Evaluation of the antioxidant effect of a phytocomplex addition in clean label pork salami enriched in n-3 PUFA.

Control and n-3 PUFA enriched raw material was used to manufacture clean label and conventional salami; the former were added with a phytocomplex having iron chelating, DPPH, and FRAP activity, obtained from olive vegetation water, oregano, green tea and blueberry leaves, and with acerola powder. Salami were dried at 3 ± 1 °C until an established decrease in the combined pH and aw values, while only the conventional ones underwent a standard process. In the cold dried salami pH changes, aw and weight decrease were delayed; the phytocomplex contributed to lower the pH, and to prevent lipid and protein oxidation, despite the n-3 PUFA enrichment and heme iron release due to nitrite removal. TBARS and protein carbonyls were the highest in the nitrite-added salami undergoing cold and standard drying, respectively. The oxidation marker MDA tended to increase in the simulated digests of salami n-3 PUFA enriched or subjected to cold drying.

Application of a non-invasive tool and identification of genetic markers in swine to enhance ham quality: a preliminary study.

A genome-wide association study (GWAS) was performed as a preliminary step to identify regions potentially related to ham quality traits. In this research, genomic information was obtained from 238 commercial hybrid pigs utilising the GeneSeek® Genomic Profiler genome-wide porcine genotyping array. Carcasses were tested for hot weight, the thickness of backfat and loin, and lean meat percentage. The corresponding fresh hams were assayed for weight and ultimate pH; the activities of Cathepsin B and Ferrochelatase of Semimembranosus muscle were determined through fluorimetric methods. The lean meat percentage of fresh ham (LMPH), salt absorbed after first (SALT1) and overall salting stages (SALT) were estimated online by the Ham Inspector™ apparatus. Hams were processed in compliance with the procedures established for Protected Designation of Origin Parma ham, and ham weight losses were measured at the main processing stages. Hot carcass weights showed a significant negative correlation with their lean meat percentage and LMPH, while LMPH was correlated positively with carcass lean meat, SALT1, SALT, and weight losses. The GWAS detected genome-wide association for 12 single nucleotide polymorphisms with Ferrochelatase activity. The results obtained in this preliminary study were achieved by combining innovative and non-destructive technologies for screening hams under processing, measures of enzymatic muscle properties relevant to dry-cured ham quality, and genomic information obtained through a GWAS. Additional studies carried out in a larger number of pigs have been planned to investigate the effect of gene variants of Ferrochelatase activity in the dry-cured ham's quality with main reference to colour development and to confirm the GWAS results obtained in this study.

Revision of the cold processing phases to obtain a targeted salt reduction in typical Italian dry-cured ham.

The objective of the study was to reduce the salt content of typical Italian dry-cured ham by at least 25%, to meet the "reduced salt" claim. Salt reduction needs process adjustments to maintain product safety and quality in the absence of nitrites. A way was to reduce the salt input and to shorten the salting period compared to the conventional process. The cold drying period of reduced salt (RS) hams was extended, to decrease aw below 0.97 in inner parts and obtain the same safety conditions of control hams (CS). In RS dry-cured hams the salt reduction was accomplished, the generation of biogenic amines was lower than the threshold values generating toxic effects, and color was the same as in the CS ones. However, in RS proteolysis increased, contributing to texture softening. A strengthened salt diffusion from backside rind could contribute to counteract the rise in proteolysis of biceps femoris muscle, depleted of salt during the process of RS hams.

Use of Magnetic Resonance Imaging for monitoring Parma dry-cured ham processing.

Protocols were developed to apply Magnetic Resonance Imaging (MRI) to the dry-curing of Italian Parma ham. NMR relaxation analyses were performed on dry-cured hams at different processing stages to evaluate the ranges of variation of (1)H relaxation times T(1) and T(2) in representative ham muscle tissues, due to dehydration and salt uptake. MRI maps of the same ham sections were acquired, allowing T(1) and T(2) average values to be computed in selected Regions of Interest (ROI) inside muscle Semimembranosus, Semitendinosus and Biceps femoris. Chloride and moisture were determined by conventional chemical methods on the same ROIs, and MRI T(1) and T(1)/T(2) ratio were selected in a model (R(2)=0.90, P<0.05) fitting the salt content of the analysed muscle cores. Short Time Inversion Recovery (STIR) sequences were also applied to green and cured hams, but on fresh samples only, a bright image, displaying a clear separation between lean and fat tissue, was obtained.

Effect of vaccination against gonadotropin-releasing hormone (GnRH) in heavy male pigs for Italian typical dry-cured ham production.

The aim of this study was to evaluate immunocastration (vaccination against GnRH using Improvac® vaccine), as an alternative to surgical castration in heavy male pigs (average live weight 165 ± 10 kg), used in the production of Italian typical dry-cured ham. A total of 60 Landrace × Large White male pigs were assigned to three groups of 20 units, including one group of surgically castrated (SC), and two of immunocastrated pigs, with two (IC2) or three (IC3) vaccine treatments, respectively. The groups were compared for green ham traits, processing weight losses, chemo-physical, and sensory properties of dry-cured hams. While IC3 were not different (P>0.05) from SC group, IC2 hams were found to differ (P<0.05) both from SC and IC3 groups in ham traits, final weight losses, texture and sensory boar taint in finished hams. Therefore, vaccination with three doses could be taken into account to control boar taint in the manufacturing of typical Italian dry-cured ham.

Fatal infantile leukodystrophy: a severe variant of CACH/VWM syndrome, allelic to chromosome 3q27.

OBJECTIVE: To describe clinical and neuropathologic studies and linkage analysis on two sisters with a severe form of leukodystrophy. METHODS: A detailed study was performed on the second sister. Genotyping markers for chromosome 3, including eight additional markers surrounding the vanishing white matter (VWM) locus, were used. RESULTS: During the first year of life, two sisters developed a severe neurologic condition after an intercurrent infection. It was accompanied by irritability and stupor with rapid loss of their motor abilities. Results of extensive metabolic studies were negative. Brain MRI showed severe and diffuse abnormalities of the encephalic white matter. Neuropathologic examination showed a severe lack of myelin with diffuse vacuolating white matter lesions in the brain, associated with an increased density of oligodendrocytes and a reduced number of astrocytes on morphometric analysis. In sharp contrast, the spinal cord white matter was preserved. The affected sibpairs shared a common haplotype for a broad region in chromosome 3. They were homozygous between markers D3S1565 and D3S3669, including the VWM locus. CONCLUSIONS: This condition is an unusual variant of childhood ataxia with diffuse central hypomyelination (CACH)/VWM, with characteristic shrinking and perivascular clustering of astrocytes. Haplotype analysis suggests that this variant is allelic to the VWM locus located on chromosome 3q27.

Effect of age at slaughter on carcass traits and meat quality of Italian heavy pigs.

Barrows and gilts (n = 128) from four breed crosses were used to investigate the effect of age at slaughter on carcass traits, proteolytic enzyme activity, and meat and fat quality. Pigs were blocked by breed cross into four blocks, and within blocks, one pen (eight barrows and eight gilts) was assigned randomly to be slaughtered at either 8 or 10 mo of age. Pigs were fed a corn-barley-soybean meal finisher diet from 104 +/- 2.5 d of age (37.7 +/- 0.33 kg BW) to the appropriate slaughter age. Carcasses from older (10 mo) pigs had lower (P < 0.01) muscularity indexes and lean cut yields than those of younger (8 mo) pigs, but dressing percentage and longissimus muscle area increased (P < 0.01) with age. Older pigs produced a redder (P < 0.01) and darker (P < 0.05) semimembranosus, with lower (P < 0.01) ultimate pH and cathepsin B and B + L activities, as well as higher (P < 0.01) aminopeptidase hydrolyzing activity than younger pigs. Moreover, the longissimus muscle of pigs slaughtered at 10 mo of age had lower (P < 0.01) drip and cooking loss percentages than that from pigs slaughtered at 8 mo of age. Ham subcutaneous fat from 10-mo-old pigs had greater (P < 0.05) percentages of oleic acid and lower (P < 0.01) proportions of moisture, linoleic, and linolenic acids than subcutaneous fat from pigs slaughtered at 8 mo of age. Results from this study indicate that fresh hams from pigs slaughtered at 10 mo of age would be more suitable for the production of high-quality, Italian, dry-cured hams.

Muscle traits for long matured dried meats.

