Reducing sugars defined

Achillea spp. A. millefolium L. contains achilleine, amorphous hydrolysed to achUletine, CnHj,04N, also amorphous, ammonia and a reducing sugar. A. moschata contains achilleine and moschatine, CjiHjjOjN, an ill-defined gluco-alkaloid.2 ((1) Zanon, Annalen, 1846, 58, 21. (2) von Planta, ibid., 1870,... 

Corn syrup solids (C5Hi2O5)n 2 (CAS. Reg. No. 68131-37-3) are defined by the FDA as dried glucose syrups (21 CFR 168.121) in which the reducing sugar content (DE) is 20.0 or higher. Corn syrup solids are presently under GRAS review along with other sweeteners and table syrups. 

The PGase activity of the unknown enzyme preparation, in terms of reducing groups generated per unit time, is based on the corrected rate of increase in galacturonic acid equivalents for the experimental enzyme/substrate test solutions. One unit of enzyme activity (katals) is defined as that amount of enzyme that liberates I mole of reducing sugar per second under the defined conditions. 

Reducing sugars are sometimes characterized by a number, Rqj, which is defined as the number of milligrams of copper reduced by 1 gram of the sugar, in which the half-reaction for the copper is... 

Filter paper activity, which describes the overall cellulolytic activity of an enzyme preparation, was determined by the method of Mandels et al. (16). A 1 x 6 cm strip of Whatman no.l filter paper (Hillsboro, OR), which equals 50 mg of cellulose, served as the substrate and was added to the sample solution containing 0.5 mL of appropriate diluted enzyme (supernatant of culture broth) and 1.0 mL of 0.05 M citrate buffer (pH 4.8). After 60 min of incubation at 50°C, the hydrolysis was terminated by the addition of 3 mL of DNS solution, and the mixture was further assayed for reducing sugar content by the DNS method. One international filter paper unit (FPU) was defined as the amount of enzyme that releases 1 pmol of glucose/min under the assay conditions. Activities were reported as FPU/milliliter. 

A standard assay for both forms of enzyme consisted of mixing 108 mL of sucrose solution (120 g/L in 0.010 M acetate buffer, pH 5.5) with 12 mL of aqueous invertase solution (diluted 1 5000 [v/v]) or 12 mL of an aqueous suspension of Dowex/invertase (100 mg of powder/mL). Hydrolysis was carried out for 6 min at 37°C under agitation (lOOrpm), as previously described by Vitolo et al. (1). One soluble or immobilized invertase unit (U) was defined as the amount of total reducing sugar (TRS) (mg) formed per minute under the conditions of the test. 

Xylanase was assayed using birchwood xylan as substrate. The solution of xylan and the enzyme at appropriated dilution were incubated at 75°C for 3 min, and the reducing sugar was determined by the dinitrosali-cylic acid procedure (12) with xylose as standard. The released color development was measured spectrophotometrically at 540 nm. One unit of enzyme activity was defined as 1 pmol of reducing sugar released 1 min under the described assay conditions. Protein concentration was measured by the Lowry method (13) using bovine serum albumin as standard. 

Calculation One unit of diastase activity, expressed as degrees diastatic power (DP°), is defined as that amount of enzyme contained in 0.1 mL of a 5% solution of the sample enzyme preparation that will produce sufficient reducing sugars to reduce 5 mL of Fehling s solution when the sample is incubated with 100 mL of the substrate for 1 h at 20°. 

Calculation One (3-glucanase unit (BGU) is defined as that quantity of enzyme that will liberate reducing sugar (as glucose equivalence) at a rate of 1 xmol/min under the conditions of the assay. 

In the early 1960s one of the first commercial products Terra Firma (Intrusion-Prepakt, Cleveland) was marketed in the United States and abroad. The patent covering this product [11] defines a calcium lignin sulfonate with reduced sugar content, sodium dichromate and aluminum sulfate catalysts, and copper sulfate and calcium chloride accelerators. The product was marketed as a dry, precatalyzed powder. It was mixed with water in varying proportions for field use. Water content was the only... 

Define the term reducing sugar. What structural feature does a reducing sugar have ... 

Xylanase activity was assayed by measuring reducing sugars released as xylose, using a dinitrosalycylic acid method [22]. The reaction mixture containing 0.9 mL of the substrate solution of birchwood xylan (5.0 g/L) in acetate buffer (pH 5.0, 0.1 M) and 0.1 mL of the crude enzyme solution was incubated at 60 °C for 10 min. One imit of enzyme activity was defined as the amount of enzyme releasing 1 pmol of xylose per minute, under the cited assay conditions. 

Dextrose equivalent (D.E.) is defined as the reducing sugar content calculated as dextrose and expressed as a percentage of the total dry substance, t Includes heptasaccharides. 

Activity of salivary a-amylase was measured by incubation of the enzyme with 0.5% soluble starch in 0.05 M phosphate buffer (0.2 ml), pH 6.8, containing 0.005 M sodium chloride at 37° for 20 min, and the reducing sugars were measured by the method of Nelson-Somogyi. One unit was defined as the amount of enzyme which produces one ymole of reducing group (as glucose) per min. Activities of other enzymes were assayed by similar methods. 

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