摘要:

ABSTRACTThe APIZYM enzyme system was assessed with respect to: enzyme activity in aqueous and saline extract filtrates from raw and heat processed (60° and 71.1°C) beef; effect of rate of heating (0.2–0.3°C, 0.4–0.5°C, and 0.9–1.0°C/min) to internal temperatures of 66.7°, 67.8°, 68.9°, 70.0°, and 71.1°C and holding times of 0, 15, 30, 45, and 60 min at these temperatures on residual enzyme activity; reduction of enzyme assay incubation time; and reproducibility of the system. Results showed that slightly higher enzyme activity in heated samples was obtained with 0.9% saline extraction compared to water. Greater enzyme activity was observed in filtrates from pork samples heat‐processed at a fast rate than at a slow rate. Enzyme activity could be detected after 2 hr incubation, but 4 hr were needed for the enzymes to react with their respective substrates. The system was found to be reproducibile. The results of this study also indicated the potential of using leucine aminopeptidase as an indicator enzyme for determining the adequacy of heat treatment of meat and

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05852.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTInhibitory effectiveness of sorbic acid was analyzed in vacuum packaged refrigerated beef by studying the modifications of bacterial growth parameters. Total counts,Lactobacillussp.,Pseudomonassp.,Enrerobacreriaceae, Brochorhrix thermosphactaand yeasts in samples of different pH values (5.70–6.20) which had been treated with potassium sorbate (27–3125 ppm) showed variations in the lag phase, growth rate, stationary phase and inhibition index. For refrigerated beef the contribution of sorbic acid dissociated fraction to the inhibitory effect was negligible, Considering growth parameters’dependence on undissociated sorbic acid concentration a mathematical model of microbial growth in treated beef was derived, which could be used to predict product shelf

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05853.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTThe isometric tension developed in strips of stretched and cold‐shortened muscle samples while heated up to 85°C showed six transitions. Preheating at 50°C or 60°C eliminated most transitions in samples from very young animals except for those near 80°C. Differential scanning calorimetry results obtained for samples from young and old animals were similar, but the peak assigned to connective tissue changed from 61°C to 65°C with age. The age effect indicated some of these differences were due to collagenous connective tissue. The transitions near 80°C were effectively eliminated by a pressure treatment known to denature actin—an indication that actin might still be structurally viable at temperatures under or clo

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05854.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTRestructured beef steaks were evaluated by consumers (n = 90 households) in Houston, TX. Consumers were selected to assure that demographic representation—age, ethnic background, income, education—was accomplished. Restructured beef steaks were manufactured from 27 beef shoulder clods (nine per treatment) that were subjected to different degrees of connective tissue removal—no trim (NT), intermediate trim (IT) and extensive trim (ET). Consumers rated ET steaks highest, IT steaks intermediate, and NT steaks lowest for overall desirability with significant differences found among the treatments. Consumers perceived this product as being intermediate in monetary value when compared to ground beef and T‐bon

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05855.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTThe effect of iron form (ferrous, ferric, heme), temperature and botulinal spores on nitrite level was determined in meat. In model systems, ferritin iron was also included, and ascorbate was used as a reducing agent. Reduced hemoglobin caused the most rapid nitrite depletion in both systems. Ferrous iron caused faster nitrite depletion in model systems than in meat. Ferrous iron reduced nitrite readily in model systems at 27°C, but not at 5°C. Ferritin iron did not affect nitrite level. In meat at 27°C, nitrite depletion was much faster in inoculated samples. Protein‐bound nitrite levels were higher in meat with added ionic iron. In cured meat with added ionic iron, iron‐NO‐protein complexes may form, lowering the amount of nitric oxide (NO) available to inhibit botulinal spore o

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05856.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTThe 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 (P0.05) yields, final microbial counts or sensory characteristics. Potassium sorbate improved visual mold scores (P<0.05) and generally reduced surface aerobic yeast and mold and staphylococci counts, with several reductions being significant at the 0.01 or 0.05 levels. It also reduced saltiness and flavor intensity scores (P<0.01) but had no effect on other sensory attributes or on cooking los

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05857.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTSurvival and growth of naturally occurring or inoculated bacteria were studied in refrigerated (5°C), vacuum‐packaged ground pork irradiated at 100 krad (1kGy). Numbers of naturally occurring mesophiles, psycbrotrophs and anaerobes or facultative anaerobes were reduced (P0.05) due to irradiation and was unaffected

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05858.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTSamples from porcine longissimus muscles were heated to temperatures ranging from 40–80°C to reach endpoint temperatures (0 min) or held at endpoint temperature for 30 min. Proteins in water‐soluble extracts of these samples were separated and quantified by reverse phase high performance liquid chromatography (RP‐HPLC). After heating to 60°C for 0 min or to 55°C and holding for 30 min, lactate dehydrogenase (LDH), pyruvate kinase (PK) and myoglobin appeared to comprise the bulk of the remaining soluble protein. RP‐HPLC analysis of water soluble extracts from longissimus dorsi, serratus ventralis and psoas major muscles from barrows and sows indicated differences in proportions of LDH and

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05859.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTThe insolubilization of added orthophosphate (1000–10000 ppm, equivalent to 0.1–1 .0% w/w) and of orthophosphate generated through enzymatic hydrolysis of added sodium acid pyrophosphate (SAPP) was studied in fresh and in cooked (65.5°C) ground pork held at 5°C for 6 days. Fresh and cooked pork linearly absorbed or otherwise insolubilized orthophosphate added directly to the meat or generated through enzymatic hydrolysis of added SAPP. Orthophosphate insolubilization was constant throughout the range of addition studied and equivalent to 70–80%. Soluble orthophosphate measurements, therefore, could not be used to estimate the proportion of added pyrophosphate that was hydrolyzed in the meat or, by difference, the proportion of residual, unhydrolyz

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05860.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTMeat mixtures were prepared containing pork lean and turkey lean in ratios of 0/100, 33/67, 100/0 and a constant fat content. Blends were prepared with and without a commercial seasoning‐antioxidant mixture (SA) and evaluated after 0, 3, 6 or 9 days (4°C) storage or 0, 14 or 28 days (‐20°C) storage. Flavor intensity scores for blends containing up to 67% turkey were not different (P>0.05); however, 100% turkey patties had lower flavor intensity scores. Off‐flavor and firmness scores were not affected by blend for products containing between 33% and 100% pork lean, while storage had no effect on off‐flavor in products containing SA. Juiciness was not affected by blend or storage. Results indicate acceptable patties can be made from blends of pork and turkey containing relatively high levels

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1987.tb05861.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY