Comparison of physicochemical and sensory changes in fresh and frozen herring (Clupea harrengus L.) during marinating

BACKGROUND: The influence of freezing on the changes during ripening is better described for salted fish than marinades. Therefore in the present study the effect of preliminary freezing of raw material on the ripening of carcasses and fillets marinated during 18 days at a temperature of 10 °C, in brine with 6% salt and 5% acetic acid was examined. RESULTS: In both cases the marinating of thawed frozen material resulted in larger mass losses and decrease of the value of meat colour parameters. The semi‐marinades from raw herring were characterised by higher values of total estimation based on sensory analysis. The statistical analysis showed weak correlation between the discriminants of sensory assessment and the studied physicochemical parameters of semi‐marinades. CONCLUSIONS: These results suggest that the semi‐marinades from raw fish are characterised by higher sensory quality, better colour parameters and higher yield than those from frozen thawed fish. Copyright © 2010 Society of Chemical Industry     

Influence of salt concentration on properties of marinated meat from fresh and frozen herring (Clupea harengus L.)

Salt concentrations of brine above 10% are still commonly used in fish marinating process. The study has showed an increasing salt concentrations affect to adversely all the properties of marinated herring meat. Increase in salt concentration from 5% to 15% resulted in significantly (P < 0.05) decrease content of water, non‐protein nitrogen and products of protein hydrolysis. Consequently, weight yield of marinated fresh herring decreased from 83% to 74%. The most palatable marinades contained 2–3% NaCl in meat only. The higher salt concentrations applied significantly (P < 0.05) worsened the taste, texture and colour of marinated herring. Texture profile analyses (TPA), free hydroxyproline content and colour analyses (L*a*b) confirmed the negative influence of high salt concentration on the marinades quality. Frozen and thawed herring tissue showed greater sensitivity to salt. Namely, marinades from frozen fish contained by 0.3 more salt (P < 0.05), and the weight yield was by 2.3–10.3 percent point lower than from the fresh herring. Meat from frozen herring when matured has significantly (P < 0.05) lower sensory value, lower content of protein hydrolysis products, free hydroxyproline and higher parameter b* value of than the fresh one.     

The reuse of brine to enhance the ripening of marine and freshwater fish resistant to marinating

Cold marinades are produced mainly from the Clupeidae fish, because meat of other fish species does not reach a desired level of ripeness in the acid-salt environment of fresh brine. Hence, this work presents an innovative idea of reusing brine including cathepsins and peptides for marinating cod, salmon, trout, and carp. The extent of marinades ripening improvement depended on fish resistance to the marinating process. The reused brine proved best in improving the ripening of fatty fish (salmon and trout), which were qualified to the first class of resistance to marinating. In the case of cod, the reuse of brine did not elicit a satisfactory improvement in meat ripening. Therefore cod was qualified to the second class of resistance. The reuse of brine resulted in decreased values of lipid oxidation indices (except for cod) and meat hardness, and in increased scores for overall sensory evaluation and total volatile bases nitrogen value.     

速冻菜肴糖醋排骨工艺优化

通过正交试验研究糖醋排骨工业生产配方及工艺条件对感官品质的影响,同时通过均匀设计试验和二次多项式逐步回归分析研究调味酱包最佳配方。结果表明：糖醋排骨最佳配方为肉500g、糖50g、酱油10g、醋70g、料酒40g;最佳工艺条件为预煮10min、腌制10min、油炸3min、收汁15min;糖醋排骨酱包最佳配方为肉50.00g、油35.00g、糖15.00g、酱油5.98g、料酒10.71g、醋30.77g、水71.93g、盐0.45g。     

Losses of nitrogen fractions from herring to brine during marinating

Fish meat is characterized by a high content of valuable nutrients. During the marinating process, however, the process of proteins diffusion and other nitrogen fractions from fish to the surrounding brine is commonly observed. It was determined that the total nitrogen loss from herring meat of industrial maturity (4-5 day) amounted to 6-19% of raw material nitrogen. Extension of the marinating time to 16-18 days increases nitrogen losses even to 18-27%. Less loss was observed during marinating of fresh than of frozen herring and during marinating of carcasses, as opposite to fillets. Higher nitrogen content in fish was not proved to influence higher nitrogen losses in a brine. The majority of loss consisted of nitrogen fractions soluble in TCA, of which one third was formed by α-amine nitrogen. Nitrogen contained in brine suspension accounted for only 1.5-4% of total nitrogen losses. With increasing salt or acid concentration the amount of total nitrogen loss was lower from fresh herring and higher from frozen one. Higher salt concentration significantly reduced the amount of non-protein nitrogen and all its fractions during marinating of fresh and frozen herring. In case of acetic acid, the influence of its concentration was diverse and depended on type of herring and its dressing.     

