摘要:

AbstractA sensory panel of experienced judges was used to determine taste thresholds of mixtures of limonin and naringin and various sweeteners. Data from these experiments showed that within the 95% confidence interval, subthreshold interactions between limonin and naringin were additive, indicating that less than threshold amounts of these compounds contributed to bitterness of a mixture. Mixtures of hesperetin dihydrochalcone glucoside (HDG), neohesperidin dihydrochalcone (NHD), naringin dihydrochalcone (ND), sucrose and naringin were neither additive nor synergistic at subthreshold concentrations. At suprathreshold levels, sucrose, (HDG) and (NHD) were effective in suppressing naringin bitterness, but (ND) was not.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251102

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractTwo means for determining the lactose and sucrose contents of sweetened condensed milk products are examined. The first of these is a simple calculation based on polarimetric measurements and gives reproducible results for lactose which agree well with conventional methods of determination. The second is a novel colorimetric method based on determination of total carbohydrate before and after degradation of lactose with alkali. This gives slightly higher values for lactose in sweetened condensed milk products than conventional methods but could nevertheless be adopted as a means of analytical control, due to its speed, simplicity and cheapness. The advantages and disadvantages of both techniques are compared with those of conventional analytical methods.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251103

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractProportions of amylose to amylopectin in the starch of leaf lamineae of timothy and sorghum were similar to those reported for starch in seeds and tubers, in the order of 20:80. Proportion of amylose to amylopectin in lucerne leaflets increased from 2:98 to 21:79, and the wavelength of maximum absorption of the iodine‐hot‐water‐solubilised starch complex increased from 580 to 605 nm, as the starch concentration increased from 6 to 37% (dr

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251104

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractFollowing an exhibition of 32 current vintage red wines of two varieties from the Southern Vales district of South Australia, a correlation was observed between colour densities and the order of ranking previously assigned by a panel of experienced judges.There was no relation between wine colour density and anthocyanin content. Amongst many wines having comparable levels of anthocyanins, the variation in colour density was as much as 3.6‐fold, and the degree of ionisation of the anthocyanin component of wine colour was found to range from 6 to 25%. These latter values were also correlated with the quality ratings.The data support the opinion that measurement of colour density and of the degree of ionisation of anthocyanins can provide an objective guide to organoleptic properties in young wines of the same variety and region. Confirmation for this view was obtained from other data concerning the subsequent vintage of Cabernet Sauvignon in the same district.Factors likely to be responsible for the varying states of anthocyanin equilibria in these wines are discussed in terms of wine composition and oenological practic

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251105

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractA simple quantitative method for determining four aliphatic fusel alcohols in beer and fermenting wort, namelyn‐propanol, isobutanol, 2‐methyl‐1‐butanol and 3‐methyl‐1‐butanol, has been developed. Samples were distilled at reduced pressure (10 Torr) and analysed by gas liquid‐solid chromatography. Graphitised carbon black deactivated with 0.3% SP‐1000 Carbowax 20 M modified with derivative of terephthalic acid and 0.3% phosphoric acid was used as column packing. Coefficients of variation determined were 3% or less. To serve as examples, contents of fusel alcohols in some commercial and experimental beers and a wort fermented for various lengths of

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251106

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThis paper describes experimental work that has been carried out to determine the normal ash, sulphated ash and potassium contents of four selected and specified green coffees, together with the relationship between extraction yield and potassium content of prepared instant coffees. In conjunction with previously published data on the mineral contents of coffees, the relationship is shown to be capable of giving only an arbitrary measure of extraction yield, primarily on account of the variability of mineral and potassium content of different green coffees, and to a leaser extent on the variable process conditions that are commercially used in extraction. The reasons for the variability of mineral content, which can be at least ±10% of the average, are discussed

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251107

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractPotatoes of 10 varieties were held for 26 days at 4 ºC and 18 ºC and their glucose, fructose and sucrose contents compared. The glycolipid and phospholipid composition of four of these varieties was also determined and showed changes which were similar to those observed when leaf tissue is chilled, but were too small to imply severe chemical degradation of membrane

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251108

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractTechniques developed earlier to measure cooking loss in beef sternomandibularis and rectus abdominis muscles under defined conditions, have here been extended to other factors affecting cooking loss. Cold shortening of the muscle has no effect. Searing of the ends before cooking causes a slight increase in loss. In samples cooked for varying times at 80 ºC, cooking loss rises gradually up to 2h, while cooking shortening and shear force reach a maximum much more quickly. Colour changes are described in meat cooked for various times, then cut and exposed to air. Slow cooking gives higher cooking losses than fast, but a lower shear force.Histological studies have shown that in frozen sections maintained in aqueous media the annular shrinkage space is small and does not vary significantly between cooking treatments. The dehydration involved in paraffin sections exaggerate the shrinkage, although these sections show best the fused and apparently intact sarcolemmas. The electron microscope, however, reveals that there are many punctures in the membranes

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251109

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe concentrations of volatile amines were determined in the eye muscle of 10 pork carcasses at the following stages of curing: immediately after slaughter, before curing, after maturation and after vacuum‐packed storage of the bacon.Methylamine (MA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA),n‐propylamine (n‐PA) and isopropylamine (iso‐PA) were detected by gas chromatography; MA was present in greatest concentration [up to 1900 μg/kg (1 part/109)], the concentration of the others being considerably less.During the course of bacon manufacture, the concentrations of DMA, TMA,n‐PA and iso‐PA increased consistently up to the end of the maturation period, despite the presence of nitrite both in the brine and in the bacon; in subsequent storage, only DMA and TMA continued to increase. MA decreased during curing and maturation, and thereafter remained unchanged; EA and DEA were unchanged throughout at very low levels. The mean value for the concentration of DMA was below 200 μg/kg before curing; higher values (maximum 520 μg/kg) were found in vacuum packed stored bacon.No nitrosamines were found above the detection limit (1 μg/kg) in any of the uncooke

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251110

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractFollowing the report of photosensitisation of albino rats when fed lucerne leaf protein (LP) and the suggestion that this was due to pheophorbide, the amounts of chlorophyll‐degradation products in LPs from a range of species were determined. The results were correlated with the chlorophyllase activity of the leaves from which the preparations were mad

ISSN:0022-5142    

DOI:10.1002/jsfa.2740251111

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY