干腌火腿脂类的研究现状

脂类物质在火腿成熟过程中有非常重要的作用,是干腌火腿主要的风味前体物质。火腿中的脂类物质主要是甘油酯和磷脂、磷脂,对风味物质形成的贡献最突出。腌制过程中,脂类物质主要发生了水解、氧化。本文综合论述了脂类物质在火腿加工过程中所发生的变化及变化机制,并讨论了这些变化在火腿风味形成中的作用。     

干腌火腿加工中脂类物质变化研究

干腌火腿加工中，脂类物质经过降解(脂解和氧化)作用，形成了大量的挥发性风味物质，这些物质对干腌火腿的最终风味起了决定性的作用。综述了干腌火腿加工中脂类物质的降解过程。     

肉与肉制品风味形成的研究进展

熟肉制品的特征风味来源于热处理过程中发生的热诱导反应,其中主要是美拉德反应和脂类的热降解瓜在,这两种反应的反应途径较复杂,均可产生大量易挥发的化合物,其中杂环化合物,尤其是含硫的杂环化合物是美拉德反应中形成烤肉香味和煮肉香味的重要风味化合物,脂类降解能产生赋予熟肉脂肪香气和不同种类畜禽肉特征香气的化合物,美拉德反应期间所形成的化合物可能也会同其它的肉类化合物发生反应,增加了香气化合物形成的复杂性,例如脂类氧化期间所形成的醛和羧基化合物很容易与美拉德反应的中间产物发生作用,该作用可使香气化合物增加,但同时也改变了形成肉类风味化合物的总体组成。该作用还控制了含硫化合物以及其它的美拉德反应易挥发物质的形成,并使其熟肉特征风味维持在最适宜的水平上。     

中国传统火腿风味分析研究进展

从中国传统火腿加工过程中的生化变化入手,结合火腿风味物质的形成过程,总结了火腿风味化合物的组成以及火腿风味的测定方法,为火腿的加工工艺控制及研究提供理论依据。     

脂肪变化和美拉德反应与肉品风味质量的关系

本文综述了肌内脂肪在肉品风味中的作用.首先阐述了肌肉的脂肪组成及引起其变化的主要因素,随后分两部分分别综述了肌肉中脂肪的水解和氧化变化,最后主要阐明了脂肪氧化产物与美拉德反应之间的相互作用,重点指出了熟肉制品中典型风味化合物及蒸煮后肉品氧化中风味化合物的形成.肌肉中的磷脂是脂肪水解和氧化的主要底物.人们对肌肉组织中的脂肪水解了解得一直很少,其在氧化中的作用也有待于探明.尽管人们已经描述过很多脂肪氧化的机理,但在肌内脂肪氧化中一直未能建立氧化模型.脂肪通过其氧化产物影响美拉德反应,该反应会减少杂环化合物的形成,尤其是含硫杂环化合物的形成.熟肉的香气成分取决于脂肪氧化与来自美拉德反应产生的化合物之间的平衡.本文在结论中还指出了目前仍需要进一步研究的内容.     

海洋磷脂氧化及其对食品风味的影响

海洋磷脂因其独特的结构和生物活性引起人们的关注。海洋磷脂广泛存在于水产品中,由于多不饱和脂肪酸含量高,在加工和储运过程中易发生脂质氧化反应、非酶促褐变反应等,这一系列反应生成的产物一方面引起水产品的酸败,降低食品的品质;另一方面适当的磷脂氧化,提供了脂质来源的风味前体物质,是水产品特征香气物质产生的关键。在水产品的挥发性风味物质中已鉴定出醇、醛、2-戊基呋喃、苯甲醛等特征香气成分,此类风味物质的形成来源于脂质氧化以及非酶褐变等反应,受这些反应共同作用的影响,形成了食品独特诱人的品质和风味。该文综述了海洋磷脂氧化及其在食品风味中的作用,为深入理解食品特征风味物质形成提供参考。     

传统干腌火腿脂类水解氧化机理的研究

主要介绍在传统干腌火腿加工中脂类物质的变化，影响脂类变化的因素及其降解产物对产品品质的影响，比较全面地反映了当前人们对传统干腌火腿加工中脂类水解氧化机理的认识。     

脂肪相关酶类在干腌肉制品风味形成过程中的作用

风味是消费者选择食品的主要依据之一。风味的形成是个复杂的生化反应过程,对其的研究至今依旧还未完全明晰。干腌肉制品由于其具有独特的风味而受到消费者的广泛欢迎,经过复杂的加工过程形成了其特征性风味物质,其中较大部分是由脂类水解、氧化而来,随之还会通过美拉德等反应形成各种风味物质。脂类物质是风味物质形成的前体物质,脂质的酶控反应是干腌肉制品风味物质产生的决定性因素。本文对国内外各类干腌肉制品中脂肪水解酶、磷脂酶和脂肪氧合酶在加工过程中的活性变化及其在干腌肉制品中的作用进行了归纳;概述了这几类酶对不同种类风味物质及产品感官品质的影响;综述了加工因素介导这些酶类对风味物质形成的调控作用。为科学认识干腌肉制品风味物质的形成机理、传统工艺改进和参数优化提供参考。     

金华火腿生产过程中脂质水解特性研究

60只重量为6.2～6.9 kg的原料腿按传统工艺加工金华火腿.分别于原料腿、盐后、晒后、成熟中期、成熟结束、后熟1和后熟2七个工艺点随机取5只腿的股二头肌为样品,分析总脂肪、甘油酯、磷酯、游离脂肪酸和相关指标的变化.结果显示：生产过程中磷脂的变化较大,约有66.67%的磷酯发生了水解.相关性分析发现：磷酯和甘油酯含量与游离脂肪酸含量之间的R2分别为0.91和0.67,磷酯是脂类物质中最主要的风味前体物质.生产过程中总游离脂肪酸含量呈上升趋势,饱和脂肪酸和单不饱和脂肪酸的相对含量提高,多不饱和脂肪酸的相对含量下降,其中亚油酸的含量下降最明显,为4.48%.亚油酸可能是氧化形成风味成分的主要脂肪酸.     

中西方干腌火腿风味成分比较及形成机理分析

风味对干腌火腿的质量十分重要 ,它与生产所用原料、生产工艺和参数密切相关。文中比较了金华火腿与欧洲几种著名火腿的风味成分 ,结果显示 ,中西方火腿的风味组成相似 ,醇、醛、酮、酯、含硫化合物、含氮化合物、烷、烯烃类物质是干腌火腿的共有成分 ,但各成分的含量在中西方火腿中存在明显差异 ,金华火腿中烷、烯烃含量最高 ,欧洲的几种火腿中醛类物质含量最高。文中同时分析了干腌火腿中各风味成分的特征和可能的形成机理。     

Lipid and protein oxidation and sensory properties of vacuum-packaged dry-cured ham subjected to high hydrostatic pressure

The effect of HHP treatment (600 MPa) on the oxidative stability of lipids and proteins of vacuum-packaged Iberian dry-cured ham and the impact on the sensory characteristics of the product was investigated. In order to assess how different commercial presentations are affected by HHP treatment, three different presentations of vacuum-packaged Iberian dry-cured ham were considered, namely, (i) intact format (IF) corresponding to non-sliced vacuum-packaged dry-cured ham, (ii) conventional-sliced format (CSF) corresponding to dry-cured ham slices placed stretched out in the package and (iii) alternative-sliced format (ASF) corresponding to dry-cured ham slices piled up horizontally. The oxidation of dry-cured ham lipids and proteins was enhanced by HHP-treatment with the presentation being highly influential on these oxidative reactions. Pre-slicing dry-cured ham results in a more susceptible product to oxidative reactions during pressurisation and subsequent refrigerated storage. Possible mechanisms, by which HHP-induced oxidative reactions would affect particular sensory traits in vacuum-packaged Iberian dry-cured ham such as colour, texture and flavour attributes, are discussed.     

游离脂肪酸在几种常见食品风味形成中的作用

游离脂肪酸在许多食品的风味形成中起着十分重要的作用,一方面是直接作为风味化合物起作用;另一方面游离脂肪酸作为风味前体物,对食品特有风味的形成做出贡献。但是,在不同的食品风味形成的过程中,游离脂肪酸的作用是不同的。文章综合论述了它在腊肉、香肠、火腿、奶酪、茶叶及啤酒等常见食品的风味形成过程中的作用。     

Changes in the volatile flavour components of Jinhua ham during the traditional ageing process

Changes in volatile flavour compounds of Jinhua ham were studied during the traditional ageing process of sun‐drying, loft‐ageing and post‐ageing. About seventy‐eight volatile compounds were tentatively identified, including aldehydes (ten to fifteen), carboxylic acids (eight to ten), alcohols (thirteen to fourteen), ketones (eight), esters (eight to ten), aromatic hydrocarbons (five), sulphur‐containing compounds (two to three) and pyrazines (zero to four) which were the main components. The percentage content of aldehydes and ketones reduced over time as the temperature rose with each stage of the process, whereas alcohols, carboxylic acids, esters, pyrazines and sulphur‐containing compounds increased gradually. Jinhua ham's high‐temperature maturating process (40 days at 30–37 °C) made the percentage content of carboxylic acids arising from Maillard reactions markedly increase (from sun‐dried ham 8.45% to fully aged ham 19.23%). This was the most obvious difference between Jinhua ham and the Mediterranean dry‐cured hams, and was the main factor leading to the unique flavour of Jinhua ham.     

Chemical and structural changes in lipids during the ripening of Teruel dry-cured ham

The aim of this paper is to investigate the chemical and microstructural changes in intramuscular and subcutaneous fat during the processing of Teruel dry-cured ham by gas chromatography and electron microscopy techniques. This paper will contribute to the specific characterisation of a product included in the European Union list of special quality products, and provides a new perspective for the identification of changes related to flavour development. There seems to be a relationship between the degradation of phospholipids and the increase in the free fatty acid content, especially polyunsaturated fatty acids. The microstructural changes of the adipose tissue during the process would explain the availability of the fat to the lipolitic enzymes and the contribution to the typical flavour and taste of cured ham.     

金华火腿特征风味物质研究进展

金华火腿是我国传统的干腌火腿,以其特殊的风味而著称。通过对金华火腿及其它干腌火腿主要风味物质、形成机理、提取及鉴定方法等研究现状的综述,表明对金华火腿特征风味物质的深入研究有利于了解风味物质形成规律,为金华火腿加工工艺控制及火腿调味料开发应用提供理论基础。     

Effect of Penicillium chrysogenum and Debaryomyces hansenii on the volatile compounds during controlled ripening of pork loins

During ripening of meat products such as dry-cured ham, the moulds and yeasts that proliferate on the surface may contribute to flavour development. However, their contribution to volatile components of dry-cured meat products is not known. One strain each of Penicillium chrysogenum and Debaryomyces hansenii, selected from dry-cured ham by their proteolytic activity, were tested to determine their effect on the volatile compounds during ripening. Sterile pork loins were inoculated and ripened for 106 days. Volatile compounds collected with a Solid Phase Micro-Extraction (SPME) fibre were analysed by GC/MS. Inoculation of pork loins with P. chrysogenum lead to a decrease in compounds attributed to lipid oxidation and to an increase of compounds derived from free amino acids. Inoculation with D. hansenii seemed to favour the formation of complex alcohols.     

Contribution of a selected fungal population to proteolysis on dry-cured ham

The proteolytic changes taking place in dry-cured hams lead to increases in free amino acids. Such free amino acids not only contribute to flavour, but also serve as precursors of volatile compounds. Several months of ripening time are required to allow the particular flavour to develop. The fungal population allowed to grow on the surface of some types of dry-cured could play a key role on proteolysis, as it has been shown for dry-cured sausages. The purpose of this work was to study the possible contribution of fungi to proteolysis in dry-cured ham. For this, a strain each of non-toxigenic Penicillium chrysogenum (Pg222) and Debaryomyces hansenii (Dh345), selected for their proteolytic activity on myofibrillar proteins, were inoculated as starter cultures. Changes in the high ionic strength-soluble proteins of an external muscle (adductor) revealed in only 6 months higher proteolysis in the inoculated hams when compared to non-inoculated control hams. Proteolytic strains among the wild fungal population on non-inoculated control hams prevented from obtaining similar differences at the end of processing. However, inoculation with Pg222 and Dh345 led to higher levels for most free amino acids at the external muscle in fully dry-cured hams. In addition, the concentration for some of the more polar free amino acids (i.e. Asp, Glu, Ser and Gln) in inoculated hams was higher at external than at internal (biceps femoris) muscles. These promising results deserve further studies to know the impact of a selected fungal population on the volatile compounds and sensory properties of dry-cured ham.     

Lipolysis in intramuscular lipids during processing of traditional Xuanwei ham

Lipolysis in intramuscular lipids during the processing of Chinese Xuanwei ham has been studied by analyzing the changes of glycerides, phospholipids and free fatty acids in biceps femoris muscle. Results showed that the glycerides accounted for 73.2% of total lipid content in fresh ham, the phospholipids represented 25.3% and the free fatty acids 2.3% of the total lipid content, respectively. A rapid lipolysis of phospholipids occurred during the first 4 months of processing and slowed down during the rest period. A preferential hydrolysis for palmitic, linoleic and arachidonic acids in phospholipid fraction was observed. Glycerides only changed a little throughout the process, while an increase of free fatty acids during processing was observed. The results suggest that phospholipids are the main substrate of lipolysis in the intramuscular lipids of Chinese Xuanwei ham.     

Volatile compounds of dry-cured Iberian ham as affected by the length of the curing process

Volatile compounds from 10 dry-cured Iberian hams ripened for two different processing times, a prolonged traditional one (600 days) and a shortened process (420 days), were analysed by purge and trap coupled to gas chromatography-mass spectroscopy. Eighty-three compounds were identified which agreed with the major classes found in other ham types. The amount of methyl branched alkanes was much higher than in other dry-cured ham types, probably due to the feeding regime. The percentages of 2- and 3-methylbutanal were higher (p<0.0001 and p<0.0003, respectively) in the longer aged hams, whereas the amounts of some compounds from lipid oxidation decreased from 420 to 600 days aging. In agreement with these observations, 600-day hams had higher scores for those odour and flavour traits usually considered to be positive attributes and lower scores for rancidity. A positive and significant correlation between 2-methyl butanal and cured flavour was found.