INFLUENCE OF INTRAMUSCULAR FAT LEVEL ON ORGANOLEPTIC, PHYSICAL, AND CHEMICAL CHARACTERISTICS OF IRRADIATED PORK. II. LOW-TEMPERATURE LONG-TIME PRE-IRRADIATION HEAT TREATMENT
Pork muscle (longissimus dorsi) was graded in three marbling levels by both visual appraisal and ether-extraction analysis of total fat. A low- temperature (121 deg F, gradually increasing to 191 deg F), long-time (19-hr) heat treatment was used for enzyme inactivation. Samples were packed under vacuum in rigid containers and irradiated to 4.5 Mrad with gamma radiation. Irradiated and frozen control samples were evaluated at intervals over a 180-day period. The heat treatment caused excessive connective-tissue breakdown as evidenced by a soft, dry texture. Marbling level had no significant effect on consumer-panel judgments of irradiated or frozen control samples (served plain, without bread). Lower degrees of marbling were preferred in irradiated sandwich items. Irradiated samples were less preferred than frozen control samples in both plain and sandwich form. Hunter L (color) values a/sub L/ (redness), hue, and saturation attributes were increased by irradiation treatment. Hunter L and b/sub L/ (yellowness) values of highly marbled irradiated sample-s were elevated. Highly marbled samples displayed greater tenderness qualities, as evidenced by mechanical tenderness measurements. Expressible moisture values were decreased by marbling degree and radiation treatment and increased by advancing storage time. As a measure of oxidation rancidity, thiobarbituric acid values were increased by increasing levels of marbling and advancing storage time, but were not influenced by preservation method. No significant differences in pH values due to marbling level or preservation method were detected. Bacteriologic counts of randomly selected irradiated samples indicated that they were commercially sterile (average of 57 colonies/g of sample). Methylene blue stains of colonles revealed Micrococcus. Frozen (control) samples contained moderate numbers of colonies (av. 2300 colonies per g of sample). Micrococcus colonies were again predominant, but a few colonles of film yeasts were also seen. Irradiated samples were negative for thermophilic anaerobic spores producing gas. Control samples were positive, containing gram-negative rods, Escherichia coli, and gram- positive cocci. (BBB)
- Research Organization:
- Univ. of Wisconsin, Madison
- NSA Number:
- NSA-18-019617
- OSTI ID:
- 4018874
- Journal Information:
- Food Technology (U.S.), Vol. Vol: 18; Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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INFLUENCE OF INTRAMUSCULAR FAT LEVEL ON ORGANOLEPTIC, PHYSICAL, AND CHEMICAL CHARACTERISTICS OF IRRADIATED PORK. I. HIGH-TEMPERATURE SHORT-TIME PRE-IRRADIATION HEAT TREATMENT
PHYSIOLOGICAL STUDIES ON RADIATION RESISTANT BACTERIA OCCURING IN FOOD
Related Subjects
ACIDITY
BACTERIA
BARBITURIC ACID
CHEMICAL REACTIONS
COLOR
DRUGS
DYES
ENZYMES
ESCHERICHIA COLI
FOOD
GAMMA RADIATION
HETEROCYCLICS
HUMIDITY
IRRADIATION
LIPIDS
LOW TEMPERATURE
MEASURED VALUES
MEAT
METHYLENE BLUE
ORGANIC ACIDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDATION
PACKAGING
PORK
PRESERVATION
QUALITATIVE ANALYSIS
RADIATION DOSES
RADIATION EFFECTS
REACTION KINETICS
SAMPLING
SPORES
STANDARDS
STORAGE
TESTING
VARIATIONS