涂膜制作低盐干腌火腿的研究

传统干腌火腿的盐分含量为9％～12％，生产周期长达6个月以上。本项研究，将新鲜猪腿肉去皮、去骨和切块后进行干腌，腌肉块经防腐涂膜处理后进行干燥和发酵，可以制成块状低盐干腌火腿，盐分含量降低到5％～7％，生产周期缩短到1个月，与传统工艺制作的干腌火腿的风味和口感相同。     

Acid/Base Status of Stress Susceptible Pigs Affects Cured Ham Quality

Twenty-four halothane positive (HP) pigs received ammonium chloride (8 g/L), sodium bicarbonate (12.6 g/L) or water (HP control) ad libitum for 4 days and were then slaughtered. Hams from HP animals were pale, soft and exudative (PSE) and of inferior processing quality. Ammonium chloride induced a metabolic acidosis which further impaired cured ham quality (greater thaw purge, lower juiciness scores and less uniform slice appearance than comparable hams from control or bicarbonate treated HP hogs). Blood pH, carbonate and chloride concentration (day 3) were related to cured ham quality, indicating that acid-base balance may influence subsequent meat quality. Use of an alkaline salt provided little protection against PSE.     

Feasibility assessment of vacuum cooling of cooked pork ham with water compared to that without water and with air blast cooling

To optimise vacuum cooling for application in the meat industry, an improved cooling method, i.e. vacuum cooling with water (or immersion vacuum cooling), was designed to cool cooked pork ham (2.2 ± 0.2 kg). It was found that the cooling time of vacuum cooling with water was significantly shorter than that of traditional air blast cooling (P < 0.05). For the cooling loss, vacuum cooling with water was significantly lower (6.99%) than that of vacuum cooling without water (13.71%) (P < 0.05). Significant differences in physical and chemical attributes were also observed for ham processed by vacuum cooling with and without water (P < 0.05). Therefore, for a certain size of pork ham, vacuum cooling with water could be an effective method to meet safety guidelines and obtain compatible quality attributes with air blast cooling.     

N-Nitrosodibutylamine and other Volatile Nitrosamines in Cured Meat Packaged in Rubber Nettings

Results from investigations of N-nitroso-n-dibutylamine (NDBA) in cured meat are compared from investigations in Denmark, the USA and Canada. NDBA was detected in very few samples and in quantities that were very low. Cured meats packaged in plastic wrappings or cotton nettings did not contain any NDBA. All cured meat packaged in elastic rubber nettings on the Danish market cannot contain more than 0.5 ppb NDBA.     

腊肉的加工工艺

主要介绍腊肉的加工方法以及加工要点.     

Time course of peptide fingerprints in semimembranosus and biceps femoris muscles during Bayonne ham processing

The aim of this work was to define reliable markers of muscle and processing time in dry-cured ham using a rapid, precise semi quantitative method for the protein fraction soluble in low ionic strength buffer. For this purpose protein labchip Agilent was used to separate proteins and peptides and accurately determine their molecular weights and concentrations electrophoretically. In this way the protein fingerprinting of dry-cured ham at different process times was characterised, together with targets and products of proteolysis. In addition, the comparison of all the electrophoregrams indicated muscle and dry-curing process markers.     

接种复合菌的干腌美国红鱼在加工过程中的品质变化

该文以植物乳杆菌和酵母菌作为复合发酵剂部分替代钠盐以制备低盐的干腌美国红鱼。通过测定其水分活度和水分含量、色差、质构及pH值、蛋白质氧化性的指标,研究复合菌对美国红鱼在干腌过程中对其氧化现象的抑制作用。研究结果表明：同时加入植物乳杆菌和酵母菌外源微生物的样品水分活度和pH值与对照组无显著性差异（P>0.05）,对照组和混菌组水分含量分别是35.21%（m/m）和35.35%（m/m）,水分含量与对照组有显著性差异（P<0.05）,说明用复合菌替代部分钠盐不影响干腌红鱼的保藏性。复合菌使干腌红鱼分别在亮度（L*）低于对照组（P<0.05）、黄度（b*）高于对照组（P<0.05）,表明复合菌有助于维持干腌红鱼肉色稳定性。此外,在加工过程中,接种复合菌可以改善干腌鱼的质构特性。复合菌研究表明,分析干腌红鱼蛋白氧化导致的蛋白羰基含量显著增长,巯基含量显著下降,羰基含量显著上升现象。该结果显示,生产时可添加复合菌代替部分钠盐,可以显著减少加工过程中的蛋白氧化现象。此外,与单独加入酵母菌的红鱼相比,单独加入植物乳杆菌的红鱼抑制蛋白氧化效果更好。     

发酵火腿的生食安全性与分类特征

火腿经过发酵,可以杀死腿肉中的寄生虫和致病菌,腿肉蛋白质发生变性和水解。发酵火腿可以生食并具有较低的食盐含量。发酵火腿应在控温、控湿和良好的卫生条件下生产。     

Influence of pre-cure freezing of Iberian ham on proteolytic changes throughout the ripening process

This work aimed to investigate the effect of pre-cure freezing Iberian hams on proteolysis phenomena throughout the ripening process. Non-protein nitrogen (NPN), peptide nitrogen (PN) and amino acid nitrogen (AN) as well as amino acid and dipeptide evolution followed the same trend in both refrigerated (R) and pre-cure frozen (F) Iberian hams during processing. At the different stages of ripening, there were no differences in the content of NPN and AN while F dry-cured hams had higher levels of PN than R hams at the final step. This seemed to be more related to the salt content (lower in F than in R hams) than to the pre-cure freezing treatment. Most amino acids and dipeptides detected showed higher concentrations in F than in R Iberian hams at the green stage, being rather similar at the intermediate phases. At the final stage, the effects of pre-cure freezing of Iberian hams were not well defined, higher levels of some amino acids and dipeptides were found in R than in F Iberian hams whereas other amino acids were lower in R than in F hams.