Characteristics of Dry-Cured Hams as Affected by Needle Tenderization and Vacuum Packaging

Needle tenderization of skinned hams accelerated salt absorption and weight loss and shortened curing time for dry-cured hams. Vacuum packaging of hams after they achieved an 18% weight loss prevented most additional weight loss thus yielding a higher percentage of moisture and a lower percentage of salt than in nonpackaged hams. Total bacterial and lactobacilli counts were higher in packaged hams but did not affect internal appearance scores or sensory evaluation scores. In general, the use of needle tenderization and vacuum packaging was helpful in reducing curing and aging time and in controlling yields in dry-cured hams.     

原料腿对金华火腿腌制及产品品质的影响

采用传统工艺和新工艺加工金华火腿,研究了原料腿重量、鲜冻状态、皮下脂肪厚度对金华火腿腌制过程和加工品质的影响。结果表明:原料腿重影响腌制用盐量、加工各阶段后的失重率、后熟后的产品质量;皮下脂肪厚度影响腌制进程和腌制失重率;冻腿可以作为金华火腿加工的原料腿,但产品加工质量略差。     

Effect of Tumbling and Tumbling Time on Quality and Microflora of Dry-Cured Hams

Thirty-two intact hams were utilized to study the effects of tumbling and tumbling time (1 hr continuous, 3 hr intermittent, 6 hr intermittent) on the quality and microflora of intact dry-cured hams. Tumbled hams had higher salt concentrations, lower moisture percentages, and showed more muscle separation and excessive surface drying. Sensory panel scores were similar for all treatments except that 3 hr intermittently tumbled hams had higher salt and lower overall satisfaction scores. Tumbling significantly accelerated salt and nitrite penetration during the Fust 2 wk of curing but had little subsequent effect. Tumbled hams generally had lower microbial counts; however, after aging all hams were of acceptable microbial quality.     

Salt and Aging Time Effects on the Viability of Trichinella spiralis in Heavy Dry-cured Hams and Shoulders

SUMMARY: 28 pigs weighing approximately 100 lb were dosed with 10,000 to 15,000 excysted trichina larvae, grown to 285 lb and sacrificed. Fresh lean samples from one ham and shoulder per carcass were digested in a pepsine-HCI solution and microscopically examined to determine infection rates. 24 of the more heavily infected hams and shoulders then were selected for further observations. The hams and shoulders were dry-cured for 2 days per lb, using an 8% cure applied in 3 equal applications at 5-day intervals. The cure contained salt, sugar, potassium nitrate and sodium nitrite. After curing, the meat was placed in salt equalization for 30 days, smoked for 24 hr at 100°F and aged at 75°F until termination of the study. Cored lean samples were taken from 8 hams and shoulders at weekly intervals after salt equalization and analyzed for salt concentrations and viability. Viable trichinae persisted throughout curing, salt equalization, smoking and 2 weeks of aging. Samples taken from hams and shoulders after 3 weeks of aging were found to be free of any live trichinae. Similar lean samples were taken at this time and force fed to rats for 5 days. After 8 weeks on a commercial ration the rats were sacrificed, artificially digested and examined. No trichina larvae could be recovered.     

EFFECT OF CURING INGREDIENTS, SKINNING, AND BONING ON YIELD, QUALITY, AND MICROFLORA OR COUNTRY HAMS

Green hams were left intact, partially skinned, fully skinned, and fully skinned and boned. They were dry-cured with or without nitrate and aged 3 months. The presence of nitrate had no effect on the variables studies. Percent moisture loss and accompanying weight loss increased with each further removal of protective fat and skin. Percent residual salt was in proportion to weight loss. Residual nitrite was low for all groups Color and aroma scores were similar for all groups. General appearance scores, however, were lowest for the drier boneless group. Shear values were greatest while organoleptic flavor and over-all satisfaction scores were lowest in the boneless group. Tenderness scores were similar for the skinless and boneless group but both were lower than for the intact or partially skinned groups. In general, microbial counts were highest for surface samples from completely skinned fresh hams and lowest for partially skinned fresh hams. Higher counts were obtained for core samples from boneless fresh hams than for intact hams. Aerobic (26° and 37°C), lactobacilli, enterococci. streptococci. yeast and mold surface, and core counts tended to decrease during the manufacture of aged dry-cured hams. No trends in counts due to ham group or cure treatment were observed during the manufacturing process. At the end of the aging period none of the hams contained bacteria of public health significance. Aged dry-cured hams of acceptable microbial quality can be manufactured using intact, partially skinned, skinned or boneless fresh hams without potassium nitrate as part of the cure mixture.     

Effects of Vacuum Packaging and Potassium Sorbate on Yield, Yeast and Mold Growth, and Quality of Dry-Cured Hams

Two trials were conducted. In the first trial hams were cured by a standard process and aged 1 month at 24°C. Group I hams were not packaged or treated. Group II hams were vacuum packaged and Group III hams were dipped in a 2.5% potassium sorbate solution and also vacuum packaged. All hams were examined after 1 month and the treated group was dipped in a 5% sorbate solution, vacuum packaged and aged an additional 2 months. Vacuum packaging practically eliminated further weight loss while potassium sorbate reduced but did not eliminate mold growth. In the second trial hams were again cured by a standard process and aged at 24°C until they were officially country hams (18% weight loss). Group I hams were not treated whereas group II hams were dipped in a 10% potassium sorbate solution. All were vacuum packaged. After aging one month they were unpacked, weighed, and examined for molds. No significant weight loss had occurred but mold counts were lower in the dipped group. The dipping procedure was reversed so that group I hams were treated and group II hams were not treated. All hams were again vacuum packaged and held a second month. No additional weight loss was noted. Mold growth, though not eliminated, was minimal, and visual and aroma scores for the cut hams were similar and highly acceptable. Tenderness, flavor, saltiness, and overall satisfaction scores for cooked slices were similar and highly acceptable. In general, mold growth can be greatly reduced by the use of potassium sorbate and weight loss can be controlled by vacuum packaging.     

Composition and Palatability of Country Cured Hams Comparing Hot Boning, Cold Boning and Intact Hams

Eighty-four hot and cold deboned and bone-in hams were dry cured and aged as country-style hams. The boneless hams had high visual mold scores due to increased exposed muscle tissue. Hot deboned hams had the highest total aerobic plate count indicating that 6% of fresh weight as cure mix may not be high enough to hinder microbial growth. The same hams were less desirable in initial and secondary flavor and in salt intensity and desirability than those from other treatments. Warner Bratzler and Instron shear values were generally lower in hot processed, boneless hams. An acceptable hot processed, boneless country-cured ham can be produced with one cure application and with a casing.     

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.     

Effect of Potassium Sorbate and Vacuum Packaging on the Quality and Microflora of Dry-Cured Intact and Boneless Hams

Intact and boneless hams were dry-cured and aged with and without potassium sorbate or vacuum packaging. Sorbate had no effect on yield but dry sorbate generally improved panel scores in boneless hams. Vacuum packaging eliminated further weight loss, decreased visual appraisal scores in intact hams but had little effect on sensory scores. After 3 months of aging, aerobic and staphylococci counts were as much as 7 logs lower in nonvacuum packaged controls than in either nonvacuum or vacuum packaged sorbate treated intact hams. Counts within all vacuum packaged groups were similar. Yeast and mold counts were lower in sorbate treated than in non-sorbate treated vacuum packaged hams. After aging, coagulasenegative staphylocci were the predominant species.     

Effects of Potassium Chloride on Properties of Country-Style Hams

Sixteen fresh hams were dry-cured over a go-day period using four curing formulations based on total and partial replacement of NaCl with KC1 (0, 33.3, 66.7 and 100.0%). Total weight loss, moisture, fat, pH, firmness, color, total Cl⁻ and residual NO⁻₂ were not different among treatments at the end of the aging period. Hams with reulacement levels of 66.7 and 100% KCl, when compared to the control, had higher levels of residual NO⁻₃, less aged flavor, were more cohesive and were unacceptable due to extreme bitterness. Samples cured with 33.3% KCl were not different from the control, except for a slight degree of bitterness. Replacement of up to one-third of the NaCl in country-style hams with KC1 appears feasible and could substantially lower the total Na⁺ content.     

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.     

Effect of Continuous Massaging on Bind, Yield, and Color of Hams

Boneless closely trimmed hams were randomly assigned to six treatment groups to determine the effect of massaging time (4, 8, 12, 16, 20, and 24 hr) on selected ham characteristics. All hams were stitch pumped 30% above green boneless weight with a pickle containing water, salt, sugar, sodium tripolyphosphate, sodium erythorbate, and sodium nitrite. Pickled hams were massaged continuously (30 mm forward-30 mm reverse cycle) at 5 rpm in a 4°C cooler. Hams were stuffed into size 7 fibrous casings and processed in a smokehouse to an internal temperature of 67°C. Results showed that a massaging time increased there were significant (P < 0.01) increases in bind, color uniformity, color intensity, and moisture retention.     

Reduction of Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7 During Processing of Country-cured Hams

ABSTRACT: The country-cured ham process, including curing, equalization, cold-smoked or nonsmoked, and aging up to 6 mo, was validated and showed its effectiveness in achieving a 6-log reduction of Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7. The viable counts of L. monocytogenes populations decreased to below detection levels after 206 d, Salmonella populations required 122 d, and E. coli O157:H7 required 66 d. However, L. monocytogenes -inoculated hams were positive and Salmonella spp-inoculated and E. coli O157:H7-inoculated hams were negative following enrichment procedures at the end of the aging process. Therefore, the survival of L. monocytogenes on country-cured ham represents a risk.     

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.     

Rigor Condition, Tumbling and Salt Level Influence on Physical, Chemical and Quality Characteristics of Cured, Boneless Hams

Influence of pre- or post-rigor conditions, short or long-time tumbling and 1.25 or 2.25% salt on the physical and chemical properties, quality and yield of hams were examined. Curing pre-rigor did not inhibit rigor, but long term tumbling slowed rigor development. Cell disruption and salt-soluble proteins extraction were enhanced more by processing pre-rigor than post-rigor. Pre-rigor intermittent tumbling for 18 hr produced a more uniform cured color and a more desirable slice appearance. Cohesiveness was improved by 18 hr intermittent tumbling. Bind strength at 6 hr intermittent tumbling of pre-rigor tissue was equivalent to that of 18 hr intermittent tumbling, suggesting that curing pre-rigor could reduce tumbling time.     

Pre-freezing Hams Affects Lipolysis during Dry-curing

An initial freezing/thawing treatment of raw hams prior to dry-curing was compared to the standard process (refrigerated hams) by assaying free fatty acid generation and carbonyl index in both biceps femoris muscle and adipose tissues throughout curing. More intense lipolysis occurred between 0 and 5 mo for muscle, and 0 and 10 mo for adipose tissue. Lipid oxidation in adipose tissue was higher than in muscle. No significant differences (p<0.05) were observed in lipolysis between refrigerated and frozen/thawed hams at the end of the process. Ham sensory evaluation after 15 mo showed that initial freezing/thawing treatment did not affect final sensory quality except for a more salty taste.     

KCI in Dry Cured Hams: Effect on Trichinae Devitalization and Chemical and Physical Properties

Thirty trichina-infected hams were dry-cured under laboratory conditions for 62 and 69 days using three curing formulations which included the partial (0%, 25% and SO%) substitution of NaCl by KCI. Each treatment rendered the product free of viable trichinae. Sixty commercial hams were processed at a dry-cured ham plant. A high incidence of spoilage (62%) was observed among hams commercially processed. The degree of spoilage appears to be associated with the final sodium plus potassium content of the product. This study suggests that potassium cnhanccs the absorption of curing ingredients thus providing better protection against spoilage microflora. Under minimal processing conditions. both NaCl and KCI have essentially the same ability to devitalize trichinae in drp-cured hams.     

金华火腿传统工艺优化和主要技术参数间的相关性分析

用JMP软件DOE程序包中custom design程序对金华火腿传统加工工艺进行了6因素3水平优化实验设计,并以144条浙江兰溪当地杂交猪后腿为原料,按照实验设计要求进行了加工试验。以成熟后和后熟后试验火腿的感官评定结果为响应值,用JMP内部分析程序对试验结果进行了方差分析,并用SPSS统计软件对加工过程中的主要技术参数和感官评定结果进行了相关分析。结果表明,腌制期、浸腿时间和成熟期的挂腿位置是影响产品质量的重要因素,最佳工艺组合为腌制期30d,浸腿时间18h。上层挂腿位置小气候成熟条件,腿胚重、用盐量和各主要工序后的产品总失重率之间,及其与产品感官质量指标之间都存在显著相关关系,可以通过原料腿标准化和控制各工序后的产品总失重率来控制产品质量。     

部分KCl替代NaCl对强化高温成熟工艺干腌火腿肌肉色泽形成的影响

采用强化高温成熟现代工艺(36℃强化高温成熟45 d,用盐量6.5%,以火腿质量计)制作干腌火腿,分析加工过程中火腿半膜肌盐分含量、水分含量、p H值、色差值、肌红蛋白氧化状态、血红素类色素和锌卟啉(Zn-protoporphyrin,Zn-PP)Ⅸ含量,研究火腿色泽的形成及KCl替代Na Cl对火腿加工过程中色泽变化的影响。结果表明:盐量30%KCl替代Na Cl对干腌火腿产品理化特性、色差值及色素状态和含量没有显著影响(P0.05);干腌火腿的独特色泽是由肌红蛋白的氧化状态、红色色素的含量及肌肉组织的状态共同形成的,火腿加工过程中氧合肌红蛋白(oxymyoglobin,OMb)和高铁肌红蛋白(metmyoglobin,MMb)相对含量分别上升约22.07%和25.21%,脱氧肌红蛋白(deoxymyolglobin,DMb)相对含量下降约47.27%,DMb与亮度L*值呈极显著正相关(P0.01),OMb、MMb与L*值呈极显著负相关(P0.01),并受OMb与MMb相对含量比值极显著影响(P0.01)。在较低范围内(0%~27.49%),MMb相对含量越高红绿度a*值越大,并且MMb的影响力大于OMb。血红素类色素和Zn-PPⅨ含量在火腿加工过程中都显著增加,约394%和5 296%,并与a*值和色饱和度C值呈极显著正相关关系(P0.01)。     

Staphylococcus aureus survival, staphylococcal enterotoxin production and shelf stability of country-cured hams manufactured under different processing procedures

Fresh hams were inoculated with Staphylococcus aureus, cured, equalized, cold smoked or non-smoked, and aged. Initial S. aureus populations of 8.57 and 8.12 Log(10) CFU/cm(2) for salt and salt+NO(2)hams decreased to below the levels of detection after the fourth month of aging. S. aureus was detected following enrichment for 75% of the inoculated and 62% of the control hams at the end of the aging period. Staphylococcal enterotoxin was detected in 40% of the inoculated and 50% of the control hams following the aging period. The NaCl content of these hams with or without nitrite were 4.45/3.37% and a(w) values 0.94/0.91. Country-cured ham products obtained from retail stores in Kentucky were all negative for S. aureus enterotoxin. These results indicate that higher salt content and lower a(w) values on country-cured hams play an important role in controlling the growth and toxin production of S. aureus.