Types Of Hams Research Articles

Classification of pre-sliced pork and Turkey ham qualities based on image colour and textural features and their relationships with consumer responses

Images of three qualities of pre-sliced pork and Turkey hams were evaluated for colour and textural features to characterize and classify them, and to model the ham appearance grading and preference responses of a group of consumers. A total of 26 colour features and 40 textural features were extracted for analysis. Using Mahalanobis distance and feature inter-correlation analyses, two best colour [mean of S (saturation in HSV colour space), std. deviation of b*, which indicates blue to yellow in L*a*b* colour space] and three textural features [entropy of b*, contrast of H (hue of HSV colour space), entropy of R (red of RGB colour space)] for pork, and three colour (mean of R, mean of H, std. deviation of a*, which indicates green to red in L*a*b* colour space) and two textural features [contrast of B, contrast of L* (luminance or lightness in L*a*b* colour space)] for Turkey hams were selected as features with the highest discriminant power. High classification performances were reached for both types of hams (>99.5% for pork and >90.5% for Turkey) using the best selected features or combinations of them. In spite of the poor/fair agreement among ham consumers as determined by Kappa analysis (Kappa-value<0.4) for sensory grading (surface colour, colour uniformity, bitonality, texture appearance and acceptability), a dichotomous logistic regression model using the best image features was able to explain the variability of consumers' responses for all sensorial attributes with accuracies higher than 74.1% for pork hams and 83.3% for Turkey hams.

Characterization of fat-connective tissue size distribution in pre-sliced pork hams using multifractal analysis

Fat-connective tissue size distribution (FSD) in hams is a fundamental physical property for its quality assessment. FSD is related to the sensory properties such as texture, taste, quality of raw meat and visual appearance. In this paper we present a tool to carry out the multifractal analysis (MFA) of two-dimensional binary images of pre-sliced pork hams through the calculation of the f( α)-spectra, Rényi ( D q ) dimensions, and associated statistical regressions and parameters. The application is presented for the structural characterization of FSD in three qualities of pork hams (high yield, medium yield and premium quality hams) using image sections of 512 × 512 pixels 2 with a spatial resolution of 0.102 mm/pixel. MFA was carried out using the method of moments in the optimized box size range of 32–512 pixels for all the ham images using powers of 2, and estimating the probability distribution for moments ranging from −10 < q < 10 in steps of 0.5. The experimental results suggest that MFA has a discriminating effect among the three types of ham using the maximum entropy ( H max ∗ ) and correlation dimension D 2. This investigation revealed the usefulness of the MFA dimensions as quantitative descriptors of texture analysis and pattern distributions of FSD in pre-sliced ham images.

Consumers’ preferences for Iberian dry-cured ham and the influence of mast feeding: An application of conjoint analysis in Spain

This paper analyzes consumers’ preferences for Iberian dry-cured ham, one of the most typical and highly prized meat products in Spain. The data were obtained by a survey carried out between April and May 2006 with a sample of 417 consumers in Extremadura (SW Spain). Conjoint Analysis was used to estimate the relative importance of the main attributes affecting preferences for Iberian ham and to create consumer segments with similar preference profiles. Results have shown that Price and Type of ham are the most important attributes for the choice of ham. Simulation analyses determined the surcharge that consumers are willing to pay for an Iberian mast-fed ham instead of an Iberian ham, thus identifying an ideal cluster for Iberian mast-fed ham.

Influence of raw matter origin and production period on fatty-acid composition of dry-cured hams

We have here investigated the fatty acid composition in the muscle (Mm. biceps femoris, semitendinosus and semimembranosus) of Vipava and Vipava-style hams made from fresh pork legs that originate from Slovenia, and from Germany and Italy, respectively. Dry-cured hams are produced under technology protected according to recognized geographical indications for Vipava ham, a salt-cured ham that is air-dried rather than smoked. The fatty acid compositions of samples were determined by gas-liquid chromatography following in-situ transesterification. On average, hams contained 6.89% of intramuscular and intermuscular fat, with the fatty-acid composition as 50.0% monounsaturated, 11.8% polyunsaturated (PUFA) and 38.0% saturated fatty acids. The origin of the raw matter has significant influence the PUFAs in hams, which were 2.0% lower in products from pigs of Slovenian (own) rearing. The important indicators of lipid nutritive value, as P/S ratio (0.31), content of n-3 (0.68%) and n-6 (9.02%) PUFAs, and ratio of n-6/n-3 PUFAs (14.1), are similar to those cited in the literature for other types of dry-cured hams from south European regions produced from pigs reared under intensive systems.

Analysis and classification of commercial ham slice images using directional fractal dimension features

This paper presents a novel and non-destructive approach to the appearance characterization and classification of commercial pork, turkey and chicken ham slices. Ham slice images were modelled using directional fractal ( DF 0 ° ; 45 ° ; 90 ° ; 135 ° ) dimensions and a minimum distance classifier was adopted to perform the classification task. Also, the role of different colour spaces and the resolution level of the images on DF analysis were investigated. This approach was applied to 480 wafer thin ham slices from four types of hams (120 slices per type): i.e., pork (cooked and smoked), turkey (smoked) and chicken (roasted). DF features were extracted from digitalized intensity images in greyscale, and R, G, B, L ∗, a ∗, b ∗, H, S, and V colour components for three image resolution levels (100%, 50%, and 25%). Simulation results show that in spite of the complexity and high variability in colour and texture appearance, the modelling of ham slice images with DF dimensions allows the capture of differentiating textural features between the four commercial ham types. Independent DF features entail better discrimination than that using the average of four directions. However, DF dimensions reveal a high sensitivity to colour channel, orientation and image resolution for the fractal analysis. The classification accuracy using six DF dimension features ( a 90 ° ∗ , a 135 ° ∗ , H 0 ° , H 45 ° , S 0 ° , H 90 ° ) was 93.9% for training data and 82.2% for testing data.

Colour and texture profiles of boneless reestructured dry-cured hams compared to traditional hams

Colour and texture, resultant of a complex process involving chemical, physical and enzymatic modifications, are important parameters for the acceptability of dry-cured hams. This study aimed to evaluate texture and colour instrumentally profiles of six types of dry-cured ham: two experimentally accelerated processed products, called CTC 3.5% and CTC 5.0% according to the initially added salt percentage; two imported (Spanish Serrano and Italian); and two Brazilian (Serrano type and Parma type) commercial products. The experimental process combined muscle-boning, transglutaminase addition, tumbling and moulding in stainless steel moulds, followed by drying and maturation. Evaluations were carried out using the Hunter colour system (A, 10º) and TPA (Texture Profile Analysis). The samples differed in lightness (lighter products - CTCs), and in red colour (higher a values - Italian and Serrano type). The more distinct texture profiles were seen in CTCs as compared to the Italian and Parma type samples, with the former having the highest values of hardness, springiness, cohesiveness and chewiness. The results showed the typical colour and texture characteristics of dry-cured hams, although each product had its own particularities likely due to differences in the raw material and processing techniques.

Quantification of zinc–porphyrin in dry-cured ham products by spectroscopic methods: Comparison of absorption, fluorescence and X-ray fluorescence spectroscopy

Zinc–protoporphyrin (Zn–pp), which has been identified as the major pigment in certain dry-cured meat products, was extracted with acetone/water (75%) and isolated from the following meat products: Parma ham, Iberian ham and dry-cured ham with added nitrite. The quantification of Zn–pp by electron absorption, fluorescence and X-ray fluorescence (XRF) spectroscopy was compared (concentration range used [Zn–pp] = 0.8–9.7 μM). All three hams were found to contain Zn–pp, and the results show no significant difference among the content of Zn–pp quantified by fluorescence, absorbance and X-ray fluorescence spectroscopy for Parma ham and Iberian ham. All three methods can be used for quantification of Zn–pp in acetone/water extracts of different ham types if the content is higher than 1.0 ppm. For dry-cured ham with added nitrite, XRF was not applicable due to the low content of Zn–pp (<0.1 ppm). In addition, XRF spectroscopy provides further information regarding other trace elements and can therefore be advantageous in this aspect. This study also focused on XRF determination of Fe in the extracts and as no detectable Fe was found in the three types of ham extracts investigated (limit of detection; Fe ⩽ 1.8 ppm), it allows the conclusion that iron containing pigments, e.g., heme, do not contribute to the noticeable red colour observed in some of the extracts.

돈육 뒷다리 부위의 발골시간이 프레스햄의 품질 특성에 미치는 영향

ABSTRACT To investigate the effects of deboning time and muscle type of ham on quality characteristics of cooked press ham, a total of twelve pigs (barrow, 100 ± 5kg) were slaughtered and split in half. The left side ham of carcasses was deboned immediately after slaughter whereas the right side ham was deboned after chilling for 24 hours at 4. Each of two muscles (SM ; Semimembranosus, BF; Biceps femoris) was used to make a press ham. The pH of hot-boning muscles was significantly (p0.05) higher than that of cold- boning muscles, and the pH of SM samples was significantly (p 0.05) higher than BF samples. Hot-boning muscles showed significantly (p<0.05) longer sarcomere length compared with cold-boning muscles. There was no significant difference in myoglobin (Mb) percentage between SM and BF muscles, but SM samples of hot-boning showed significantly (p<0.05) lower L* value compared to hot-boning BF samples. The lightness (L*) of hot-boning muscles was significantly (p<0.05) lower than that of cold-boning muscles. These results suggested that the dark color of hot-boning samples might be due to not only the high muscle pH but also the long sarcomere length without difference in Mb percentage. Hardness and gumminess of hot-boning press ham were significantly (p<0.05) lower than those of cold-boning samples. These results implied that color and pH of press ham did not affected by deboning time or muscle type of ham. However data suggested that texture and panel test of press ham might be improved by using hot-boned muscle due to long sarcomere length of raw meat. (

Mass spectrometric evidence for a zinc–porphyrin complex as the red pigment in dry-cured Iberian and Parma ham

Extracts containing red pigment complexes from the two types of dry-cured hams, Italian Parma and Spanish Iberian ham, were obtained using water and acetone as extraction solvents followed by a crude purification with C18 column filtration. The purified extracts were then analyzed spectroscopically by recording absorption and fluorescence spectra ( λ ex = 420 nm), which both indicate the presence of chemically identical red chromophores with properties similar to a complex of transition metals and protoporphyrin IX. Electrospray ionization mass spectrometry (ESI-MS) in the positive ion mode confirms the presence of identical chemical compounds. ESI-MS in the negative ion mode detects a cluster of seven isotopologue ions (that of m/ z 623.2 as the most intense) with a pattern matching that of a Zn protoporphyrin IX complex. Based on mass spectral data it is concluded that a Zn–porphyrin complex constitutes a major chromophore in dry-cured Iberian ham as well as in Parma ham.

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 relevance Iberian 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.

Artificial olfactory system for the classification of Iberian hams

An array of semiconductor sensors has been tested as an artificial olfactory system for the classification of Iberian hams. Iberian hams can be classified into different types: “Montanera” hams and “Pienso” hams according to the rearing system. The multisensor is composed by 15 sensing elements formed by tin oxide thin layers deposited by rf reactive sputtering.Hams were analysed by using two sampling methods: static headspace generation and purge and trap method. The extraction conditions have been optimised for both methods. A good discrimination of the two types of Iberian ham has been obtained through the statistical method of principal component analysis (PCA).

Electronic nose for the identification of pig feeding and ripening time in Iberian hams

An electronic nose system to control the processing of dry-cured Iberian ham is presented. The sensors involved are tin oxide semiconductors thin films. They were prepared by RF sputtering. Some of the sensors were doped with metal catalysts as Pt and Pd, in order to improve the selectivity of the sensors. The multisensor with 16 semiconductor sensors, gave different responses from two types of dry-cured Iberian hams which differ in the feeding and curing time. The data has been analysed using the PCA (principal component analysis) and backpropagation and probabilistic neural networks. The analysis shows that different types of Iberian ham can be discriminated and identified successfully.

An ab initio quantum chemical investigation of the error-coding model of nucleotide alphabet composition

In the error-coding model of nucleotide alphabet composition [MacDónaill, D. A., 2002, Chem. Comm., 2062], the recognition features of nucleotides are mapped to 4-digit binary numbers, capturing the hydrogen acceptor/donor patterns (3 bits) and the purine/pyrimidine size motif (1 bit). Optimal alphabets, from the perspective of fidelity, are those corresponding to parity check codes in which the purine/pyrimidine feature relates to the acceptor/donor pattern as a parity bit. The validity of the model depends on a broad parallel between the interaction energies of potentially associating nucleotides and a measure of complementarity, namely a Hamming type distance derived from the XNOR product of the corresponding binary interpretations. In this paper we model both complementary and non-complementary purine—pyrimidine associations at the ab initio 6–31G* level of approximation. The results suggest that the 4 bit representation of nucleotides, on which the error-coding model is based, adequately captures nucleotide interactions for the purposes of considering the composition of the alphabet. The results also indicate that a single mismatch in H-bonding positions between non-complementary nucleotides is insufficient to ensure replication fidelity, which requires that non-complements mismatch in two of three positions, a requirement satisfied by a parity code structure.

Identification and quantification of cholesterol and cholesterol oxidation products in different types of Iberian hams.

Cholesterol and cholesterol oxidation products (COPs) were determined in four different groups of dry-cured Iberian hams, based on the feeding received by pigs and their degree of crossbreeding. After lipid extraction, GC-FID for cholesterol determination and GC-MS to analyze COPs were used. Cholesterol content ranged from 30 to 34 mg/100 g of muscle. Some of the COPs analyzed, such as 7alpha-hydroxycholesterol, 7beta-hydroxycholesterol, and 7-ketocholesterol, were detected in all of the samples. The major cholesterol oxide was 7-ketocholesterol; its concentration ranged from 57 to 71 microg/100 g of muscle. The content of cholesterol and cholesterol oxides in intramuscular lipids of hams was not affected by diet or crossbreeding of Iberian pigs.

Detection of Iberian ham aroma by a semiconductor multisensorial system

A semiconductor multisensorial system, based on tin oxide, to control the quality of dry-cured Iberian hams is described. Two types of ham (submitted to different drying temperatures) were selected. Good responses were obtained from the 12 elements forming the multisensor for different operating temperatures. Discrimination between the two types of ham was successfully realised through principal component analysis (PCA).

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.

Near Polygons from Partial Linear Spaces

We construct a nondegenerate near polygon from a partial linear space without isolated points. We also prove that the points of a near polygon at distance at most 2 from a fixed point induce a near polygon, which is related to the class of the near polygons obtained from the construction. We give also a characterization of the near polygons of Hamming type in terms of parallelism.

Headspace Solid Phase Microextraction for the Analysis of Volatiles in a Meat Product: Dry-Cured Iberian Ham

The application of solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry for the analysis of dry-cured Iberian ham volatile compounds has been studied. To determine the optimal conditions to extract volatile compounds, several extraction times and temperatures conditions were tested. The majority of the 82 volatile compounds tentatively identified coincided with those reported for different types of dry-cured ham in the literature. In addition, SPME successfully extracted high molecular weight compounds, some of them being reported for the first time in this type of meat product. Both extraction time and temperature dramatically increased less volatile compounds' chromatographic area and consequently total area (P < 0.0001). Keywords: Dry-cured Iberian ham; solid-phase microextraction (SPME); gas chromatography/mass spectrometry; volatiles

Volatile compounds present in six types of dry-cured ham from south European countries

A study was conducted to compare the volatile fraction of six types of dry-cured hams from south European countries: (1) France: Bayonne and Corsican hams; (2) Spain: Iberian and Serrano hams; (3) Italy: Parma and Light Italian Country hams. The analysis of the volatile compounds was carried out using a dynamic-head space technique coupled to gas chromatography–mass spectrometry. One hundred and nine compounds were identified and analyzed: aldehydes (15), alcohols (14), ketones (17), esters (11), sulphur compounds (5), nitrogenous compounds (10), terpenes (18), n-alkanes (7) and aromatic and cyclic hydrocarbons (12). The possible formation pathways of these compounds are discussed. The results show that there are important differences among the six types of hams depending on the type of raw material and the technology used, the longer-processing time hams (Iberian and Corsican) being richer in volatile compounds.

Flavour differences between northern and southern European cured hams

In this study two procedures for isolation of volatiles from hams were compared: simultaneous steam distillation-extraction (SDE Likens-Nickerson) and dynamic headspace. Because reliable semi-quantitative data were aimed at, according to our results, SDE extraction should be preferred over dynamic headspace isolation. About 70 volatile components were identified and quantified in several types of ham: southern European dry-cured hams (Serrano, Parma), northern European brine-cured hams and some experimental dry-cured hams with different ripening times. It was shown that the dry-cured hams had a more intense pattern of a whole series of volatiles related to fat oxidation, but also of some compounds related to amino acid degradation. Principal component analysis was used to visualize the relationships between the different ham objects. Some meaningful clusters of hams could be obtained and related to their volatile composition.