Sugar analyzer

The composition of the products was monitored by HPLC (Sugar Analyzer, Waters Associates HPX-87C column, BioRad Corp. with deionized water, 40 ppm in calcium acetate as mobile phase). During fermentation, the sucrose levels dropped and fructan started to appear in 2 days thereafter, sucrose level gradually decreased as fructan increased. Glucose was the major by-product. A small amount of fructose and other unidentified fermentation products smaller in molecular weight were also observed. The pH of the growth medium was controlled, and fell from... 

For the study of soluble polysaccharides, a treatment with diluted TFA is sufficient and the reaction time can be kept short (7). Soluble polysaccharides of wood are separated from holocellulose by extraction with alkali. Wise et al. (10) term the extract with 5% KOH polyoses (hemicelluloses) A. Polyoses A can be hydrolyzed completely with 2N TFA within 1 hr. The chromatograms of the hydrolysates of polyoses A from spruce and beech holocelluloses recorded with a sugar analyzer (Biotronik ZA 5100) are shown in Figure 1. 

Smith and coworkers - have subjected starch dextrins to the classical techniques of structural carbohydrate chemistry. In one study, four commercial maize-dextrins were fractionated from aqueous ethanol to obtain a sub-fraction which was the most resistant to periodate oxidation. This material was then methylated, the product hydrolyzed, and the resulting methylated sugars analyzed by column chromatography. Table II shows the results. The complexity of the dextrin structure is shown by the fact that only components 1, 2, and 5 arise in any large proportion from the methylation of maize starch. It is of interest that no traces of a methyl... 

The main difference between MPLC and HPLC is not only in height of the performance, speed of the separation process, and the pressure required, but also in the instrumentation. A home made MPLC apparatus (Fig. 4.5.1) can be improvised in nearly every laboratory using, e.g., spare parts of amino acid analyzers or sugar analyzers. However, for the HPLC methods it is usually necessary to use commercial equipment or parts, because here the requirements of construction are much more rigid. For the separation of low and middle molecular weight substances HPLC methods are mostly used. 

GC are therefore expected in the direction of fully automated sample preparation and sample introduction systems. Some instrumentation nowadays is already tailor-made for a given application. More can be expected in the future and development may result in specific instruments, such as a pesticide analyzer, a PCB analyzer, or a sugar analyzer. 

Evaporation from a spray of charged droplets produced from a stream of liquid yields ions that can be analyzed in a mass spectrometer. Thermally labile and normally nonvolatile substances such as sugars, peptides, and proteins can be examined successfully. 

Sucrose quantitation has also been performed by colorimetric methods. However, in recent years, automated enzymatic analyzers and instmmental methods (eg, ion chromatography and hplc) have become increasingly popular, as they provide greater sensitivity and accuracy. Near infrared (nir) spectroscopy is currendy under evaluation as a tool for sucrose quantitation in sugar mills and food processing operations. 

Moisture. In relatively pure sugar solutions, moisture is deterrnined as the difference between 100 and Brix. In crystalline products, it is usually deterrnined by loss-on-drying under specified conditions in an oven or by commercial moisture analyzers that have built-in balances. Moisture in molasses and heavy symps is deterrnined by a special loss-on-drying technique, which involves coating the sample onto sand to provide a greater surface area for oven drying. The result of this test is usually considered dry substance rather than moisture. 

Frequently, column problems are caused by the samples that are being analyzed. This type of problem is more likely to occur on capillary columns because of their low capacity for contamination. Contamination results when the sample contains nonvolatile or even semivolatile materials such as salts, sugars, proteins, and so on. Column contamination is more frequently observed with splitless injection because larger amounts of material are being injected on the column. 

Cello- and malto-oligosaccharides up to nonasaccharides in the presence of various metal salts have been analyzed by f.a.b.-m.s. The structures of two methyl alduronates obtained by flash hydrolysis of wood chips was deduced by using f.a.b.-m.s., n.m.r. spectroscopy, and sugar analysis. ... 

Basically, there are four major types of measures that are used in taste intensity measurements (a) threshold measures or estimates of the physical level at which the sensation of sweetness begins, (b) equal-sweetness matches between a sugar and other sweeteners, (c) category or rating scales, and (d) ratio scales. Each method has found its adherents and uses, and each possesses specific advantages and defects that indicate its use for one application, but contraindicate its use for another. These methods and their applications have been critically analyzed and reviewed, " " and it is, therefore, superfluous to deal with the topic here. 

Fractions were pooled as indicated in the figure and analyzed for their sugar compositions (Table 3). The sugar compositions clearly show that most of the neutral sugars were concentrated in the large fragments that eluted close to the void volume of the column (Fraction... 

PA-1 was partially hydrolyzed with O.IM TFA (40°C, 24 h) and the three fractions (PA-l-I, PA-l-II and PA-l-III) were obtained by Bio-gel P-6. Especially, about 50% of TBA-positive material (PA-l-III) was eluted in the fraction of small oligosaccharide. Permethylated oligosaccharide-alditols from PA-l-III were analyzed by GC-EIMS, and three disaccharide-alditols (IP, 2P and 3P) were detected. EI-MS and component sugar analysis suggested that the major peak, IP was Rha-(l- 5)-Kdo-ol and the minor peaks, 2P and 3P were two epimers of Araf-( l->5)-Dha. 

Gel chromatography on Sephadex GlOO (2.8x50cm) of polysaccharide fraction I (Sample 2). The polysaccharide fraction was dissolved in a phosphate buffer at pH 6. After centrifugation, the supernatant was applied to the column at a flow rate of 0.8 ml/min. The elution was performed with a phosphate buffer and fractions of 10 ml each were collected. The refraction of each fraction was measured interferometrically. Fractions with coincident peaks were collected and analyzed for content of galacrturonic acid, neutral sugars and protein. 

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