Alternative method of reducing sugars determination in some selected fizzy drinks and fruits by chromic acid reagent

2020 ◽  
Vol 15 (1) ◽  
pp. 32-34
Author(s):  
Mustapha A. Olajide

Chromic acid reagent as an alternative colorimetric method for the quantitative determination of reducing sugars and ascorbic acid in some selected fizzy drinks: Seven Up, Limca, Mirinda, Cocoa-Cola, Fanta, Pepsi Cola, Maltina, Guinness Malt, Hi-Malt and Maltonic) and fruits: pineapple (Ananas cosmoses), sweet orange (Cimifi sinensis), grape fruit (Dints paradise) and tangerine (Citrus reticulate) has been studied. Chromic method involves sugar solution of about 1% concentration. treated with an equal volume of concentrated nitric acid and a few drops of a 5% solution of potassium dichromate was added, a blue colour develops in less than a minute in the cold and the absorbance taken in a Spectronic 20D Spectrophotometer at 560 um. Results obtained from the simple chromic acid as test method compares well with those obtained from the titrimetric methods of Association of Official Analytical Chemists (AOAC, 2012) and Pearson (1991) as control, with negligible variations. Apart from being a very powerful oxidizing agent, its reaction with monosaccharide, disaccharides and ascorbic acid are less-time consuming, showed distinct colour development and its easy preparation, made chromic acid reagent a faster, better and suitable alternative method for the quantitative determination of reducing sugars and ascorbic acid in routine analyses of foods. Keywords: reducing sugar, ascorbic acid, chromic reagent.

1962 ◽  
Vol 39 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Roger A. Gorski ◽  
Charles A. Barraclough

ABSTRACT We have previously suggested that the failure of the androgen-sterilized, persistent-oestrous rat to ovulate, following electrical stimulation of the median eminence structures of the hypothalamus, is due to an insufficiency in adenohypophyseal LH concentration. Using the ovarian ascorbic acid technique for quantitative determination of pituitary LH content, the present studies have demonstrated that the sterile rat pituitary gland contains one-third the LH content of the normal prooestrous gland. Furthermore, not only does progesterone priming of this persistent-oestrous rat result in a 75 % increase in LH concentration, but on hypothalamic stimulation sufficient LH is released to induce ovulation. The decrease in LH concentration which accompanies ovulation in the progesterone-primed, sterile rat is approximately 45 % of the total gland content as compared with a 51 % decrease in pituitary content in the normal cyclic rat.


1976 ◽  
Vol 59 (4) ◽  
pp. 766-769
Author(s):  
Albert B Karasz ◽  
John J Maxstadt ◽  
Juergen Reher ◽  
Frank Decocco

Abstract A procedure is described for the examination of large numbers of ground beef samples for the 4 most commonly used preservatives. A single sample solution is prepared and aliquots are taken for the various tests. Sulfite is determined colorimetrically with acid-bleached p-rosaniline. Ascorbic acid is titrated with 2,6-dichloroindophenol. Benzoic and sorbic acids are measured by ultraviolet absorption. Negative samples are rapidly sorted out in this procedure and positive samples are completed for quantitative determination of the preservative. Recoveries are 95% for sodium sulfite, 103% for sodium benzoate, 90% for potassium sorbate, and 81 % expected recovery for sodium ascorbate. The limit of detection is 0.005% for potassium sorbate, and 0.01% for the 3 other preservatives.


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