摘要:

Sensory evaluations and chemical measurements were made on freshly cooked (conventionally heated), conventionally‐reheated (after 5 wk frozen storage), and microwave‐reheated pork loin muscle. Freshly cooked and microwave‐reheated pork had sweeter aroma and less metallic flavor than conventionally‐reheated pork. Microwave reheated pork was less juicy than pork heated by the other treatments. Freshly cooked pork had the lowest TBA values and the highest moisture content. Heating treatment did not affect ninhydrin‐reactive compounds or nitrogen content in the various extracted protein

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02813.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

A hand‐operated biting instrument which is quick and simple to use was developed to investigate the possibility of assessing the tenderness of raw meat at the carcass or wholesale cut stage. Comparison with the Warner‐Bratzler shear device revealed an overall close relationship for cooked meat (r = 0.96, n = 66), greater response in terms of proportional change in readings per unit change in tenderness (P<0.01) but a greater variability in a series of readings on meat cores from the same steaks (P<0.001). Relationships between readings on raw and cooked samples were low. It is suggested that this may be due to the fact that the effects of cold shortening and aging on cooked meat tenderness are not apparent on the tenderness of raw meat. The response to cold shortening in terms of tenderness appears to develop as meat is heated from 50°C to 60°C while the response to aging is already partially developed at a cooking temperature of 50° C. It is concluded that although the instrument may be better than existing methods under some situations due to its simplicity, it is unlikely to be useful on r

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02814.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

The combined effects of aging, freezing rate, frozen storage and cooking method on beef quality and yield were studied in a multifactorial experiment, using 1.5 cm slices of LD muscles from young steers. Aging for 2 wk resulted in significantly more tender, but slightly less juicy frozen meat than aging for 4 days. Prolonged frozen storage gave tougher meat and a larger tenderness difference between aging times. Freezing rates of 13, 2.0 and 0.04 cm/h differed but little in their effect on sensory quality, but slightly lower yield and redness value were noted for the lowest rate. Pan frying directly from the frozen state resulted in slightly higher juiciness and cooking yield, with larger differences in yield between freezing rates, than cooking after previous thawing. Significant interactions were noted for cooking method × freezing rate and for aging time × frozen storage ti

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02815.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

The effects of administering low levels of aflatoxin B1‐14C by crop intubation daily for 14 days to layer chickens were determined. Studies on the distribution of14C in the blood, selected organs, tissues, eggs and excreta were conducted. No toxic effects were observed in layer chickens during the course of the experiment. The layer chickens excreted 92.15% of the14C administered. Of the14C retained, 19.5, 16.1, 3.9, 7.2, 26.4 and 26.9% were detected in the blood, liver, heart, gizzard, breast and leg, respectively. No radioactivity was detected in egg samples collected. Chemical assay of those samples demonstrating radioactivity revealed that 81.2% of the radioactivity in these substrates was soluble in aqueous extracts while approximately 10% was ex tractable by classical extraction procedures. Treatment of the aqueous extracts for conjugated steroids by treatment with Beta‐glucuronidase revealed that 31.5% of the14C detected in the aqueous extract was a liberated glucuronide conjugate of aflatoxin M1

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02816.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Hand deboned leg and thigh tissues from broilers and mechanically de‐boned broiler neck meats were extruded and texturized using a dry heat process. During heat processing of all meat tissues, there was a significant (P<0.05) reduction of moisture content and significant increases in fat and protein levels as heating time increased. Meat strands from the texturization process became firm, possessing structural integrity as determined by the binding strength among meat tissue particles and strand resistance to shearing. Significant (P<0.05) increases were observed in tissue water‐holding capacity and emulsion stabilizing capacity although salt‐soluble protein extractability was significantly (P<0.01) reduced by the heating during texturi

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02817.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

The postmortem biochemical changes in intact raw shrimp during iced storage were investigated and the relationship between these changes and the quality of the cooked product was evaluated. Changes in pH, microbial numbers, total and nonprotein nitrogen, tyro‐sine and carotenoid pigment content, proteolytic and polyphenolase enzyme activities and levels of trimethylamine‐oxide, trimethylamine, dimethylamine and formaldehyde were determined. Chemical changes were shown to be mediated by a combination of bacterial action and endogenous enzymatic activity. The washing action of melting ice could have played a major role. Organoleptic quality as shown by flavor panel evaluations progressively declined during an 8‐day storage period. Dimethylamine and formaldehyde levels in intact shrimp progressively increased as flavor panel scores decreased and may offer additional sensitive indices of cooked meat q

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02818.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Total plate, halophilic and staphylococcal counts were determined in quick‐salted fish cakes after 0, 1, 2 and 3 months' storage without packaging at an ambient temperature of 35–40°C. A rancidity (thiobarbituric acid or TBA) index was also determined in sun‐dried and tunnel‐dried cakes, before and after desalting, stored under the same conditions for the same lengths of time. Species studied were skipjack, mullet, Spanish mackerel and shark from the Gulf of California. It was found that total plate and halophilic counts behaved similarly, initially increasing with time, passing through a maximum, and then decreasing. Counts increased with decreasing salt and increasing moisture contents of the cakes. Maximum counts obtained were of the order of 106per gram for cakes made from shark, while negative counts were obtained with cakes made from skipjack after 3 months. No growth of staphylococci was obtained at any time in any of the plated dilutions (10−1to 10−6). Rancidity of the cakes increased with time, depending upon the following factors: oil content of the species; degree of unsaturation of the oil; drying time of the cakes; presence or absence of hematin pigments; presence or absence of sunlight when drying. Some of the rancid components in the cakes were removed by desalting in boiling water. In a limited taste panel evaluation of the cakes, order of preference was found to correlate well with decreas

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02819.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

The effect of microwave finish drying of potato chips on their texture, color and oil content was studied. The intermediate moisture content (IMC) of the chips before microwave application and the reducing sugar content of the raw potatoes were the primary variables. The slices were individually submerged in oil at 320° F to various IMC and finish dried with 2500 watts microwave power for 1–3 min. Chip color was rated against PC11 Color Standards. Texture was evaluated subjectively by a panel and objectively by the L.E.E. Kramer Shear Press. Oil determination was made by Soxhlet extraction. The results showed that potato chips removed from the oil at IMC above 13% were unacceptably tough after microwave drying. Potatoes containing more than 0.9% reducing sugar had to be removed from the oil at IMC above 13% in order to obtain acceptable color of the microwave‐finished product. Therefore, microwave finishing raises the limiting reducing sugar content from about 0.4 to about 0.9%. Oil content of microwave‐finished chips was 90% that of conventional c

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02820.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Potato flakes, produced experimentally to test the effects of raw material and processing variables on storage stability, were examined by a trained taste panel and by GLC analysis for evidence of oxidative and other flavor changes. Air‐packed samples produced from unpeeled potatoes, defective raw material and potatoes cooked with excess water were more highly oxidized than conventional flakes after 12 months storage at 23° C. Raw material sugar content and piece size had no effect on stability. The flavor of nitrogen‐packed samples was not affected by storage for 12 months at

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02821.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

A pilot plant IQB blancher was field tested at a California freezing plant. The system included: a warming and drying preconditioning unit, a steam chamber for single layer belt heating, a deep moving‐bed holding chamber for temperature equilibration and enzyme inactivation and an air‐water spray cooling unit. IQB with and without preconditioning were compared to conventional, steam blanching at equivalent levels of enzyme inactivation in green beans, lima beans, Brussels sprouts and green peas. Effluent volume and total‐solids concentration were measured. Product yields were determined by measuring residual peroxidase activity, chlorophyll conversion and ascorbic acid content as well as by sensory panel testing for color and flavor. Results showed that vegetables blanched with IQB and IQB with preconditioning were essentially the same in quality as those blanched at commercial conditions. Solids loss in the effluent was substantially less with IQB and preconditioning than with conventional steam bla

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1973.tb02822.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY