摘要:

SUMMARY–The storage stability of frozen pond‐raised channel catfish from five commercial processing plants was examined. Three distinct types of processing treatment were included in the five lots. Fish samples were evaluated initially and at regular intervals during frozen storage up to 270 days. The evaluations included changes in moisture, pH, fat stability (TBA value) and shear press values of the uncooked fish, and in sensory ratings for appearance, aroma, color, texture and flavor of the cooked products. Moisture losses and changes in pH during frozen storage were not statistically significant (P = 0.05). Thiobarbituric acid (TBA) values indicative of changes in fat stability, incresed in all five lots of fish with prolonged storage but were not closely correlated with changes in flavor rating. Sensory ratings for quality of the cooked product decreased significantly with successive storage periods. The regression patterns representing changes in quality during storage varied among the different losts of fish. Certain variations were related to the processing treatme

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03323.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY–Fresh and frozen stored mechanically deboned turkey meat was incorporated into frankfurters at the 15% level and compard to red meat frankfurters. Mechanically deboned turkey meat exhibited higher emulsifying capacity than beef but lower than pork on a protein basis. This trend for emulsifying capacity was reversed when reported on a total meat basis. Emulsion stability was not essentially affected by the addition of 15% mechanically deboned turkey meat in red meat frankfurters. Differences flavor tests, preference flavor tests, and TBA values indicated that frankfurters containing 15% mechanically deboned turkey meat were comparable to all red meat frankfurters in flavor stability if fresh deboned poultry meat is used. The use of mechanically deboned poultry meat, which had undergone 90 days of frozen storage, resulted in a significantly inferior product as indicated by flavor evaluation and TBA values. Color evaluation showed slight color fading of all frankfurter treatments during storage. Microbial loads in the three frankfurther treatments showed some increased in total counts during refrigerated storag

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03324.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—When chicken broiler backs containing varying amounts of skin were mechanically deboned, the product obtained was shown to be directly affected by skin content. As the skin content on the backs increased in relation to muscle and bone content, the fat content of the deboned meat increased and the moisture and protein contents decreased. The connective tissue protein content of the meat was not affected by increasing skin content on the backs. Data obtained from passing backs as well as isolated poultry skin through the deboner indicate that the fat from the skin was expressed through the screen along with the meat. The majority of the skin protein, collagen, did not pass through the screen but was passed out in the residue along with the bone. The meat from the backs containing large amounts of skin may have poor emulsifying characteristics because of its high fat and low protein conten

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03325.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY–A total of 488 fresh hams were stratified according to method of cure (regular‐cured and water‐added) and quality scores (gross morphology, color and firmness). Each ham was pumped, cured and smoked using commercial procedures. Individual weights for each ham were obtained at each stage of the processing sequence. Center slices from 50 processed hams were evaluated for muscle color, chemical composition and organoleptic properties. Among both regular‐cured and water‐added hams, gross morphology groups were not significantly (P<0.05) related to weight gains (fresh to chilled), weight losses during the period in transit (125 km), or to flavor, saltiness, moisture (%) or pigment concentration for the combined muscles of the center slices. A comparison of individual ham muscles revealed that the biceps femoris (BF) was less tender than the semitendinosus (ST); the ST was less salty than the semimembranosus (SM) and the ST had a higher fat content on a moisture‐free basis than other muscles for both regular‐cured and water‐added hams. Significant differences (P<0.05) among muscles for flavor and juiciness were evident for the regular‐cured hams; however, there were no significant differences for the hams in the water‐added group. There were significant differences in pigment concentration among muscles from the center‐cut slices from water‐added hams. Regular‐cured hams in gross morphology group 5 were significantly (P<0.05) more juicy and more tender than hams in the other four quality groups. Also, center slices from hams in the high quality gross morphology group (group 5) were more uniform in muscle color, more desirable in lean color and contained more fat than hams in group 1. Regular‐cured hams in gross morphology group 5 also produced individual muscles which were more desirable in lean color (SM, BF), more flavorful (SM), more juicy (ST, BF) and more tender (ST, BF) than hams in group 1. Water‐added hams in gross morphology group 5 did not differ from hams in group 1 in any of the traits but were significantly (P<0.05) more

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03326.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY–The observed curvilinear correlation between metmyoglobin formation and lipid oxidation in beef gluteus medius samples (3 mm thick) stored in polyethylene at ‐5°C was dependent (P<0.001) on initial treatment, namely freeze‐thawing, delayed freezing or mincing. However, these initial treatments accelerated both metmyoglobin formation and lipid oxidation. In slices initially held in 1% oxygen at 0°C to increase the relative amount of metmyoglobin, the concentration of this pigment was first reduced during frozen storage at ‐5°C before increasing again. High initial metmyoglobin concentrations had no effect on the rate of lipid

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03327.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY–The effect of specific wavelengths of visible light on fresh meat color was investigated. 2‐in. diam cores of meat were aseptically prepared from top rounds (adductor muscle and semimembranosus muscle). Freshly oxygenated face‐to‐face cuts were used as the sample and control. The sample and control were packaged in mylar polyethylene pouches and cooled moist filtered air was circulated through the pouch for the duration of the experiment. Samples were exposed to the following wavelengths at an energy level of 0.5 mw/cm2: 420.0, 510.0, 550.0, 570.0, 590.0 and 632.8 nm. Experiments were conducted at 34°± 1°F and 41°± 1°F for 2 and 5 days of exposure. The controls were next to the sample but kept in darkness during the exposure period. There was no temperature differential between the sample and control. Oxidized heme pigment content was determined by reflectance spectrophotometry. No wavelength enhanced the formation of oxidized heme pigment more than any other, however illuminated samples contained an average of 5.5% more oxidized heme pigment than did the controls. Oxidized heme pigment content increased with lengthened storage time and increased temperature. The increase in oxidized heme pigment content as a result of illumination may be due to a photochemical activation of a compound such as riboflavin which then may react with oxygenated heme pigments to form oxidized

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03328.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY–The hydration capacity of shrimp undergoing microbial spoilage at low temperatures was followed by means of water‐holding capacity (WHC), extract‐release volume (ERV), viscosity and swelling measurements. All four techniques showed marked changes in hydration capacity from shrimp freshness to frank spoilage, with significant decreases in ERV, and increases in WHC, and swelling. Of these, the ERV technique was found most suitable for detecting incipient spoilage. Employing a low pH buffer (phthalate, pH 4.6), the pH of fresh or freshly thawed shrimp homogenates was lowered towards the isoelectric range of shrimp proteins, resulting in low hydration and large amounts of extracts. When first signs of microbial spoilag were noted, these amounts decreased by 33%. The ERV test is simple to perform, fast and reproducible. On further extensive testing, it holds promise as an index of spoilage for s

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03329.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY–A simple, rapid method for the qualitative identification of animal proteins as to species was developed for fresh meat. Gamma globulin isolated from species‐specific rabbit antiserum was mixed with a heated extract of skeletal muscle of beef, horse lamb and pork. The mixture was allowed to set for 30 min at room temperature and then centrifuged. The presence of a precipitin indicated a positive reaction. There were no cross reactions between meat samples from different species. This method requires a maximum time of only 1–2 hr, as compared with the 3 days required for double‐gel diffusion. In addition, it is much more sensitive than gel di

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03330.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—The increased production and consumption of frozen, further‐processed turkey products has created a need for more information on their microbiological quality. Samples of frozen, further‐processed turkey products including roasts, rolls, turkey in gravy and turkey with stuffing and gravy were purchased either in a retail market or directly from the processor. Numbers of aerobic and anaerobic organisms, Staphylococcus aureus, Clostridium perfringens and coliform bacteria in each product were determined. Conventional agar plate count and multiple‐tube dilution‐to‐extinction techniques were employed. In addition, enrichment techniques were used to ascertain the presence of salmonellae and C. perfringens. More than one procedure was utilized in each analysis for comparisons of methodology. Results of analyses carried out on these products show a wide range in total numbers of microorganisms present. In the 35 raw products examined, all were found to contain coliform types, 19 E. coli, 25 S. aureus, 7 C. perfringens; salmonellae were found in only 3 samples. In the 38 cooked products analyzed, the incidence of these types of organisms was lower. Neither salmonellae nor E. coli were found, whereas, 16 of 38 contained coliform types, 6 of 38 contained C. perfringens and only one of 38 was positive fo

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03331.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—Samples of deboned meat from broiler necks and backs, whole fowl and turkey racks were obtained from commercial sources and examined for total aerobic counts, fecal coliforms, salmonellae, Clostridium perfringens, coagulase positive staphylococci and psychrotolerant microorganisms. The raw materials were either deboned immediately after birds were processed (conventional processing) or held in the plants at 3–5°C for 5 days prior to deboning (delayed processing). The storage studies were conducted by holding the deboned meat at 3°C for 0, 3, 6 and 12 days and at ‐15°C for periods of 3, 6 and 9 months. The total aerobic counts of delayed processed samples were shown to be higher than conventionally processed meat and remained the same throughout the storage period. In all instances, the total aerobic counts increased during the storage at 3°C. The MPN fecal coliforms were high for all samples and remained relatively the same throughout the storage period at 3°C. Freezing resulted in a significant reduction of fecal coliforms. Only six out of 54 samples were contaminated with salmonellae while four showed the presence of C. perfringens and none was contaminated with S. aureus. Pseudomonas, Achromobac‐ter and Flavobacterium dominated the psychrotolerant genera isolated in this i

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03332.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY