Characterization of traditional Istrian dry-cured ham by means of physical and chemical analyses and volatile compounds

The aroma-active compounds of Istrian dry-cured ham were investigated by using headspace-solid phase microextraction and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated by measuring physical and chemical characteristics: moisture, protein, fat, ash and NaCl content, a(w) value; colour: L*, a*, b* and oxidation of fat: TBARS test. About 50 volatile compounds were identified and quantified which belonged to several classes of chemical: 5 alcohols, 8 aldehydes, 7 alkanes, 1 ketone, 2 esters, 9 monoterpenes and 15 sesquiterpenes. Except volatile compounds derived from lipolysis and proteolysis the most abundant constituents were terpenes (62.97; 41.43%) that originate from spices added in the salting phase of the production process.     

The effects of castration on the eating quality of dry-cured ham

The influence of the castration of entire male pigs on the eating quality of dry-cured ham was evaluated. Forty-eight dry-cured hams (435-day aged) were studied from entire and castrated males of two different crossbreeds. The proximate composition of the meat and the androstenone, indole and skatole fat content were determined. The entire hams were classified according to the androstenone and skatole content. Sensory analysis was carried out by a trained panel, evaluating marbling, juiciness, saltiness, graininess, toughness, overall flavour, boar odour and boar flavour. Also carried out was a preference and acceptability paired test by consumers. Castration increased meat fattening and reduced the androstenone and skatole levels of the fat. Significant differences (P<0.05) were found between entires and castrates for the average values given in all the sensory attributes studied. The dry-cured ham from castrates was scored as more flavoured, more marbled and softer. It was also perceived as less grainy, less salty and having less boar odour and flavour. The sensory perception of boar odour was more intense than that of flavour in dry-cured ham and appears to be related to the level of androstenone and skatole in fat. Dry-cured ham from castrated males was also more accepted and more preferred by consumers, especially women and habitual consumers. Castration of male pigs contributes to improve the quality of dry-cured ham. The rejection caused by boar odour and flavour is reduced, improving the overall flavour, texture and juiciness. In addition, the saltiness is less pronounced in ham from castrates. For this reason, the production of high quality dry-cured ham will have to shoulder the extra costs associated with processing castrated pigs.     

Relations between compositional traits and sensory qualities of French dry-cured ham

The left hams of 20 pig carcasses were processed by dry-curing for either 179 (n = 10) or 273 days (n = 10). The Biceps femoris was taken at the end of the processing and submitted to chemical and sensory analyses. The following chemical traits were determined: pH, moisture, salt content, fatty acid content and composition of lipid classes (triglycerides, phospholipids, free fatty acids), nitrogen fractions (soluble and insoluble protein, non-protein nitrogen, free amino acids) and volatile compounds. Sensory analysis was performed by a panel of 12 trained members, who scored texture traits (firmness, dryness, fibrousness, mellowness), taste (salty, acid), intensity of aromas (typical of dry ham, fresh meat, fat, cured meat, rancid, metal), persistence of dry ham aroma, persistence of taste after deglutition, persistence of astringency, persistence of metallic taste. The sensory qualities of dry-cured ham showed noticeable changes between days 179 and 273. Firmness, dryness and intensities of aromas typical of dry-cured ham and cured meat were enhanced with time. Neither pH, moisture nor salt content played a noticeable role in determining the sensory quality of dry-cured ham. Among the volatile compounds, the levels of several ketones and 1-butanol were significantly correlated with the aromas of dry ham and cured meat, while rancid aroma was related to aldehydes, ethylacetate, 2,3-pentanedione and nonane. Therefore, the aromas of dry ham and cured meat appeared to be determined mainly by the products of lipid oxidation. However, they were related also to unidentified volatile compounds, whose identification would be of particular interest.     

Evaluation and selection of yeasts isolated from dry-cured Iberian ham by their volatile compound production

One hundred and seventeen yeast strains isolated from dry-cured Iberian ham from the four different protected designations of origin of Spain were investigated for their volatile compound production. The yeast strains were grouped into the two main yeast species usually found in this product (Debaryomyces hansenii and Candida zeylanoides) and 10 different biotypes by restriction mitochondrial DNA analysis. Yeast strains were grown in a designed model culture medium under conditions representative of dry-cured ham processing. Volatile compounds were extracted from this medium using solid-phase micro-extraction and were analysed by gas chromatography/mass spectrometry. Marked differences in volatile compound production were found between D. hansenii and C. zeylanoides and between the mitochondrial DNA patterns of these species. Two of the mitochondrial DNA patterns of D. hansenii exhibited the highest production of the volatile compounds involved in the dry-cured flavour. Consequently, these patterns of D. hansenii should be proposed as starter cultures for dry-cured ham.     

Flavour profile of capers (Capparis spinosa L.) from the Eolian Archipelago by HS-SPME/GC–MS

This paper presents the first investigation of the flavour profile of capers (Capparis spinosa L.) from the Eolian Archipelago. In all, 145 volatile compounds were identified and quantified in capers, by HS-SPME/GC–MS analysis. Aldehydes (22.2%) and esters (21%) were the most abundant chemical classes; five sesquiterpenes and ten monoterpenes were identified for the first time; among sulphur compounds (8.42%), methyl-isothiocyanate was the major one, followed by benzyl-isothiocyanate. The application of this solvent-free extraction technique combined with the GC–MS analysis, showed its potential as a simple routine method for analyzing food flavour.     

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.     

Analysis of the volatile profile and identification of odour-active compounds in Bayonne ham

The aim of this work was to reliably identify odour-active compounds in dry-cured ham using powerful analysis methods for the volatile fraction. For this purpose, dynamic headspace gas chromatography combined with eight-way olfactometry using a panel of eight sniffers was used. One- and two-dimensional gas chromatography coupled with mass spectrometry and (or) olfactometry were also used. More than 600 compounds from the volatile fraction of dry-cured ham were identified and their biochemical origins are discussed. They covered a wide diversity of structures and chemical functions. Only 29 of them proved odour-active. Comparison of the results of GC–O analysis with those obtained by orthonasal sniffing of the dry-cured ham helped to gain a better understanding of how these substances contributed to the overall aroma of the product. Thus, “Fruity–Floral”, “Green–Vegetable” or “Plastic–Chemical” odours intensively perceived by GC–O have been poorly perceived by orthonasal sniffing. By contrast, “Animal–Meat products” or “Butter–Lactic–Cheesy” odours have been much better perceived by orthonasal sniffing. These results indicate that to understand the interactions between odour-active compounds, experimental doping with carefully selected odour-active compounds will be necessary.     

基于SPME-GC-MS、电子鼻、电子舌技术联用对不同替代盐干腌火腿风味成分表征

研究不同食盐配方对干腌发酵火腿理化特性、细菌菌群变化、挥发性风味物质、风味特征的影响.以4种盐配方发酵火腿,分别为对照组(CK:100％氯化钠)、替代组1(K:30％乳酸钾+70％氯化钠)、替代组2(K+L:18％乳酸钾+12％赖氨酸+70％氯化钠)、替代组3(K+J:18％乳酸钾+12％精氨酸+70％氯化钠).结果表...     

Development of volatile profile of Kumpiak podlaski dry-cured ham during traditional ripening

Main aim of this research was to trace the development of volatile profile of Kumpiak podlaski dry-cured ham during traditional curing and ripening for 30 weeks. Volatiles were extracted from each 6-week period of ripening, and overall fifty-three aroma compounds were identified. Changes in chemical groups share between cured and fully ripened ham were observed: aldehydes (35.49 → 31.37%), ketones (25.18 → 14.62%), alcohols (17.97 → 15.74%), esters (3.37 → 12.04%), hydrocarbons (7.69 → 6.81%), fatty acids (0.02 → 0.53%), terpenes (2.26 → 9.70%) and heterocyclic aromatic compounds (0.99 → 0.78%). The 18th week of ripening is crucial for the aroma of Kumpiak podlaski ham due to start of continuous decrease in ketones and increase in esters’ and terpenes’ share. Formation of esters and terpenes originated from the presence of local herbs and the development of microflora. Principal component analysis (PCA) showed clear separation of samples from each 6-week period of ripening. Obtained results relying on thirty-seven compounds enabled to make a preliminary determination of ripening markers.     

Influence of pig crossbreed on the composition, volatile compound content and flavour of dry cured ham

The extraction of volatile compounds from dry-cured ham using a dynamic head-space method coupled with gas chromatography mass-spectrometry (GC-MS) enabled the identification of a large number of components. Some of these compounds exhibited intense sensory characteristics during odour assessment. Using similar technology, the effect of pig crossbreeds: Landrace × Large-White, Duroc × Gascon-Meishan, Piétrain × Gascon-Meishan and Large-White × Gascon-Meishan, on both volatiles and the flavour of dry-cured hams was limited, although differences were observed in aromatic compounds like 1-octen-3-ol (mushroom), 2,3-butanedione and acetoin (butter like).     

Effects of the applications of oil drip onto surface and of the use of a temperature of 35 °C for 4 days on some physicochemical,microbiological and sensory characteristics of dry-cured ham

The effects of: a) applications of oil drip (from aged salted pork fat) onto dry-cured ham surface and b) application of a temperature of 35 °C for 4 days after 234 days of processing (HTST treatment) were evaluated. The oil application reduced moisture, proteolysis and white film in semimembranosus, microbial counts in adductor and the intensity of hollow extent, toasted flavour, adhesiveness, pastiness (in semimembranosus) and chewiness (in semimembranosus and biceps femoris) and increased the intensity of nutty flavour (in both muscles), aged flavour, hardness, fibrousness and overall liking (in semimembranosus). The HTST did not affect any ham characteristics.     

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。     

Effect of irradiation on colour and lipid oxidation of dry-cured hams from free-range reared and intensively reared pigs

The effect of irradiation dose (0, 5 and 10 kGy) of vacuum-packaged Iberian dry-cured ham slices from pigs fed on concentrate (CON) or free-range reared (FRG) was studied in relation to TBA-RS, hexanal content and instrumental colour changes. TBA-RS values increased after irradiation in the two sets of hams and the increase was dose-dependent. FRG samples showed higher TBA-RS values than CON samples in all treatments, although differences in the rate of formation of thiobarbituric acid-reactive substances were different in the two types of hams, being higher in CON samples than in FRG ones. Irradiation of dry-cured ham slices significantly increased hexanal contents in both sets of hams. Irradiation produced statistically significant increases in vacuum-packed dry-cured ham slices lightness (L^⁎-value), yellowness (b^⁎-value) and chroma (C^⁎-value). Irradiation resulted in significantly lower hue angle (h°) values and higher a^⁎-values in both sets of hams indicating a redder colour of irradiated samples than non-irradiated, and these changes were greater in FRG samples than in CON samples. Differences in composition characteristics of raw material could play an important role in the irradiation-induced changes on colour and lipid oxidation of vacuum-packaged dry-cured ham slices.Industrial relevanceIberian ham is dry-cured meat product with a high sensory quality due to pig fattening feature and the characteristics of its processing. Both factors lead to a product with characteristic cured red colour of the lean, an intense, characteristic and pleasant flavour, unique in dry-cured hams, derived from intense lipid oxidative phenomena. New commercialization formats of dry-cured Iberian hams include vacuum-packed sliced ham. Although the low Aw, NaCl and nitrite/nitrate contents make dry-cured ham not adequate for the growth of pathogens and spoilage microorganisms (cocci gram+ and yeast), those may be present on the surface of whole hams and reach the sliced product during the final boning, slicing and packaging operations even with the observation of strict hygienic procedures despite the implementation of modern technologies and HACCP systems, constituting a permanent risk of contamination. Dry-cured Iberian ham, as a result of its chemical characteristics, is a product with a long shelf-life at refrigeration temperature, however the risk of spoilage or pathogen growth could increase in the case of temperature abuse for a long stored period. Finally, due to health concerns, salting and curing process of dry-cured Iberian hams tend to a reduction in levels of NaCl and nitrite used. That could increase the risk associated to microorganism presence in dry-cured sliced hams. The use of irradiation could minimizes this risk, however irradiation could have important effects on overall quality of dry-cured Iberian products in which colour and extent of lipid oxidation and lipid oxidation-derived volatile compounds play an important role in consumer acceptation of the product.     

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.     

Influence of sensory characteristics on the acceptability of dry-cured ham

The influence of different sensory attributes on the acceptability of dry-cured Iberian ham was studied. Partial least squares regression analysis showed that juiciness and several flavour traits were the major attributes positively influencing acceptability of dry-cured Iberian ham, whereas yellowness of the fat, dryness and fibrousness showed a negative influence. Using stepwise multivariate regression, juiciness and flavour intensity were the two traits that better explained the acceptability of dry-cured ham, the linear model obtained showing a regression coefficient of 0.526. The regression coefficient of acceptability with juiciness and flavour intensity was higher using a piecewise linear regression model (R²=0.759) showing, therefore, a discontinuous relationship between these variables. However, results on product acceptability have been obtained using trained panellists and it might be possible that the use of a consumer panel would change these conclusions.     

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.     

Development of volatile compounds during the manufacture of dry-cured "lacón," a Spanish traditional meat product

Volatile compounds were determined throughout the manufacture of dry-cured "lacón," a traditional dry-salted, and ripened meat product made in the north-west of Spain from the foreleg of the pig following a similar process to that of dry-cured ham. Volatiles were extracted by a purge-and-trap method and analyzed by gas chromatographic/mass spectrometry. One hundred and two volatile compounds were identified. In raw material, only 34 volatile compounds were found and at very low levels. The number of volatile compounds increased during processing. The substances identified belonged to several chemical classes: aldehydes (23), alcohols (9), ketones (15), hydrocarbons (37), esters (4), acids (3), furans (4), sulphur compounds (1), chloride compounds (1), and other compounds (4). Results indicated that the most abundant chemical family in flavor at the end of the manufacturing process was aldehydes, followed by hydrocarbons and ketones. Lipids were the most important precursor of flavor compounds of dry-cured "lacón."     

A study of volatile flavour substances in Dalmatian traditional smoked ham: Impact of dry-curing and frying

Volatiles from Dalmatian prosciutto were isolated by solvent extraction (SE), simultaneous distillation extraction (SDE) and nitrogen purge and steam distillation (NPSD) and analyzed by GC and GC–MS. In all, 46 compounds were identified by SDE and SE (including fatty acids, aldehydes, phenols, esters, ketones and others), while 81 compounds were identified by NPSD (headspace volatiles including phenols, aldehydes, hydrocarbons, ketones, alcohols, esters and heterocyclic compounds). Regarding the impact of dry curing period on the volatiles, an increase in the percentages of aldehydes and esters during the ripening of the prosciutto was observed. Quantitative percentage differences among fried and raw samples were particularly evident in respect of aldehydes (SDE and SE). The NPSD method provided additional information of the volatiles from fried ham, since the pyrazines and most of the lower aldehydes that are important thermally derived flavour compounds were only isolated by NPSD (not by SE and SDE).