Quality of Sour Cream Packaged in Cups with Different Light Barrier Properties Measured by Fluorescence Spectroscopy and Sensory Analysis

ABSTRACT:  In this study, photooxidation of sour cream packaged in cups with different light barrier properties was investigated. The sour cream was light exposed for 36 h with a standard fluorescent light tube, simulating storage conditions in many Norwegian grocery stores. Three different cups were evaluated: a white cup, a cup with medium light barrier (LB), and a cup with high LB. The quality of the sour cream was evaluated by sensory analysis and front face fluorescence spectroscopy. The sour cream stored in white cups became very rancid during the light exposure, with a rancid flavor score of 7.8 on a scale from 1 to 9, where 9 is the highest intensity. Cups with high LB gave best protection against the light. The sensory assessors could not distinguish between sour cream stored in cups with high LB and sour cream stored in the dark. The rancid flavor intensity for the cups with medium LB was significantly different ( P  < 0.05) from both the white cup and the cup with high LB. The sensory flavor intensities indicated that with 36 h of light exposure, only a cup with high LB will protect the sour cream sufficiently. The fluorescence measurements corresponded well with the sensory analysis as the photosensitizers were somewhat degraded for sour cream stored in cups with medium LB and most degraded in the white cups. For the cups with high LB, the fluorescence peaks that originated from the photosensitizers were all intact.
PRACTICAL APPLICATION: Dairy products such as sour cream will develop off-odor and taste faults ("sunlight taste") in a few hours if exposed to sufficient fluorescent lightning in the grocery stores. A light barrier can be incorporated in the packaging material to protect the dairy products from the light. Our experiment showed that the incorporation of a black pigment into 1 of the 3 plastic layers in the cup for packaging of sour cream protected the sour cream from degradation when exposed to light.     

蓝莓-酸樱桃复合果醋的醋酸发酵工艺优化及抗氧化性研究

以蓝莓和酸樱桃为原料,制备蓝莓-酸樱桃复合果醋。以总酸、感官评分和花青素含量为评定指标,考察沪酿1.01（巴氏醋杆菌）（Acetobacter pasteurianus）接种量、酒精度、发酵温度和发酵时间对复合果醋品质的影响,并在单因素试验的基础上进行响应面试验,确定蓝莓-酸樱桃复合果醋醋酸发酵工艺,并对蓝莓-酸樱桃复合果醋的品质指标与抗氧化性进行评价。结果表明,最佳醋酸发酵工艺参数为：醋酸菌接种量10%,酒精度9%vol,发酵温度30 ℃,发酵时间8 d。在此优化条件下,复合果醋的总酸含量可达（5.01±0.17）g/100 mL,花青素含量为（102.26±0.89） mg/100 mL,感官评分为（87.00±0.42）分。抗氧化实验结果表明,最大DPPH自由基清除率可达（94.1±0.22）%,还原力（OD700 nm值）为（2.21±0.27）,表明其抗氧化性较好。     

酸性蛋白酶对酸肉发酵过程中菌群结构和风味品质的影响

为改善酸肉的生产工艺,研究商品化酸性蛋白酶对酸肉发酵过程中菌群结构、理化特性和风味品质的影响,利用高通量测序技术分析酸肉发酵过程中细菌和真菌群落组成。结果表明,蛋白酶的添加影响了酸肉发酵过程中乳杆菌、芽孢杆菌和葡萄球菌的相对丰度,降低了真菌的丰富度,并提高了酸肉中游离氨基酸总量。气相色谱-质谱分析结果表明,蛋白酶的添加提高了成熟酸肉中醇类、酸类、酯类、酮类和醛类物质的种类和含量。相关性分析结果显示葡萄球菌属与3-羟基-2-丁酮含量呈显著正相关,芽孢杆菌属与1-辛烯-3-醇含量呈显著正相关。感官评定结果表明,蛋白酶的添加提高了酸肉的滋味、气味和总体可接受度。因此,酸性蛋白酶对酸肉的菌群结构和风味品质具有重要影响,研究结果为改善酸肉生产工艺提供了理论依据。     

Sensory Optimization of a Mayonnaise-Type Spread Made with Rice Bran Oil and Soy Protein

ABSTRACT:  The optimum formulation for mayonnaise-type spreads containing rice bran oil (RBO) and soy protein concentrate (SPC) was determined based on sensory acceptability. RBO and SPC were used due to their health benefit claims such as lowering risk of heart disease. The effects of the proportions of high-impact ingredients (RBO, SPC, and water) on sensory acceptability of the spreads were determined. The 10 spread formulations, prepared following a 3-component constrained simplex lattice mixture design, were subjected to a consumer acceptance test to identify sensory attributes driving consumer acceptance and purchase intent. Predictive regression models were used to plot mixture response surfaces of the critical sensory attributes (taste, mouthfeel, and overall liking) that influenced purchase intent. Areas within the contour plots of these critical sensory attributes, having acceptability scores ≥ 68 ("moderately like" on the 100-mm bidirectional labeled affective magnitude scale) were chosen and superimposed to obtain a predicted optimum formulation range (37% to 43% RBO, 4% to 7% SPC, and 52% to 57% water). The formulation containing 37% RBO, 6% SPC, and 57% water, which was located within the optimum region, was selected as a base for further developing flavored (sour cream & onion, cheddar & sour cream, or Monterrey Jack dried cheese) products. All flavored spreads were significantly more acceptable than the plain formulation. Purchase intent of all flavored products also significantly increased once consumers had been given the information about potential health benefits associated with RBO and SPC in the spreads.     

Ropiness in the brine of sugar-salted herring

Ropiness formation in the brine of sugar-salted herring has been a considerable problem in the industry for years. This paper describes the results of bacteriological and chemical work on ropy brine and it presents ways of controlling this problem. The slime-producing bacteria, isolated from ropy brine, were Gram-negative, aerobic, non-motile, oxidase-positive rods. The strains were halophilic in nature; optimum growth was at 10% NaCl. Optimum growth temperature was 22°C and a neutral pH was preferred. Chemical tests showed that a polysaccharide composed of fructose units (levan) had formed in ropy brine and in the slime of bacteria cultivated from that brine. No polysaccharide was observed in unspoilt sugar brine. Addition of slime-producing bacteria to the brine of sugar-salted herring resulted in ropiness formation in 4–5 weeks at 10°C storage. Ropiness did not appear in barrels containing glucose instead of sucrose. It was found that the levan-producing strains were very sensitive to potassium sorbate. Results from salting experiments confirmed that sorbate was very effective in preventing ropiness. Furthermore, this preservative considerably increased the keeping quality of the herring as judged by organoleptic properties.     

臊子肉加工工艺优化

采用单因素试验和正交试验考察专用香辛料用量、醋用量和辣子面用量3个因素对臊子肉蛋白质含量及感官指标的影响。结果表明:最优工艺配方为100g原料肉、专用香辛料2g、醋84g、辣子面20g。按照该工艺配方生产出的臊子肉不仅感官品质好,而且蛋白质含量较高。     

Coagulation of buffaloe's milk and resultant Domiati cheese characteristics as affected by salting and replacement with sour cream butter milk

The action of rennet on buffaloe's milk replaced by 5, 10 or 15% of sour cream butter milk salted by either 6 or 10% before renneting or after the rennet action was studied as the non protein nitrogen (NPN) content. Buffaloe's milk without replacement of butter milk was taken as a control. Results revealed that addition of salt to milk before renneting inhibited the rennet action and consequently increased the coagulation time. The inhibition increased with the increase in the salting percent. In contrast, replacement of buffaloe's milk by sour cream butter milk enhanced the rennet action and shortened the coagulation time compared with the control. This effect was increased proportionally by the increase in sour cream butter milk. Enhanced protein breakdown, slightly higher accumulation of free fatty acids and good quality were observed in Domiati cheese treated with sour cream butter milk compared with the control. This effect was pronounced in case of 15% sour cream butter milk.     

