Dong Ouk Noh

Preparation of angiotensin I converting enzyme inhibitor from corn gluten

Hydrolysates were prepared from corn gluten containing powerful angiotensin I converting enzyme (ACE) inhibitory activity with low bitterness. Among six commercial proteases, Flavourzyme showed the highest ACE inhibitory activity (IC50: 0.18 mg solid). Flavourzyme (complex type), Pescalase (endo-type), and Protease A (exo-type) were used to evaluate corn gluten hydrolysates according to the enzyme specificity. ACE inhibitory activities of the hydrolysates had the same trend as protein content. Flavourzyme and Pescalase showed high ACE inhibitory activity (IC50: 0.18 mg solid and IC50: 0.17 mg solid, respectively) after 8 and 1 h of hydrolysis, respectively. However, Protease A showed no changes of ACE inhibitory activity after 1 h of hydrolysis. A mixture of Pescalase and Protease A (1:1, w/w) was applied to the preparation of corn gluten hydrolysate. The hydrolysis time using the enzyme mixture was reduced from 8 to 4 h compared with Flavourzyme. Surface hydrophobicity of the hydrolysate with the enzyme mixture was lower than that of the hydrolysate with Flavourzyme, but there was no significant difference at P<0.05. Average hydrophobicity (Q value) of the hydrolysates with the Flavourzyme and the enzyme mixture was to be less than 1400 kcal/mol. It was assumed that there was no difference in bitterness between the hydrolysate with Flavourzyme and that with the enzyme mixture.

Physiological effects of formulation containing tannase-converted green tea extract on skin care: physical stability, collagenase, elastase, and tyrosinase activities

Background Green tea contains numerous polyphenols, which have health-promoting effects. The purpose of this study was to evaluate the effect of tannase-converted green tea extract (TGE) formulation on the physical stability and activities of skin-related enzymes. Methods Physical stability was evaluated by measuring the pH, precipitation, and colors at 25 ± 2 °C/ambient humidity and at 40 ± 2 °C/70% ± 5% relative humidity for 4 months. Activities of collagenase, elastase, and tyrosinase as skin-related enzymes were assessed on TGE formulation. Results The concentrations of epigallocatechin-3-gallate and epicatechin-3-gallate in green tea extract were greatly decreased to the extent of negligible level when treated with tannase. The formulation containing 5% tannase-converted green tea extract showed relatively stable pH, precipitation, and color features for 16 weeks. When TGE was added to the formulation, there was a significant increase in the inhibition of elastase and tyrosinase activities (p < 0.05) compared with the formulation containing 5% normal green tea extract. Conclusion The TGE could be used in cosmetics as skin antiwrinkling or depigmenting agent.

Peyer’s patch-mediated intestinal immune system modulating activity of pectic-type polysaccharide from peel of Citrus unshiu

An intestinal immune system modulating polysaccharide (CUI-3IIb-3-2, 18kDa) was purified from Citrus unshiu peel. CUI-3IIb-3-2 mainly comprised GalA, GlcA, Ara, Gal and Rha, and it consisted of 4-linked GalA, terminal Araf, 4- or 5-linked/3,4- or 3,5-branched Ara, terminal Gal, and 2-linked/2,4-branched Rha. After CUI-3IIb-3-2 digestion by endo-α-d-(1→4)-polygalacturonase, its hydrolysate was fractionated into PG-1 and PG-2. Methylation analyses of PG-1 and PG-2 using base-catalysed β-elimination suggested that CUI-3IIb-3-2 be assumed as pectic-type polysaccharide. Since the activities of PG-1 and PG-2 were potently decreased, the whole polysaccharide structure of CUI-3IIb-3-2 would be essential to maintain the activity. Meanwhile, when CUI-3IIb was orally administered in mice, bone marrow cell proliferation and GM-CSF/IL-6 production from Peyers patch cell were significantly higher (1.76- and 2.03/2.51-fold, respectively) than a saline. Therefore, a pectic-type polysaccharide from citrus peel could stimulate Peyers patches and produce hematopoietic growth factors resulted in bone marrow cell proliferation.

