摘要:

AbstractChanges in the composition of the outer walls of glasshouse tomatoes during ripening have been studied. The fruit, mainly of the variety ‘Potentate’, was carefully graded by colour into either five or six categories from mature green to red.The content of sugars and total solids in the expressed juices increased significantly from the green to the red stage. The nitrogen content showed little variation from the green to the orange stage, but increased significantly on reaching the fully red condition.The titratable acidity of the juices increased significantly from the green to the green‐yellow stage of ripeness, accompanied by decreasing pH. No consistent changes in acidity could be established after the first appearance of yellow colour, the acidity rising in some series and decreasing in others. A tentative explanation of this behaviour, which differs from that of the juices from the locules and from the whole fruit, is disc

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130301

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractA comparative study has been made of some components of the green and red areas of the walls of ‘blotchy’ tomatoes. The juices expressed from the green areas showed a significantly lower titratable acidity than those from the red areas, and had a lower content of sugars and nitrogenous compounds. Juices from the green areas also contained less soluble solids, as determined by oven‐drying, and had lower refractive indices.The content of ethanol‐soluble total sugars and free and total acids was significantly lower in the green than in the red areas. The proportion of alcohol‐insoluble solids was higher in the green areas.The results are discussed in relation to the changes in composition previously found during ripening. Some aspects of the results suggest that ‘blotchy’ cannot merely be attributed to delayed ripening in the a

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130302

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractA vacuum distillation procedure is described which, when applied to 10 g. of fat, will recover quantitatively added aliphatic aldehydes ranging in volatility from propanal to dodecanal at a concentration of 0.1 μmole/g. With autoxidising fats the method estimates, more directly than chemical tests for rancidity in present use, the class of substances responsible for rancid and reverted off‐flavou

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130303

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractFour additional sesquiterpenoid constituents of the oil have been identified as α‐gurjunene, α‐santalene, β‐elemene and ca

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130304

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractThe effect of two antibiotics (chlor‐ and oxy‐tetracycline) on the spoilage of whole iced herring is studied. Spring and summer herring were improved (taste panel assessment, determination of total volatile bases) by the antibiotics, but autumn herring were unaffected. This is attributed to a seasonal variation in the nature of the bacterial flora present on the fish. Peroxide values were higher for oil from treated compared with that from untreated fish, but the production of free fatty acids and volatile fatty acids was not affected. The production of some free amino‐acids was higher in the treated compared with the untreated fish. An attempt is made to explain these re

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130305

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractSamples of ‘phytin’ isolated from different cereals were not identical in composition. Moreover phytin fractions obtained from a given hydrochloric acid extract of wheat bran, oats, barley or rye varied considerably, and evidence is presented to show that magnesium is more strongly held than calcium. More calcium was precipitated from solution by oat than by wheat phytate, suggesting that this may be one reason for the observation that oats are more rachitogenic than wh

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130306

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractPyrethrins I and II and cinerins I and II were isolated from commercial pyrethrum extract by displacement chromatography and were also reconstituted from the naturally derived acids and alcohols. The samples of each constituent isolated from both sources had identical chemical and physical properties, and were of the same insecticidal potency within the limits of experimental error. The relative toxicities of the four constituents to female house flies (Musca domesticaL.), determined at 20° by a measured drop technique, were: pyrethrum extract, 1.0; pyrethrin II, 1.3‐ 1.5; pyrethrin I, 0.9‐1.0; cinerin II, 0.5‐0.6; cinerin I, 0.4‐0.5. The insecticidal activity of a mixture of the four constituents was examined statistically for simple similar joint action, assuming that the probit‐log‐dose lines for the separate constituents were not parallel; the predicted results are in good agreement with the experimental data. The procedures for computing the responses predicted by simple similar joint action a

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130307

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractBalance studies with Leghorn hens in good production were conducted to estimate their calcium and phosphorus requirement. The requirement, defined as the dietary level of calcium that maintained calcium equilibrium and optimum shell thickness, was found to be 3 g./hen/day. Percentage calcium retention (% retention) at high levels of calcium intake was a linear function of the reciprocal of calcium intake, the slope being equal to absolute calcium retention, but at levels below the requirement % retention increased at a decreasing rate. In the zone of calcium requirement % retention was 50‐55.Phosphorus excretion behaved as a linear function of phosphorus intake. The failure of the extrapolation method to estimate endogenous phosphorus excretion in the laying hen is discussed. Phosphorus requirement, defined by phosphorus equilibrium, was found to be between 0.24 and 0.36 g./hen/day.Measurements of plasma alkaline phosphatase and plasma inorganic phosphorus substantiated the respective requirements for calcium and phosphorus as determined by balance studie

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130308

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractPork protein heated with an equal weight of water for 24 h. at 110° showed losses of dry weight, nitrogen, sulphur and all the amino‐acids. The protein value of the heaated material as shown by bioassay fell by a greater extent than could be accounted for by losses of lysine, available lysine or the sulphur amiono‐acids. The limiting amino‐acids in both original and heated material were the sulphur amino‐acid. Balance studies of nitrogen, sulphur and lysine carried out concomitantly showed that the fall in the utilisation of lysine was largely accounted for by a reduction in its digestibility: the falls in utilisation of nitrogen and sulphur were mainly due to a reduced retention of the absorbed elements. The results are discussed in relation to possible types of reaction involved in the heat damage of

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130309

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractAn instrument was made for measuring the comparative opacities of samples of fish muscle. Differences between fresh and thawed fish were only apparent where myotome tissue freed from myocommata was used, thawed fish being more opaque. Such opacity varied according to the speed at which the fish was originally frozen. Although thawed fillets can be seen visually to become progressively whiter in appearance after increasing time in the cold‐store, the opacity as measured by the instrument showed no obvious increase with storage time. The probable reason for this is discussed.The method cannot therefore be used to assess cold‐storage changes in the muscle, although it will distinguish thawed fish from fr

ISSN:0022-5142    

DOI:10.1002/jsfa.2740130310

出版商:John Wiley&Sons, Ltd    

年代:1962

数据来源: WILEY