冻罗非鱼片的复配冰衣护色效果研究

针对冷冻罗非鱼片在贮运过程中色泽品质退化的问题开展试验,寻求一种防止冻鱼片贮藏期间变色的新方法。采用响应面试验设计,在发色罗非鱼片和不发色罗非鱼片的冰衣中加入不同添加剂,测定鱼片中高铁肌红蛋白含量,比较组氨酸、抗坏血酸钠、异抗坏血酸钠、山梨酸钾及烟酰胺对鱼片的冰衣护色效果。结果显示,山梨酸钾与异抗坏血酸钠为较优的添加剂组合。以高铁肌红蛋白含量拟合公式中变色系数为试验指标,得到未发色鱼片护色的优化配方为:异抗坏血酸钠0.32‰,山梨酸钾0.68‰,此时变色系数为13.79;发色罗非鱼片的最适护色组合为:异抗坏血酸钠0.32‰,山梨酸钾0.68‰,变色系数为10.42。研究表明,冰衣护色法对防止冷冻罗非鱼片的褪色及褐变是有效果的,可作为罗非鱼片出口加工和贮运的实用技术,能有效减缓冷冻罗非鱼片的褐变速度,延长其鲜红色或原色的保持时间。     

罗非鱼片非一氧化碳发色方法的研究

为研究罗非鱼(Oreochromis mossambicus)鱼片非一氧化碳(CO)发色的新方法,获得安全有效的罗非鱼片发色工艺,以色差值为鱼片色泽的主要评价指标,在亚硝酸钠质量浓度、碳酸氢钠质量浓度、浸泡时间为单因素进行实验的基础上,采用Box-Behnken中心设计原理,对发色方案进行响应面实验优化分析。结果表明,用亚硝酸钠质量浓度0.4 g·L~(-1)、碳酸氢钠质量浓度5.0 g·L~(-1)的复合溶液浸泡罗非鱼片22 min的发色处理效果良好,优化后的鱼片红色肉的Δa*为1.97,提升了17.35%,鱼片整体色泽较好,得到了一种罗非鱼片非CO发色的新方法。     

速冻温度对罗非鱼片品质的影响

通过测定不同冷冻方式冻罗非鱼片的理化指标,试图找到最优处理方式,并为冻罗非鱼片工厂化生产提供参考。通过设置双螺旋冷冻机不同的冷冻温度(-35℃、-38℃、-41℃、)冻结新鲜罗非鱼片,将冻结后的鱼片置于-18℃的冷库贮藏,每隔7 d对鱼片样品的pH、水分活度(Aw)、质构参数、挥发性盐基氮(TVB-N)等物理及化学指标进行检测并分析结果。数据表明,冷冻温度对鱼片色差值、失水率、硬度有较大影响,且冷冻温度越低,鱼片品质越好,对咀嚼性、弹性、TVB-N影响不大,对pH则无明显影响。综上,在现有加工工艺的冷冻温度波动范围内,选择较低冷冻温度,提高冻结速率可延缓冻罗非鱼片品质劣变速度,故建议企业加工时,将冷冻温度控制在-40℃,冷冻时间控制在40 min以尽可能保持鱼片品质。     

高压静电场结合冰温气调保鲜技术对罗非鱼鱼片品质的影响

文章研究了高压静电场结合冰温气调保鲜技术对罗非鱼鱼片的保鲜效果,通过罗非鱼片贮藏过程中肉汁渗出率、菌落总数、感官品质、色差值、总挥发性盐基氮(TVB-N)、脂质氧化(TBA)、p H等指标的变化情况,分析比较3.8 kV、1.8 kV、0 V高压静电下罗非鱼肉品质指标的变化。结果表明,高压静电场能够显著改善鱼肉的品质,贮藏至第30天,样品无异味,感官品质良好,可显著抑制肉汁渗出;可有效抑制微生物的生长和挥发性盐基氮的增加,在一定程度上抑制了鱼肉内脂肪氧化,具有较好的保鲜效果。总体上3.8 kV高压静电对鱼肉的保鲜效果优于1.8 kV高压静电,可延长肉片的保质期至30 d。     

