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Hams were placed in cure after thawing by 3 methods: at 2C, at 16C, and in water at 37C. A fourth group was placed in cure while still frozen. Microbiological populations and fat rancidity tests were determined at various intervals during processing. Sensory scores and tenderness values were determined after 3 months of aging. Clostridium perfringens , Bacillus cereus , Escherichia coli , coliforms and enterococci were not detected after salt equalization. Hams cured without thawing had lower initial bacterial, yeast and mold counts but no differences among thaw groups were observed in counts during aging. Hams thawed in water had lower flavor and overall satisfaction scores than the other groups. Fat breakdown as noted by FFA, TBA and peroxide values increased with aging but were erratic although ham cured without thawing had lower peroxide values. Satisfactory dry-cured aged hams were produced regardless of method of thawing. However, since hams cured without thawing had less weight loss, lower peroxide numbers, lower initial microbial counts and similar final microbial counts and sensory scores, it appears that hams do not need to be thawed to produce dry-cured aged hams.

The effects of needle tenderization on the curing processes and final cured ham properties of packer style and skinless hams were investigated. Skinless hams absorbed salt faster and lost weight faster than packer style hams. Needle tenderized hams also absorbed salt faster and had more weight loss than nontenderized hams in both the packer style and the skinless groups. Two months'aging resulted in excess dehydration and lowered quality in the skinless tenderized group. In skinless hams, curing, salt equalization and aging times were reduced so that acceptable, though mild flavored, hams that met the USDA requirements for weight loss and salt content were produced within 5 wk.

Hams were cured and aged by three methods, two using nitrite and nitrate but with long or short aging times at controlled temperature, and one using no nitrite or nitrate with ambient aging temperature. Hams were sliced, vacuum-packaged and stored at 0°C, 10°C or 21°C for 8 wk and examined weekly for white film, aroma, and aerobic, staphylococci, lactobacilli, yeast and mold counts. White film development was erratic. Aroma was closely related to aerobic counts. At 0°C bacterial counts and aroma remained normal for 8 wk. At 10°C many packages had acceptable counts and aroma at 8 wk but some were unacceptable by 4 or 5 wk. At 21°C many slices were unacceptable microbiologically and sensorily by 3 wk. Storage at or near 0°C is recommended for long shelf life.

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.

Fifty frozen hams were thawed for 3 d at 2-3°C, skinned and partially defatted. Half the hams were passed twice through a Ross Industries needle tenderizer and half were not tenderized. All hams were dry-cured for 16 d with a mixture of salt, sugar, sodium nitrate and sodium nitrite. Cores of 2.54-cm diameter were obtained from the cushion of 5 hams from each group weekly for 5 weeks. Outer, middle and inner portions of the cores were analyzed for salt and nitrite. After curing, all hams were held at 13°C for 14 or 15 d for salt equalization. The intact hams were smoked and aged at 24°C until a yield of 82% or less was achieved. Half the hams in each group were then placed in vacuum bags and half were left uncovered. All were aged 4 additional weeks at 24°C. Hams were cut and examined visually, by a palatability panel, by shearing and by analyzing a center slice for moisture, salt and nitrite. Tenderization allowed faster salt and nitrite absorption but resulted in slightly lower flavor and overall satisfaction scores. Tenderized hams achieved the required 18% weight loss (82%) approximately 10 d sonner than non-tenderized hams. Vacuum packaged hams had higher final yields and contained a higher level of moisture and lower level of salt than non-vacuum packaged hams. Shear values in semitendinosus muscles were greater for tenderized than for nontenderized hams while shear values in biceps femoris muscles were higher in non-vacuum packaged than in the vacuum packaged hams. Aerobic and yeast and mold counts were higher while lactobacillus counts were lower in non-tenderized than in tenderized hams. Aerobic and lactobacillus counts were higher in vacuum packaged than in non-vacuum packaged hams. In general, tenderization allowed faster curing and aging while final aging in vacuum bags allowed higher yields.

