Acid In Hydrolysate Research Articles

Improvement of Prebiotic Properties and Resistant Starch Content of Corn Flour (Zea mays L.) Momala Gorontalo Using Physical, Chemical and Enzymatic Modification.

Probiotics are a non-digestible food ingredient that promotes the growth of beneficial microorganisms in the intestines. One of the functional food ingredients, Momala corn flour, is a source of prebiotics with a resistant starch content of 4.42%. Thi s study aimed to improve the prebiotic properties and resistant starch content of modified corn flour (MCF) Momala Gorontalo by using physical, chemical, and enzymatic modification processes. The research methods include physical modification (heat moisture treatment, annealing, autoclaving-cooling cycling, microwave), chemical modification (acid hydrolysis), and enzymatic modification (debranching pullulanase). The results showed that the modified by heat moisture treatment (HMT) increased RS levels 1-fold, annealing modification (ANN) 8.9-fold, autoclaving-cooling one cycle modification (AC-1C) 2.9-fold, autoclaving-cooling two cycles modification (AC-2C) 2.0-fold, microwave modification (MW) 1.3-fold, acid hydrolysis (HA) modification 5.0-fold, and debranching pullulanase (DP) modification 3.8-fold compared with corn flour control without modification. The value of the prebiotic activity of MCF hydrolysed acid (HA) is 0.03, and debranching pullulanase (DP) is 0.02 against Enteropathogenic Escherichia coli (EPEC). The prebiotic effect value of MCF HA and DP were 0.76 and 0.60, respectively. The prebiotic index value of MCF HA and DP were 0.60 and 0.48, respectively. This study confirms that MCF HA and DP are good prebiotic candidates because they have resistant starch content, low starch digestibility, and resistance to simulated gastric fluid hydrolysis than unmodified corn flour.

Cystine Content of Wool

Disulfide bonds in wool were reduced with tri-n-butylphosphine in 50% n-propanol at pH 7.6. Native and generated sulfhydryl groups were then alkylated in the same medium with 2-vinylpyridine. Cystine and the original of cysteine residues were thus changed quantitatively to residues of S-β-(2-pyridylethyl)-L-cysteine (2-PEC). Occurrence of this new amino acid in hydrolyzates of the modified wool was confirmed by independent synthesis. 2-PEC is stable to acid hydrolysis and is eluted from the basic physiological column of an amino acid analyzer as a discrete peak before arginine. Quantitative modification of sulfhydryl groups in reduced keratins to 2-PEC permits quantitative determination of cysteine or of cystine via cysteine by two independent techniques-ion-exchange chromatography and ultraviolet spectroscopy. The new procedure is suitable for routine analyses.

Automated ion-exchange chromatography of uronic acids and uronic acid containing oligosaccharides

An automated anion-exchange chromatographic procedure for the separation of uronic acids and uronic acid containing oligosaccharides is described. The method has been applied, in particular, to the separation and quantitation of l-iduronic and d-glucuronic acid in hydrolyzates of dermatan sulfate, and the hydrolysis conditions required for optimum yield of uronic acids have been determined. Whereas uronic acids and aldobiuronic acids were successfully separated by elution with formic acid, hyaluronic acid oligosaccharides and, especially, the highly charged chondroitin sulfate oligosaccharides were more conveniently resolved in a chloride system by elution with a nonlinear LiCl gradient. This system was also employed for the separation of unsaturated and saturated disaccharides obtained by chondroitinase digestion of chondroitin and chondroitin sulfate. The effluent from the columns was analyzed by the automated orcinolsulfuric acid method of the Technicon sugar chromatography system.

Galacturonic acid in hydrolyzates of defatted human brain

Galacturonic acid in hydrolyzates of defatted human brain

Composition of purified mucopeptide from the wall of Aerobacter cloacae.

Molecular proportions of glucosamine, muramic acid, alanine, glutamic acid, and diaminopimelic acid in purified mucopeptide (MP) from the wall of Aerobacter cloacae NRC 492 have been estimated. Crude walls, obtained by fractional centrifugation of disintegrated log-phase cells, were treated with trypsin, ribonuclease, and pepsin to remove cytoplasmic contaminants. Of a number of protein solvents tested on the isolated walls, saturated aqueous sodium lauryl sulphate gave the purest MP in the highest yield. Molar ratios of glucosamine, muramic acid, alanine, glutamic acid, and diaminopimelic acid in hydrolyzates of the MP, corrected for the loss of hexosamines under the conditions of acid hydrolysis, were 2:2:3:2:2 respectively. These ratios indicate the presence of two types of peptide, with one peptide chain attached to each disaccharide unit. Analysis showed the absence of phosphate and therefore of teichoic acid from the purified MP.