Proteolysis,Texture, and Sensory Characteristics of Serrano Hams from Duroc and Large White Pigs during Dry‐Curing

Proteolysis, texture, physicochemical, and sensory characteristics of Serrano hams from Duroc and Large White pigs at 5, 7, 9, 12, and 15 m of curing (3 hams per breed per curing time) were investigated. Higher concentrations of some sarcoplasmic and myofibrillar proteins, peptides with molecular mass in the ranges 3700 to 12000 Da, 700 to 2000 Da, and below 450 Da, and total free amino acids were recorded for Large White hams, while hydrophobic peptides were at higher levels in Duroc hams. A 40 kDa peak in the low‐ionic‐strength soluble protein fraction and 2 peaks of 40 and 45 kDa in the high‐ionic‐strength soluble protein fraction found only in Duroc hams could be of use in discriminating products from different breeds. Physicochemical and textural characteristics of both types of hams evolved similarly during curing and differences in organoleptic traits between breeds were negligible. Flavor intensity and flavor quality of hams were strongly correlated to curing time, with r² values over 0.95 for flavor intensity and over 0.90 for flavor quality, and to the concentration of total free amino acids, with r² values over 0.90 for both flavor intensity and flavor quality. The sensory evaluation scores of Duroc hams, at least as high as those of Large White hams, make the production of high‐quality Serrano ham from pure breed Duroc pigs feasible. Practical Application: Duroc breed crosses are advantageous in the production of dry‐cured hams, resulting in higher marbling, enhanced flavor and lower processing losses, but the characteristics of pure breed Duroc hams have not been investigated. The similar evolution of the compositional, proteolytic, textural, and sensory characteristics of Serrano hams from Duroc and Large White pigs during dry‐curing recorded in the present work makes the production of high‐quality dry‐cured hams from pure breed Duroc pigs feasible. Three protein peaks found only in Duroc hams can be of use to discriminate products from different breeds.     

Associations between two gene markers and indicator traits affecting fresh and dry-cured ham processing quality

The study objective was to evaluate the effects of mutations in two genes, PRKAG3 and CAST, on fresh and dry-cured processing characteristics. Processing and curing followed normal commercial procedures. A 100 g sample of the semimembranosus was excised and frozen for later DNA harvest. Genotypes for CAST, and PRKAG3 were determined after DNA extraction from the frozen samples. The PRKAG3 marker had no affect on dry-cured ham processing characteristics. The CAST gene marker was a significant source (P<0.05) of variation for cured ham moisture content and tended to be a significant source (P<0.10) for yield, ham weight loss, salt content and Minolta color change. The data demonstrate that the CAST 11 genotype is associated with greater processing yields. Alternatively, selection or sorting for the CAST 22 genotype should produce cured hams that exhibit more efficient moisture loss and, as a result, require less processing time and contain greater salt content.     

PALATABILITY AND VISUAL CHARACTERISTICS OF HAMS AND LOIN CHOPS FROM SWINE TREATED WITH RACTOPAMINE HYDROCHLORIDE

This study was designed to evaluate the visual and palatability characteristics of boneless cured hams and fresh loin chops from pigs fed diets containing 0, 5, 10 or 20 ppm of the phenethanolamine, ractopamine hydrochloride (RAC). Sixty pigs were blocked by starting weight and randomly assigned to pens (four pigs/pen) within each of three blocks. Treatments were then randomly assigned to pens (six pens of the 0–ppm level and three pens each for the 5, 10 and 20 ppm RAC levels). Animals were slaughtered by weight block after approximately 48 days on trial. Fresh pork hams and loin sections (10–14th rib) were removed from the right side of the carcasses for subsequent analysis. Boneless hams were manufactured using commercial curing procedures. RAC had no effect (P > 0.05) on visual or palatability attributes of ham slices or boneless loin chops. Moisture content of the longissimus muscle from RAC treatments was lower (P < 0.05) than controls; however, this difference was small. These results indicate that RAC had no affect on the visual or palatability characteristics of boneless cured and smoked hams or fresh boneless pork loin chops.     

Pig sire type and sex effects on carcass traits,meat quality and physicochemical and sensory characteristics of Serrano dry‐cured ham

This study demonstrates that improvements in animal line selection by breeding enterprises exert a strong effect on carcass traits, meat quality and sensory characteristics of Serrano dry‐cured ham. A total of 461 pigs from the offspring of a Duroc (DU) × Landrace (LD) sow mated with two DU boars and a DU × Large White (LW) boar from three breeding enterprises were evaluated. The two DU terminal sires were significantly different (P < 0.05) in carcass conformation, backfat thickness, ham and loin yields, raw ham traits, myoglobin concentration and total pigments formed during the curing process; in addition, the two lines provided different percentages of hams (54 vs 91%) with sufficient subcutaneous fat and weight to manufacture dry‐cured Serrano hams using a slow ripening process (11 months). The DU × LW sire had the best carcass and ham traits from an economic standpoint and obtained highest scores for sensory characteristics of Serrano ham evaluated by a trained panel test; furthermore, this line provided 84% of total hams suitable for manufacturing Serrano hams by a slow process. When the sex effect was analysed, carcass and ham traits of females were more favourable, but females presented a higher incidence of pale, soft and exudative (PSE) meat and a lower percentage of hams with sufficient subcutaneous fat and weight to produce Serrano hams using a slow ripening process (61% for females and 91% for castrates). On the other hand, castrates provided Serrano hams cured by a slow procedure with better organoleptic characteristics than females. Right and left hams were similar. Copyright © 2005 Society of Chemical Industry     

Lipolysis,Lipid Peroxidation,and Color Characteristics of Serrano Hams from Duroc and Large White Pigs during Dry‐Curing

Lipolysis, lipid peroxidation, and colorimetric characteristics of Serrano hams from Duroc and Large White pigs along a 15‐mo curing period were investigated. Physicochemical parameters of both types of hams evolved similarly during curing. Twelve of 13 free fatty acids (FFAs) increased during curing, eicosatrienoic acid being the only exception. Linoleic, stearic, and arachidonic acids and the minor heptadecanoic acid reached lower concentrations, and the rest of minor FFAs higher concentrations, in Duroc hams than in Large White hams. The index measuring the early stage of lipid peroxidation declined from month 5 onwards, indicating that the phenomenon had been completed by month 5, while the index of the secondary stage of lipid peroxidation increased with curing time. Higher values were found for the 1st index in Duroc hams. Curing affected color parameters. Lightness decreased and redness increased in both types of hams, while yellowness decreased only in Duroc hams. Lower redness values were found for Duroc hams. Major differences in color parameters were found between muscles. Principal components analysis of FFAs yielded 2 main principal components. The 1st factor, correlated with all FFAs excepting eicosatrienoic acid, allowed discrimination between curing times. The 2nd factor, correlated with eicosatrienoic acid, permitted discrimination between breeds.     

THE STUDY OF INGREDIENTS AND PROCESSING TECHNIQUES OF XUANWEI STYLE HAM

Xuanwei style ham is one of the famous dry-cured hams in the world. The influences of different ingredients and processing techniques on sensory properties, brine diffusing rate, chemical composition and hygienic quality of Xuanwei style cured ham were studied. Modified cured ham processing techniques were employed in this study. Massaging of green ham and injection of curing solution improved brine diffusing rate ( P <  0.05) and reduced curing time from the traditional 28 days to 21 days (weight of green ham about 13 kg). Ninety mg/kg sodium nitrite was used for improving cured ham color ( P <  0.05), and its residue still met the Chinese cured ham standard of 20 mg/kg. The hygienic and sensory qualities were not significantly affected by the addition of sodium ascorbate and polyphosphate ( P >  0.05).

PRACTICAL APPLICATIONS

The paper studied the Chinese famous Xuanwei dry-cured ham, modified curing ingredient and processing techniques of Xuanwei ham are beneficial for improving the ham quality and important to shorten the traditional cured ham processing procedure such as longer processing time and seasonal processing method to adapt to the new industrial procedures of manufacturing and marketing of Xuanwei cured ham.     

Phenotypic correlations among quality traits of fresh and dry-cured hams

In this study, fresh and processing quality traits were collected on a total of 312 Country Hams. Phenotypic correlations between traits were estimated and numerous values were significantly different (P<0.05) from zero. Yield was significantly correlated with several fresh pork quality traits measured on the fresh hams, including subjective color (0.34) and lipid percentage (0.32). Some meat color traits were significantly correlated, including associations between the color scores taken on the fresh and cured hams. Correlations between fresh pork quality traits were also determined, with results showing significant correlations between ultimate pH and other pork quality traits. The results indicate that yield can be maximized if hams with good fresh pork quality parameters are used for curing. The correlations estimates are helpful for understanding of the biological mechanisms behind the production of dry-cured hams and can potentially be used to improve the efficiency of the dry-cured ham production chain.     

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.     

A RESEARCH NOTE EVALUATION OF RESTRUCTURED LOW-FAT HAM CONTAINING WHEY

Restructured, low-fat boneless ham was formulated with 0 (control samples), 20, and 30% liquid whey to replace water in the cure formulation. Sensory characteristics, visual traits, objective color, tenderness measurements, weight and cooking loss, proximate analysis, and microbial load were determined to compare this product with that from a conventional cure formulation. No differences (P>0.05) in traits (except percentage moisture) were found among samples with 0, 20, and 30% liquid whey in the formulated hams. A lower (P<0.05) moisture content among samples with 30% of this adjunct when compared to the controls was observed. However, samples with 20% liquid whey addition did not differ (P>0.05) from those with 0 and 30%. These results suggest that up to 30% liquid whey may be incorporated in a cured, low-fat ham formulation with similar results to products cured with a conventional formulation.     

不同来源和年份诺邓火腿的理化和呈味性质

为研究市售常见诺邓火腿的差异,对具有地域特色的诺邓火腿进行综合评价。以洋三元白猪、诺邓黑猪为原材料,按照诺邓火腿工艺加工1、3 年火腿,测定其理化指标、质构特性和游离氨基酸含量,并用电子舌分析其滋味特性差异。结果表明：4 组火腿质地存在明显差异;4 组火腿中均分离出18 种游离氨基酸,精氨酸含量最丰富,亮氨酸、赖氨酸和谷氨酸次之;洋三元白猪火腿（W组）的游离氨基酸含量高于诺邓黑猪火腿（B组）,B组的鲜味氨基酸相对含量高于W组,氨基酸的释放量可明显将1 年和3 年的火腿区分开;电子舌结果表明,B1组的滋味丰富性最大,B3组的咸味最大但鲜味最小,W1组的鲜味较大但丰富性较小,W3组的咸鲜味和丰富性适中。综上,鲜味、丰富性和咸味是诺邓火腿重要的味觉指标,诺邓黑猪火腿滋味较为丰富,B3组硬度、咸味最大,加工过程中要控温控湿。     

Determination of the viability of Toxoplasma gondii in cured ham using bioassay: influence of technological processing and food safety implications

Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii and distributed worldwide. Ingestion of viable cysts from infected raw or undercooked meat is an important route of horizontal transmission of the parasite to humans. Little information is available concerning the effect of commercial curing on cysts of T. gondii. This study is the first in which the influence of processing of cured ham on the viability of T. gondii has been evaluated, using bioassay to assess the risk of infection from eating this meat product. Naturally infected pigs were selected for the study, and a mouse concentration bioassay technique was used to demonstrate viable bradyzoites of T. gondii in porcine tissues and hams. No viable parasites were found in the final product (14 months of curing) based on results of the indirect immunofluorescence assay and histological and PCR analyses. Our results indicate that the consumption of hams cured as described here poses an insignificant risk of acquiring toxoplasmosis. However, additional studies are required to evaluate the safety of ham products cured under different conditions of curing time, salt, and nitrite concentration.     

Incubation of curing brines for the production of ready-to-eat, uncured, no-nitrite-or-nitrate-added, ground, cooked and sliced ham

Salt concentration, vegetable juice powder (VJP) concentration and temperature were investigated to determine necessary conditions for incubation of curing brines including VJP and a starter culture containing Staphylococcus carnosus prior to production of naturally cured, no-nitrate/nitrite-added meat products. Subsequently, incubated brines were utilized to produce no-nitrate/nitrite-added sliced ham in which quality characteristics and residual nitrite concentrations were measured to determine feasibility of brine incubation for nitrate conversion prior to injection. Two ham treatments (one with VJP and starter culture; one with pre-converted VJP) and a nitrite-added control were used. No differences (P>0.05) were found for color in the VJP treatments. Control sliced ham was redder after 42 days of storage, retaining significantly (P<0.05) greater a* (redness) than either of the VJP treatments. Residual nitrite concentration was greater (P<0.05) in the control hams during the first week of storage. While the nitrite-added control retained greater red color and initially had more residual nitrite than the VJP treatments, the two VJP treatments did not differ from each other.     

Salt, Moisture and Aging Time Effects on the Viability of Trichinella spiralis in Pork Hams and Shoulders

SUMMARY– Twenty-four weanling pigs were infested with Trichinella spiralis , by dosing with trichina larvae. The hogs were raised to market weight and slaughtered. Lean samples from each ham and shoulder were digested in a pepsin-HCI solution and microscopically examined. The samples contained respectively an average of 192 and 175 larvae per gram.
The hams and shoulders were dry-cured for 2 days per pound, using 8 pounds of cure per 100 pounds of meat. The mixture contained salt, sugar, potassium nitrate, and sodium nitrite. After being cured, the meat was hung for 30 days for salt equalization, rinsed, allowed to dry, smoked for approximately 24 hr at 90 to 100°F, and aged at 75°F.
Cores were taken from randomly selected hams and shoulders at weekly intervals and analyzed for salt and moisture while part was digested and examined for live trichinae. Live trichinae persisted through the curing and salt equalization periods but began to be reduced in number after one week of aging. Samples taken from hams and shoulders aged for one month were found to be void of any live trichina larvae.
Meat from similar samples was force-fed to rats for 5 days. After 8 weeks the rats were sacrificed and the carcasses digested and examined. No trichina larvae were found.     

Acid/Base Status of Stress Susceptible Pigs Affects Cured Ham Quality

Twenty-four halothane positive (HP) pigs received ammonium chloride (8 g/L), sodium bicarbonate (12.6 g/L) or water (HP control) ad libitum for 4 days and were then slaughtered. Hams from HP animals were pale, soft and exudative (PSE) and of inferior processing quality. Ammonium chloride induced a metabolic acidosis which further impaired cured ham quality (greater thaw purge, lower juiciness scores and less uniform slice appearance than comparable hams from control or bicarbonate treated HP hogs). Blood pH, carbonate and chloride concentration (day 3) were related to cured ham quality, indicating that acid-base balance may influence subsequent meat quality. Use of an alkaline salt provided little protection against PSE.     

Validation of Dry Cured Ham Process for Control of Pathogens

ABSTRACT: The dry curing process for hams to control Salmonella spp., Escherichia coli O157:H7, Listeria monocytogenes , and Staphylococcus aureus was evaluated. Fresh hams, surface inoculated with each microorganism, were processed by a commercial style process. There was no significant (p < 0.05) difference in reduction of microbial populations between ham sampling locations (cushion, butt, hock). Interaction of salt concentration (8%), pH (5.5), ham storage temperature (20 °C), and ham aw (0.92) limited staphylococcal proliferation. Mean log reduction of Salmonella spp., E. coli O157:H7 and L. monocytogenes populations on inoculated hams after 69 d of curing were 5.5, 5.5, and 4.0 CFU/cm², respectively and after 120 d were 5.7, 5.5, and 4.8 CFU/cm², respectively. Keywords: dry cured ham, Salmonella, Esherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus     

Qualitative effects of fresh and dried plum ingredients on vacuum-packaged,sliced hams

Boneless ham muscles (Semimembranosus + Adductor) were injected (20% w/w) with a curing brine containing no plum ingredient (control), fresh plum juice concentrate (FP), dried plum juice concentrate (DP), or spray dried plum powder (PP) at 2.5% or 5%. Hams were cooked, vacuum-packaged, stored at <4 °C and evaluated at 2-week intervals over 10 week. Evaluations were performed on sliced product to determine cook loss, vacuum-package purge, Allo–Kramer shear force, 2-thiobarbituric acid-reactive substances (TBARS), proximate analysis, objective color, sensory panel color and sensory attributes. FP, DP and 2.5% PP increased (P < 0.05) cook loss by 2% to 7% depending on treatment and level, but the highest cook loss (17.7%) was observed in hams with 5% PP. Shear force values increased as the level of plum ingredient increased (P < 0.05) from 2.5% to 5%, and the highest shear values were observed in hams containing 5% FP. There were no differences (P > 0.05) in lipid oxidation among treatments as determined by TBARS and sensory evaluation. FP and PP ham color was similar to the control, but DP had a more intense atypical color of cured ham. Minimal changes in physical, chemical and sensory properties were observed during storage of all treatments.     

Effect of intensifying high‐temperature ripening on proteolysis,lipolysis and flavor of Jinhua ham

BACKGROUND: The flavor quality of dry‐cured ham comes from proteolysis, lipolysis and lipid oxidation, Maillard reaction and Strecker amino acid degradation. Intense proteolysis, lipolysis and lipid oxidation make major contributions to flavor development of dry‐cured ham. Increasing the temperature in fermenting and ripening could promote these reactions and accelerate flavor development in dry‐cured hams. The specific aroma flavor of Jinhua ham is developed only during long‐time high‐temperature ripening in July and August. Our objective was to effectively shorten the process time by intense high‐temperature ripening based on the flavor and quality features of traditional Jinhua ham. RESULTS: Muscle dehydration rate of 80‐day ripened hams (29.43 ± 1.16%) was higher than that of the traditional process (P < 0.05). The total free fatty acids in ripened hams of 45–80 days were all higher than that of traditional hams (P < 0.05) and the level of TBARS was significantly lower (P < 0.01). The flavor profile of modern‐processed hams was different from that of the traditional Jinhua ham. The contents of carboxylic acids and aldehydes were obviously higher than those of the traditional products (P < 0.05). The results of organoleptic evaluation for flavor and quality showed that 80‐day ripened hams reached the first‐grade level of traditional Jinhua ham. CONCLUSION: Long‐time (25–30 days) intensifying high‐temperature ripening (35–37 °C) could accelerate the proteolysis, lipolysis, lipids oxidation, flavor development and effectively shorten the process time based on the traditional flavor and quality features of dry‐cured ham. Copyright © 2009 Society of Chemical Industry     

Effects of breed and age at slaughter on degradation of muscle lipids during processing of dry‐cured hams

Hams from Landrace, Duroc and Hampshire pigs slaughtered at ages 6, 7.5 and 9 months were processed to generate Norwegian Parma‐style hams. Lipid contents and the compositions of fatty acid classes (ΣSFA, ΣMUFA, ΣPUFA) within neutral lipids, phospholipids and free fatty acids were determined. Small differences in lipid degradation and composition of the classes were revealed. However, significant sensory differences related to lipids were observed. Breed was more important than age. Dry‐cured Hampshire hams gave a more intense mature odour that may be associated with higher overall lipid degradation. Unexpectedly, these hams also demonstrated high juiciness and tenderness, which could be related to the melting characteristics of the fat. Dry‐cured Duroc hams showed a higher susceptibility towards rancidity, presumably associated with preferential oxidation of n‐6 fatty acids relative to C18:1 n‐9. Dry‐cured Landrace hams showed the lowest juiciness and tenderness, likely due to their lower fat content (marbling).     

Study of the branched hydrocarbon fraction of intramuscular lipids from Iberian dry-cured ham

Branched hydrocarbons from the unsaponifiable lipid fraction of intramuscular fat from Iberian dry-cured hams were analyzed. Thirty-four hams were distributed into four groups according to the feed system of the pigs (extensive system "Montanera" and intensive system "Pienso") and genotype (Iberian and Iberian×Duroc). A total of 35 different hydrocarbons were identified in this study. Some differences were found in the levels of branched, cyclical and unsaturated hydrocarbons as a function of the diet of the pigs (3-hexyl-1,1-dimethyl cyclopentane, p<0.05; 3-octadecene, p<0.01; neophytadiene, p<0.001; 1-ethylundecyl benzene, p<0.01; cyclohexadecane, p<0.001; cyclotriacontane, p<0.05). However, the genotype had a limited effect in the level of branched hydrocarbons found. The study of branched hydrocarbons in intramuscular fat from dry-cured Iberian ham allows differentiation between the pigs management systems.     

Sex and crossbreed effects on the characteristics of dry-cured ham

The right ham of 76 gilts and 82 barrows from five different crossbreeds, which included Duroc (DU), Landrace (LR), Large White (LW) and Belgian Landrace (BL) lines - DUx(LRxLW), LWx(DUxLW), LWx(LRxLW), BLx(DUxLW) and BLx(LRxLW) - were processed to produce dry cured hams. The external appearance of the hams, and the colour and thickness of the subcutaneous fat were determined. Chemical analyses, appearance, texture, flavour and odour were evaluated on biceps femoris (BF) muscle. The hams from the barrows showed a thicker and whiter layer of subcutaneous fat, higher marbling and lower processing loss than those from gilts. Hams from DU-sired pigs presented the highest marbling, but the worst texture characteristics. The texture characteristics of the hams from the LBx(LRxLW) cross were similar to those of the hams from DU-sired pigs. The hams from the LW-sired crosses showed the highest intensity of holes surrounding the coxo-femoral joint. The LBx(DUxLW) could be the most suitable among the five crosses studied for dry-cured ham production under the processing conditions used in this study.