The effects of mechanical pressing and a 10% potassium sorbate dip on microbial and organoleptic properties of boneless dry-cured hams were studied. Pressing resulted in higher nitrite levels, higher cooking losses and lower Warner-Bratzler shear values (P 0.05) yields, final microbial counts or sensory characteristics. Potassium sorbate improved visual mold scores (P

Forty-two similar weight hams were held 3 and 6 days postmortem at 2 C, dry-cured, and held at 13 C for 4 weeks for salt equalization. Half were then smoked and half were not smoked. All hams were aged for 3 months at 24 C. Six hams from each group were selected for external microbial evaluation and three were selected for internal microbial evaluation before curing, after curing, after salt equalization or smoking, and after aging 1, 2 and 3 months. Aerobic counts were higher in hams held 6 days than in those held 3 days but the difference decreased as processing time progressed. Smoking decreased surface counts. Enterococci, Bacillus cereus and fluorescent pseudomonads counts were initially low and these organisms were virtually absent after aging 1 month. Coliforms were initially low and were not detected after salt equalization. Staphylococci increased through 3 months of aging with very few isolates being coagulase-positive. Yeasts and molds increased gradually through processing and aging. No Clostridium perfringens or Salmonella were detected in uncured hams. There were no significant differences in palatability traits due either to pre-cure holding time or smoking.

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.

SEVENTY-TWO HAMS were utilized to study the effects of KCl replacement level (100:0, 70:30, 50:50 ratios of NaCl and KCl), boning time and mechanical tenderization on the quality and microflora of boneless dry-cured hams. Boning time had no effect on palatability or final yield. Hotboned hames had higher levels of residual nitrite and slightly higher microbial counts. Mechanical tenderization improved tenderness and microbial quality. However, tenderized hams had lower flavor preference and overall satisfaction scores. The replacement of NaCl with KCl at a level of 30% had no effect on palatability or microbial quality. NaCl replacement at a level of 50% severely decreased palatability and increased microbial numbers.

Four groups of 15 hams each were divided as follows: Group 1 was placed in cure while frozen. Groups 2, 3 and 4, respectively, were placed in cure after thawing at 3°C, 15°C or in running water at 38°C. After curing 4 wk at 3–4°C and salt equalization at 13°C for 4 wk, they were smoked 24 hr at 38°C and aged 3 mo. at 24°C. Hams were sliced, evaluated for color and odor, cooked, evaluated by a palatability panel and sheared for tenderness; lean was analyzed for moisture, salt and nitrite. Various microbial counts were made on surface and core samples at different processing periods. Group 1 had the least weight loss with no differences between groups 2, 3 and 4. Color, aroma, general appearance and palatability scores and nitrite content were similar for all hams. Shear values were lower for the semimembranosus muscle in group 1. Other shear values were similar. Group 1 was lower in salt and higher in moisture than groups 2, 3 and 4, with no differences among the latter three groups. No bacteria of public health significance were detected in or on hams before curing or after 3 mo aging. Freezing and storage seemed to cause injury to some microbial species and resulted in failure to recover selected pathogens and some nonpathogens from thawed hams. Higher initial surface counts were obtained from hams thawed before curing than from hams cured frozen. Hams cured frozen had higher surface counts after curing than hams thawed before curing. The results probably are related to the lower salt and higher moisture levels of hams cured frozen, as well as to the method used to thaw the 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.

Histological properties from the longissimus (LD) and semimembranosus (SM) muscles of 51 wether and ewe lambs from Hampshire rams and two ewe genetic types (SR, 1/2 Suffolk and 1/2 Rambouillet, and FS, 1/2 Finnish Landrace and 1/2 Southdown) and three slaughter live weights (32, 41 and 50 kg) were compared. Fibers in both muscles were classified as beta R (red), alpha R (intermediate) or alpha W (white). All LD muscle fiber types from FS ewe lambs increased in diameter from 32 to 41 kg, but decreased in diameter from 41 to 50 kg. Also, this quadratic effect with slaughter weight was found in alpha R and alpha W fibers from the SM muscle of FS wether and ewe lambs. However, diameters of alpha R and alpha W fibers from SR wether and ewe lambs and beta R fibers from SR ewe lambs increased linearly in the SM muscle with increasing slaughter weight. As slaughter weight increased, the proportion of alpha R fibers decreased in both the LD and SM muscles for SR wether and FS wether and ewe lambs. Concurrent with the increase in slaughter weight and decrease in alpha R fiber percentage, the proportion of alpha W fibers increased in the LD muscle of SR wether lambs, the SM muscle of SR ewe lambs and both muscles of FS wether and ewe lambs. Genetic type and sex groups, except SR ewe lambs, support the theory of transformation of alpha R to alpha W fibers with increasing slaughter weights. Fat-cell diameters increased in both muscles of SR wether and FS ewe lambs with increasing slaughter weights. Increases in fat traits of lamb carcasses were related to increases in red-fiber size. Alpha red fiber numbers were inversely related (P less than .05) to alpha W fiber numbers in both the LD and SM muscles (r = -.83 and -.79). The proportion of alpha R to alpha W fibers might be used as an indicator of physiological maturity for lambs.

60 hams of approximately number 3 quality (Wisconsin Score) were divided into three groups of 20 hams each. Group 1 was unskinned, group 2 was normally skinned and group 3 was fully skinned. All hams were processed by standard dry-cure procedures and weighed at each processing step. 30 hams, including 10 from each group, were evaluated organoleptically and tested for peroxide values, salt content and moisture content, after 1 months’ aging and the remaining 30 after 3 months’ aging. The skinned hams had significantly higher skinning loss, shrinkage, salt content and shear values than the normally skinned or unskinned hams. The unskinned hams had the highest tenderness scores and lowest shear values and salt content. The normal skinned hams were scored highest for flavor. Overall eating satisfaction and rancidity values appeared to be unaffected by skinning.

Thirty-three wether and ewe lambs of two breed groups- Suffolk ram x Suffolk-Rambouillet ewe (Su x R) and Suffolk ram x Finnish Landrace-Southdown ewe (Su x F x So)-and two slaughter weight groups (32 and 41 kg) were studied. Carcass studies, including histological examinations of muscle fiber types, sarcomere lengths and fat cell, were made. The longissimus (LD) muscle at the 13th rib and a sample of the semimembranosus (SM) from the upper proximal location were used. Fibers in both muscles were classified as beta R, alpha R or alpha W. Su x F x So lambs had more alpha W fibers and fewer alphaR fibers in both muscles. Breed type appeared to cause a physiological shift from alpha R to alpha W fiber types. Furthermore, beta R fibers were larger in the SM of the Su x F x So lambs than in that of the Su x R lambs. beta Red fibers in the LD, and all three types fibers in the SM, increased in size with increased weight. Wethers had fewer alpha R fibers in the SM, while ewe lambs had larger alpha R and alpha W fibers in the SM. The more phasic LD muscle had fewer beta R fibers, more alpha W fibers and smaller alpha R and alpha W fibers than the more tonic SM. Su x F x So lambs were fatter, as indicated by larger fat cells in both muscles. In addition, as slaughter weight increased, there was a concurrent increase in fat cell diameters in both muscles. Fat cells were larger in the LD than in the SM. Sarcomere lengths were not affected by breed, slaughter weight or sex. However, sarcomeres were longer in the SM than in the LD. Fat cell size and beta Red cells size for the LD were positively correlated with carcass fat indices, while shear values were negatively correlated with fat cell diameters. There was also a positive relationship between sarcomere length and fat cell size in the SM.

The Barton-Kirton (B-K) method of lamb carcass analysis, using large samples, was compared with routine, AOAC analysis, using small samples. Correlations between the two methods were highly significant for moisture, fat, and protein but not for ash. Regression equations for predicting ash, based on fat content, were developed and appear to be more accurate for estimating ash than the B-K technique.

Physical and chemical composition and carcass measurements were determined on a total of 126 lamb carcasses from nine New Zealand export grades (seven wether and seven ewe carcasses per grade). In general, carcasses of the Down (Prime Down Cross) and Prime (Prime Crossbred) grades of comparable weight were similar in composition, while carcasses of the Y (Second or F.A.Q. — fair average quality) and Alpha grades contained more lean and bone and less fat and had more protein and moisture and less chemical fat than the carcasses in the Down and Prime grades. Ash patterns were not consistent. Mean external and internal measurements showed that angular carcasses of the Y grades were longer and generally narrower in the forequarter, and had smaller and shallower ribeyes than the blockier carcasses of the Down grades.

Aged ham slices, bone-in or boneless, were vacuum-packaged and stored at 2°C or 24°C for 8 wks. White film was more abundant on bone-in slices. Color was not affected by treatment. Aroma remained normal at 2°C for all slices but abnormal aromas developed in some 24°C packages by 2 wk and in all packages by 8 wk. Aerobic and staphylococci counts on bone-in and boneless slices at 24°C were high at 2 wk and remained high, while lactobacilli counts were highest at 2 wk, decreased to initial levels by 4 wk and increased again to 8 wk. Yeast and mold counts at both temperatures decreased with storage but at a faster rate in bone-in hams.

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.