摘要:

ABSTRACTCrude protein content, amino acid composition andin vitroprotein digestibility of fresh, dried and rehydrated Argentina squid(Illex argentinus)were studied. Most of the nonamino acid nitrogenous compounds in the mantle muscle dissolved in water during rehydration. Rehydration improved the nutritive value of protein in dried squid. Rehydration decreased the concentration of proline relative to total amino acids in muscle. Aromatic amino acids were limiting essential amino acids in fresh and dried squid but not in rehydrated squid. Amino acid scores increased with the extent of rehydration, more so in alkali than in water. The alkali rehydration also increased thein vitroprotein digestibility of dried squid.

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1996.tb00581.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACTThe effects of a diverse range of putative inhibitors on o‐diphenol oxidases (o‐DPOs) from apple, banana and mushroom and a fungal laccase (p‐DPO) were compared. The results show that inhibitors varied widely in their effect on DPOs from different sources. In some cases prevention of melanin formation (browning) was due to the direct inhibition of the enzyme catalyzed reaction. In other cases, inhibition was indirect, i.e., due to blocking subsequent melanin‐forming reactions of the enzymically formed quinone p

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1996.tb00582.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACTAcidic proteases were extracted and purified from the stomach of orange roughy(Hoplostethus atlanticus).Protease I and II were glycoproteins with molecular weights of 33.5 and 34.5 KDa, respectively. Protease I had an isoelectric point of 5.30. The two forms of protease II (a and b) had isoelectric points of 4.35 and 4.40, respectively, and N‐terminal sequence identity for 12 amino acids.The proteases exhibited optimal temperature activity at 37C. They had high activity at low temperatures and low thermal stability compared to mammalian pepsins. They were stable in the pH range of 2–4.5 and unstable above pH 6.5. Protease I and II had pH optima of 2.5 and 3.5, respectively, and Km’values for the hydrolysis of hemoglobin (pH 3.0, 37C) of 124 μM and 517 μM, respectively. Enzyme activities were inhibited by pepstatin A and high NaCl concentrations, and were slightly stimulated by Ca2+a

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1996.tb00583.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACTBovine serum extract containing α2‐macroglobulin was added to bluefish meat pastes to various final concentrations of 0% (control), 0.05%, 0.10%, or 0.20%, and gels were prepared from the treated fish pastes by heat at 60C for 60 min, or by hydrostatic pressure at 3,742 atm for 30 min. α2‐Macroglobulin caused significant color changes in the gels even though increasing inhibitor concentration showed no further changes. L* values were increased by inhibitor addition while a* and b* values were decreased. Storage studies at 0C indicated that hardness and elasticity of the heat‐induced gels were higher for the α2‐macroglobulin containing samples than the control samples within 7 days of storage, whereas a similar effect was not observed with pressure‐induced gels. SDS‐PAGE studies indicated that pressure treatment retained more myosin in the fish gels than the heat treatment. The heat‐induced gels with α2‐macroglobulin also retained more myosin than those without the

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1996.tb00584.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACTThe thermal and retrogradation properties of oat starches from two cultivars (NO 753‐2 and AC Stewart) were characterized in the presence of glucose, fructose and sucrose at a concentration of 36% w/v. In both oat starches, amylose leaching (AML) and swelling factor (SF) decreased in the presence of sugars (sucrose>glucose>fructose). These decreases were more pronounced in AC Stewart starch. The decrease in AML showed that sugars interact with amylose chains within the amorphous regions of the starch granule. The gelatinization transition temperature and the enthalpy of gelatinization increased in the presence of sugars (sucrose>glucose>fructose). The above increase was also more pronounced in AC Stewart starch. The decrease in SF and the increase in gelatinization parameters indicated that these changes were influenced by the interplay of factors such as starch‐sugar interaction, changes in water structure in the presence of sugars, and the antiplastizing properties of sugars relative to water. The retrogradation enthalpy and the X‐ray diffraction intensities of NO 753‐2 and AC Stewart starch gels (stored at 4C) increased in the presence of sugars (glucose>fructose>sucrose). These changes were more pronounced in NO 753‐2 starch. The results showed that interaction (during storage) between leached amylopectin and sugar molecules was the main causative factor influencing oat starch retro

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1996.tb00585.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Book reviewed in this article:PRACTICAL FOOD MICROBILOGY, 2nd edition. Edited by D. Roberts, and W. Hooper, M. Greenwood.

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1996.tb00586.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1996.tb00580.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY