Zinc-protoporphyrin formation in nitrite-free Parma Ham and its relationship with intrinsic parameters and red color profile of processed hams.

A total of 134 fresh hams, assayed for Ferrochelatase (FeCH) activity and ultimate pH (pH48), were processed in compliance with the procedures established for PDO Parma ham and finally, analyzed for salt, moisture, Zinc Protoporphyrin IX (ZnPP), heme, iron and zinc contents, and proteolysis index (PI). The variation in ZnPP content was related to the intrinsic parameters of fresh and matured hams by a Partial Least Square Regression model. The most favorable factors on the formation of ZnPP were total iron content (representative of the initial hemoprotein content), and FeCH activity, demonstrating the main role played by these raw matter-specific predictors in the long matured dry-cured hams. To a lesser extent, zinc content and pH48 were involved with a positive and negative role, respectively. Salt content and PI of matured hams showed an inhibitory and a favorable influence, respectively, toward the ZnPP formation. Principal Component Analysis showed the associations between the sensory red color profile and the physicochemical traits of matured hams. The red color intensity increased in agreement with the red-violet and red-pink hues scores. The formation of a high amount of ZnPP was associated with the increased perception of the red-violet shade, with a lower lightness (L*) and Hue angle (h°). Moisture increase contributed to the shift in color perception to red-pink, while marked progress in PI strengthened the perception of the red-brown shade. ZnPP and final heme favored the red color of matured hams, although a high concentration of these pigments increased in particular the red-violet perception.

Investigating the Features of PDO Green Hams during Salting: Insights for New Markers and Genomic Regions in Commercial Hybrid Pigs.

Protected Designation of Origin (PDO) dry-cured hams production is greatly dependent on raw meat quality. This study was performed to identify genetic markers associated with the quality of dry-cured ham. Carcass traits of 229 heavy pigs belonging to three commercial genetic lines were registered (weight, EUROP classification). Phenotypic traits (Semimembranosus muscle ultimate pH, ham weight and lean meat content, adsorbed salt) of the corresponding thighs, undergone PDO ham process in three different plants, were measured, using a fast and non-invasive technology. Green ham weight and lean meat percentage influenced the estimated salt content and the weight loss during salting, even if the processing plant greatly affected the variability of the measured ham traits. The genomic data were obtained with the GeneSeek Genomic Profiler (GGP) 70k HD Porcine Array, using the slaughter day and the sex of the animals in the statistical analyses. The phenotypic traits were associated with the genotypes through GenAbel software. The results showed that 18 SNPs located on nine porcine chromosomes were found to be associated with nine phenotypic traits, mainly related to ham weight loss during salting. New associations were found between markers in the genes Neural Precursor Cell Expressed Developmentally Down-Regulated 9 (NEDD9, SSC7), T-Cell Lymphoma Invasion and Metastasis 2 (TIAM2, SSC1), and the ham quality traits. After validation, these SNPs may be useful to improve the quality of thighs for the production of PDO dry-cured hams.

Impact of salt levels on the sensory profile and consumer acceptance of Italian dry-cured ham.

BACKGROUND: Reduction of the salt (NaCl) content in typical Italian dry-cured ham is intended to reduce sodium dietary intake to meet World Health Organization (WHO) recommendations for the prevention of serious diseases. This reduction is a complex issue because of the multiple roles that salt plays in the product. Hams that were processed to obtain a final product with target salt levels (hams with reduced salt concentration and controls) were analyzed using chemical parameters (salt, moisture, fat, and proteolysis indexes). Their sensory properties were described by a trained panel and 87 consumers evaluated the impact of salt reduction on their liking for the products. RESULTS: The dry-cured hams under investigation are representative of Italian dry-cured hams, which are considered to be low and medium to high in terms of salt content. Consistent with the role of salt in proteolytic enzymes inhibition, there was an increase in the proteolysis index in fully matured dry-cured hams with reduced salt content. Salt level affected saltiness perception but also texture, color, and, to a lesser extent, flavor intensity in matured dry-cured hams. On average, reduced-salt dry-cured hams resulted in increased consumer liking. However, the resulting three consumer segments (37%, 27%, and 36% of the consumer cohort, respectively), differed in the acceptability ranking given to reduced-salt hams and controls. CONCLUSION: The tested reduction in salt content, besides improving the nutritional profile of dry-cured ham, was effective in increasing consumers' acceptance. These results were useful for exploring the effect of reducing salt concentration on consumer liking for dry-cured hams. © 2020 Society of Chemical Industry.

Association study between single nucleotide polymorphisms in porcine genes and pork quality traits for fresh consumption and processing into Italian dry-cured ham.

Single nucleotide polymorphisms (SNPs) of six genes (TTN, PRKAG3, CAST, CTSB, CTSF, and MYPN), known for associations with carcass and meat quality traits, post mortem proteolysis, were screened in a commercial crossed population of 368 heavy pigs (Large White x Landrace)×Duroc, reared according to the rules of Italian Protected Designation of Origin (PDO) dry-cured ham. Carcass, longissimus thoracis et lumborum muscle (LTL), and green ham traits were obtained after slaughtering, main weight losses of dry-cured hams were collected during processing. The results showed the impact of CAST variants on carcass weight, of CTSF on LTL tenderness, ham weight and fatness, of PRKAG3 and TTN on ultimate pH, hamweight. This study, while confirming significant associations between SNPs of genes and qualitative traits of carcass, longissimus and ham, supports CTSF as candidate gene suitable for fresh consumption purpose (tenderness of longissimus at 24h post mortem), and for dry-cured ham processing (higher thickness of ham subcutaneous fat).

Effect of extended aging of parma dry-cured ham on the content of oligopeptides and free amino acids.

The effect of the dry-curing processing time on the release of oligopeptides and amino acids was evaluated with 158 Parma hams subdivided into three groups: (1) traditional processing (450 days); (2) extended processing (570 days); and (3) extended aging (690 days). Most of the oligopeptides and free amino acids detected increased up to the last deadline (690 days); a sharp increase of peptides below 400 Da was the main change in most aged hams. In particular, gamma-glutamyl dipeptides showed a remarkable increase during ham extended aging, acting like permanent taste-active compounds, being unsuitable for further enzymatic breakdown. The pH of fresh hams showed negative relationships (P < 0.001) with most peptides. With regard to free amino acids, the pattern was modified by different processing lengths, together with their taste categories, so that the amino acids having monosodium glutamate-like and bitter tastes were enhanced in more aged hams.