葡萄糯米香醋发酵工艺的优化

该研究以葡萄和糯米为原料制备葡萄糯米香醋,以酒精度和感官评分为评价指标,采用正交试验设计优化其酒精发酵工艺条件;以总酸含量和感官评分为评价指标,优化其醋酸发酵工艺条件,并对该产品的挥发性成分、理化指标及感官品质进行分析。结果表明,最佳酒精发酵工艺条件为：葡萄与糯米质量比2∶1、初始糖度23%、葡萄酒高活性干酵母添加量0.22%、发酵温度28℃;最佳醋酸发酵工艺条件为：初始酒精度7%vol、醋酸菌（Acetobacter aceti）接种量5%、发酵温度30℃。在此优化条件下,葡萄糯米香醋共检出31种挥发性成分,其中醇类7种、醛类3种、酸类7种、酯类13种、苯类1种,总酸、总酯含量分别为4.70 g/100 m L、3.18 g/100 m L,葡萄糯米香醋呈红褐色、澄清透亮,口感醇厚、酸甜柔和,具有浓郁的果香和醋香。     

Antioxidant capacity and functionality of oleaster (Elaeagnus angustifolia L.) flour and crust in a new kind of fruity ice cream

In this study, the influence of milled crust and flour from oleaster (Elaeagnus angustifolia L.) separately added at different levels (1%, 2% and 3%) on the physical, chemical, sensory, colour properties and antioxidant properties of ice creams were investigated. The increment of crust and flour level caused an increase of dry matter, acidity, viscosity, first dripping, complete melting and vitamin C content. Flour increased overrun values in ice cream. Our results indicated that lyophilised oleaster extracts contain remarkable phenolic compounds. It was observed that lyophilised oleaster extracts exhibited a moderate in vitro antioxidant capacity. The addition of oleaster flour and crust positively affected sensory properties. The sensory results showed that ice cream containing 2% oleaster flour was the highest scored by the panellists. Oleaster flour and crust increased the sweetness of ice cream samples. These results showed that considerable nutritive and functional improvement could be attained by the addition of oleaster flour to ice cream formulation so that it could be used as natural antioxidants in ice cream as a source of flavour with complacency.     

红心火龙果醋饮料调配工艺研究

以红心火龙果发酵型果醋为原料,感官评分为评价指标,通过单因素及正交试验对其调配工艺进行优化。结果表明,红心火龙果醋饮料调配工艺配方确定为：红心火龙果原果醋添加量8%,白砂糖添加量3%,木糖醇添加量1%。在此工艺条件下,所得红心火龙果醋饮料感官评分为86分,总酸含量为5.6 g/L,可溶性固形物含量为5.4%。红心火龙果醋饮料呈淡琥珀色、澄清透明、无肉眼可见沉淀及悬浮物、有清淡的火龙果香味、酸甜爽口、酸味柔和、风味独特、无异味。     

Effects of breed and marination on the sensory attributes of pork from Large White and Hampshire-sired pigs

The effects of breed and marination were tested for their effects on meat pH, water holding (marinade uptake and losses) and eating quality (tenderness, juiciness and flavour).

Loins were removed from one side of 20 Large White-sired and 20 Hampshire-sired pigs after slaughter, cut into four pieces and injected to 112% of their initial weight with water, a polyphosphate-containing marinade (pH 7.7) or a high pH marinade (pH 10.3). An uninjected piece of loin served as control. Samples were left overnight and then frozen before being thawed, cooked and assessed by a trained ten member sensory panel using 1–8 category scales.

Hampshires had higher intramuscular fat (0.95%) than Large Whites (0.62%) but otherwise the effects of breed were small compared with marination. Both marinades significantly increased meat pH from 5.5 (control) by 0.2 U, significantly reduced the cooking loss and increased the meat yield from about 80% to 90%. Water-injected samples lost large amounts of added water as drip after thawing and had a yield (76%) similar to the control. Marinaded samples retained more water post-cooking. Both marinades significantly increased tenderness (p < 0.001) and juiciness (p < 0.001) by about 1.0 U compared with the control (4.4 for tenderness and 4.2 for juiciness). Pork flavour, however, was significantly reduced (p < 0.001) and abnormal flavour was significantly increased (p < 0.001) by marination. Tenderness was positively correlated with pH after injection (0.83) and yield (0.75); juiciness was also positively correlated with pH after injection (0.78) and yield (0.87).

The absence of any significant difference in eating quality between control and water-injected samples, and the relatively large effects of marination, suggest that retained water (after cooking) is crucial in determining perceived tenderness and juiciness in pork.     

低盐红油萝卜的研制

目的开发低盐红油萝卜新产品,并通过试验确定其最佳配方。方法以腌制白萝卜为主要原料,以酸味剂、味精、白糖和红油为考察因素,通过单因素实验和正交试验,研究各因素对低盐红油萝卜产品感官品质的影响。结果制作低盐红油萝卜的最优配方为酸味剂添加量为2.3%(食醋添加量2%,柠檬酸添加量0.3%),味精添加量为0.5%,红油添加量为3%,白糖添加量为5%。在此最佳配方下生产的产品,感官评分为87.7分,食盐含量4.23%,亚硝酸盐含量15.3 mg/kg,大肠菌群24.7个/100 g,细菌总数5667个/g,无致病菌检出。结论该配方可以开发出低盐红油萝卜产品,在此工艺条件下制得的低盐红油萝卜产品色泽淡红,组织脆嫩,辣度适中,酸甜适口,鲜味突出。     

葵花籽油体富集物添加量对低脂冰淇淋浆料及产品品质的影响

为了探究葵花籽油体富集物在冰淇淋中应用的可行性,以葵花籽油体富集物作为脂肪来源制备低脂冰淇淋,在无均质条件下研究葵花籽油体富集物添加量对低脂冰淇淋浆料和产品品质的影响。结果表明：冰淇淋浆料的黏度、储能模量和损耗模量都随葵花籽油体富集物添加量的增加而增大,当葵花籽油体富集物添加量为3.5%～4.0%时黏度与对照组相当;浆料中不易流动水和结合水的比例随着葵花籽油体富集物添加量的增加逐渐增大,在4.0%时达到最大;冰淇淋的膨胀率和抗融率随着葵花籽油体富集物添加量的增加先增大后减小;添加葵花籽油体富集物的冰淇淋色泽较差;冰淇淋的硬度和咀嚼性变化规律一致,都是随着葵花籽油体富集物添加量的增大呈现先减小后增大的趋势,弹性变化则相反;冰淇淋黏附性随着葵花籽油体富集物添加量的增加而升高;葵花籽油体富集物添加量为2.5%时冰淇淋感官评分最高。合适的葵花籽油体富集物添加量可以起到与棕榈油相似的效果,因此葵花籽油体富集物可以应用在冰淇淋中。     

基于质构评价的糖醋白姜贮藏时间预测

铜陵白姜质地脆嫩，用食糖和食醋腌制而成的糖醋白姜是当地的特色产品。在腌渍中，脆嫩的质地易变韧而失去商品价值。为了明确糖醋白姜保持良好质地的贮藏时间，分析了不同贮藏温度（25、35、45、55 ℃）下糖醋白姜感官品质和咀嚼指数的变化规律；根据Arrhenius方程，得到咀嚼指数与贮藏时间之间的动力学模型，以咀嚼指数为指标建立了贮藏时间预测模型。结果表明，在贮藏过程中糖醋白姜的整体感观评分呈下降趋势，其中，脆嫩度下降，咀嚼中的韧劲感提高，贮藏温度越高，咀嚼的脆嫩感降低得越快；在25～55 ℃的贮藏温度下，咀嚼指数随着贮藏时间的延长而下降，贮藏温度越高，下降幅度越大；咀嚼指数随时间的变化遵循一级反应动力学模型，据此得到糖醋白姜贮藏时间预测模型为y=41.694e?0.024x（y表示咀嚼指数，x表示贮藏时间，R2=0.9913），基于质构评价的糖醋白姜品质变化动力学模型具有较高的拟合精度（R2>0.95）；根据不同贮藏温度感官评分60分时对应咀嚼指数的平均值，确定糖醋白姜的咀嚼指数终点值为100.9，以此测定的贮藏时间预测值与实测值的相对误差小于6%，准确性较高。该模型可应用于基于质构指标的糖醋白姜贮藏时间预测。