The distinctive flavour of aged pork products is a complex mix of taste, smell and even touch. To meet increasing consumer's preference for ethnic foods or foods addressing linkage with specified geographic origin or complying with traditional manufacturing and breeding guidelines, efforts should be made to encourage selection of processing techniques and raw materials targeting desired end product qualities. Thanks to research carried out with sensory analysis and chemical and physical characterisation of raw and matured pork, as well as breeding and genetics, improved knowledge is now available relating dried meat properties to raw matter or manufacturing. The achievement of the distinctive taste and texture properties of aged products through genetics (animal selection for the enhancement or the removal of some muscle traits), breeding (effect of diet and slaughtering age on pork properties) with reference to current findings about this type of products is discussed.

Quality control in the meat industry by multivariate statistics. The case of raw ham.

Two multivariate statistical techniques were tested on sensory and instrumental data from raw ham technology. (1) Cluster analysis, applied to parameters ranging from the beginning of processing to the end of resting, originated three groups which provided an explanation of the observed trends in the occurrence of microbial defects. (2) Partial-least-squares (PLS) regression, used to relate three sensory descriptors to five instrumental variables, provided a fully instrumental method for the assessment of quality of aged ham. Application of both techniques for prediction and description purposes is discussed.

Relationship between cathepsin B activity and compositional parameters in dry-cured hams of normal and defective texture.

Thirty-eight Italian dry-cured hams were analysed for cathepsin B activity, proximate composition and proteolysis index and results were related to lean tissue texture, as assessed by an expert panel, in order to search for relationships between excessive softness, a major problem in the raw ham industry, and chemical parameters. Softness was found to be related to protein breakdown which, in turn, was linked with higher residual cathepsin B activity and, to a lesser extent, to lower salt content. Results suggest that the use of raw ham of controlled enzyme activity would improve the texture quality of the end product.

Changes in volatile compounds of Parma ham during maturation.

Changes in the aromatic profile of Parma ham caused by the normal course of aging up to 12 months were examined in order to identify distinctive signals for different maturing periods (6, 9, 12 months). The 28 samples analysed, divided among the three periods mentioned above, provided an aromatic profile in which methyl esters were the most relevant signals, followed by carbonyl compounds and alcohols. The greatest discriminating power is to be ascribed to components such as 3-methylbutanal and ethyl esters, and alcohols like 1-propanol, 1-butoxy-2-propanol and 2-butanol. These compounds were present in higher percentages at 12 months of aging.

Lipolysis in dry-cured ham maturation.

Thirty light Parma hams were tested for muscle lipolytic activity (acid and neutral lipase activity) and free fatty acid (FFA) amounts in M. semimembranosus and biceps femoris, during progressive phases (0, 3, 6, 10 months) of dry-cured ham manufacturing. No correlation was found between the activities of acid and neutral lipases in fresh M. semimembranosus, while during processing the activities were positively related (p<0.1), probably due to effects of muscle composition changes on lipolytic activities. In each processing step tested, acid lipase activities were higher in the M. semimembranosus than in the M. biceps femoris, and FFA amounts varied accordingly, the only exception being for the very dehydrated 10-month old M. semimembranosus, which yielded lower FFA than in the corresponding M. biceps femoris. FFAs in the end product correlated positively with acid and neutral lipase activities of green ham, suggesting that FFA production could be influenced by both raw meat properties and muscle composition during processing.

Analysis of raw meat to predict proteolysis in Parma ham.

Four hundred and thirty-seven pigs (223 purebred Italian Large White, 97 Italian Landrace, and 117 Duroc), were studied to examine the effect of breed on meat quality and assess the possibility of relating proteolysis of dry-cured hams to raw meat quality. The Duroc pigs had intramuscular fat contents and water holding capacities (M. Semimembranosus) significantly higher than those of the Large White and Landrace. The latter had a significantly higher pH(24h) and cathepsin B activities significantly lower than the Duroc breed. The dry-cured hams (M. Biceps femoris) from the three breeds were significantly different in proximate composition, proteolysis and weight loss at the end of ageing. Data for green hams (including salt content) were used to compute a model to fit the proteolysis of the corresponding dry-cured hams. The variables included in the model (R(2)=0.53 and P<0.01) were cathepsin B activity of raw ham, pH(24h), weight loss after the first salting step, and the salt content of the dry-cured ham. The raw hams with the highest cathepsin B activities, the lowest pH(24h), and the highest weight loss after the first salting were those in which greatest proteolysis occured.

Evaluation of cathepsin B levels in fresh thighs selected for cured raw ham production.

Excessive meat tenderization in cured raw Parma ham has recently been correlated with abnormal levels of cathepsin B in freshly slaughtered thigh meat. We have developed a visual assay employing the substrate Z-Arg-Arg-NNapOMe for the quantitative detection of active cathepsin B levels in pork thigh muscle homogenates. The work was based on a kinetic characterization, in steady state condition, of pig muscle cathepsin B with several peptidyl chromophoric substrate analogs. This assay can easily and safely be performed by non-specialized personnel directly in the slaughterhouse or in the factory, for an early quality evaluation of thighs selected for Parma ham production. Our characterization has further indicated that the catalytic properties of porcine muscle cathepsin B and those of isoforms from other animal and plant species are practically identical. This is particularly evident in the commercially available bovine spleen isoform, which was employed as a model enzyme in most of the experiments.

[Sampling and determination of aldehydes in ambient air]. / Prélèvement et dosage des aldéhydes dans l'air ambiant.

A method for the determination of aldehydes involving the formation of their 2,4-dinitrophenylhydrazones on solid adsorbents and subsequent HPLC/UV analysis with internal standard was tested with dynamically generated samples and applied in a few real situations. The sampling train is suitable for personal sampling.

Single nucleotide polymorphisms in several porcine cathepsin genes are associated with growth, carcass, and production traits in Italian Large White pigs.

To identify DNA markers associated with performance, carcass, and meat production traits including muscle postmortem cathepsin activity, several porcine genes encoding for lysosomal proteinases (cathepsin B, CTSB; cathepsin D, CTSD; cathepsin F, CTSF; cathepsin H, CTSH; cathepsin L, CTSL; and cathepsin Z, CTSZ) and for a cathepsin inhibitor (cystatin B) were investigated. Single nucleotide polymorphisms were identified in CTSD, CTSH, CTSL, and CTSZ genes with a combination of in silico expressed sequence tag database mining and single-strand conformation polymorphism analysis. Sequencing and PCR-RFLP protocols were used to validate the identified polymorphisms. Allele frequencies at these loci were investigated in Italian Large White, Landrace, Duroc, Piétrain, Belgian Landrace, Hampshire, and Meishan breeds. Genotyping CTSD and CTSH markers made it possible to genetically map these genes to SSC 2 and 7, respectively. Markers in CTSD, CTSH, CTSL, and CTSZ genes, together with mutations we previously reported in cystatin B, CTSB, and CTSF genes, were genotyped in an Italian Large White sib-tested population (272 or 482 animals). For these animals, meat quality traits (cathepsin B activity, pH measured at 2 h postmortem, pH measured at 24 h postmortem, glycogen, lactate, and glycolytic potential of semimembranosus muscle) and EBV for ADG, lean cuts (LC), backfat thickness (BFT), ham weight (HW), and feed:gain ratio (FGR) were determined. Analyzed markers did not show any association with muscle cathepsin B activity. Thus, it could be possible that different genes, other than these investigated candidates, affect this trait, which is correlated with the excessive softness defect of dry-cured hams. The results of association analysis confirmed the effects we already reported in another study for CTSF on ADG (P = 0.008), LC (P = 0.001), and BFT (P = 0.02). Moreover, CTSD was associated with ADG, LC (P < 0.0001), BFT, HW, and FGR (P < 0.001); CTSH was associated with FGR (P = 0.026); and CTSZ was associated with ADG (P = 0.006), LC (P = 0.01), HW (P = 0.024), and FGR (P = 0.029). The biochemical and physiological functions of the lysosomal proteinases, together with the results obtained in our investigation, suggest that the cathepsin gene family might play important roles affecting economic traits in pigs.

Dynamics and characterization of yeasts during ripening of typical Italian dry-cured ham.

The evolution of the yeast population during manufacturing and ripening of dry-cured Parma ham was investigated. Contamination levels ranged from 10(5) to 10(7) cfu/g on muscle surface, 10(4) to 10(6) cfu/g on covering fat and exceeded 10(7) cfu/g on spreadable fat mince ("sugna"). Two hundred and sixty one yeast isolates underwent identification test, showing that the predominant species of yeast population during the whole maturing process were Debaryomyces hansenii, Candida zeylanoides, Debaryomyces maramus, and to a lesser extent, Candida famata and Hyphopichia burtonii. The species Candida catenulata, Candida guilliermondii, Candida edax and other genera like Cryptococcus and Wingea were occasionally found. The yeast counts and species distribution changed according to the stage of processing and to the ham sampling location. At the end of the cold phase, the washing procedure was effective in lowering the yeast count in muscle and fat surface layers, but during the next ageing stages, yeast colonization of unskinned ham muscle increased again, though species distribution changed if compared to previous manufacturing phases. The ripening steps taken into account from the end of the cold phase to the final outcome, were always characterized by more than one yeast species, suggesting that yeasts other than Debaryomyces spp. could play a remarkable role on the sensory and safety properties of typical Italian dry-cured ham.

A new validated HPLC-FLD method for detecting ochratoxin A in dry-cured meat and in blue cheese.

In the present study, a fast and sensitive method for the quantification of ochratoxin A in two lipidicproteic food matrices has been developed. In particular, the sample preparation procedure has been optimized for dry-cured meat products and blue cheeses and tested for several validation parameters (LOD, LOQ, recovery, repeatability and within-laboratory precision). The procedure has been then applied to several dry-cured meat products and blue cheeses from the market.Ochratoxin A has been occasionally found in dry-cured and smoked ham from the market and the contamination occurred both in the outer and in the inner part of the products. Concerning the blue cheese, the occurrence of ochratoxin A is reported for the first time: OTA was occasionally found at low levels (0.1-3 µg/kg) in commercial samples of Roquefort from France and Gorgonzola from Italy, opening a new issue for risk assessment and quality control.

Copper(II) complexes of diamino-diamido-type ligands as chiral eluents in the enantiomeric separation of D,L-dansylamino acids by reversed-phase high-performance liquid chromatography.

For purpose of studying the mechanism of chiral recognition in high-performance liquid chromatography (HPLC) (reversed phase), a model system is proposed, i.e., copper(II) complexes of diamino-diamido-type ligands containing L-amino acids (AA-NN-n) which added to the eluent are able to perform the enantiomeric resolution of dansylamino acids on C8 and C18 columns. Being potentially tetradentate, this system should be more liable to give an apical or outer-sphere interaction with the enantiomer rather than a simultaneous dechelation of two binding sites, as in the classical ligand-exchange mechanism. This model allows the variation of several parameters, such as the structural and electronic features of the initial complexes, their relative stabilities and lipophilicities and their correlation with enantioselectivity in HPLC.

Investigation of candidate genes for meat quality in dry-cured ham production: the porcine cathepsin B (CTSB) and cystatin B (CSTB) genes.

Excessive softness is a serious defect of dry cured hams which seems related to high activity of lysosomal cysteine proteinases, such as cathepsin B, in fresh pork muscles a few days after slaughtering. As it has been shown that cathepsin B activity has a moderate heritability in Italian Large White pigs we started a candidate gene approach to identify the gene(s) that affect(s) this parameter. Here, we studied two candidate genes: cathepsin B (CTSB) and cystatin B (CSTB). We amplified and sequenced porcine DNA fragments for these two genes that were used to identify polymorphisms by SSCP and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Four and two alleles were detected at the CTSB and CSTB loci, respectively. Sequencing of the CSTB alleles showed a missense mutation that changes a codon for aspartic acid into a codon for asparagine in exon 3 of the gene. Allele frequencies for the two loci differed among the pig breeds studied (Large White, Landrace, Duroc, Belgian Landrace, Hampshire, Piétrain, Meishan, Cinta Senese, Casertana, Calabrese and Nero di Sicilia). Linkage, somatic cell hybrid panel and radiation hybrid panel analyses assigned CTSB to porcine chromosome (Sscr) 14 and CSTB to Sscr 13. The markers identified at the CTSB and CSTB loci were used in association studies with several traits of economic importance including parameters that may indicate the suitability of pig meat to produce dry-cured hams. Significant associations were observed between CTSB and back-fat thickness and between CSTB and average daily gain. In this study, cathepsin B activity was not associated with the polymorphisms identified at the CTSB and CSTB loci.