mathematical modeling of the heat transfer process and protein denaturation during the thermal treatment of Patagonian marine crabs

Southern Ocean swimming crab Ovalipes trimaculatus and the Patagonian stone crab Platyxanthus patagonicus are fishing resources with commercial value. Thermal treatment of crabs is necessary to denature muscle proteins, facilitating meat detachment from the crab shell (picking procedure). The proximal composition, protein patterns of crab muscle, thermophysical properties and heat transfer coefficients were determined. Heat transfer during thermal processing of body (i.e., cephalothorax) and claws of both crab species was simulated using a finite element computational code; the simulations were experimentally validated. Color changes in crab muscle during the heating process were measured. Thermal denaturation kinetics of myofibrillar proteins was determined using Differential Scanning Calorimetry (DSC) in small samples previously heated in water under controlled conditions. DSC thermograms of raw crab muscle showed two peaks at 49.0 ± 0.4 and 77.5 ± 0.6 °C corresponding to myosin and actin respectively. Activation energies for the denaturation of myosin (145.70 kJ/mol) and actin (156.42 kJ/mol) were calculated from Arrhenius equation. The degree of denaturation achieved by the myofibrillar proteins at the coldest point of the muscle in body and claws during the heating process was established by considering the protein denaturation kinetics determined by DSC, the activation energies and the heat penetration curves. Adequate conditions for the detachment of meat from the crab exoskeleton were established. The obtained results may help in determining the optimal heating times during the industrialization of these crustaceans.     

Preparation and characterization of surimi-based imitation crab meat using coaxial extrusion three-dimensional food printing

This study proposes a novel approach to implementing the filament structure of imitation crab meat by coating potato starch (PS) solution on the outside of surimi using coaxial extrusion 3D food printing. To determine the optimum concentration, experiments were conducted using a 0–15% PS solution. Surimi-based imitation crab meat using a 12% PS solution showed the best results in terms of printing characteristics, water-holding capacity, and cooking loss. In addition to the aligned-rectilinear pattern generally used in imitation crab meat, this study presents the change in texture according to the internal structure using rectilinear and concentric patterns. The 3D-printed imitation crab meat with the aligned-rectilinear pattern was similar to the commercial reference imitation crab meat. This study successfully tested fiberization—a challenging process for 3D food printing—using coaxial extrusion 3D food printing. This system can be applied to other 3D-printed foods that require a filament structure and fiberization.     

缢蛏振动筛分装置的优化与试验

目的：提高缢蛏壳肉分离效率。方法：采用参数法对振动筛分装置主要参数进行设计,以连云港双头蛏为试验对象,以振动频率、振幅、筛面倾角为试验因素,以筛分效率和肉中带壳比率为主控目标进行单因素试验,利用Design-Expert 软件对试验结果进行方差分析,建立频率、振幅、筛面倾角与筛分效率和肉中带壳比率相匹配的回归模型。采用响应面优化分析法,得到了缢蛏壳肉分离筛分装置的最佳工作参数匹配。结果：当出料比率控制为1.2 kg/s、开壳比率控制为97%,振动频率设定为21.6 Hz、振幅设定为3.6 mm、筛面倾角度设定为9°时,缢蛏筛分效率为97.60%,肉中带壳比率为4.52%。结论：所设计的缢蛏振动筛分装置筛分效率高、适应性好,可满足初步加工要求。     

五种开壳方式对牡蛎开壳效率和品质的影响

为了探明不同开壳方式对牡蛎开壳效率和品质的影响,采用水煮、蒸煮、微波、超高压和电击5种开壳方式对牡蛎进行开壳,以开壳率、张壳大小作为开壳效率的评价指标,以生鲜度、汁液流失率、闭壳肌蛋白质变性程度作为品质评价指标,综合对比几种开壳方法的开壳效率和品质,并分析其应用于牡蛎开壳的可行性.研究结果显示:微波开壳的效率最快,30...     

Carotenoids in crabs from marine and fresh waters of India

Quantitative and qualitative distribution of carotenoids in meat and shell of major marine crab (Charybdis cruciata) and fresh water crab (Potamon potamon) from Indian waters was assessed. The total carotenoid content was low in both species of crabs analysed, highest being 11.0 μg/g in shell of marine crab. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) of carotenoid extracts indicated that the marine crab contained astaxanthin and its esters as major carotenoids and zeaxanthin was major carotenoid in fresh water crab extract. Astaxanthin and its esters contributed 67.6 and 65.5 g/100 g of total carotenoids in meat and shell of marine crab. The zeaxanthin content (g/100 g) in the carotenoid extract of meat and shell of fresh water crab was 42.0 and 74.8 of total carotenoids. The carotenoid extracts from both the crabs had higher level of unsaturated fatty acids. Oleic acid (C18:1) and palmitoleic acid (C16:1) were the predominant unsaturated fatty acid in carotenoid extract from meat of marine and fresh water crab, respectively. In the carotenoid extract from shell, eicosenoic acid (C20:1) in marine crab and linolenic acid (C18:3) in fresh water crab were the major unsaturated fatty acids.     

多功能圆笼除尘机组的技术性能分析

为解决现有除尘机组存在的问题,经对比各种除尘机组中的滤料布置形式、吸嘴形式、吸臂形式,设计了多功能圆笼除尘机组.该机组采用轮带式轮流吸尘机构、具有专利技术的粉尘分离压紧器、FM滤料、XF3型纤维分离器等,并将一级圆盘过滤器的吸棉风机置于纤维分离器之前,结构设计有利于纤尘的集中回收.经模拟试验,该机组的粉尘处理能力大于30 kg/h,纤维处理量可达150 kg/h以上.     

对虾去头方法试验与研究

针对人工去虾头劳动强度大、工作效率低,虾肉易受细菌污染和机械一刀切式对虾去头方法对虾肉浪费严重的问题,提出了一种双弹性圆柱对挤式对虾去头方法,对其进行理论分析的同时进行了挤压试验。实验表明双弹性圆柱对挤式对虾去头过程分为两个阶段,第一阶段动弹性圆柱自动导正到虾头与虾体连接的薄弱部位并初步压紧;第二阶段动弹性圆柱沿着定弹性圆柱一侧曲面搓擦,使虾头与虾体进一步分离,虾头与虾身分离完全彻底,虾肉缺损几乎为零。并通过优化试验,确定了当动弹性圆柱下移速度v=10mm/s、偏离距离e=1.29 mm和预留距离H=0 mm时去头效果最好,由一刀切式对虾去头与双弹性圆柱对挤式去头对比试验结果可得双弹性圆柱对挤式对虾去头比一刀切式对虾去头虾身得率提高11.13%。双弹性圆柱对挤式对虾去头方法为今后对虾去头装置的研制提供了新的思路和依据。     

电子束辐照对细点圆趾蟹肉营养及滋味成分的影响

以细点圆趾蟹蟹肉为材料,研究电子束辐照对蟹肉营养和滋味成分的影响,为电子束辐照技术在水产品加工中的应用提供依据。结果表明：辐照处理后7 kGy及以上剂量组蟹肉总氨基酸和非必需氨基酸含量下降比较明显;辐照没有改变蟹肉的第1和第2限制性氨基酸种类,各组蟹肉必需氨基酸与总氨基酸之比和必需氨基酸与非必需氨基酸之比均分别超过40%和60%,为质量较好的蛋白质;脂肪酸分析结果显示,电子束辐照对蟹肉饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸总量均无显著影响;随着辐照剂量增加,蟹肉中的游离氨基酸总量呈下降趋势,但呈鲜、甜鲜味的游离氨基酸含量有所增加,说明适当的辐照剂量对蟹肉氨基酸的呈味有改善作用;蟹肉中的主要呈味核苷酸是5’-肌苷酸二钠,辐照后蟹肉5’-腺苷酸和5’-肌苷酸二钠含量有所上升,而5’-鸟苷酸二钠含量有所下降,辐照对蟹肉鲜味有提升作用;结合鲜味氨基酸和呈味核苷酸的鲜味协同效应,各辐照组味精当量值均高于对照组,其中1 kGy组蟹肉的味精当量值最高,达到17.92%。综合蟹肉氨基酸、脂肪酸组成和滋味成分的变化规律分析,认为1～9 kGy剂量电子束辐照对蟹肉营养和滋味没有明显的负面影响,可用于对蟹肉进行前处理。