MICROBIOLOGY AND QUALITY ATTRIBUTES OF AGED HAMS PRODUCED FROM FROZEN GREEN HAMS

Abstract

ABSTRACT48 hams of similar weight and quality were frozen at ‐29°C and then stored for about 8 wk at ‐18°C. The hams were divided into 4 equal groups for thawing and curing. Groups 1 and 2 were placed in cure after thawing at 13°C for 24 hr, while Groups 3 and 4 were cured frozen. Groups 1 and 3 were cured with salt, sugar, potassium nitrate (KNO,) and sodium nitrite, and groups 2 and 4 were cured with the same ingredients with the omission of KNO,. Surface swab samples were obtained from hams in each group when fresh, after cure, after salt equalization and after aging 1, 2 and 3 months and evaluated for aerobes and pseudomonads (7, 26 and 37°C), lacto‐bacilli, enterococci, streptococci, and yeasts and molds. Pseudomonads were not enumerated after salt equalization or after 1 and 2 months aging. Enumerations were made for coliforms before curing and after aging 3 months and for staphylococci after aging 3 months. Weight loss was recorded periodically as processing and aging progressed. After aging 3 months the hams were cut, evaluated visually and by a palatability panel, sheared for tenderness and analyzed for moisture, salt and nitrite. Coliforms were detected only on the thawed hams before curing. Coliforms were not detected after aging 3 months. No coagulase‐positive staphylococci were detected after aging. Except for the Pseudomonas count at 7°C (P < 0.05), all counts were higher (P < 0.01) for thawed hams than for frozen hams before curing. After curing, thawed hams had higher counts than hams cured frozen, but only the difference for aerobic count (37°C) was significant (P < 0.01). Hams cured without KNO3 tended to have higher counts than hams cured with it, but the differences were not significant. No differences were observed after salt equalization and after aging 1 and 2 months. Frozen hams cured without KNO3 tended to have counts that were higher than the hams cured with KNO3+ NaNO2. Only the differences between the aerobic counts at 7°C and yeast and mold counts after aging 3 months were significant (P < 0.01). There were no differences in color, aroma, or general appearance, organoleptic scores, or composition due to the presence or absence of KNO3. Hams placed in cure while frozen had less weight loss and lower salt content than those thawed before being placed in cure. Color, aroma, general appearance, palatability scores, shear values, moisture and nitrite content were similar in the frozen and thawed groups.