浸泡工艺对即食型鮰鱼皮质构的影响

研究了浸泡工艺对即食型斑点叉尾鮰鱼皮质构的影响。采用脆度来反映其质构变化,并用破碎力来表征其脆度。在单因素实验的基础上,采用二次回归正交设计方案和响应面分析法,确定最佳浸泡条件:NaOH溶液浓度0.106%、NaOH溶液浸泡时间15.4min、NaHCO3溶液浓度3.1%、NaHCO3溶液浸泡时间63.2min时,破碎力有最小值,为887g。      

斑点叉尾鮰鱼皮明胶制备工艺的优化

以斑点叉尾鱼皮为原料,采用低浓度氢氧化钠短时间浸泡鱼皮制备明胶。用中心组合实验设计(CCD)展开实验,以研究自变量氢氧化钠浓度(%,X1)、碱浸泡时间(h,X2)、水抽提温度(℃,X3)和水抽提时间(h,X4)对变量凝胶强度(g,Y)的影响。采用响应面分析优化工艺条件为:X1=0.889%,X2=25.794h,X3=49.295℃,X4=4.902h时,指标Y有最大值620.988g。测定了最优工艺条件下所得明胶的产率、凝胶强度和氨基酸组成。      

斑点叉尾鮰鱼冷冻鱼片加工工艺

我国淡水渔业已发展到相当规模，产量迅速提高。据统计，目前产量达1000万吨，占全年淡水鱼总量的70％。由于渔业经营链条短，加工业落后，以至一些水产品市场疲软，价格低迷，生产效益下降。本研究在广泛收集资料的基础上，系统地介绍了斑点叉尾鮰鱼的特性、冷冻鱼片冷冻加工技术，尤其对加工过程中的关键点进行了初步探讨。     

响应面法优化斑点叉尾鮰鱼内脏油脂肪酸提取工艺研究

采用皂化酸解工艺,对斑点叉尾鮰鱼内脏油中的脂肪酸进行提取,并对其提取工艺参数进行响应面优化。以KOH浓度、反应温度、反应时间作为影响因素,脂肪酸酸值作为响应值,在单因素试验的基础上,通过响应面模型优化后的最佳工艺参数为:KOH浓度0.22mol/L、反应温度90℃、反应时间140min,预测脂肪酸酸值KOH为196.78mg/g,实际脂肪酸值KOH为195.92mg/g,预测值与实际值基本吻合。     

斑点叉尾鮰鱼皮明胶的制备

目的以斑点叉尾鮰鱼皮为原料,采用酸碱法制备鱼皮明胶;方法选用NaOH溶液和H2SO4溶液进行明胶的提取,通过单因素试验和正交试验,确定斑点叉尾鮰鱼皮明胶最佳制备工艺;结果NaOH质量分数为0.3%,H2SO4质量分数为0.4%,处理时间均为120 min,提取温度45℃,提取时间6 h,此时,所得明胶的凝胶强度和黏度分别为672.2 g和9.46 mPa·s,明胶提取率为65.21%.     

斑点叉尾鮰鱼片的加工工艺、营养成分及质构分析的研究

通过对斑点叉尾鮰鱼片的加工工艺、操作要点的介绍和对鱼片的营养成分、质构的详细分析,得出:斑点叉尾鮰鱼片中含有多种人体必须氨基酸,氨基酸总量14.93%,粗蛋白质含量15%,粗脂肪含量3%。经工厂化加工的鱼片无刺,解决了吃鱼被卡带来的烦恼。冻斑点叉尾鮰鱼片是一种营养价值高、食用方便的产品,具有良好的市场前景。     

不同冷冻方式对斑点叉尾鮰鱼片品质的影响

研究不同的低温冷冻预处理方式,即-20℃慢冻、-20℃、-40℃、-60℃速冻至-20℃,进行鮰鱼片的冷冻,随后于-20℃冻藏,考察储藏期间鮰鱼片理化性质的变化情况。结果表明,随着冻藏时间的延长,不同方式的冻结鮰鱼p H值、Ca~(2+)-ATPase活性、活性巯基均呈下降趋势,MDA值、TVB-N值、表面疏水性呈上升趋势,速冻处理组的样品各指标变化趋势明显低于或迟缓于慢冻组,且速冻温度越低,效果越显著。考虑到成本因素,可以结合其他保鲜手段适当提高冻结温度至-20℃~-40℃以保证产品品质。     

Nisin、溶菌酶用于斑点叉尾鮰鱼片保鲜的研究

以Nisin(乳链菌肽)、溶菌酶及VC(抗坏血酸)为保鲜剂,用于斑点叉尾鮰鱼片的冷藏保鲜,采用正交试验对复合保鲜剂的配比进行优选,并以细菌总数、TVB-N 值、pH 值及感官评分为鲜度指标,测定复合保鲜剂的保鲜效果。结果表明：复合保鲜剂最优配比为0.5% Nisin+0.3% 溶菌酶+3.0% VC,并用乳酸调节pH4.5,用此保鲜剂处理再结合真空包装能使斑点叉尾鮰鱼片在0℃条件下保鲜21d。     

乳酸提取鮰鱼皮胶原蛋白工艺优化

以斑点叉尾鮰鱼皮为实验材料,选用乳酸从中提取胶原蛋白。通过单因素试验分别考察pH值、料液比和时间3个参数对胶原蛋白提取率的影响,在此基础上,利用Box-Benhnken中心组合试验设计和响应面分析法对乳酸提取鮰鱼皮胶原蛋白条件进行优化。结果表明,乳酸提取鮰鱼皮胶原蛋白的优化工艺为pH2.3、料液比1:60(g/mL)、时间46h,在此条件下鮰鱼皮胶原蛋白的提取率达到46.28%。     

斑点叉尾鮰鱼皮火腿肠的研制

以斑点叉尾鮰鱼皮、冷冻鱼糜为原料研制鱼皮火腿肠,在保持鱼肉火腿肠原有风味同时,提高其口感和营养价值,同时丰富了火腿肠的种类,为斑点叉尾鮰鱼皮的利用提供了新的途径。通过正交试验得出鱼皮与冷冻鱼糜的质量比1∶9,猪肥膘添加量为15%,淀粉添加量为10%,冰水添加量为10%时可达到较好的感官品质。     

天然抗氧化剂对斑点叉尾鮰内脏精炼鱼油的抗氧化效果研究

以过氧化值(POV)为指标,采用Schaal烘箱法研究了D-异抗坏血酸钠、迷迭香、茶多酚对斑点叉尾鮰内脏精炼鱼油的抗氧化效果,结果表明当抗氧化剂的添加浓度为0.02%时,抗氧化性能由大到小顺序为茶多酚>迷迭香>D-异抗坏血酸钠,茶多酚的抗氧化效果与其浓度呈剂量效应关系。添加维生素C和柠檬酸对茶多酚的抗氧化效果均有协同增效作用,但维生素C对茶多酚抗氧化能力的增效略大于柠檬酸。     

2-step optimization of the extraction and subsequent physical properties of channel catfish (Ictalurus punctatus) skin gelatin

ABSTRACT:  To optimize the extraction of gelatin from channel catfish ( Ictalurus punctatus ) skin, a 2-step response surface methodology involving a central composite design was adopted for the extraction process. After screening experiments, concentration of NaOH, alkaline pretreatment time, concentration of acetic acid, and extraction temperature were selected as the independent variables. In the 1st step of the optimization the dependent variables were protein yield (YP), gel strength (GS), and viscosity (V). Seven sets of optimized conditions were selected from the 1st step for the 2nd-step screen. Texture profile analysis and the 3 dependent variables from the 1st step were used as responses in the 2nd-step optimization. After the 2nd-step optimization, the most suitable conditions were 0.20 M NaOH pretreatment for 84 min, followed by a 0.115 M acetic acid extraction at 55 °C. The optimal values obtained from these conditions were YP = 19.2%, GS = 252 g, and V = 3.23 cP. The gelatin obtained also showed relatively good hardness, cohesiveness, springiness, and chewiness. The yield of protein and viscosity can be predicted by a quadratic and a linear model, respectively.     

Functional properties of protein fractions of channel catfish (Ictalurus punctatus) and their effects in an emulsion system

Abstract: This study demonstrated the feasibility of producing soluble protein (CFSP) and insoluble protein (CFISP) fractions from catfish muscle protein. CFSP and CFISP contained 60.6% and 73.8% protein and 8.6% and 20.3% fat, respectively. Both CFSP and CFISP contained essential amino acids. Differences were observed between physicochemical properties of the 2 protein fractions, including nitrogen solubility, emulsion stability, and fat adsorption capacity. The flow and viscoelastic properties of the emulsions prepared with CFSP and CFISP were investigated using a rheometer. The power law model and the Casson model were used to determine the flow behavior index (n), consistency index (K), and yield stress. Emulsion containing CFSP (ECFSP) had a higher K value than emulsion containing CFISP (ECFISP). Both ECFSP and ECFISP emulsions exhibited pseudoplastic behavior and viscoelastic characteristics. The G′ (an elastic or storage modulus) and G″ (a viscous or loss modulus) values for ECFSP were higher than ECFISP. Catfish muscle tissue can be easily separated into soluble and insoluble protein powders that have desirable functional properties.     

以鱼类下脚料制备风味蛋白粉的研究

以鱼类下脚料为原料,经生物酶解、酸解制备了风味水解蛋白粉。文中介绍了制作方法和生产工艺,以及产品的相关技术特征。     

Variation of lipid and tocopherol composition in three strains of channel catfish (Ictalurus punctatus)

Three strains of channel catfish (Ictalurus punctatus), which were designated as ‘AQUA’, ‘LSU’ and ‘MSU’, were examined for their lipid and tocopherol composition to delineate if genetic strains exhibited the potential to vary in their susceptibility to lipid oxidation. Since age, diet and environmental conditions were similar for all strains, growth and compositional differences were ascribed to genetic factors. Significant differences were noted between strains in their muscle tissue for triacylglycerol (TG) levels, fatty acid composition, and tocopherol levels. The largest quantity of TG was found in the LSU strain whereas the smallest quantity was found in the AQUA strain. Levels of polyunsaturated fatty acids (PUFA) in the TG and total lipid (TL) fraction were highest in the AQUA strain and lowest in the MSU strain. Similarly, a peroxidizability index, which took into account the differences in susceptibility of unsaturated fatty acids to oxidize, was highest in AQUA and lowest in MSU for the TG and TL fractions. The peroxidizability index for the phospholipid fraction did not vary between strains. Adopting a relative antioxidant effectiveness value of 0.31 for γ-tocopherol, the LSU, MSU and AQUA catfish strains were calculated to contain 37.72, 22.79 and 42.49 nmol of α-tocopherol equivalents, respectively. The MSU catfish strain exhibited the highest ratio (nmol PUFA/nmol α-tocopherol equivalents) suggesting that its tissue would be the least stable to oxidation.     

Performance, composition and sensory quality of adult channel catfish (Ictalurus punctatus) fed a dried waste egg product

The growth and carcass quality of adult channel catfish (176 mm, 76 g average length and weight) fed diets (6000 fish/diet) containing 14% and 28% dried, inedible whole egg were compared to similar fish fed a commercial or a formulated diet containing fish meal as the primary protein source. After 4 months, the fish fed 28% dried egg diet were 5–8% longer and 17–31% heavier, and had consumed 0.06–1.11 1b feed per 1b weight gain less than fish fed the other diets. Fish fed the egg diets had 0.9–1.2% less dress-out and 0.3–2% more visceral cavity fat than fish fed the non-egg diets. Diets containing eggs did not affect the sensory quality or shear press values of the cooked fish fillets.     

鸡骨泥水解蛋白的酶法制备

以新鲜鸡骨泥为原料,选用Alcalase对其水解,确定酶解的最佳条件为:鸡骨泥经90 ℃加热预处理30 min,配制成10%的鸡骨泥悬浮液,控制反应体系温度为60 ℃,pH=9.5,加酶量6 000 U/g,反应2.5 h,此时水解度可达17.3%.酶水解液颜色为淡黄色,气味芳香,适宜作鸡肉香精的原料.     

Characterization of edible film fabricated with channel catfish (Ictalurus punctatus) gelatin extract using selected pretreatment methods

ABSTRACT:  Farm-raised catfish are important to the economy of the southeastern states in the United States, and catfish processing produces about 55% of by-products for inexpensive sale. Therefore, the utilization of catfish by-products is of great interest to the catfish industry. The objectives of this research were to determine the optimum pretreatment method to extract catfish gelatin for edible film application, and to characterize physical, mechanical, and barrier properties of edible films fabricated with catfish skin gelatin. Catfish skins obtained from a local plant were treated with 6 selected pretreatment methods. The main extraction was performed with deionized water at 50 °C after pretreatment. The gelatin yield was calculated and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to characterize molecular weight (MW) profile. Color, tensile strength (TS), elongation, and water barrier property were determined to characterize the fabricated catfish gelatin films. From the results of gelatin yield, color, SDS-PAGE, as well as mechanical and barrier properties of the film, the pretreatment method with 0.25 M NaOH and 0.09 M acetic acid, followed by extraction at 50 °C for 3 h, was determined as the optimum extraction method. The catfish gelatin exhibited higher MW fractions than commercial mammalian gelatin. The catfish gelatin extracts possessed film-forming properties determined by TS, elongation, and water vapor permeability (WVP) comparable to those of commercial mammalian gelatin. The selected formula for catfish gelatin film was determined as 1% gelatin and 20% glycerol, resulting in greatest TS and lowest WVP.