摘要:

Seventy‐five foods were analyzed for the vitamin pantothenic acid using a microbiological assay and a new radioimmunoassay (RIA). The food sample extract used in both assays was the result of dialysis after enzyme hydrolysis. In the method used previously, the food‐enzyme mixture had been filtered.A very high correlation (r2=.94) between the results from the RIA and the microbiological assay was found. There was a statistically significant difference between the two assay results for all foods and for the subgroups meats, breads and cereals, and fruits and vegetables at p=.05. At p = .01 breads and cereals and fruits and vegetables did not have significantly different results between the two assay methods. For all foods and all subgroups, the microbiological assay produced a higher mean result than the RIA.The RIA is an acceptable method for assaying pantothenic acid in breads and cereals and fruits and vegetables. Futher study is needed to determine how components of meat interact with one or both assay syst

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1980.tb00774.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The amount of protein extracted from chicken breast muscle at low salt (0–50 mM NaCl) increased as the salt concentration of the extracting solutions increased. The addition of 10 mM sodium phosphate buffer pH 7 (Pi) caused a marked increase in protein extractability at all salt concentrations. A particular polypeptide chain of about 150,000 daltons appeared to be particularly sensitive to the extraction conditions. At high salt (0.6M NaCl, 50 mM sodium phosphate buffer pH 7.0) a second extraction still contained significant amounts of protein. The amount of protein extracted was maximized at a 1/20 dilution. On the other hand, the protein extract‐ability of trout white muscle, showed a smaller Pieffect and very little dependence on low salt concentration. The protein extractability of lobster flexor muscle showed little change with either increased salt or Pi. For all three muscles extraction over time with either high or low salt remained essentially constant after the first day with the most protein being extracted from lobster muscle and the least from chicken mus

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1980.tb00775.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The water holding capacity (WHC) of natural actomyosin (NAM) extracted at pH 9.2 in 0.6M KCl was measured in the presence and absence of various combination of sodium pyrophosphate (PPi), MgCl2and CaCl2using a modification of the classical centrifugation technique. Samples, in the presence of 0.15M NaCl and 20 mM sodium phosphate buffer pH 6, were spun at 30,900 X G (as measured at the bottom of the centrifuge tube) for 15 min at 2–4d̀C. The results show that between 17 and 20 g water/g protein were bound over a wide range of NAM concentrations. In each case the amount of water held by the experimental sample was equal to or less than the amount held by a control run at the same time: 5 mM PPi= 100%; 5 mM PPi+ 5 mM MgCl2= 58%; 5 mM MgCl2= 85%; 5 mM PPi+ 5 mM CaCl2= 68% and 5 mM CaCl2= 92% of the control. Thus polyphosphate addition in the presence of divalent cations lowers the WHC of NAM. The absence of the organized structure of muscle in NAM is postulated to be the reason that polyphosphate plus divalent cation reduced WHC in these samples. A series of preliminary experiments were run in order to determine the effect of experimental parameters on W

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1980.tb00776.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The water holding capacity (WHC) of natural actomyosin (NAM), of both contracted and uncontracted glycerinated myofibrils and of pre‐ and post‐rigor chicken meat was investigated in the presence and/or absence of sodium pyrophosphate (PPi), Kena, CaCl2and MgCl2. In these experiments PPicaused a small decrease in the WHC of NAM which was further decreased either by Ca or even further by Mg. PPiwith or without Ca or Mg had almost no effect on the WHC of glycerinated myofibrils. Pre‐rigor meat showed a slight decrease in WHC of PPiwhich was further decreased with Mg or even further by Ca. With post‐rigor meat the WHC increase with PPiwas decreased by the addition of Mg or even further decreased by the addition of Ca. The actual WHC of pre‐rigor meat was almost twice that of post‐rigor meat. Once rigor had occurred no major changes in WHC were observed up to 5 days. Kena caused a slight decrease in the WHC of NAM. Using myofibrils and the meat samples, Kena gave an increase in WHC. The addition of Ca and Mg again tended to decrea

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1980.tb00777.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The water holding capacity (WHC) of rainbow trout(Salmo gairdneri)white muscle and lobster(Homarus americanus)tail muscle did not change from pre‐ to post‐rigor. The trout muscle WHC values were similar to those of post‐rigor chicken breast muscle and were not affected by the addition of sodium pyrophosphate (PPi), Mg, Ca or combinations of these. In contrast, the WHC of lobster muscle was like the WHC of pre‐rigor chicken breast muscle. The pre‐rigor lobster muscle showed a large increase in WHC values with the addition of pyrophosphate (205% of control) but with the further addition of Mg to the sample the increase was depressed (166% of control). Ca addition to the pyrophosphate sample even more markedly depressed the WHC (90% of control). In both cases, Mg and Ca seemed to have approximately the same effect on WHC whether PPiwas present or not. Kena, on the other hand, increased the WHC of both pre‐ and post‐rigor trout and lobster muscle. Ca seemed to negate the increasing effect Kena had on WHC. Kena plus Mg caused a large increase in the WHC of the prerigor lobster muscle; the WHC capacity with Kena alone was 123% of control while the WHC with Kena and Mg was 23

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1980.tb00778.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Total lipids, phospholipids (PL), free fatty acids, TBA, carbonyl values, fatty acids and amino acid composition of filleted sucker (FS) and mechanically deboned minced sucker (MDMS), were determined. Higher PL concentration (534 mg/100 g versus 370 mg/100 g) and higher carbonyl values (0.89 μmoles/g versus 0.61 μmoles/g) were found in MDMS. There were no significant differences between FS and MDMS in fatty acid composition of total lipid and phospholipids. The protein content and amino acid composition of FS and MDMS were simila

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1980.tb00779.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Book reviewed in this article:Microbial Technology. Second Edition. Edited by H. J. Peppler and D. PerlmanFood Texture and Rheology. P. Sherman (Editor)Uses of Enzymes and Immobilized Enzymes. Francis X. HasselbergerChemistry and Control of Enzyme Reactions. K. G. Serimgeour

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1980.tb00780.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY