Hydrolytic stability of water-soluble spruce O-acetyl galactoglucomannans

Abstract Water-soluble native O-acetyl galactoglucomannan (GGM) from spruce is a polysaccharide that can be produced in an industrial scale. To develop GGM applications, information is needed on its stability, particularly under acidic conditions. Therefore, acid hydrolysis of spruce GGM was investigated at various pH levels and temperatures. The results allow an estimation of the stability of GGM under food processing conditions and in biological systems. Determination of the average molar mass demonstrated that spruce GGM was stable at pH 1 and 37°C, as well as at pH 3 and 70°C. GGM was hydrolysed at pH 1 and 90°C. GGM oligomers and monomers were detected after degradation. Some of the oligomers contained O-acetyl groups. Monosaccharides were the predominant products in the hydrolysates after treatment at pH 1 and 90°C for 48 h. Pentoses, present in GGM samples as impurities, were released more easily than GGM hexoses. Glucose was more difficult to release than mannose. Traces of 6-deoxy-mannose and levoglucosan were found in the hydrolysates, indicating further degradation of hydrolysed monosaccharides.

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Inter-laboratory evaluation of SEC-post-column calcofluor for determination of the weight-average molar mass of cereal β-glucan

Carbohydrate Polymers ◽

10.1016/j.carbpol.2015.02.019 ◽

2015 ◽

Vol 124 ◽

pp. 254-264 ◽

Cited By ~ 10

Author(s):

Anne Rieder ◽

Svein Halvor Knutsen ◽

Ann-Sissel T. Ulset ◽

Bjørn E. Christensen ◽

Roger Andersson ◽

...

Keyword(s):

Molar Mass ◽

Laboratory Evaluation ◽

Average Molar Mass

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A simple procedure using trinitrobenzenesulphonic acid for monitoring proteolysis in cheese

Journal of Dairy Research ◽

10.1017/s0022029900033379 ◽

1988 ◽

Vol 55 (4) ◽

pp. 585-596 ◽

Cited By ~ 52

Author(s):

Anna Polychroniadou

Keyword(s):

Simple Procedure ◽

Water Soluble ◽

Acid Solutions ◽

Amino Groups ◽

Total N ◽

Cheese Ripening ◽

Amino Acid Solutions ◽

Hydrolysis Of ◽

Good Agreement

SummaryA simple, rapid and sensitive spectrophotometric assay was developed and evaluated for monitoring proteolysis during cheese ripening, based on the fact that α-amino groups released by hydrolysis of cheese proteins react with trinitrobenzenesulphonic acid to form products that absorb strongly at 420 nm. A linear relationship was shown to exist between A420 and concentration of free α amino groups up to 0·5 HIM (r = 0·999, 38 df, P < 0·001). Repeatability of the method was satisfactory. The coefficient of variance was 0·53% for amino acid solutions and 1·19% for cheese extracts. Average recovery of glycine added to the cheese was 104 ± 2·9%. A comparison of the above method with that of determination of water-soluble N to total N ratio showed that there was good agreement between these two methods of assessment of proteolysis in cheese (r = 0·857, 32 df, P < 0·001). Mainly Feta and Teleme cheese were examined, but a similar correlation was obtained with hard Greek cheeses. Analytical conditions of the procedure are discussed.

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SYNTHESIS OF NEW SUBSTITUTED PROCAINE HYDROCHLORIDE COMPOUNDS AND THEIR USE IN SPECTROPHOTOMETRIC DETERMINATION OF TETRACYCLINE HYDROCHLORIDE THROUGH DIAZOTIZATION-COUPLING REACTIONS

Periódico Tchê Química ◽

10.52571/ptq.v18.n39.2021.02_sadiq_pgs_14_32.pdf ◽

2021 ◽

Vol 18 (39) ◽

pp. 14-32

Author(s):

Hind Sadiq Al-WARD ◽

Mouayed Qassssim AL-ABACHI ◽

Mohammed Rifaat AHMED

Keyword(s):

Stability Constant ◽

Thermodynamic Parameters ◽

Coupling Reaction ◽

Water Soluble ◽

Procaine Hydrochloride ◽

Effect Of Temperature ◽

Basic Medium ◽

Fast Method ◽

The Stability

Background: Tetracycline is one of the most important antibiotics. It is used to treat many different bacterial infections. It is often used in treating severe acne, or sexually transmitted diseases such as syphilis, gonorrhea, or chlamydia. In some cases, tetracycline is used when penicillin or another antibiotic cannot be used to treat serious infections such as the ones caused by Bacillus anthracis, Listeria, Clostridium, Actinomyces. Aim: synthesized a new novel reagent used to determine TCH spectrophotometrically by using diazonium and coupling reaction. Methods: Four new substituted procaine derivatives were prepared by simple organic methods using aniline derivatives. A spectrophotometric approach was established for the micro-determination of TCH. The stoichiometry was investigated using mole ratio and continuous variation methods, and the stability constant was also estimated. The ΔG, ΔH, and ΔS were determined as thermodynamic parameters for evaluating the effect of temperature on the reaction. Results: Substituted procaine derivatives were prepared, and o-hydroxy procaine seems to be the best reagent used to determine TCH by diazotization and coupling reaction. The result was a yellow water-soluble dye with a maximum absorbance of 380 nm. The reaction conditions were studied and optimized. Beers law was obeyed over a concentration range (2.5–50) μg.mL-1 for TCH. The molar absorptivity was (14.4669.103) L.mol-1.cm-1, and the detection limit was (0.5052) μg.mL-1. The stoichiometry of the formed product was found 1:1 (o-hydroxyprocaine: TCH). The stability constant indicated that the product formed was stable, and the thermodynamic parameters showed that the diazonium salt reaction was preferred to occur at a low temperature. Conclusions: a simple, accurate, and fast method was developed to determine TCH in pure form and pharmaceuticals by coupling the TCH with a newly synthesized procaine derivative reagent (o-hydroxy procaine) in a basic medium.

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Determination of the Average Molar Mass of the Vapour Above Molten Sodium Chloride by the Transpiration Method.

Acta Chemica Scandinavica ◽

10.3891/acta.chem.scand.33a-0407 ◽

1979 ◽

Vol 33a ◽

pp. 407-412 ◽

Cited By ~ 5

Author(s):

Halvor Kvande ◽

Oldrich Strouf ◽

Pär Svanström ◽

Elina Näsäkkälä ◽

Eberhard Hoyer ◽

...

Keyword(s):

Sodium Chloride ◽

Molar Mass ◽

Average Molar Mass ◽

Molten Sodium ◽

Transpiration Method

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SOME OBSERVATIONS ON THE PANCREATIC AMYLASE AND INTESTINAL MALTASE OF THE CHICK

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y63-238 ◽

1963 ◽

Vol 41 (1) ◽

pp. 2107-2121 ◽

Cited By ~ 6

Author(s):

B. M. Laws ◽

J. H. Moore

Keyword(s):

Small Intestine ◽

Amylase Activity ◽

Pancreatic Amylase ◽

Ph Optimum ◽

Modified Method ◽

Mucosal Cells ◽

Small Intestinal ◽

The Stability ◽

Hydrolysis Of

The digestive enzymes amylase and maltase were studied in acetone-dried powders or homogenates of the pancreatic and small intestinal tissues and small intestinal contents obtained from chicks of various ages. The stability of pancreatic amylase, which was relatively low in 0.15 M sodium chloride, was increased markedly by the presence of 0.02 M barbiturate buffer. The pH optimum of pancreatic amylase (chloride-activated) was 7.0 whereas that of intestinal maltase was 6.9. High levels of pancreatic amylase activity were found in the newly-hatched chick but these levels decreased during the following 20 days and then remained constant. The contrast between the high amylase and low maltase activities in the contents of the small intestine suggested that molecules of maltose, formed by the hydrolysis of starch, were absorbed as such by the mucosal cells. It appeared that maltose could be absorbed with equal facility from all sections of the small intestine of the 10-day-old chick but in the older birds maltose absorption seemed to occur more readily from the upper small intestine than from the duodenum and lower small intestine. A modified method for the determination of maltase activity is described.

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