• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1575-1581
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• 2011

Rapeseed cake, which is the organic waste remaining after rapeseed oil production, is readily available and considered an ecologically-friendly resource with very low cost and high dietary fiber content. This research was carried out for two reasons. First, it was done to analyze the liberated reducing sugar content of rapeseed cake. Second, it was done to investigate the effects on the sugar yield of the various concentrations of acidic and alkaline catalysts used for the hydrolysis of rapeseed cake and the concentrations of rapeseed cake in each catalyst. Several amounts of ground rapeseed cake, 0.5 g, 1 g, and 2 g, were put into 100 mL of catalysts such as sulfuric acid (0.5~2%), hydrochloric acid (0.5~2%), and sodium hydroxide (0.5~2%). Then they were hydrolyzed for 5 min at 121$^{\circ}C$. After hydrolysis, HPLC equipped with an RI detector was used to analyze liberated reducing sugars such as sucrose, glucose, galactose, fructose, and arabinose separated from rapeseed cake. The degradation rate of rapeseed cake was the highest in hydrochloric acid. As the catalyst concentrations used for hydrolysis of rapeseed cake increased, the degradation rate of rapeseed cake also significantly increased. Total reducing sugar content was the highest in hydrochloric acid, and it increased with the increase of catalyst concentrations. However, as the amount of rapeseed cake increased, the total reducing sugar content decreased, exceptionally sucrose in the case of sodium hydroxide.

• Food Science of Animal Resources
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• v.21 no.4
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• pp.367-373
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• 2001

Glycoproteins PAS-6(50 kDa) and -7(47 kDa) from the bovine milk fat globule membrane share a common protein core but differ in their carbohydrate moiety. We have analyzed and proposed the structures of the N-linked sugar chains of PAS-7 by Oxford Glyco System(OGS) RAAM2000. The N-linked sugar chains were liberated from PAS-7 by hydrazinolysis and, after modifying the reducing ends with 2-aminobenzamide(2-AB), were separated into one neutral(7N, 55%) and two acidic(7M, mono-, 43%; 7D, di-, 2%) sugar chain groups. 7N was finally separated into 5 chains(a, b, c, d, and e), respectively. The structure of this 2AB-neutral sugar chain was determined by sugar analysis, exoglycosidase digestion with OGS glycosidase Kit and OGS RAAM2000 system. The results show that fraction e was the same of reported 7N1A, the biantennary complex type with a fucose on reducing end and two N-acetyllactosamine branch on non-reducing end. Therefore, it was proved that OGS RAAM2000 method is in conformity with conventional analysis of sugar chain structure from bovine PAS-7.

• Journal of Dairy Science and Biotechnology
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• v.21 no.2
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• pp.138-147
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• 2003

We here analyzed and proposed the structures of the N-linked sugar chains of PAS-7 from bovine milk fat globule membrane. The N-linked sugar chains were liberated from PAS-7 by hydrazinolysis and, after modifying the reducing ends with 2-aminopyridine (PA), were separated into one neutral (7N,55%) and two acidic (7M mono-, 43%; 7D, di-, 2%) sugar chain roups. The latter were converted into neutral groups (7MN and 7DN) by sialidase digestion. The structure of each of these PA-neutral sugar chains was determined by sugar analysis, sequential exoglycosidase digestion, partial acetolysis, and 1H-NMR spectroscopy. The results show that the 10 sugar chains were of the biantennary complex type with and without fucose. The structure of 7N2A one of the major sugar chains, was proposed as; [structure: see text] A structural comparison between PAS-6 and -7 indicated that although they shared the same protein core, their sugar moiety was markedly different, involving the existence of a different pathway during the post-transcriptional modification.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.520-527
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• 1987

This study was attempted to identify microorganisms in fermenting soybean curd residues (SCR). The changes in contents of free amino acids, nucleosides, reducing sugars, and oligosaccharides were also studied. The fermentation of SCR which was by change inoculation was carried out at $55^{\circ}C$ for 48 hrs. pH increased gradually during fermentation and isolated microorganisms were identified as Bacillus subtilis and Bacillus licheniformis. Moisture content decreased from 80.8% to 58.4% at 48 hrs of fermentation and other proximate composition did not show any changes during fermentation. The content of total free amino acids increased rapidly and the number and quantities of each amino acid analyzed also increased during the course of fermentation. Glutamic acid, phenylalaine, lysine and aspartic acid were rapidly liberated during fermentation. As to the changes of nucleotides, 5'-AMP little changed during the first 36 hrs but subsequently decreased to approximately 1/6 after 48 hrs of fermentation. On the other hand, 5'-IMP plus 5'-GMP did not show almost any change during the first 36 hrs but increased about 3.5 times at 48 hrs of fermentation. However, 5'-XMP was not detected. The reducing sugar level showed rapid and steady increase throughout the fermentation and that of stachyose plus raffinose decreased slightly. From these results, a possible way of utilization of fermented SCR was proposed as a substitute for soybean in meju preparation.