摘要:

The physicochemical and immunological properties of three Sudanese gum arabic samples and four gum tahla samples (two Sudanese, one West African and one Tanzanian—Acacia seyalvar.seyal) were compared. The optical rotation (ca‐30°) and rhamnose (12–14%), arabinose (24–29%), galactose (36–42%), glucuronic acid (16–17%), nitrogen (0.327–0.365%) and protein (2.16–2.41%) contents of the gum arabic samples were consistent with the FAO (1990) specification forAcaciagum. In contrast the gum tahla samples had positive [α]Dvalues (+45° to +54°), lower rhamnose (3–4%) and higher arabinose (41–45%) contents and lower nitrogen (0.147–0.175%), and hence protein (0.97–1.15%), contents. All of the gum arabic samples precipitated withβ‐glucosyl Yariv reagent and hence were shown to contain arabinogalactan‐protein(s) (AGPs), whereas in all but one of the gum tahla samples AGPs were not detected. The strong interaction of gum tahla with a monoclonal antibody known to recognize arabinose residues present in AGPs and arabinogalactans (AGs) was consistent with the observed higher levels of arabinose present in the gum tahla samples relative to the gum arabic samples. The data presented confirm that there are a number of physicochemical and structural differences between gum arabic (A. senegalgum) and gum tahla (A. seyalgum), and that a quick and simple immunological technique (immunodot blots) using an antiAGP/AG monoclonal antibody (MAC 207) could be used to screen for the presence of gum tahla in gum arabic consignments.

ISSN:0265-203X    

DOI:10.1080/02652039609374485

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The distribution profiles of sulphur in commercial caramel colours I, III and IV on a gel‐filtration column were studied with a high performance liquid chromatograph (HPLC) connected directly to a vacuum‐ultraviolet inductively coupled plasma‐atomic emission spectrometer (ICP). A small sulphur peak of sulphate was detected in most products of caramel III, whereas caramel I products did not exhibit a sulphur peak, as predicted from the total sulphur concentration. In caramel IV products, sulphur was detected continuously in the fractions of the colouring ingredients with high molecular weights. The molar ratio of carbon relative to sulphur in the colouring ingredients was 14–25, suggesting that one sulphur was bound to every 2–4 molecules of original hexose. However, sulphur was also contained in lower molecular weight fractions which were not the colouring constituents, the content being over twice that of the colouring ingredients.

ISSN:0265-203X    

DOI:10.1080/02652039609374486

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Food and Drink Laboratory Accreditation—A practical approach.S. Wilson and G. Weir (Chapman and Hall, London, 1995). Pp. xxiv+262. Price £35.00. ISBN 0–412–59920–1.

ISSN:0265-203X    

DOI:10.1080/02652039609374487

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0265-203X    

DOI:10.1080/02652039609374488

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0265-203X    

DOI:10.1080/02652039609374474

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor