Effect on protein digestibility of different processing conditions in the production of fish meal and fish feed

The effect of processing conditions on protein digestibility and fluorodinitrobenzene (FDNB)‐reactive (available) lysine in the production of fish meal and extruded fish feed has been studied under pilot and commercial conditions using mink as model animals. Fish meal produced under pilot‐plant conditions at processing temperatures below 70–80 °C (FM1) had protein digestibility of 929 (grams of protein digested per 1000 g protein consumed) compared with 905 when processed at temperatures above 100 °C (FM2). A low‐temperature‐processed commercial fish meal (CFM1) had protein digestibility of 940 compared with 888 for a standard commercial fish meal (CFM2). Pilot‐produced extruded fish feed had protein digestibility of 913 when based on FM1 as the main protein source (95% of total protein) compared with 892 when based on FM2. Commercial extruded fish feed had protein digestibility of 912 when based on CFM1 compared with 871 when based on CFM2. Varying extrusion conditions at the pilot scale, ie temperatures from 100 to 126 °C and moisture contents from 21 to 12%, did not affect protein digestibility. Similarly, under commercial conditions, variation in temperature from 89 to 110 °C and moisture from 24.5 to 19.5% did not affect FDNB‐reactive lysine and protein digestibility. The FDNB‐reactive lysine content and protein digestibility of the extruded feed were less than the values calculated from the ingredient mixture before extrusion. Thus, despite different extrusion conditions not giving different FDNB‐reactive lysine and protein digestibility, the total process, ie extrusion, drying and oil coating, caused a reduction. Copyright © 2003 Society of Chemical Industry     

酶水解技术在鱼下脚料加工中的应用

酶水解技术高效、安全、条件温和,因而在鱼下脚料深加工和活性成分提取方面得到广泛应用。本文较全面的综述了近年来酶水解技术在鱼下脚料(包括鱼皮、鱼头、鱼骨、鱼鳞和鱼内脏等)深加工中的应用现状,并且展望了酶水解加工鱼下脚料的发展方向,以期为鱼下脚料的工业化综合利用提供一定的依据。      

Evaluation of the sensory and physical properties of meat and fish derivatives containing grape pomace powders

The wine industry produces tons of pomace that, in a circular economy model, should be valorised. The phenols fraction of grape pomace represents a source of food colorants, but also of natural food preservatives. Furthermore, the pomace contains dietary fibre, unsaturated lipids, antioxidants and minerals that have been recognised as wholesome and technologically useful. The main drawback of using grape pomace is represented by its chemical and microbiological instability. Different authors proposed strategies to overcome these limitations, and different approaches for the use of grape pomace as an ingredient have been described. Here, we sum up the chemical and microbiological solutions for the stabilisation of grape pomace, describing the approaches used to transform this waste in a functional ingredient, and comparing the physiochemical characteristics of the resulting products. We further describe the studies concerning sensory aspects of the products by enriching animal fleshes with different pomace powder preparations.     

Utilizing waste products from the food production and processing industries

Waste in the food industry is characterized by a high ratio of product-specific waste. Not only does this mean that the generation of this waste is unavoidable, but also that the amount and kind of waste produced, which consists primarily of the organic residue of processed raw materials, can scarcely be altered if the quality of the finished product is to remain consistent. The utilization and disposal of product-specific waste is difficult, due to its inadequate biological stability, potentially pathogenic nature, high water content, potential for rapid autoxidation, and high level of enzymatic activity. The diverse types of waste generated by various branches of the food industry can be quantified based on each branches' respective level of production. Moreover; the origins of each type of waste and a tabulated overview of the traditional agricultural methods for reusing the waste are discussed. Additionally, alternative methods of waste management have emerged, which target the most important contents of the waste. In conclusion, new possibilities for the utilization of food industry waste are described.     

大曲丢糟生产假丝酵母饲料蛋白的研究

白酒酿造产生大量的酒糟废弃物,其可转化为营养丰富、易被动物吸收的高效价生物活性蛋白饲料。以大曲丢糟为主要原料,假丝酵母为菌种进行饲料蛋白的发酵研究,通过正交试验得到最佳的饲料生产工艺条件为丢糟:麸皮=4:1,30℃培养3d,发酵终产物的粗蛋白和还原糖的含量分别达到了17.5%和1.13%。     

Production of feed enzymes from citrus processing waste by solid‐state fermentation with Eupenicillium javanicum

Bingtang sweet orange processing waste was utilised to produce four feed enzymes (Endoglucanase, β‐glucosidase, pectinase and xylanase) by the solid‐state fermentation (SSF) with Eupenicillium javanicum. The factors related with SSF including moisture content, temperature, initial pH, time, carbon source (0.5 g), nitrogen sources (0.05 g), inorganic mineral salts (0.1 g) were investigated separately. The corresponding optimal condition was: moisture content 80% (w/w), temperature 30 °C, natural pH, time 96 h, wheat bran 0.5 g, (NH₄)₂SO₄ 0.05 g or NaNO₃ 0.05 g, CaCl₂ 0.1 g. The L₉(3⁴) orthogonal experiment results showed that the optimal condition for producing above multiple enzymes was: moisture content 80% (w/w), temperature 30 °C, wheat bran 1 g, (NH₄)₂SO₄ 0.05 g, NaNO₃ 0.05 g, CaCl₂ 0.1 g, fermentation time 96 h and natural pH. Under this condition, the average activity of Endoglucanase (CMCase), β‐glucosidase, pectinase and xylanase by E. javanicum could reach 46.80, 49.64, 51.87 and 106.42 U g^?1, respectively, which was significantly higher than those in single factor experiments. Our present results demonstrated that E. javanicum could also be an effective and useful fungus for multienzyme preparation especially for β‐glucosidase and xylanase from citrus processing wastes.     

饵料中不同鱼饲比对黄鳝生长性能和肉质的影响

探索饵料中不同鱼饲比对黄鳝生长性能和肉质的影响。结果表明:当饵料中鱼饲比从T(4∶1)降到T(1∶2),黄鳝的生长性能未受到影响;当鱼饲比降至T(1∶4),黄鳝的相对增重率显著下降。与野生黄鳝相比,采用冰鲜鱼与膨化饲料投喂的黄鳝,其基本营养成分蛋白质和部分氨基酸含量略低于野生黄鳝,随着饵料中鱼饲比的不断降低,黄鳝肌肉蛋白质含量和部分氨基酸含量也有下降的趋势。     

基于棉籽粕优质水产饲料配方的优化

该文利用棉籽粕替代水产饲料中鱼粉,作为主要蛋白源,以降低养殖成本,改善水体生态环境.以蛋白质和磷的体外消化率为评价指标,对棉籽粕以及钙磷的添加量做了优化.结果表明,棉籽粕替代33.33％的鱼粉,磷需要量为0.8％,并添加2.0％石粉时,饲料的体外消化率达到最大值.     

影响颗粒饲料外观质量的因素及改善对策

分析了影响颗粒饲料外观质量的有关因素,并有针对性地提出了改善对策。     

不同低聚糖对小龙虾饲料物理指标及消化特性的影响

为研究不同低聚糖对小龙虾饲料品质的影响,分别将低聚异麦芽糖和低聚木糖以不同添加量添加至饲料中,混匀制粒后测定饲料的含粉率、质量体积、硬度、黏弹性、沉降速度、吸水性、稳定性等物理指标,在此基础上进行体外模拟消化试验.试验结果表明,较低添加量下低聚异麦芽糖饲料的含粉率、硬度和黏弹性高于低聚木糖,较高添加量下则相反;低聚木糖...     

我国餐厨废弃物用作动物饲料现状及其对策分析

针对中国餐厨废弃物用作饲料的现状,对餐厨废弃物用作饲料易滋生大量病菌、易产生毒素威胁、易污染饲料并感染动物、造成人畜共患病的传播等六大潜在的问题进行了综合分析,并提出了相应的对策和建议。     

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。     

Microwave processing technology influences the functional and structural properties of fish gelatin

The objective of this study was to evaluate the effects of microwave processing technology (MPT, 240–800 W, 1 and 4 min) on the functional and structural properties of fish gelatin (FG). It showed that MPT could increase gel strength and texture properties of FG, especially for 240 W. MPT greatly increased emulsifying activity index (EAI) of FG, but decreased its emulsion stability index (ESI). Rheology results showed that MPT increased viscosity of FG, but decreased gelation times. Intrinsic fluorescence and Fourier transform infrared (FTIR) spectroscopy results indicated that MPT could unfold gelatin, contributing to the formation of H-bonds. Scanning electron microscopy (SEM) analysis revealed that low power and short time of MPT-treated gelatin gels had much more dense and less voids. This work provided guidance for the applications of MPT to improve the functional properties of FG, and the results show that MPT-treated FG can replace mammalian gelatin and meet the religious requirement.     

HPLC determination of ethoxyquin and its major oxidation products in fresh and stored fish meals and fish feeds

A new method was developed to determine 1,2‐dihydro‐6‐ethoxy‐2,2,4‐trimethylquinoline (EQ, ethoxyquin), 2,6‐dihydro‐2,2,4‐trimethyl‐6‐quinolone (QI) and 1,8′‐di(1,2‐dihydro‐6‐ethoxy‐2,2,4‐trimethylquinoline) (DM) in fish meals or fish feeds, QI and DM being the oxidation products of EQ. The sample was first extracted with hexane. After the removal of hexane the three analytes were extracted from the resulting oil with acetonitrile and determined by C₁₈ reverse phase high‐performance liquid chromatography with a UV detector set at λ = 280 nm. The mobile phase was acetonitrile–0.01 M ammonium acetate (80:20 v/v). The recoveries for EQ, QI and DM from the samples spiked at different levels varied in the ranges 90–100 per cent, 75–85 per cent and 90–100 per cent respectively. At room temperature, QI and DM were the major oxidation products of EQ in stored fish meals and fish feeds. Loss of EQ from fish meals is faster than that from feeds, resulting in relatively higher accumulations of QI and DM in the fish meals. Both QI and DM, especially the former, were not stable during storage of either and could be further oxidised to unidentified compounds. The residue levels of these two compounds were thus unpredictable during storage intervals. When the storage temperature was increased to 50 °C, EQ disappeared more rapidly, but neither QI nor DM accumulated. © 2000 Society of Chemical Industry     

Development of a healthy low-fat fish sausage containing dietary fibre

In order to develop a healthy low-fat fish sausage containing dietary fibre (DF), three fundamental changes were made to an ordinary pork sausage recipe: incorporation of 4% (w/w) of Swelite^® (a DF obtained from inner pea), different levels of pork meat replacement (0%, 50% and 100%) by hake mince and the combination of varying amounts of Fibruline^® (a DF obtained from chicory root) and hake mince (Fibruline: additional hake mince, 2.6:5.2, 5.2:2.6 and 7.8:0.0, % w/w) as a substitute for pork fat. It was found that the addition of Swelite to pork sausage favoured greater gel strength and hardness. On the contrary, increasing levels of pork meat replacement by hake reduced the sausages’ gel strength and hardness. Finally, sausages without pork fat showed promising textural and colour parameters. High-Fibruline sausages were less cohesive and chewable than pork fat sausages (control), but also exhibited a greater gel strength. Low-Fibruline ones presented almost all textural properties similar to the control, with exception of hardness and gumminess. Therefore, regarding some key textural parameters, it was possible to produce low-fat fish sausages similar to the ordinary pork sausages.     

Levels of synthetic antioxidants (ethoxyquin,butylated hydroxytoluene and butylated hydroxyanisole) in fish feed and commercially farmed fish

Several synthetic antioxidants are authorized for use as feed additives in the European Union. Ethoxyquin (EQ) and butylated hydroxytoluene (BHT) are generally added to fish meal and fish oil, respectively, to limit lipid oxidation. The study was conducted to examine the concentrations of EQ, BHT and butylated hydroxyanisole (BHA) in several commercially important species of farmed fish, namely Atlantic salmon, halibut and cod and rainbow trout, as well as concentrations in fish feed. The highest levels of BHT, EQ and BHA were found in farmed Atlantic salmon fillets, and were 7.60, 0.17 and 0.07?mg?kg^?1, respectively. The lowest concentrations of the synthetic antioxidants found were in cod. The concentration of the oxidation product ethoxyquin dimer (EQDM) was more than ten-fold higher than the concentration of parent EQ in Atlantic salmon halibut and rainbow trout, whereas this dimer was not detected in cod fillets. The theoretical consumer exposure to the synthetic antioxidants EQ, BHA and BHT from the consumption of farmed fish was calculated. The contribution of EQ from a single portion (300?g) of skinned fillets of the different species of farmed fish would contribute at most 15% of the acceptable daily intake (ADI) for a 60?kg adult. The consumption of farmed fish would not contribute measurably to the intake of BHA; however, a 300?g portion of farmed Atlantic salmon would contribute up to 75% of the ADI for BHT.     

Antioxidant activity of phytogenous industrial waste and derived extracts for the production of feed and food additives

Organic wastes as well as their ethanolic, water and heptane extracts and fermented products derived from herbs, fruit and vegetables obtained worldwide from food and pharmaceutical industries were investigated regarding their antioxidant activities using different methods [1.1‐diphenyl‐2‐picrylhydrazyl, Fe^III‐reduction method and photochemiluminescence (PCL)]. The highest antioxidative activities were exhibited by different products of grape seed wastes (350–830 mg rosmarinic acid equivalent g^?1 dried material = rae g^?1 dm) followed by ethanolic extracts of blueberry (475 mg rae g^?1 dm), larch (219 mg rae g^?1 dm), willow (193 mg rae g^?1 dm) and sunflower presscake (154 mg rae g^?1 dm). Ethanolic extracts of the residues showed comparatively higher activity than water extracts. The least antioxidative capacities were found in heptane extracts of serenoa products (0.4; 0.6 mg rae g^?1 dm) and fermented waste of carrots (1.6 mg rae g^?1 dm). Correlating different assay methods, the strongest correlation was found between Fe^III‐reduction and DPPH‐method (correlation coefficient r² = 0.99**) and the weakest between Fe^III‐reduction and PCL method (r² = 0.57**) for raw materials.     

Fish industry waste: treatments, environmental impacts, current and potential uses

Fish waste management has been one of the problems having the greatest impact on the environment. Fish farming detrimental effects on the marine environment in particular have become an issue of public concern. In European Union, numerous Directives, Decisions and Regulations were voted in an attempt to minimise the environmental impact of fisheries within the frame of Integrated Coastal Management. Treated fish waste has found many applications among which the most important are animal feed, biodiesel/biogas, dietic products (chitosan), natural pigments (after extraction), food‐packaging applications (chitosan), cosmetics (collagen), enzyme isolation, Cr immobilisation, soil fertiliser and moisture maintenance in foods (hydrolysates). In this review, an update of both environmental impact (inputs and outputs) and treated fish waste uses is provided by means of six comprehensive tables and seven figures.     

鱼油混浊现象及其冬化工艺研究应用

针对鱼油混浊现象和原因,通过试验实践绘制鱼油冷却曲线,确定鱼油冬化采用两段慢速结晶工艺。第一段结晶温度为16℃,冷却速率为1℃～2℃/小时,14℃养晶12小时;第二段结晶温度为6℃,冷却速率为0.5℃～1℃/小时,4℃养晶12小时,搅拌速度2～5 rpm;并分析影响鱼油结晶效果因素,同峙提出鱼油冬化前需预精炼。