利用热泵装置干燥罗非鱼片试验研究

为了充分利用热泵干燥装置的优势,以罗非鱼片为试验材料,研究了干燥温度、风速、物料厚度及形状等因素对罗非鱼片干燥特性的影响,获得了不同风速、不同厚度、不同温度条件下鱼片干燥曲线。结果表明,热泵干燥过程中各因素的合理匹配能有效提高罗非鱼片的干燥速度,强化热泵干燥的良好效果。不同厚度的鱼片只有找到匹配的温度和风速条件,才能使干燥阶段达到传热传质的平衡状态,在降低临界湿含量的同时维持后期的干燥速度,避免局部干缩而影响物料品质和外观。越薄的鱼片越易找到匹配的条件,厚3 mm鱼片更容易找到匹配的干燥条件。     

水产加工

020722添加一氧化碳对加工罗非鱼鱼片的影响=Effeetof。ar加n monoxide treatmentapplied to tilapla fillet[刊,茱]厅angG(二,LeeK一H,Chow伪//台湾农业化学与食品科学杂志一2001,39(2)一1 17一121 罗非鱼是台湾人重要的食用鱼之一,然而由于罗非鱼鱼肉片本身着色灰暗而不能引起消费者青睐,为改变暗褐色为鲜红色,加工商不时用100%(:(〕作为气调包装处理罗非鱼,这样做的后果会引起鱼肉中高CO残留,甚至有损人体健康。调查比较研究了不同CO浓度处理罗非鱼鱼片的物理及化学变化,尤其是低C()浓度下肌红蛋白与CO的快速反应,”当罗非鱼鱼片用…     

植物精油对冷藏大黄鱼优势腐败菌的抑制作用及其机制

为探讨天然植物精油对冷藏大黄鱼贮藏过程中优势腐败菌的抑制作用及其机制,实验首先对冷藏大黄鱼的优势腐败菌进行分离纯化,并通过16S r DNA序列分析及生理生化实验进行菌株鉴定;采用纸片扩散法和微量肉汤稀释法检测14种植物精油或其组分对腐败菌株的抑菌活性;在阐明植物精油抗菌活性的基础上,再对植物精油处理后的大黄鱼气味进行感官可接受度检验,以筛选出具有高效抗菌活性和良好感官接受性的精油保鲜剂;实验通过细菌形态扫描电镜观察、胞内乳酸脱氢酶及核酸释放研究山苍子精油对不同腐败菌株的膜损伤作用,以初步阐明其抗菌机制;最后,通过检测微生物数量、产硫菌数量、挥发性盐基氮(TVB-N)及组胺含量变化来考察山苍子精油对冷藏大黄鱼潜在的保鲜效果;从冷藏大黄鱼中分离得到6株优势腐败菌,分别为腐败希瓦氏菌4株,热杀索丝菌1株,温和气单胞菌1株;14种植物精油对腐败菌株具有不同抑制活性,其中肉桂醛抑菌活性最强,最低抑菌浓度为0.125μL/mL,其次为丁香酚、百里香酚、柠檬醛、柠檬草及山苍子精油,最低抑菌浓度均≤0.5μL/mL;丁香酚、百里香酚、柠檬醛、柠檬草及山苍子精油使用后未导致大黄鱼气味的感官劣化,且可矫正大黄鱼肉的腥味;山苍子精油可破坏腐败菌株的细胞膜,并导致胞内蛋白酶和核酸外泄。经4μL/mL山苍子精油处理后,冷藏过程中大黄鱼片的菌落总数、产硫菌数、TVB-N及组胺含量显著降低。研究表明,肉桂醛、丁香酚、百里香酚、柠檬醛、柠檬草及山苍子精油对大黄鱼特定腐败菌具有显著抑制作用,芳香酚和富含柠檬醛的精油使用后不影响大黄鱼的感官接受性,有望作为天然保鲜剂用于冷藏海产品的保鲜。     

调味膨化罗非鱼片的研制

酥脆的膨化食品深受人们欢迎,尤其深受儿童欢迎。但膨化食品大多以淀粉原料加工而成,蛋白质含量较低,儿童长期食用易造成营养缺乏。鱼肉中含有丰富易消化的优质蛋白质,将鱼肉片晒干后,采用微波处理,可以得到微波膨化鱼片,其蛋白质含量高,口感类似于淀粉膨化品。我国大宗淡水养殖品种罗非鱼具有生长快、产量高、食性杂、繁殖力强、养殖周期短、疾病少、味鲜肉嫩等优良性状。本研究以罗非鱼为原料,制取调味膨化罗非鱼片,制品深受消费者喜爱。一、工艺流程罗非鱼→去头、内脏→解冻→去鳍、去皮→鱼肉调整→切片→浸液浸泡→沥水→挤压→自然烘…     

一氧化碳发色处理对罗非鱼鱼片暗色肉贮藏过程色泽影响分析

以罗非鱼（Orochromis niloticus♀×0．aureus♂）为研究对象,分析了一氧化碳（CO）发色处理对鱼片背部暗色肉贮藏过程中色泽的影响。结果表明,CO发色处理可以明显提高鱼片的红绿色值（a^＊）,并影响贮藏过程中色泽变化,特别是表征鱼片色泽的a^＊。冷藏初期发色鱼片a^＊略有上升,而后缓慢下降,但未发色鱼片则始终呈缓慢下降的趋势,冻藏期间3种处理鱼片a^＊均缓慢下降;发色鱼片冷藏期间保持鲜红色泽达13d,冻藏达半年。其他2项色泽指标亮度（L^＊）和黄蓝色值（b^＊）贮藏过程中变化趋势基本一致。贮藏过程中a^＊的变化情况与肌肉组织对CO的结合程度及稳定性密切相关,一般经CO发色处理的鱼片贮藏1～2d后鱼片的a^＊会进一步提高,这在冷藏过程中表现尤为明显。CO发色处理对鱼肉中的色素成分肌红蛋白（Mb）起到一定的保护作用,在某种程度上抑制或减缓了Mb氧化反应的发生,阻止高铁肌红蛋白（met—Mb）的生成。     

罗非鱼片贮藏过程中品质变化动力学模型

研究不同温度贮藏条件下罗非鱼片挥发性盐基氮（TVB—N）和菌落总数随时问的变化规律及其动力学特性，建立了TVB-N和菌落总数与贮藏温度和贮藏时间的动力学模型，以预测和控制罗非鱼片在贮藏过程中的品质和货架期。贮藏过程中罗非鱼片的TVB-N和菌落总数增加，随着贮藏温度的升高，鱼片品质劣化速度加快。TVB-N和菌落总数均符合一级化学反应动力学模型，并且与Arrhenius方程有很高的拟合度。罗非鱼片的贮藏期可通过模型进行预测。     

Suitability of Antimicrobial Grouper Bone Gelatin Films as Edible Coatings for Vacuum-Packaged Fish Steaks

ABSTRACT

Grouper bone gelatin films were prepared along with chitosan (GC), clove (GL), and pepper (GP) essential oils and examined for their mechanical, barrier, and antimicrobial properties. GC films had a high tensile strength (TS) of 28 MPa, and GL and GP films had a high elongation at break (EAB) of 162 and 166%, respectively. Water solubility and water vapor transmission rate (WVTR) were low in GL films. All the films exhibited inhibitory activities against Staphylococcus aureus, Aeromonas hydrophila, and Listeria monocytogenes. Vacuum-packed fish steaks coated with GC and GL film extended the shelf life from 4 days to 8 days at 4ºC.     

Development,Characterization, and Antimicrobial Activity of Gelatin/Chitosan/ZnO Nanoparticle Composite Films

ABSTRACT

In order to enhance antimicrobial activity of the film, zinc oxide (ZnO) nanoparticles were incorporated in gelatin/chitosan composite film, and the physical-mechanical properties were investigated. The film-forming solution of gelatin/chitosan/ZnO films showed increased gel strength (GS), elastic modulus (G’), and viscous modulus (G’’) compared to that of the Control. Fish gelatin/chitosan/ZnO films showed lower water vapor permeability (WVP), higher glass transition temperatures (T_g), and antibacterial activities against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Vibrio parahemolyticus. Fourier transform infrared spectra (FTIR) and microstructure studies indicated gelatin, chitosan, and ZnO interactions determined the properties of the composite film.     

Quality changes of shrimp cracker covered with fish gelatin film without and with palm oil incorporated during storage

Impact of fish gelatin film incorporated without and with palm oil on the quality changes of fried shrimp cracker stored for 15 days at room temperature was investigated, in comparison with nylon/linear low-density polyethylene (nylon/LLDPE) film. The moisture content and water activity of shrimp cracker packaged with all films increased during storage (p < 0.05). The lowest moisture content and water activity were found in the sample packaged with nylon/LLDPE film throughout the storage (p < 0.05). Sample packaged with fish gelatin films incorporated with palm oil generally had lower moisture content than those without oil added during the first 12 days of storage (p < 0.05). During 15 days of storage, shrimp cracker packaged with nylon/LLDPE film generally had the lower PV and TBARS value as well as volatile compounds, except for n-nonanal, than those stored in fish gelatin films, regardless of oil incorporation. The decrease in crispiness and increase in toughness occurred in all samples during the 15 days of storage. Nevertheless, the lower changes were observed in the sample packaged with nylon/LLDPE film. Overall, gelatin film showed excellent oxygen barrier property, which was associated with the retardation of lipid oxidation. The incorporation of oil into gelatin film could lower WVP, but negatively increased oxygen permeability of the resulting film. Thus, the improvement of gelatin film is still required.     

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.     

Oxygen permeability and antioxidative properties of edible surimi films

The oxygen permeability (PO₂) and antioxidative activity of edible surimi films were investigated. Surimi films with lower PO₂ were successfully prepared by heating the film-forming solutions (pH 3) at 70°C for 20 min. On the other hand, it was revealed that surimi films themselves possess antioxidative properties based on 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity and reducing power. Sardine oils in surimi film pouches were stored for 40 days at 40°C in the dark. Both peroxide value and thiobarbituric acid reactive substances values increased slightly during the initial period of storage but decreased significantly at the later stage of storage, indicating that oxidation of sardine oil was effectively hindered by packing in surimi film pouches. Furthermore, polymerization of myosin heavy chain in surimi films was observed during the storage at 40°C.     

Development of Optimized Edible Packaging Based on White-cheek Shark (Carcharhinus dussumieri) Skin Gelatin Biopolymer: Mechanical,Water Vapor Permeability,and Structural Properties

White-cheek shark skin gelatin (WSG) edible films were optimized with respect to their barrier, mechanical, and structural properties using response surface methodology (RSM), with the introduction of gelatin concentrations (1–4% w/v based on film forming solution) and glycerol contents (15–35% w/w based on gelatin weight) as the independent variables. WSG films with moderate levels of glycerol had higher tensile strength (TS), elastic modulus (EM), and elongation at break (E@b) depending more significantly on gelatin content. Adding higher levels of glycerol, film roughness was observed to decrease exponentially but water vapor permeability (WVP) increased linearly. Structural analysis using Fourier transform infrared spectroscopy (FTIR) showed more aggregated protein structures at higher gelatin content, which could be strongly related to the notable increase of contact angle. According to the model, the optimum conditions for the WSG film formula were found to be 3.3% WSG and 19.3% glycerol, giving a predicted maximum E@b, TS, EM, roughness, and contact angle of 183%, 4.4 MPa, 92 MPa, 4.93 nm, and 101°, respectively, with a predicted minimum WVP of 11.8 g.mm/day.m².kPa.     

Effect of Organic Acids on Physical-Mechanical and Antifungicidal Properties of Anchovy Protein Films

The use of active biodegradable films from renewable sources like anchovy, with the incorporation of organic acids, such as sorbic acid (SA) and benzoic acid (BA), is an alternative to decrease environmental pollution and minimize the development of fungi in foods. This study investigated the respective influences of SA and BA at 0, 0.50, 0.75, and 1.50% on the growth of Aspergillus flavus and Rhizopus oryzae and on Argentine anchovy protein film properties (L*, a*, b*, tensile strength, elongation at break, solubility in water, water vapor permeability, and Fourier transform infrared spectroscopy (FTIR)). Results showed that the incorporation of SA or BA at different levels significantly increased the water vapor permeability, water solubility, and elongation at break of the films, but decreased the tensile strength and L* parameter (p < 0.05). FTIR evidenced an interaction between the BA and Argentine protein isolate. Also, the influences of the SA or BA concentration on antifungal activity was observed. The greatest effectiveness was obtained for films containing SA against R. oryzae compared to BA film treatments. In conclusion, the Argentine anchovy protein films could retain their antifungal property by incorporation of these organic acids.     

Current Practice and Innovations in Fish Packaging

ABSTRACT

Fish and seafood are food products of high commercial value but with short shelf life. The objective of this article is to review the available packaging techniques and their applications on fish products, focusing on research and latest innovations. Modified atmosphere packaging (MAP) has been investigated for the selection of optimum packaging conditions for different fish products. Recent innovations include the combined application of MAP with other preservative factors, such as minimal processing or the addition of antioxidant and/or antimicrobial compounds. Smart packaging, including active packaging and quality control and monitoring systems (gas and moisture control, antimicrobial/antioxidant packaging, smart labels) and edible films and coatings are innovative packaging technologies, which may result in higher quality and extended shelf life of perishable food. The market for active and intelligent packaging methods is anticipated to rise significantly in the near future with their integration into fish packaging.     

Evaluation of Plasticizing and Antioxidant Properties of Silver Carp Protein Hydrolysates in Fish Gelatin Film

Physico-mechanical and antioxidant properties of glycerol plasticized fish gelatin films were investigated at different levels of fish protein hydrolysates (FPH) from silver carp muscle (5, 10, 15, and 20 g FPH/100 g gelatin). The films supplemented with FPH, especially at higher concentration showed significant increase in 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 20-azinobis-(3-ethylbenzothiazoline-6-sulfnic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP), elongation at break, difference of color, water vapor permeability and opacity, while tensile strength, elastic modulus, L*, b*, and contact angle decreased markedly (p < 0.05). However, no significant differences were observed for a* and solubility of all samples (p > 0.05). Films prepared using 20% FPH had lower glass transition temperature and more homogeneous structure, compared with control film. Also, Fourier transform infrared (FTIR) spectroscopy confirmed the increase of free groups of hydrolysates and lower interaction between chains of film incorporated with the highest content of FPH. Thus, these results indicate that FPH enhanced the antioxidant activities and affected some characteristics due to less interaction between gelatin and FPH.     

Evaluation of antimicrobial products used in tilapia (Oreochromis spp.) and whiteleg shrimp (Litopenaeus vannamei) aquaculture

Despite the importance of aquaculture increases for feeding the growing world population, professional farm management and proper use of aquaculture products or drugs are needed. It is important to know the quality of commercial antimicrobial products on the market while there is wide use of antimicrobials to treat fish diseases. The most commonly used antimicrobial products were identified from a previous survey, included amoxicillin, enrofloxacin, florfenicol, sulphadiazine, sulphamonomethoxine and sulphadimidine. Eight local chemical supply shops were randomly sampled in representative aquaculture areas in Maoming and Zhanjiang districts of south China in 2013. In this study, only eight products contained active substances within ±10% of the concentration declared on the product label among the 30 different most used commercial products; while six products did not contain any of the declared antimicrobials. Three products without labels were sold as ‘pure antimicrobial’ and had high concentrations of active antimicrobials. Furthermore, most products only provided ambiguous information on the packages on both antimicrobial usage and dosage; and only one product stated how to prepare medicated feed which is important for efficient usage. The results of this study showed that the aquaculture antimicrobial products sold on the market were of low quality and thus compromised effective fish disease treatment. Moreover, insufficient information on products’ labels would provide limited instruction on correct antimicrobial usage. Inspection and supervision by both private companies and the government's sector require strengthening.