风味蟹肉软罐头护色工艺优化

以小规格蟹的蟹肉为原料,研究了风味蟹肉软罐头制备过程中的护色工艺优化.以L*值、b*值及相对褐变程度作为评价指标,通过单因素试验和正交试验设计研究4种护色剂(柠檬酸、D-异抗坏血酸钠、抗坏血酸和植酸)的浓度、护色时间对风味蟹肉高温灭菌后色泽的影响.最终得到风味蟹肉的最佳护色工艺为:0.4％柠檬酸和0.2％D-异抗坏血酸...     

Partial replacement of sodium chloride with potassium chloride in marinated rabbit meat

This study was aimed at evaluating the consequences of sodium chloride reduction by potassium chloride up to 50% on technological, sensorial and microbiological traits of marinated rabbit meat. In total, 226 rabbit loin meat samples were obtained and subjected to vacuum tumbling using solutions with different NaCl/KCl ratios. Replacing of sodium chloride up to 30% by potassium chloride did not change microbiological traits (total aerobic mesophilic and lactic acid bacteria maximum cell loads), sensorial acceptability (perceived saltiness and overall liking) and technological traits (pH, colour, texture, cooking loss and yield). Otherwise, reduction in sodium chloride to 50% significantly decreased perceived saltiness (4.15 vs. 4.73; P < 0.05) and reduced microbial shelf life by 1 day when compared to control, even if there was still no effect on technological traits. In conclusion, it is feasible imparting an added value for processed rabbit meat products by reduction in sodium content that could increase market interest.     

美洲雁肉常温真空复合保鲜效果的研究

采用醋酸、姜汁和抗坏血酸(VC)3种保鲜剂处理鲜雁肉,再结合真空包装,研究常温下各种保鲜剂对雁肉的保鲜效果,并以不同配比的保鲜剂进行组合,进行正交实验,以肉样感官评价、TVB-N含量和菌落总数为评价指标,优选出保鲜效果最佳的复合保鲜剂。实验结果表明:复合保鲜剂使用效果优于单一保鲜剂,0.4%醋酸+6%姜汁+1%抗坏血酸的复合保鲜剂保鲜效果最佳,常温下可使美洲雁肉保质期达11d。     

Stability of antioxidant peptides from duck meat after post‐mortem ageing

The stability of antioxidant peptides from aged duck meat during processing and simulated gastrointestinal digestion was investigated. The antioxidant peptides preserved a high stability in the presence of diverse NaCl or upon various time heating. The antioxidant activities were strengthened by the addition of 4–8% glucose or by heating at 100 °C, whereas they were lost under alkaline conditions. During in vitro digestion, the antioxidant activities increased with pepsin treatment but then decreased following trypsin digestion. Pepsin hydrolysed peptides into short fragments and results in the increased exposure of internal hydrophobic amino acids. With further treatment by trypsin, peptides can be hydrolysed completely and more free amino acids were released, leading to the decline in surface hydrophobicity. These variations might be responsible for the change in antioxidant activity during in vitro digestion. The antioxidant peptides from aged duck with high stability can be used as functional food ingredients to improve human health.     

Dietary administration of ewe diets with a distillate from rosemary leaves (Rosmarinus officinalis L.): Influence on lamb meat quality

The effect of including distilled rosemary leaf in the diet of pregnant ewes on subsequent lamb meat quality was studied. Thirty-six Segureña ewes were randomly assigned to three homogeneous groups. One group was fed a basal diet (BD) as control while the diet of the other two groups was modified by substituting 10% (R₁) and 20% (R₂) of the BD with a pellet made from 50% barley and 50% of distilled rosemary leaves (DRL). Meat spoilage (TVC, PSY and MYC), TBARS, CIELab coordinates and the sensory characteristics contribution of fresh lamb meat packed in MAP (70% O₂:30% CO₂) were analyzed on days 0, 7, 14 and 21. In general, R₁ and R₂ had higher a^* values, better scores for meat and fat colour (P < 0.05) and lower TBARS and rancid odour (P < 0.05), than the control samples. The total viable count was lower in meat DRL. No statistically significant differences were detected between the two treatments (10–20% DRL).     

A critical examination of some experimental variables in the 2-thiobarbituric acid (TBA) test for lipid oxidation in meat products

By comparison of various procedures for the determination of TBARS (2-thiobarbituric-acid-reactive substances) in non-cured meat samples, it was found that a direct extraction procedure with trichloroacetic acid gave significantly higher reaction yields than a rapid Kjeltec steam distillation procedure (50 ml distillate in 2.5 min). When optimizing the distillation procedure with regard to distillation principle (heating by thermal conductivity or steam injection) and rate, the reaction yield was more affected by changes in distillation principle than by changes in distillation rate. Simple distillation (conduction heating) yielded significantly higher TBA values than steam distillation at the same distillation rate. The reproducibility of the distillation procedure was found to be about 5–10 times poorer than of the extraction procedure and, because of the high reaction yields and robustness of the extraction procedure, the use of the extraction procedure is recommended with food matrices such as non-cured meat samples with less than 14–18% fat and no artificial colorants.     

Anionic Trypsins from Crayfish Hepatopancreas: Effects on Protein Degradation of Tail Meat

Four anionic trypsins, tentatively labeled trypsin A, B, C, and D, isolated from crayfish hepatopancreas, had high casein activity between pH 5.5 and 10.0. Temperature optima for hydrolysis of casein were 45°C for A and B, and 50°C for C and D. Trypsin D had the highest substrate turnover number (V_max) for casein reaction compared with the other trypsins at pH 6.8. Trypsins A and D had higher activities against myofibrilla and sarcoplasmic proteins from crayfish tail meat than did B and C. Results suggested that trypsins A and D are important in development of mushiness in crayfish tail meat compared with other trypsins present.     

Characterization of Minced Meat Extracted from Blue Crab Picking Plant By-Products

Blue crab meat was mechanically extracted from picking-room byproducts to produce the following minced meat yields: 3.18%, white; 10.71%, mixed; 6.39%, claw, and 2.62%, leg. Each meat had distinct visual, textural, and flavor attributes. Aerobic plate counts of unpasteurized minced meat ranged from 10⁵ to 10⁷ CFU/g. Extraction within 1.5 hours of picking or icing of by-products prior to mechanical extraction stabilized microbial levels. Meat pasteurized at 80.6°C darkened or blued significantly less than meat processed at 83.3°C. Addition of citric acid-phosphate buffer to meat pasteurized at 80.6°C further reduced darkening of meats.     

European intercomparison on electron spin resonance identification of irradiated foodstuffs

The results of a co-trial organized by the Community Bureau of Reference on the use of Electron Spin Resonance spectroscopy for the identification of irradiated food in 21 laboratories are presented. The trial was qualitative on beef and trout bones, sardine scales, pistachio nut shells, dried grapes, and papaya, and quantitative on poultry bones. There was no difficulty in identifying irradiated meat bones, dried grapes, and papaya. In the case of fish bones there is a need for further kinetic study on different species. Identification of irradiation in pistachio nuts is more complicated and additional research is needed before further trials. All laboratories were able to distinguish between chicken bones irradiated at 1 to 3 kGy or 7 to 10 kGy although there was a partial overlap between the results.     

发酵马肉中乳酸菌的分离筛选研究

从发酵马肉中分离纯化出7株乳酸菌,对它们的主要发酵特性如耐盐、耐硝,产黏液、产气等进行了测定,并比较了它们在不同温度下的生长和产酸情况以及发酵过程中的pH值的变化,发现其中3株乳酸菌具有较好的发酵特性,如生长快、产酸快,能够耐6%NaCl、耐150 mg/kg NaNO2,不产气、不产氨,H2O2实验、H2S实验、V-P反应均为阴性等,符合发酵肉制品生产菌种的要求.