摘要:

SUMMARYThe ascorbic acid content of a total of 120 specimens of each species of edible liver was estimated by the N‐bromosuccinimide method. Statistical analysis of the results is given. Differences were found occasionally between males and females in liver ascorbic acid content, but were not statistically significant. The effect of cooking on liver ascorbic acid content is show

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00287.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYA method was developed for the determination of water activities of flour at high moisture contents. In this method a flour sample was allowed to equilibrate with water contained in a porous membrane while under a certain constant mechanical pressure. The cell was fitted with a porous membrane which allowed the transfer. of moisture from and to the sample. After equilibrium was achieved the sample was analyzed for moisture content. A thermodynamic relationship enabled calculation of the water activity corresponding to the pressure used in the cell. Results obtained with this method were in agreement with those obtained with the constant‐relative‐humidity desiccator technique in the over‐lapping range of water activities. The two methods were also in agreement that the water activity of flour was not affected by the particle size distrib

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00288.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYMethods were developed for the preparation in reproducible yield (2–5 ppm) of odor concentrate from fresh ripe tomatoes. Sufficient concentrate was obtained to allow its separation by gas chromatography and collection of its components for direct investigation. Examination of the fractions resulted in rigorous identification of previously unknown tomato constituent

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00289.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYIce cream mix and frozen ice cream were studied. The aspects examined include the importance of the electrical charge on fat globules to the stability of mix against flocculation, the flow properties of mix at low rates of shear, the coagulation of mix at low temperature, the churning and coagulation of fat when mix is frozen, and the rheology of frozen ice cream. From the accumulated data a theory is proposed which indicates factors likely to influence the texture of frozen ice cream. A small initial fat globule size is desirable. This should be accompanied by rapid denaturation of milk protein during emulsification and homogenization. When mix is frozen, the solid fat particles produced by churning and coagulation should remain relatively small and be distributed throughout the lamellae between the air cells as small aggregates. The strength of the lamellae, on which texture largely depends, is also influenced by ice‐crystal size and distribution, and the resistance of air cells to deformation. The fat particles in the aggregates are held together by van der Waals attraction force

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00290.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYPepsin rapidly decreases the viscosity of a glutenin dispersion having an acid reaction and rapidly increases‐the amount of water‐soluble fragments. The molecular weight of the solubilized fragments, estimated by the gel‐filtration method, indicates that most of the fragments are large and have: molecular weights greater than 10,000. A comparison of data obtained by gel filtration and by determination of terminal amino acids in pepsin hydrolysates of glutenin indicates that cleavage of a few pep‐tide bonds rapidly produces these large molecular polypeptides from glutenin. Further pepsin action causes a substantial increase in small peptide fr

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00291.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYPectinesterase (PE) was inhibited by sucrose at the same concentrations that delayed gelation of papaya purée. The inhibitory effect was linear with sucrose concentration throughout the range investigated (up to 50% sucrose). Conditions for optimum PE activity, pH 7.5 and 0.21M NaCl, were not affected by inhibitory concentrations of sucrose. Evidence was obtained against competitive inhibition, transferase activity, and an effect on the binding of PE as possible mechanisms for inhibition. Other sugars tested, including glucose, maltose, and corn syrups of varying degrees of hydrolysis, as well as glycerol were also inhibitory

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00292.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYThe influence of feeding, activity and pasteurizing doses of gamma irradiation on the nucleotide composition and breakdown in English sole (Parophrys vetulus) was studied. Feeding did not cause any significant change in the total amount of nucleotides. Active fish had lower amounts of ATP and increased levels of IMP, but this difference was not significant after they had been stored 7 days in ice. In contrast to the results reported for other species of sole, inosine was present in English sole after 7 days in ice. Irradiation, 0.5 and 1.0 Mrad, did not affect the changes in the nucleoside and nucleotide composition.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00293.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYVolatile components from the steam above peas in a commercial blancher were isolated by adsorption on charcoal, freeze‐drying of the charcoal, solvent extraction, and distillative concentration. The concentrate was further fractionated by distillation and gas chromatography. Ethanol and dimethyl sulfoxide were most abundant. The latter compound formed by the oxidation of dimethyl sulfide adsorbed on the charcoal. The less abundant components of the concentrate fractions were identified by capillary‐column gas‐chromatography fast‐scan mass spectrometry. The most novel group of minor components thus identified was the diethyl acetals of C1‐C6aldehydes. It was not possible to determine from model experiments if the acetals were original components of the blancher steam or artifacts of the isolation. A control concentrate from unexposed charcoal and purified solvent differed quantitatively and qualitatively from the blancher steam co

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00294.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYPectinolytic and cellulolytic enzymes in cucumber flowers, when added to small‐scale cucumber fermentations, were effectively reduced in activity by the use of a brine extract of sericea (Lespedeza cuneataDon) and by a freeze‐dried substance isolated from this plant. Reduction of enzyme activity in the fermenting brines was directly related to the inhibitor concentration used. Higher levels of the inhibitor resulted in an increase in firmness of the cured salt‐stock cucumbers. The judges rated the salt‐stock from all inhibitor treatmentsgoodtoexcellentas to acceptability for commercial use. The addition of sericea, either as the brine extract or the isolated substance, appeared to exert no lasting inhibitory effect on the lactic acid bacteria responsible for acid fermentation in the experimental

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00295.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYTwo varieties of snap beans that had been mechanically harvested were stored at 35, 55, and 85°F for 1, 3, and 5 days to determine the relationship of chemical changes to the quality of the resultant canned beans. Only approximately 50% of the weight loss during storage was regained by increase in drained weight in blanching and canning. There were losses in total sugars, starch, Calgon‐soluble pectin, and hemicellulose, but gains in water‐soluble pectin and cellulose. Higher storage temperature accelerated these changes. Variety and sieve‐size influenced most of the chemical and physical changes. Storage increased sloughing in canned beans. Softening of canned beans occurred despite a loss of moisture during storage, and an increase in cellulose. There were significant changes in color, apparent in an increase in browning of bruised and broken beans, and a decrease in the Hunter ‐a

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1965.tb00296.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY