ISSN:0022-5142    

DOI:10.1002/jsfa.2740010202

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe water contents of some dehydrated plant products have been determined in atmospheres of known humidity within the range 0% to 80% saturation, usually at a temperature of 50° F. (10° C.) and also at 98–6° F. (37° C), 140° F. (60° C.) and 176° F. (80° C.) with dried potato and dried carrot.The non‐diffusible colloids and soluble constituents each play a definite part in affecting the water content at any humidity; the colloids have a relatively high water content at low humidities and the soluble constituents have a low water content.The humidity/water relations of mechanical mixtures, such as soup powders, can be calculated from the proportions and properties of the c

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010203

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractSome eggs recently imported into the United Kingdom under refrigeration were characterized by amber‐coloured whites and enlarged yolks. ThepHof white and yolk, also the lipoid‐ and water‐content of the yolk were abnormal. It has been reported that a similar condition arises during the cold storage of eggs laid by hens that have oaten malvaceous plants, seeds or oils. It has now been shown that the same abnormalities result if normal eggs are frozen above — 6° C. and stored in the thawed state. It is suggested that “amber whites” are not always caused by the die

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010204

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe component fatty acids of a West African dika fat were found to be capric 1.6, lauric 43.0, myristic 46.4, palmitic 6.2, oleic 2‐6, linoleic 0.2% (wt.). Exhaustive crystallization of a portion of the fat failed to resolve it into any one individual triglyceride fraction. The chief component glycerides present were found to be trilaurin 7.1, myristodilaurin 32‐5, caprolauro‐myristin 5.2, lauromyristopalmitin 13.1, laurodimyristin 28.7, trimyristin 5.1, and oleolauromyristin 5.1%. The experimental evidence indicates that the tri‐acid glycerides are the components primarily responsible for the lack of sharp resolution on crystallization. Further, it shows that this fat is built up according to the general principle of even distribution, although the values for its component glycerides accord tolerably well with those computed for random distribution. This circumstance is due to the increased number of component acids present, and does not connote any essential difference in the mode of synthesis of the fat in t

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010205

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe interference of ferrous iron in the titration of ascorbic acid in a metaphosphoric acid medium with 2.6‐dichlorophenol‐indophenol can be avoided by the use of other acid media. The present work shows that the use of a sodium acetate‐hydrochloric acid buffer ofpH0.65 instead of the more usual metaphosphoric acid, as an extractant for canned foods, avoids the complications due to ferrous salts. The stability of ascorbic acid in the two media is si

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010206

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe seed fat of the Umbelliferous plantAmmi visnagaLinn, has been analysed, and the composition of the fatty acids has been shown to be palmitic acid 5%, petroselinic acid 50%, oleic acid 32%, linoleic acid 13%.This species thus resembles other members of the family Umbelliferae, which are characterized by major proportions of petroselinic acid in the seed fat. The presence of the chromone, khellin, in the seeds has been confirmed.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010207

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractA method is described for examining biscuits, with and without chocolate couverture, for the presence of extraneous materials such as rodent and other animal hairs, insect fragments and mould spores. The application of this method to the problem of “good housekeeping” in this type of food manufacture is briefly discus

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010208

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractTwo methods are outlined for the colorimetric determination of aluminium in the presence of iron. They differ only in the reagent used to inhibit the iron colour, the finalpuof the lake and the amount of iron that can be present. Thioglycollic acid and hydroxylamine hydrochloride are used to prevent the formation of the colour due to iron, thioglycollic acid being the more effective. As the solubility of the lake increases with increasing alkalinity theph in the alkaline method is carefully controlled at 7.5 ± 0.2 by means of ammonium borate solution. Other factors influencing colour development are discussed. The limits of tolerance of elements that interfere in colour production are given, and the application of the methods to the determination of aluminium in soil extracts, soils and clays is described

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010209

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe rate of combination of SO2with glucose, with acetaldehyde, with mixtures of the two and with heated glucose solutions has been compared with the rate of combination with orange juice. The velocities of combination and of breakdown of the bisulphite compounds formed can be accounted for by reactions observed in pure solutions (although the exact nature of the aldehydic compounds remains to be elucidated), at any rate as far as concerns the changes in the first few hours.Glucose and the other aldehydes behave in asimilar way towards SO2, the differences being merely of degree; thus they all combine more rapidly (but less completely) at higher temperatures, and more rapidly (but to about the same extent) at higher pH's.These general trends are discernible withconcentrated orange juices, but they cannot be properly demonstrated till better methods for determining free SO2in such jiices are available. There remain much slower changes, extending sometimes over several days, which are characterized by high degrees of combination, variability from jiice to juice, by fluctuation, even of free SO2in an individual jiice and by inversion of the temperature‐effect; these changes take place even at tmperatures where breakdown of the juice seems unlikely, and their nature and duration cannot apparently be explained simply by reactions of aldehydes etc.; their cause remains to be discovered.It is noted, finally, that the nature and quantity of any active aldehydes may be greatly modified by heat‐processing of the jiice, and that combination of SO2with such substances might well interfere with browning reaction. The possibility of delaying combination by acidification is also envisa

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010210

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010201

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY