摘要:

ABSTRACT—The importance of obtaining a high degree of correlation between instrumental method and sensory evaluation is apparent when we are searching for a method to replace the conventional and expensive taste panel test. Unfortunately, discouraging results have been reported in regard to the degree of their correlation. Attempts have been made to clearly define what is actually being measured in both the objective and subjective methods. However, few reports have dealt with methods of data analysis. The purpose of our study was to present a method of analysis of data for removing sources of variation influencing objective and subjective measurements. Statistical models were developed for the Warner‐Bratzler and taste panel methods of tenderness evaluation. It was found that by expressing the experimental data as a deviation from their contemporary mean, extraneous sources of variation were minimized, resulting in a substantial improvement in the degree of correlation as theoretically expected. A contemporary mean is defined as an average value derived from observations collected in the same substratum which is assumed to be homogeneous by virtue of proper experimental des

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04021.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACT—The longissimus (modest degree of marbling) from forty beef ribs selected 48–56 hr post‐mortem was used in two trials. Trial I involved A, C and E maturity ribs (10 each classification). Each rib was subjectively scored for texture (fresh) and adjacent longissimus samples were removed for the determination of protein solubility (fresh) and tenderness. Tenderness (cooked muscle) was measured with a Warner‐Bratzler shear and taste panel. Protein solubilities were determined using 0.154M Krebs‐Ringer‐Bicarbonate buffer, 0.2M KCl + 0.01M K phosphate buffer, 1.1M Kl + 0.1M K phosphate buffer, and 0.03M K phosphate buffer. Trial II involved 10 A maturity ribs. The 0.2M KCl, 1.1M Kl and 0.03M K phosphate buffers as described for trial I were used for protein extraction. Additionally, sarcomere length was measured in formalin. Multiple regression equations were developed to predict tenderness in trial II. Protein solubilities were not significantly different between the carcass maturity groups although there were trends toward increased solubility as maturity increased. Tenderness tended to decrease from A to E maturity indicating a negative relationship between protein solubility and tenderness. Several significant negative correlations between protein solubility and tenderness were found in trial I (A maturity group) and trial II. Additionally, several significant negative correlations between texture and solubility were calculated. Correlations within the C and E maturity groups were variable and showed no definite trends. Multiple regression analyses showed that a combination of protein solubilities, texture score and sarcomere length accounted for 88% of the variation in shear force and 72% of the variation in taste panel

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04022.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACT—An examination of the means and range coefficients of the total serum, intramuscular (longissimus) and subcutaneous lipids, the major lipid classes and fatty acid compositions of the 3 tissue sites from 30 heifers and 31 bulls of the Hereford breed revealed some interesting aspects of lipid metabolism. When placed on a concentration (percent of tissue) basis, significant differences due to sex, environment and sires were shown by an analysis of variance for many of the lipid components. Phenotypic correlations, also computed on a concentration basis, gave indications of the growth and development of the animals, in addition to showing the associations of various lipid components of the 3 tissue sites to various carcass cutout traits and flavor. With a few exceptions, low positive correlations were shown for the serum lipid components with flavor, whereas, most of the marbling and subcutaneous fat components exhibited low negative correlations with flavo

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04023.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACT—Newborn veal, 11.5‐month‐old steers, 14.5‐month‐old heifers and 9 to 10.5‐year‐old cows were used to identify the polysaccharide types present in the epimysium and to determine the relationship between the amount of connective tissue polysaccharides and the amount of collagen in the epimysium. Trimmed muscle was used for tenderness evaluation by shear force. Average amounts of 332, 247, 230 and 202 mg dry polysaccharides per 100g dry, defatted epimysium were isolated from the veal, steer, heifer and cow groups, respectively. A negative correlation was obtained between age of animals and amount of isolated polysaccharides. Only 20% of the hexosamine in the dried defatted epimysium was extracted as soluble connective tissue polysaccharides. It is possible that some selective solubilization of certain polysaccharides occurred during extraction and, consequently, the extracted polysaccharides may not reflect the actual polysaccharide composition of the intact tissue. Considering this, it was found by using Dowex 1 x‐2 chromatography that an average of 42% of the total uronic acids of the veal and heifer groups was eluted with 0.5M NaCl. 17 and 19% of the cow and steer uronic acids, respectively, were eluted with 0.5M NaCl. In the veal and heifer groups, 37 and 38% of the total uronic acids were eluted with 1.5M NaCl, whereas in the cow and steer groups the amount represented 71 and 70%. The percentages of uronic acids eluted with 2.0M NaCl were 20, 11, 19 and 12% in the veal, steer, heifer and cow groups, respectively. Dermatan sulfate was found to be the main polysaccharide eluted with 1.5M NaCl for the veal, heifers and cows. It also represented an important type in the steers, although other sulfate polysaccharides seemed to be present. Cellulose polyacetate electrophoresis confirmed that hyaluronic acid and dermatan sulfate were present in the epimysium. The ratio of hexosamine to insoluble collagen in the epimysium was positively associated with mu

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04024.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACT—Samples of raw and heat‐treated beef semimembranosus muscle were examined histologically to determine how deep‐fat frying, oven roasting, oven braising and pressure braising to 70°C affected histological characteristics of the muscle. A panel of three persons used an ocular micrometer to measure muscle fiber width, observed color and type of connective tissue and distribution of fat and estimated quantity of connective tissue of 475 histological sections. Differences among heat treatments in muscle fiber width and relative proportion of straight and wavy connective tissue were not significant. However, there was a significantly (P<0.05) larger quantity of granular tissue in deep‐fat fried, pressure braised, and oven braised samples than in oven roasted samples. Intact fat cell walls were observed in both raw and heated

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04025.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACT—The rates of pH fall and of changes in glycolytic intermediates and cofactors in ox sternomandibularis muscle minced soon after slaughter were compared with the rates in unminced muscle. Mincing caused about a three‐fold increase in the rates of most of the post‐mortem changes but a much greater increase in the rate of loss of nicotinamide‐adenine dinucleotide (NAD). Glycolysing muscle minces were diluted with 1 vol of a solution containing potassium chloride, with or without added potassium phosphate. Increasing the potassium chloride concentration resulted in a higher ultimate pH of the diluted preparation, whereas inclusion of inorganic phosphate (Pi) in 0.16M potassium chloride solutions resulted in lower ultimate pH values, the maximum effect being obtained usually with 50 mM Piin the diluent. The ultimate pH was then about the same as in the undiluted mince, provided that glycogen was not exhausted. Comparisons were made of the glycolytic metabolism in undiluted minces and in minces diluted with 0.16M potassium chloride containing 0, 50 or 100 mM potassium phosphate (pH 6.7). Dilution without addition of Pidecreased the glycolytic resynthesis of adenosine triphosphate (ATP) without affecting the initial adenosine triphosphatase (ATPase) activity. Consequently ATP was lost faster, metabolism caused sooner and the ultimate pH was higher than in the undiluted mince. Inclusion of Piin the diluent stimulated the glycolytic resynthesis of ATP without affecting the initial ATPase activity. Consequently loss of ATP was delayed until, due to loss of NAD, the glyceraldehyde‐3‐phosphate dehydrogenase step became rate‐limiting for lactate production and fructose‐1,6‐diphosphate and the triose phosphates accumulated. Phosphorylase, phosphofructokinase and ATPase activities were calculated from the changes in glycolytic products and intermediates, and ‘high‐energy’ phosphates. Reasons are discussed for the differences in the activities of these enzymes among the differe

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04026.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACT—Samples of mince, prepared from ox sternomandibularis muscle about 75 min postmortem, were diluted with one volume of 0.16M potassium chloride containing 0, 50 or 100 mM potassium phosphate with or without 1 mg of nicotinamide‐adenine dinucleotide (NAD)/ml. Changes in pH and in the concentrations of glycolytic intermediates and the principal nucleotides were followed for about 6 hr after dilution. NAD was lost rapidly, its adenine moiety being converted to inosine nucleotide by the enzymes present. When the diluent did not contain inorganic phosphate (Pi) inclusion of NAD resulted in a somewhat faster loss of adenosine triphosphate (ATP), earlier cessation of glycolysis and higher ultimate pH. Inclusion of NAD in the preparations containing added Piled to a reduction in both phosphorylase and phosphofructokinase activity. It also prevented the accumulation of fructose diphosphate. This was the result of lowering the phosphofructokinase activity rather than of increasing the glyceraldehyde‐3‐phosphate dehydrogenase activity. Adenosine triphosphatase (ATPase) activity, after an initial period during which it was unaffected by inclusion of NAD, was greater in the preparations containing added Piand NAD than in the corresponding preparations without ad

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04027.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACT—Volatiles in aqueous extrack of raw, canned, and freeze‐dried carrok were isolated and concentrated by an on‐column entrainment procedure. Twenty‐three compounds were identified by GLC‐MS in the raw carrot. Of these, diethyl ether, acetaldehyde, acetone, propanal, methanol, ethanol and β‐phellandrene had not been previously reported in raw carrots. Several other compounds were tentatively identified. Acetaldehyde, sabinene, myrcene, and terpinolene wzre considered important character‐impact compounds in raw Carrot aroma; however, compound(s) responsible for carrot aroma remain elusive. Differences in volatile composition between canned, freeze‐dried and raw carrok were found to be mainly quantitative rather than qualitative. Ethanethiol, dimethyl sulfide and dimethyl substituted styrene compounds formed with canning. Canning resulted in an approximate 50% loss of “higher boiling” compounds; however, it produced an increase in “lower boiling” compounds, particularly methanol, which increased from 0.05–60 ppm. Freeze drying resulted in an approximate 75% loss of total volatile content. Ethanethiol, dimethyl sulfide, acetaldehyde, octanal, 2‐decenal and possibly dimethyl substituted styrene compounds are considered impor

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04028.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACT—The volatile composition of carrot varieties lmperator (Long lmperator Crookham), Nantes, Royal Chantenay, Autumn King, Oregon 4362, and Wisconsin 5 were analyzed by GLC on‐column entrainment. Differences were quantitative rather than qualitative. Variation in concentration of individual terpenes and their summation (5–27 ppm) appeared to be consistent with descriptions of the flavor characteristics of different varieties. Studies on effects of maturity revealed that of the “low boiling’ constituents, acetadehyde and particularly ethanol increased in late season whereas acetone, propanal, and methanol remained relatively constant. Regarding “higher boiling’ constituents, their total concentration remained relatively constant while the concentration of individual terpenes constantly changed. Mature carrots stored for 5 wk accumulated large quantities of acetaldehyde and ethanol. The concentration of other volatiles did not change

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04029.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACT—Portions of a distinctively flavored commercial maple sirup were heated by autoclaving at 15 psig (250°F) for 1.5 and 4 hr. A GLC flavor profile of the treated and untreated sirups showed that 25 components in their flavor fractions changed in relative amounts. In the light colored original sirup, acetol and compounds related to lignin (vanillin, syringaldehyde, dihydroconiferyl alcohol) predominated. As the sirup was heated, carbohydrate breakdown products began to appear and then to predominate (acetol, furanones, cyclotene, and HMF). As the carbohydrate degradation products increased the sirup darkened in color and became acrid in flavor; at this point vanillin began to decrease. From this preliminary study it would seem possible, after identifying all the compounds in the profile, to produce various levels of different flavor in maple sirup by a regulated heat process. The need is indicated for a complete study of the production of maple flavorants by heat, starting with a flavorless sap concentra

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb04030.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY