Effects of iota carrageenan, carboxymethyl cellulose and xanthan gum on the stability of formulated minced fish products

Iota carrageenan, carboxymethyl cellulose and xanthan were used as additives (5 g/kg) in the manufacture of different types of minced fish products (fish chips and fish sticks). Samples of these products were stored at — 18°C and were evaluated at regular intervals for weight loss, fat uptake, physical properties, formation of dimethylamine and formaldehyde and sensory properties. All additions had a significant cryoprotective effect on weight loss and texture during frozen storage. Sensory attributes correlated well with the instrumental measurements of texture and weight loss. After 8 months of frozen storage, the fish chips with carboxymethyl cellulose and xanthan were significantly preferred to the controls. After 14 weeks of frozen storage, the fish sticks with iota carrageenan were not significantly preferred to the control. Xanthan was not a suitable additive for this type of product. Iota carrageenan, and to some extent carboxymethyl cellulose, decreased fat uptake during frying.     

Texture Changes of Frozen Stored Cod and Ocean Perch Minces

During frozen storage, minced cod and ocean perch were examined by expressible moisture (EM), water binding potential (WBP) and computerized texture profile analysis (TPA). The results suggested that a microcomputer interfaced with the Instron efficiently performed TPA. The texture and water loss of all fish minces changed more rapidly at -7°C storage than at -20°C and -40°C. Furthermore, cod, a gadoid with the ability to degrade trimethylamine oxide to dimethylamine and formaldehyde, deteriorated faster than ocean perch, which did not have this ability. EM was useful for examining the water loss of frozen fish at - 7°C only during the first two weeks of storage. The WBP at -7°C storage showed a good correlation with storage time for cod and ocean perch. This suggests that WBP might be a good indicator for examining water holding ability of fish proteins.     

Gel Forming Additive Effects on Properties of Thermally Induced Minced Fish Gel

Water-binding capacity (WBC) and hardness of minced chum salmon flesh decreased after 3 mo frozen storage. Additives with phosphate, carrageenan, soy protein isolate increased the WBC of fresh and frozen minced chum salmon flesh, and the texture profile analysis (TPA) hardness of the thermally-induced myofibrillar protein gels of salmon flesh. TPA hardness was a useful index for characterizing sensory hardness of the cooked minced products. The observation of gel structure by scanning electron microscope showed additives modified the microstructure of fish myofibrillar protein gel and the ability of the gel network to bind water, thus resulting in minced flesh with different WBC and gelling ability.     

Short-term capture-based aquaculture of Atlantic cod (Gadus morhua L.) generates good physicochemical properties and high sensory quality during frozen storage

The annual global catch of Atlantic cod (Gadus morhua L.) is above 1,000,000 tons, and a large proportion is preserved and sold as frozen products. In Greenland, a new innovative fishing method centred on capture-based aquaculture has been developed. To compare the new fishing and processing method with the conventional method, the texture, colour, water holding capacity, salt soluble proteins and sensory properties of fillets were evaluated during 12 months of frozen storage. High quality life (HQL) and practical storage life (PSL) were determined for each fishing and processing method based on sensory evaluation, and by using water holding capacity and the salt soluble protein fraction as indices of quality. Capture-based aquaculture fishing and related processing increased frozen storage durability regarding texture attributes, blood content and sensory properties compared to the conventional method. Lowering the storage temperature to −40 °C increase the HQL to >12 months compared to a HQL of 4–6 months at −20 °C.     

