摘要:

ABSTRACTThe present study was undertaken to evaluate the oxidative deterioration of oils and foods by using the single photoelectron counting system, which was designed for the measurement of ultraweak chemiluminescence. Thermally oxidized soybean oils were prepared and their chemical characteristics and chemiluminescence were measured. The results showed that the increase of emission intensity was closely correlated to the oxidative deterioration of oils, instant Chinese noodles and milk powder. This new method has a great advantage in measuring the quality of food in a short period of time by a nonexpert without any prior treatment.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09094.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTAn alkaline protease immobilized on Dowex MWA‐1 by glutaraldehyde was applied to a step of cheese‐making process. By reversing the order of the lactic acid fermentation process and the “rennetting” (hydrolysis) process in the traditional cheese‐making method, and by raising pH of milk to 7.0, coagulation of milk in the alkaline protease column was avoided. As a result of these modifications, it became possible to operate a stable hydrolysis process of milk proteins at 50°C. Average degree of hydrolysis was about 3%. Curd was prepared from this milk after lowering pH to 6.2 by lactic acid fermentation and was processed to make Cheddar‐type cheese. After ripening this cheese for 6 months at 10°C, its ripening ratio was similar to that of cheese prepared by the traditional method. It is concluded that the immobilized alkaline protease could be used for

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09095.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTA study was undertaken to develop a bean protein concentrate (BPC) from a mixture of five varieties of cull beans. The chemical composition, microbiological quality, and the nutritive value of the BPC were determined. The BPC was isolated from the bean flour by extraction with a dilute salt solution followed by acid precipitation. Protein recovery was 56% as BPC by extracting the cull bean flour with a 0.2% sodium chloride solution followed by precipitation at 90°C, pH 4.0. No detectable amount of toxic substance was found in BPC as assayed for heavy metals and mycotoxins. The microbiological and protein nutritional quality (PER) of the final products were determined. The PER data indicated that the BPC obtained by acid precipitation at room temperature had a higher nutritional quality than did BPC acid precipitated at 90°

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09096.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTEquivalent levels of chlorine and chlorine dioxide (generated on‐site) were established on the basis of bactericidal action in bird chiller water. When introduced directly into the chiller water after processed birds had begun to enter the chiller, 5 ppm CIO2and 34 ppm CI2were equally bactericidal. When introduced into the chiller with the fresh‐water input, 20 ppm CI2and 3 ppm CIO2were equally effective. The use of about 1/7 as much CIO2as CI2would be less corrosive to processing equipment and provide the poultry industry with an alternative bactericide to chlor

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09097.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTEstimates were made of panel variation and of repeatability for an untrained sensory panel using beef loins as the test product. Prior to testing, the beef loins were placed in one of three groups (tender, intermediate, tough) based on Warner‐Bratzler shear value. The sensory panel evaluated each steak for juiciness, tenderness, connective tissue amount, flavor desirability and overall desirability using an eight‐point scale. The accuracy of the untrained panel was not different from the accuracy of trained sensory panels. A considerable amount of variation was observed for individual judges, but this did not affect the accuracy of the panel as a whole. The repeatability of the panel and of individual judges was used as a measure of precision. The repeatability of the whole panel was much higher than the repeatability of the individual judges. Tenderness was found to be the most repeatable palatability characteristic evaluated. The panel as a whole and each individual judge were more repeatable or precise in their evaluation of nine samples per session than three samples per session. This indicates that no panel fatigue occurred during this study. Repeatabilities for the panel and the individual judges were found to be higher for the tougher loins than for more tender lo

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09098.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTPaired muscles were used to assess the merits of a water bath method for the preparation of rare beef as compared to a conventional oven using a long‐time, low‐temperature process. Samples prepared in a water bath were more uniformly rare in cross‐section, had significantly greater cooked yields, and were significantly more tender than oven‐cooked roasts. A sensory panel found water bath samples to be significantly more tender and preferred them overall to oven‐cooked samples. In addition to the above advantages, the more rapid rate of heat penetration and the potential for reduced energy requirements suggest that the water bath procedure should be examined in greater depth with an eye towards more wides

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09099.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTUSDA Choice and Utility grade boneless beef loins were used to determine the palatability, bacteriological and histological characteristics of steaks mechanically tenderized. There was a significant improvement in taste panel ratings of tenderness for the Utility tenderized steaks, but only a small improvement (P>0.05) for the Choice tenderized steaks. None of the total aerobic bacterial surface counts or the interior counts for total aerobic, psychotropic or anaerobic bacteria was significantly different, between tenderized and nontenderized steaks compared at 1, 2, 5 and 10 days of storage at 5°C. Histological studies showed a definite pattern of blade penetrations in the tenderized samples at low magnifications. At very high magnifications, the muscle fibers were torn and fragmented by the blade rather than evenly cut

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09100.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTThe study was conducted to determine process requirements and formulations necessary to prepare a coarse textured smoked fish sausage. Sausages prepared from Spanish mackerel, using two different comminution processes and different levels of shortening, soy protein fiber (SPF) and added ice, were evaluated for texture using both instrumental methods and taste panels. Previous work has shown that fish muscle chopped with NaCl and polyphosphate in a silent cutter had a texture similar to a hard gelatin gel when steam cooked and a mushy texture when cooked in a smokehouse. The cooked fish sausages had a sponge‐like texture after freezing and thawing. These unacceptable textural characteristics were overcome by the incorporation of at least 12g shortening/100g fish muscle, and SPF at 15:85 SPF/fish muscle using a two‐stage comminution process. Shear and compressive strength were markedly diminished when ice was added in excess of 15%. The addition of shortening at the level of 12 g/100g fish muscle and SPF significantly improved taste panel ratings on texture relating to the structure of material and increased juiciness. The mechanical properties of the sausages were significantly modified by addition of SPF in a ratio 30g SPF/70g of fish muscle. A comminution process for the formulation containing 25g shortening/100g fish muscle resulted in significantly reduced strength and water‐holding capacity and increased brittle‐ness of the cooked product. There were no significant differences in texture and general acceptability between products prepared from the mechanically deboned as compared to the filleted fish if the moisture content and bone residue in the raw material were carefully con

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09101.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTMinced carp tissue was cooked by baking and deep‐fat frying and stored at ‐18°C for periods up to 8 wk. Phospholipid (PL) levels decreased whereas free fatty acids (FFA) increased during frozen storage of all samples. Samples treated with antioxidants gave significantly (P<0.05) higher values for FFA compared to the controls Thiobarbituric acid (TBA) values were higher in the cooked samples compared to the raw samples. Samples without antioxidants had considerably higher TBA values than those containing antioxidants. The carbonyl content of the samples fluctuated during storage. There was no significant change in the composition of the fatty acids during sto

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09102.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTThe stability of adenosine deaminase and AMP deaminase from pink and brown shrimp muscle extracts was assayed during postmortem ice storage. AMP deaminase activity was lost rapidly during the early stage of ice storage, and no activity could be detected after 10 days for pink and 16 days for brown shrimp. Even though there was a gradual loss in activity, adenosine deaminase could be detected in both species through the entire storage period of 21 days. The stability of these two enzymes was also correlated with the traditional spoilage indicators: total volatile nitrogen (TVN), total plate count (TPC) and organoleptic evaluations. During the lag‐phase of bacterial growth, AMP deaminase lost 50% of its original activity while adenosine deaminase remained active. During the log phase, bacterial counts and TVN values gradually increased to 103/g and 30 mg TVN‐N/100g, respectively, while AMP deaminase lost its activity. Finally, during the stationary phase, adenosine deaminase (with low activity) was the only ammonia producing tissue enzyme that could be detected. The activity of adenosine deaminase and AMP deaminase could potentially be used as quality indices for fresh shrimp held on

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb09103.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY