淀粉种类对草鱼鱼糜凝胶特性的影响

通过分析草鱼鱼糜流变学特性、草鱼鱼糜凝胶特性等,研究不同种类淀粉的添加对鱼糜凝胶性能的影响。结果表明,添加不同种类淀粉(马铃薯淀粉、玉米淀粉、木薯淀粉、乙酰化二淀粉磷酸酯和醋酸酯淀粉)能不同程度地影响草鱼鱼糜的保水性和凝胶品质,包括硬度、凝胶强度、胶着性以及咀嚼性;流变学结果也表明,适量添加淀粉能有效促进草鱼鱼糜凝胶的形成。其中,添加醋酸脂淀粉对草鱼鱼糜的凝胶特性影响最大,使得草鱼鱼糜凝胶强度、持水性和白度均达到最大值。因此,添加醋酸酯淀粉可以显著改善草鱼鱼糜流变及凝胶特性,有助于淡水鱼高值化利用与产业化升级。     

金线鱼鱼肠工艺配方的优化研究

金线鱼肉质细嫩、蛋白质含量丰富、鱼肉具有较好的弹性和白度,是加工海水鱼糜和鱼糜制品的主要海水鱼原料之一。为获得品质和风味较好的金线鱼鱼肠,结合现代风味评价技术—电子鼻技术,以产品的感官评价和凝胶强度值为指标,采用单因素和正交试验的方法,以金线鱼鱼糜、淀粉和脂肪三个主要因素,对金线鱼鱼肠工艺配方进行优化。试验结果表明:当鱼糜、淀粉、脂肪的添加量分别为62.0 g、4.0 g和10.0 g时,凝胶强度和感官评定的综合评分最高,由此确定金线鱼鱼肠的最佳工艺配方为鱼糜62.0 g、淀粉4.0 g、脂肪10.0 g、糖3.5 g、盐2.0 g、大豆蛋白5.0 g、味精0.2 g、IG 0.3 g、水10.0 g。采用该工艺所制作得到的金线鱼鱼肠品质好,风味和口感俱佳,为新型低脂鱼肠的开发提供一定的参考价值。     

变性淀粉对鲢鱼糜冻结速率及凝胶特性的影响

为了比较4种变性淀粉与商业抗冻剂(4%蔗糖+4%山梨醇)对鲢鱼糜在冻结过程(-20、-80℃下静止冻结)中的影响,对冻结速率、冻结相变热特性参数、凝胶强度和持水性能进行了测定。结果表明,鱼糜在-80℃下的冻结速率均显著高于-20℃下;同一冻结温度下,几种添加物均会降低鱼糜的冻结速率及冻结相变焓,而提高冷冻鱼糜凝胶的持水性能,且变性淀粉组的持水性都显著高于商业抗冻剂组(P0.05)。在-80℃冻结时,添加交联酯化淀粉与醋酸酯化淀粉的鱼糜的冻结速率相近,且均显著小于其他组(P0.05)。在2种冻结温度下,醋酸酯化淀粉组的凝胶强度均与商业抗冻剂组无显著性差异,而显著高于其他实验组(P0.05)。研究表明,4%蔗糖+4%醋酸酯化淀粉可有效地防止鱼糜在冻结过程中的品质变化,可代替商业抗冻剂应用在冷冻鱼糜中。     

壳聚糖对鲢鱼糜凝胶特性的影响

将壳聚糖添加到鲢鱼糜制品中,测定鱼糜制品的凝胶强度、全质构(TPA)、失水率和色泽,研究壳聚糖的脱乙酰度(DD)、分子量(MW)以及添加量对鲢鱼糜凝胶特性的影响,采用电镜扫描观察凝胶的微观结构,结果表明,壳聚糖DD对鱼糜制品凝胶特性影响较大,DD为64%时,凝胶强度提高了约34%,失水率减少了29.1%;壳聚糖MW对鱼糜制品的凝胶强度影响小;随着壳聚糖添加量的增加,鱼糜凝胶强度、TPA都有明显的增加,失水率减少(P<0.05),添加1.0%壳聚糖的鱼糜凝胶强度与添加4.0%淀粉的鱼糜凝胶强度相当;微观结构可看出壳聚糖与鱼糜形成网络结构。结果说明壳聚糖是鱼糜制品良好的品质改良剂。     

钙离子添加量对未漂洗海鲈鱼糜凝胶特性的影响

为探明钙离子(Ca~(2+))能否提高未漂洗海鲈鱼糜的凝胶品质,为海鲈鱼糜生产提供新方法。以海鲈鱼为原料,比较氯化钙(CaCl_2)不同添加量(0.01～0.08 M)对采肉后未经漂洗工序直接制成海鲈鱼糜的凝胶强度、质构特性(TPA)、持水力、白度、微观结构等的影响,并与传统方法制备的海鲈鱼糜进行比较。结果表明Ca~(2+)对未漂洗的海鲈鱼糜品质有显著影响(P0.05);CaCl_2的添加可显著提高未漂洗海鲈鱼糜凝胶强度、TPA、持水力和白度,使鱼糜组织结构紧密均匀;当CaCl_2添加量在0.02 M时,未漂洗的海鲈鱼糜的凝胶特性(凝胶强度7 364.21 g·mm、持水力88.93%、硬度421.8 g、弹性10.03 mm、胶着性229.5 g、咀嚼性22.21 mJ、白度86.72)与传统鱼糜品质相近,其效果最好;而当CaCl_2添加量达到0.08 M时,Ca~(2+)与鱼肉蛋白过度交联,形成钙桥结构,造成凝胶强度和硬度增加、弹性下降。研究表明,适量添加Ca~(2+)可使海鲈鱼糜不需经过漂洗工序而达到传统漂洗生产鱼糜的品质,这为开发营养流失少、节水、节能的海鲈鱼糜加工提供理论和技术支撑。     

添加圆苞车前子壳粉的鲢鱼糜凝胶工艺优化及其凝胶特性

圆苞车前子壳粉(psyllium husk powder, PHP)是一种富含膳食纤维的食品亲水胶体。为了解其在鱼糜制品中的作用,本实验以冷冻鲢鱼糜为研究对象,以凝胶强度和持水性(water holding capacity, WHC)为考察指标,研究了PHP的添加量、凝胶化温度和凝胶化时间3个因素对鱼糜凝胶特性的影响。在单因素试验的基础上,进行了三因素三水平的正交试验和验证试验。正交试验结果得到最佳工艺条件:PHP添加量0.1%,凝胶化温度45°C,凝胶化时间2 h。单因素试验结果表明,添加适量PHP (0.1%～0.3%)能够增加鱼糜凝胶的硬度和WHC,但对破断距离有不利影响;根据验证试验中蒸煮损失率、SDS-聚丙烯酰胺凝胶电泳(SDS-polyacrylamide gel electrophoresis, SDS-PAGE)和扫描电镜(scanning electron microscopy, SEM)分析,PHP的添加降低了较高凝胶化温度时凝胶的蒸煮损失,PHP或许可以促进肌球蛋白重链(myosin heavy chain, MHC)分子间交联,减缓蛋白质降解,形成更加致密的凝胶结构。本研究对PHP作为一种新型食品原料应用于开发优质健康鱼糜制品进行了初步的探究,以期为丰富亲水胶在影响鱼糜凝胶特性中的应用研究提供一定的参考。     

不同添加物对微山湖四鼻鲤鱼糜凝胶性的影响

鱼糜制品的凝胶强度是评价鱼糜制品质量的重要指标,本研究以微山湖四鼻鲤(Cyprinus carpio L.)为原料,经过一定的处理后,探讨添加物玉米淀粉、蛋清蛋白、卡拉胶对鱼糜凝胶品质的影响。实验结果表明,通过单因素实验,确定了玉米淀粉、蛋清蛋白和卡拉胶对改良鱼糜凝胶性的最佳添加量为玉米淀粉25%、蛋清蛋白6%、卡拉胶2.0%。通过正交实验确定了玉米淀粉、蛋清蛋白和卡拉胶对鱼糜凝胶性最佳添加组合为玉米淀粉25%、蛋清蛋白6%、卡拉胶1.8%,此组合对鲤鱼糜凝胶品质的改善作用最强。本研究可为今后制备高品质的四鼻鲤鱼糜制品提供一定的参考。     

羟丙基二淀粉磷酸酯对虾糜凝胶特性及其蛋白结构的影响

为考察羟丙基二淀粉磷酸酯（hydroxypropyl distarch phosphate, HPDSP）对中华管鞭虾Solenocera melantho虾糜凝胶性能的改善效果，在虾糜中分别添加1%、3%、5%、7%、9%的HPDSP，以凝胶强度、质地剖面分析、持水性、凝胶微观结构等为指标，并提取虾糜溶胶、凝胶化虾糜、虾糜凝胶中的肌原纤维蛋白，通过圆二色光谱分析蛋白分子二级结构，探究HPDSP对虾糜凝胶性能的影响及其机理。结果表明：添加HPDSP能提高虾糜凝胶的凝胶强度和持水性，并在添加量为7%时达到最大值；HPDSP使虾糜凝胶a*值和b*值下降，但L*值和白度除9%添加量组外，均没有显著变化；适量HPDSP能提高虾糜凝胶硬度、弹性、粘聚性和咀嚼性，促进虾糜形成更加致密稳定的凝胶网状结构。在虾糜凝胶化过程中，加热引起肌原纤维蛋白的α-螺旋含量降低，β-折叠和无规卷曲含量升高，同时HPDSP会对肌原纤维蛋白热变性和聚集产生影响，从而改变其二级结构，影响虾糜凝胶的形成。结论：在中华管鞭虾虾糜中，添加7%的HPDSP能显著改善虾糜凝胶性能。     

淀粉对鱼肉凝胶形成能的影响

１ 介绍 鱼糜和盐混合、加热、形成三维蛋白质网络．一般认为这是蛋白质分子变性、变性分子相互作用形成十字联结的原因。决定鱼肉的凝胶形成能的因素有：鱼种、鱼质、含盐量、蛋白质含量和加工方法。 为了改善鱼肉凝胶结构性质、常在鱼糜中添加淀粉．糊化过程中连续发生了几个变化：颗粒膨胀、结晶区破裂、双折射降低、粘性提高和颗粒分裂。淀粉加热时鱼糜凝胶中淀粉的糊化可在一定范围内提高弹性、淀粉与鱼糜蛋白质的关系不明。 本文研究了添加淀粉对鱼肉凝胶弹性的影响、即淀粉颗粒膨胀糊化与鱼糜蛋白质凝胶的相互作用。２ 材料和方法２…     

北太平洋鱿鱼肌肉蛋白质凝胶特性的研究

以北太平洋鱿鱼为原料,从擂溃工艺、弹性补强剂、品质改良剂以及加热方式对鱿鱼肌肉蛋白质凝胶特性进行了较为系统的研究.先利用正交试验设计分别确定擂溃参数,淀粉、植物蛋白和水的添加量,并在此基础上通过单因素试验确定转谷氨酰胺酶、柠檬酸钠、多磷酸盐的添加量及加热方式.研究结果表明,在试验范围内,擂溃温度3 ℃,空溃5 min,盐溃10 min;添加8%植物蛋白,10%淀粉,20%水分,凝胶弹性较好.采用二段加热,柠檬酸钠、转谷氨酰胺酶、多磷酸盐的添加量分别为0.2%、0.2%、0.3%,鱼糜的凝胶性能较好.     

Characterization of Lotus Stem (Nelumbo nucifera) Starches Purified From Three Lakes of India

Starch was isolated from lotus stem obtained from three lakes of Jammu and Kashmir, India, and their physicochemical, morphological, and pasting properties were studied. Protein, fat, and amylose content varied significantly (p ≤ 0.05) among the different starches, but no significant difference was found in ash content. Amylose content was highest in lotus stem starch from Manasbal (30.0%), followed by the Dal (28.3%), and the Wular (25.0%). Functional properties like swelling, solubility, and water absorption showed an increasing trend with an increase in temperature from 50–90°C. Scanning electron microscopy of lotus stem starches showed small rounded and typical oval shaped granules with a smooth surface. The starch extracted from Wular and Dal lotus stems had larger granules than Manasbal starch. All the starches obtained from the three sources gave a similar B-type X-ray diffraction pattern. Pasting properties—such as pasting temperature, peak viscosity, breakdown, setback, and final viscosity—significantly differed among starches.     

Size-based physical properties of hard-shell clam (Mercenaria mercenaria) shell relevant to the design of mechanical processing equipment

The knowledge of physical properties of food products is of fundamental importance for efficient design, dimensioning, manufacturing and operation of different mechanical equipment used in the processing of these products. Clams of different sizes are utilized during processing, thus, all the sizes must be given adequate consideration for efficient processing. This study was conducted to investigate the size-based physical properties of hard-shell clam (Mercenaria mercenaria) shell relevant to the design of mechanical processing equipment. The sizes of the clam shells were identified and categorized as small, medium and large; and its effect on the physical properties were studied. The parameters investigated were length, width, thickness, arithmetic and geometric diameters, surface area, sphericity, aspect ratio, moisture content, bulk and true densities, porosity, clam shell weight, coefficient of static friction and angle of repose. Increase in the length and width of clam shells increased the arithmetic and geometric diameters, and the surface area, but decreased the sphericity and aspect ratio. Moisture content, bulk and true densities, porosity and clam shell weight increased with increase clam shell size. Coefficient of static friction of clam shell was highest on rubber surface and lowest on glass surface, and was positively correlated with size; while angle of repose decreased with size. There was an excellent agreement between the prediction of the normal distribution and the actual distribution of the clam shell sizes. All the parameters were significantly different with respect to clam shell size at p < 0.05, which makes a strong case for the consideration of clam shell size during processing.     

Reflecting on the Recent Publisher's Report

Research was conducted to determine the effects of potassium sorbate applications (0, 1, 3, and 5% w/v) on the shelf life of pearl mullet (?nci Kefali; Chalcalburnus tarichi) fillets packaged with vacuum. Fillets kept at 4 ± 1°C were subjected to microbiological (total aerobic mesophilic bacteria, psychrotrophic bacteria, lactic acid bacteria, Enterobacteriaceae, molds, and yeasts) and chemical (pH, thiobarbituric acid—TBA, total volatile base nitrogen—TVB-N, water activity, and biogenic amines) analyses on certain days (0, 3, 6, 9, and 12 days) of storage. It was determined that potassium sorbate had effects on total aerobic mesophilic bacteria, psychrotrophic bacteria, Enterobacteriaceae, mold-yeast counts, TVB-N values, phenylethylamine, putrescine, tryptamine, and pH of fillets at a significant (p < 0.01) degree. Retarded bacterial growth was observed as the antimicrobial effect increased with the degree of its concentrations. Storage time had significant (p < 0.01) effects on bacteria count, TBA, TVB-N values, and biogenic amines; all of which were increased by longer storage. It was concluded that application of potassium sorbate, especially at a 5% level, and vacuum packaging helps cold stored fillets maintain their biogenic amines and microbiological and chemical qualities longer.     

Seasonal Variations in Physicochemical and Textural Properties of North Atlantic Cod (Gadus morh.ua) Mince

Abstract

Seasonal variations in physicochemical and textural properties of minced cod muscle from Icelandic coastal areas were evaluated. Measurements were performed on mince from the white muscle. Compared to the winter and summer values, hardness and cohesiveness, as measured by Instron, showed a drop in March to May and another drop was observed for cohesiveness during the autumn months. Expressible moisture changed slightly from March to August whereas results from the winter months indicate greater fluctuations. A minimum was observed for protein solubility in March and July. The surface hydrophobicity of proteins, increased gradually from November to May followed by a sudden drop, then a gradual increase again.     

Properties of Edible Films Made From Anchovy By-Product Proteins and Determination of Optimum Protein and Glycerol Concentration by the TOPSIS Method

In the present study, the physicochemical and mechanical properties of films made from anchovy (Engraulis encrasicholus) by-product proteins (ABPs) were characterized as a function of protein (3, 4, and 5%) and glycerol (30, 40, 50, and 60%) concentration. In particular, the thickness, color, transparency, water vapor permeability (WVP), solubility, oxygen permeability (OP), and mechanical properties of the films were measured, and generally, these properties were affected by both protein and glycerol concentration. The thickness, redness, WVP and solubility values of films increased, while their lightness and yellowness values decreased as protein concentration increased. Furthermore, lightness, yellowness, and elongation at break (EAB) values were found to increase at higher glycerol concentrations within ABP films, whereas tensile strength (TS) and elastic modulus (EM) values decreased. ABP films became more transparent with increase of glycerol concentration and decrease of protein concentration. The OP values of all films decreased depending on protein and glycerol concentration. The techniques for order performance by similarity to ideal solution (TOPSIS) method was used to determine optimum protein and glycerol concentrations. According to this method, an edible film containing 4% protein and 40% glycerol was the best film with a C value of 0.6665.     

Characterization of Spray-Dried Hydrolyzed Proteins from Pink Perch Meat Added with Maltodextrin and Gum Arabic

In the present study, spray-dried pink perch meat protein hydrolysate (PPH) and hydrolysate with maltodextrin and gum arabic (PPHMG) were characterized in relation to their physical, rheological, functional, antioxidant, thermal, and sensory properties. The Herschel–Bulkley model was suitable to explain the flow behavior of PPH and PPHMG emulsions. Both the samples exhibited functional and antioxidant properties. Antioxidant activities were significantly higher for PPH compared with PPHMG (p<0.05). PPH and PPHMG alone did not exhibit antimicrobial activity but enhanced the activity of chitosan against pathogens. Sensory acceptability of the samples in soup revealed that PPHMG of up to 4% was highly scored without any traces of bitterness, whereas for PPH, a concentration of up to 3% was acceptable.     

三种梭子蟹血清凝集素的细胞凝集活性比较

利用凝集试验及糖抑制试验测定三种梭子蟹的血清对红细胞、藻类细胞、微生物细胞或孢子的凝集活性，同时进行糖抑制、热稳定性、pH及Ca^2 影响试验。结果显示：三种梭子蟹中远洋梭子蟹对红细胞最敏感，而三疣梭子蟹对单细胞藻类和微生物细胞或孢子最敏感；红星梭子蟹血清对鹌鹑红细胞的凝集可被供试的7种糖所抑制，而供试的7种糖均不能抑制远洋梭子蟹血清对鹌鹑红细胞的凝集；远洋梭子蟹血清具有广泛的pH适应性，在pH为4．0～10．0范围内对鹌鹑红细胞都具有凝集活性，且具有较强的热稳定性，经60℃保温10min后仍具凝集活性；三种梭子蟹的凝集活性均依赖于Ca^2 。     

饥饿对鳗li某些血液指标的影响

鳗li(Anguilla japonica)饥饿４－２０d后，红细胞数（ＲＢＣ），红细胞比容（ＨＣＴ），全血比重（ＲＳＧ）及红细胞脆性（ＥＯＢ）均下降，血红蛋白含量（Ｈb）则上升到一定水平后维持稳定，其中红细胞性指标，（即红细胞最大抵抗值），对饥饿反应敏感，且离散率低，可以作为衡量鱼营养状态的又一良好指标。     

金乌贼肌肉中三甲胺脱甲基酶的分离纯化及酶学性质

为了提取纯化金乌贼肌肉中的三甲胺脱甲基酶(TMAOase),本研究采用含有0.1 mol/L NaCl、pH 7.0、浓度为20 mmol/L的三羟甲基氨基甲烷(Tris)-醋酸缓冲液提取粗酶液,经透析、浓缩处理后,通过DEAE-52阴离子交换柱层析和Sephacryl S-300柱层析得到了纯化的TMAOase,并对其酶学性质进行了研究。结果显示,经Sephacryl S-300柱层析的TMAOase相比粗酶纯化了209.54倍;粗酶和纯化酶的最适温度分别为55和50°C,当温度高于最适温度时,酶活性开始出现显著下降,粗酶在80°C仍残留21.9%的活性;而纯化酶在80°C时,几乎检测不到酶活;粗酶和纯化酶的最适p H均为7.0,中性条件下表现稳定,在酸性和碱性条件下稳定性下降,p H为9.0时,粗酶残留60.7%的活性,而纯化酶的活性仅为20.5%。以双倒数作图法(Lineweaver-Burk法)测得纯化的TMAOase的Km值为22.8 mmol/L;经SDS-PAGE电泳分析,测得其分子量为21.3 ku;在化学物质中,柠檬酸和CaCl_2对酶活性具有显著的促进作用,H_2O_2和Na_2S对TMAOase活性有显著抑制作用。     

水产胶原蛋白的特性及应用研究进展

水产胶原蛋白是一种天然高分子物质,在水生动物体的皮、鳞、骨、韧带中含量较高,不仅来源广泛而且具有独特的结构和功能,其结构主要以Ⅰ型胶原蛋白为主.本文论述了水产胶原蛋白的理化特性及其应用现状,并对今后的研究方向与前景作了展望.