增稠剂提高牛肉持水性的配方研究

肉的持水性指肉在冻结、冷藏、解冻、腌制、绞碎、斩拌、加热等加工处理过程中肉中的水分以及添加到肉中的水分的保持能力。肉的持水性直接关系到肉制品的质地、嫩度、切片性、弹性感,出品率等项质量指标和经济指标。为研究提高肉及肉制品的持水性,本文通过添加不同增稠剂(黄原胶、海藻酸钠、卡拉胶)对离心法测定牛肉持水性的影响,以单因素试验确定最佳添加量,并进行正交试验。确定显著提高牛肉持水性的最佳组合添加量为黄原胶0.2%,海藻酸钠0.2%,卡拉胶0.3%。     

Freshness Assessment of Thawed and Chilled Cod Fillets Packed in Modified Atmosphere Using Near-infrared Spectroscopy

Near-infrared reflectance (NIR) spectra was recorded of 105 samples of cod mince prepared from chill stored thawed cod fillets of varying quality in modified atmosphere packaging (MAP). Traditional chemical, physical, microbiological and sensory quality methods developed for assessing fresh fish products were determined on the same cod fillets. The purpose was to evaluate the potential of NIR spectroscopy for estimating (i) frozen storage temperature, (ii) frozen storage period and (iii) chill storage period of thawed-chilled MAP Barents Sea cod fillets. Furthermore, the potential for measuring of selected quality attributes as drip loss, water holding capacity and content of dimethylamine by NIR was evaluated. The results of the investigation were presented using multivariate modelling methods such as partial least-squares regression (PLSR) and discriminant partial least-squares regression (DPLSR). Systematic differences in the NIR measurements on minced cod fillets were primarily due to the chill storage duration (days at 2°C) on thawed-chilled MAP fillets. PLSR models based on wavelengths selected by a new Jack-knife method resulted in a correlation coefficient of 0.90 between measured and predicted duration of chill storage period (days at 2°C). The root-mean-square error of cross-validation (RMSECV) was 3.4 d at 2°C. NIR measurements provided promising results for evaluation of freshness for thawed-chilled MAP cod fillets completing the traditionally quality methods. However, it is necessary to study the effect of e.g. sample preparation, season, fishing ground and cod size together with more sophisticated pre-treatments of NIR spectra before the NIR method can be integrated as a method for evaluation of thawed-chilled MAP cod fillets.     

不同保水剂对可微波预油炸鸡肉串品质的影响

针对可微波预油炸鸡肉串加工工艺,考察了不同保水剂对产品品质的影响.选用卡拉胶、变性淀粉、柠檬酸钠作为混合磷酸盐的替代物,通过单因素和正交试验,得出变性淀粉对肉品的保水性影响最大,卡拉胶次之,柠檬酸钠最小,三者的最佳配比是卡拉胶质量分数为0.05%,变性淀粉质量分数为0.30%,柠檬酸钠质量分数为0.05%,与最佳配比条件下的复合磷酸盐相比,两者的持水效果基本相同.但在相同的冻藏条件下,添加无磷保水剂的肉品微波失水率显著低于添加磷酸盐保水剂的肉品,无磷酸保水剂的添加使肉品在长时间冻藏后依然具有较好的持水能力.     

Frozen storage of minced prawn flesh: effect of sorbitol, egg white and starch as protective ingredients

 The functionality of minced prawn flesh during frozen storage, with and without added ingredients as protectants, was examined in terms of water-holding capacity, protein solubility, viscosity, texture and gel-forming capacity. Different lots containing sorbitol, egg white and starch were studied. Minced prawn showed high protein solubility which remained constant after 3 months of frozen storage, regardless of the ingredients used. A slight increase in shear strength during the storage period was suppressed by the addition of ingredients; however, these were not effective at substantially improving the gel-forming capacity of the minced prawn. Viscosity was the property most affected by frozen storage, and was improved by the addition of ingredients.     

不同冻藏时间的猪肉品质比较及其变化机制研究

为了解冷冻储藏期间猪肉品质变化的原因及其可能的机制,分别比较了冻藏4个月和冻藏8个月猪肉的持水性、质构、颜色等品质指标;并通过低场核磁（low-field nuclear magnetic resonance,LF-NMR）检测了猪肉样品中水分的种类和分布,探索了不同水分分布与持水性、质构间的相关性;通过电子鼻和基于高分辨质谱的脂质组学分析探讨了猪肉风味成分的变化以及引起变化的特征物质的种类。结果表明,与冻藏4个月的猪肉相比,冻藏8个月猪肉的品质明显劣变,而其肌纤维形貌更加松散、水分弛豫时间延后、峰面积减小。而猪肉的持水性和质构等品质指标与冻藏时间存在正相关性,与水分弛豫时间和面积之间存在负相关性,也说明经过长时间冻藏,猪肉中结合水和不易流动水的迁移与损失可能是引起猪肉质构品质发生劣变的主要原因。通过对猪肉电子鼻数据的偏最小二乘回归分析（PLS-DA）发现,经过长期冻藏后猪肉的风味成分也明显改变,发生变化的风味成分主要为烷烃、芳香类成分、弱极性化合物、甲烷和醇类化合物。而通过高分辨质谱鉴定出5种与脂质氧化相关的差异化合物,推测经过长时间冻藏后,猪肉风味物质发生的明显变化可能是由于肌肉组织中的脂类被氧化造成的。     

A method for characterising cook loss and water holding capacity in heat treated cod (Gadus morhua) muscle

The currently available methods for measuring water holding capacity (WHC) have been developed for raw material characterisation and have been applied to processed (cooked) muscle samples. The intrinsic shortcoming of the methods is that they do not allow rapid and uniform heating, which make them unsuitable for investigating the kinetics of cook loss and WHC. A new method and associated equipment (sample cups) for rapid and uniform heating that allows studying cook loss, water holding capacity and texture of fish samples was developed. After heating and cooling of samples in the sample cup it is feasible to gravimetrically determine the cook loss with a standard deviation within 30% of the total cook loss for minced samples. Both intact and coarsely minced muscle of farmed cod was used to investigate the abilities and limitations of the method with respect to WHC.     

A sensometric approach to cod-quality measurement

The quality index method was used for describing the sensory quality of thawed whole cod and raw fillet and the quality of boiled fillet was assessed by profiling analysis. These data were compared to the water holding capacity of the minced cod by principal component analysis (PCA) and partial least squares regression. The sensory data and the water holding capacity were correlated to an extent that made possible the prediction of high and low values of water holding capacity. Multivariate methods were also used for extracting some information about the assessor variability. This was done by determining the ability of the assessors to predict the water holding capacity through partial least squares regression and by examining the distances between PCA-models of profiling data from the single assessors.     

K型与I型卡拉胶对白鲢鱼糜持水性及质构冻藏稳定性的影响

目的:以常见的白鲢鱼糜为原料,研究I型和K型卡拉胶对鱼糜质构和持水性差异,以及在反复冻融循环中的影响。方法:对分别加入I、K两种胶体的鱼糜反复冻融后持水性和TPA指标进行显著性分析。结果:未冻融时,I型卡拉胶对降低鱼糜硬度、胶着性、咀嚼性,增加恢复性作用比K型更强(p <0.05);对照组、I型卡拉胶组和K型持水性基本相同(p> 0.05)。反复冻融试验结果表明,添加I卡拉胶对鱼糜硬度、黏性、黏附性、咀嚼性和弹性的保护作用强于添加K卡拉胶,但会降低鱼糜的弹性和持水能力。结论:I型K型卡拉胶鱼糜对TPA影响有差异,I型卡拉胶鱼糜的反复冻融TPA与持水性稳定性更好。     

Effect of added lipids on the texture of minced hake (Merluccius merluccius L.), megrim (Lepidorhombus whiffiagonis W.) and sardine (Sardina pilchardus W.) during frozen storage.

The effect of added cod liver oil and oxidized cod liver oil on the measurement of texture in minced hake (Merluccius merluccius L.), megrim (Lepidorhombus whiffiagonis W.) and sardine (Sardina pilchardus W.) has been measured during frozen storage (-18 degrees C). The results show that added neutral and oxidized lipids, even at high rancidity levels, do not affect shear resistances measured by the Kramer shear-compression cell in non-formaldehyde forming species such as megrim and sardine, over the frozen storage period. However, in a formaldehyde-forming species such as hake, in the presence of neutral and oxidized lipids at the end of the storage period, the values of shear resistances may be lower than in the absence of these lipids, probably owing to formation of less formaldehyde in these cases. Although it is very difficult to estimate the importance of a single compound or group of compounds on texture, these results seem to indicate that formaldehyde is a much more important factor than oxidized lipids in changes of texture in fish.     

卡拉胶寡糖对冷冻南美白对虾的抗冻保水作用

目的:研发冷冻南美白对虾虾仁的抗冻保水剂并探索其应用效果。方法:以冷冻虾仁解冻损失率、明度、p H值、肌原纤维蛋白含量、Ca~(2+)-ATPase活性、弹性和咀嚼性为评价指标,以焦磷酸钠为阳性对照,研究卡拉胶寡糖对冷冻虾仁的抗冻保水效果及微观组织结构的影响情况。结果:卡拉胶寡糖和焦磷酸钠浸泡处理能有效抑制冷冻虾仁解冻损失率的增加,减少肌原纤维蛋白含量和Ca~(2+)-ATPase活性的下降,对虾仁pH值、明度和质构特性的保护效果显著,且3g/100 m L处理组的保护效果整体高于1 g/100 m L处理组;同时,3 g/100 m L卡拉胶寡糖处理对虾仁肌原纤维蛋白的保护效果显著高于3 g/100 m L焦磷酸钠处理(P0.05);微观结构观察发现,冻藏6周后,3 g/100 m L卡拉胶寡糖处理组虾仁肌纤维排列紧密,完整性较好,与新鲜冷冻虾仁组织结构较为相近。结论:3 g/100 m L卡拉胶寡糖浸泡处理有利于冷冻虾仁品质的保持。研究结果可为开发一种低甜味、低热量的虾仁抗冻剂提供参考。     

The impact of dietary oil source and frozen storage on the physical,chemical and sensorial quality of fillets from market-size red hybrid tilapia, Oreochromis sp.

Red hybrid tilapia (Oreochromis sp.) were fed one of four diets containing either fish oil, crude palm oil, palm fatty acid distillates or refined palm olein as the only added oil. Post-harvest fillet quality was then evaluated at 1, 10 and 30 weeks of frozen storage. Dietary oil source did not significantly (p > 0.05) influence the liquid holding capacity and texture of fillets but both these parameters were increased by frozen storage. Fillets from fish fed palm oil-based diets exhibited significantly higher oxidative stability during frozen storage, compared to fish fed the fish oil diet. Dietary oil source and frozen storage had little impact on sensory attributes. Unlike fillet proximate composition, fillet fatty acid composition was significantly affected by both diet and frozen storage. Total n-3 polyunsaturated fatty acids decreased significantly in the fillet lipids of all fish after 30 weeks of frozen storage.     

Texture changes in frozen cod mince measured by low-field nuclear magnetic resonance spectroscopy

Studies were carried out on changes in water proton relaxation, Instron parameters, dimethylamine (DMA) content and sensory texture scores during storage of cod mince at -10°C, -20°C and -70°C. The longest transverse proton relaxation time measured by pulsed low-resolution nuclear magnetic resonance (NMR) spectroscopy increased with temperature and duration of frozen storage. These variations in the NMR parameter paralleled changes observed with analytical methods commonly used for evaluating fish texture, ie Instron measurements, as well as dimethylamine and sensory analyses. It is concluded that the NMR method can be an alternative tool to study textural modifications of cod during frozen storage. © 1997 SCI.     

冻藏时间及pH值对宰后不同部位羊肉保水性变化的影响

-18℃条件下将新疆巴什拜羊的肩肌、臀肌、背最长肌分别冻藏1、3、5、7、15、30d后,对其保水品质特性进行检测分析.结果表明:肩肌系水力随冻藏时间延长不断降低,冻藏时间延长至15、30d时有所回升;臀肌系水力随时间延长有所下降,蒸煮损失随冻藏期间延长不断增加,冻藏30d蒸煮损失最高,解冻滴水损失随冻藏时间延长而增加;背最长肌系水力随着冻藏时间的延长下降,蒸煮损失随冻藏时间延长呈增加趋势,在冻藏1d时最低,与冻藏15、30d差异显著(P＜0.05);pH值与各部位肌肉系水力值均呈正相关,与蒸煮损失则呈负相关.故冻藏时间对新疆巴什拜羊不同部位保水性影响较大.随着冻藏时间的延长,各部位羊肉的水分含量、解冻滴水损失、系水力、蒸煮损失均会发生变化,这一过程中,pH值的变化对保水性各指标变化影响也较大.     

不同冷冻策略下木薯淀粉对龙头鱼鱼糜凝胶品质的影响

目的 探究三种冷冻策略下,即冷冻-预凝胶-熟化(Freezing-Setting-Heating,FSH)、预凝胶-冷冻-熟化(Setting-Freezing-Heating,SFH)、预凝胶-熟化-冷冻(Setting-Heating-Freezing,SHF),木薯淀粉的添加对龙头鱼鱼糜凝胶性能及品质的影响。方法 以龙头鱼为原料,通过冻藏期间的质构特性、水分含量、持水性和微观结构观察,阐明不同冷冻策略及木薯淀粉添加对其凝胶品质的影响。结果 随着冻藏时间的增加,鱼糜质构特性逐渐下降,水分含量减少。在相同冻藏时间下,淀粉的添加有利于提高鱼糜凝胶的品质,其硬度、胶粘性和咀嚼性显著提高(P<0.05),持水性显著增强(P<0.05)。其中,经60天冻藏后,SFHW(含淀粉)及SHFW(含淀粉)组样品剩余水分含量分别为48.60%和47.06%,较同一周期下未添加淀粉组及FSHW(含淀粉)组取得较好的实验效果。经微观结构观察,木薯淀粉在加热糊化过程中吸水膨胀并起到一定填充作用,添加淀粉的鱼糜凝胶解冻及复热后较未添加淀粉的样品,均具有更小的孔隙,且孔隙大小趋势为FSHW> SFHW> SHFW。结论 添加木薯淀粉并经预凝胶或熟化后冷冻对龙头鱼鱼糜凝胶品质起到积极作用,可为冷冻龙头鱼鱼糜制品提供理论支持并为其工业化生产提供可能性。     

包装方式对养殖大黄鱼冻藏品质的影响

以养殖大黄鱼为研究对象,以感官特性、色差、持水力、质构、K值、挥发性盐基氮(Total volatile basic nitrogen,TVB-N值)、硫代巴比妥酸(Thiobarbituric acid value,TBA值)为评价指标,研究在冻藏120d镀冰衣、真空包装和无包装对养殖大黄鱼品质的影响。结果表明:随着冻藏时间的延长养殖大黄鱼的感官综合评分、质构、持水力均逐渐降低,3种包装处理下养殖大黄鱼TVB-N值,TBA值均随时间延长而增加,K值与TVB-N变化一致。与镀冰衣组和无包装组相比,真空包装下的养殖大黄鱼TVB-N值、TBA值和K值增加较缓慢。综合各指标变化,冻藏条件下真空包装有利于保持养殖大黄鱼较好新鲜度及冻藏品质。     

二次杀菌时间对猪肉糜持水性的影响

测定猪肉糜二次杀菌前后的蒸煮损失、质构特性以及自旋-自旋弛豫时间,研究85℃条件下二次杀菌时间(0、5、10、15、20、25 min)对猪肉糜持水性的影响。结果表明:二次杀菌导致蒸煮损失率显著增加(P0.05),当杀菌时间超过15 min时,质构特性参数值显著降低(P0.05),不易流动水相对含量显著(P0.05)降低,而自由水相对含量则显著(P0.05)升高。说明二次杀菌时间会影响肉糜中蛋白质的保油保水性,进而影响肉糜制品的质构特性。