Debittering of corn gluten hydrolysate with active carbon

Corn gluten hydrolysates were treated with active carbons to remove the bitterness. After treatment with active carbons, the ACE (angiotensin-converting enzyme) inhibitory activity decreased in the order of active clay, Junsei (fine and granule) and Koent CPG (67.2, 65.4 and 64.9% respectively) in TP 10K. In addition, that of PP 10K treated with Junsei (fine and granule) and active clay decreased to 75.6, 72.2 and 74.7% respectively. In PP 10K, Koent PWA and active clay effectively reduced the bitterness. PP 10K treated with Koent PWA and active clay was reported to taste as trace of bitterness to slightly bitter. TP 10K treated with Koent RC and CPG tasted as trace of bitterness to slightly bitter, and that treated with Koent PWA and Junsei (granule) tasted as slightly bitter to bitter. After treatment with active carbons, the amounts of T-N (total nitrogen) in PP 10K and TP 10K reduced from 148 and 135 mg to 136–42 and 134–108 mg respectively. Before treatment with active carbons, PP 10K and TP 10K consisted of peptides with APLs (average peptide lengths) 14.4 and 12.8 respectively. After Junsei (fine) treatment, the APLs of PP 10K and TP 10K were 16.9 and 16.2 respectively. After treatment with the other active carbons, the APLs of PP 10K and TP 10K were 14.4–2.78 and 14.4–3.5 respectively. Before treatment with active carbons, the surface hydrophobicities of PP 10K and TP 10K were 38 and 29.9 respectively. However, after treatment with active carbons, the surface hydrophobicities of PP 10K and TP 10K were reduced, except for PP 10K treated with active clay. In PP 10K, treatments with Koent PWA and active clay markedly reduced the surface hydrophobicity from 38 to 13.3 and 14.2 respectively. The surface hydrophobicity of TP 10K treated with Koent RC and CPG was markedly reduced from 29.9 to 9.9 and 11.1 respectively. © 2000 Society of Chemical Industry

Preparation of Egg White Liquid Hydrolysate (ELH) and Its Radical-Scavenging Activity

In the present study, an optimum protease was selected to hydrolyze the egg white liquid protein for the antioxidant peptides. Alcalase treatment yielded the highest amount of α-amino groups (15.27 mg/mL), while the control (no enzymatic hydrolysis) showed the lowest amount of α-amino groups (1.53 mg/mL). Alcalase also gave the highest degree of hydrolysis (DH) value (43.2%) and was more efficient for egg white liquid hydrolysis than the other enzymes. The Alcalase hydrolysate had the highest radical-scavenging activity (82.5%) at a concentration of 5.0 mg/mL. The conditions for enzymatic hydrolysis of egg white liquid with Alcalase were selected as substrate : water ratio of 2:1. Five percent Alacalse treatment did not show significant (P>0.05) increases of DH and α-amino nitrogen content after 24 h-hydrolysis. Thirty two hour-hydrolysis with 5% Alcalase is sufficient to make antioxidative egg white liquid hydrolysate from egg white liquid. DPPH and ABTS radical-scavenging activities were significantly (P<0.05) higher after enzymatic digestion. These results suggest that active peptides released from egg-white protein are effective radical-scavengers. Thus, this approach may be useful for the preparation of potent antioxidant products.

SHORT COMMUNICATION: Pet foods with yeast hydrolysate can reduce body weight and increase girth in beagle dogs

Kim, J. H., Jung, E. Y., Hong, Y. H., Bae, S. H., Kim, J. M., Noh, D. O., Nozaki, T., Inoue, T. and Suh, H. J. 2012. Short Communication: Pet foods with yeast hydrolysate can reduce body weight and increase girth in beagle dogs. Can. J. Anim. Sci. 92: 207-210. Beagle dogs fed pet foods that included yeast hydrolysate (YH) were used in the present study to assess the possible use of YH as a functional anti-obesity ingredient in pet food. The change in weight and girth in the YH groups was significantly (P<0.05) lower than that in the control. Plasma malondialdehyde was significantly (P<0.05) lower in the YH groups compared with that in the control. Plasma levels of the reduced form of glutathione were significantly (P<0.05) higher in the YH groups than those in the control. Therefore, YH could be recommended as an anti-obesity functional feed source for dogs.

Complex-oligosaccharide composed of galacto-oligosaccharide and lactulose ameliorates loperamide-induced constipation in rats

The purpose of this study was to compare the beneficial effects of galactooligosaccharide (GOS), lactulose, and a complex-oligosaccharide composed with GOS and lactulose (Com-oligo) on loperamide-induced constipation in SD rats. Rats were randomly divided into the following eight groups: the normal group (Nor); constipation control group (Con); and 6 constipation groups fed low and high doses of GOS, lactulose (Lac), and Com-oligo, respectively. Com-oligo increased intestinal transit ratio and relieved constipation in loperamide-treated rats. The group receiving a high dose of Com-oligo favorably regulated gastrointestinal functions such as pellet number, weight, moisture content, short chain fatty acid, intestinal transit ratio, and bifidobacterium number in constipated rats. In addition, Com-oligo restored peristalsis of the small intestine, morphology of colon, and increased interstitial cells of Cajal area. Thus, providing Com-oligo as an oligosaccharide ingredient in nutritional formulas could benefit the health of the gastrointestinal tract.

Effect of explosion-puffed coffee on locomotor activity and behavioral patterns in Drosophila melanogaster

We hypothesized that the administration of explosion-puffed coffee, containing γ-aminobutyric acid (GABA) and 5-hydroxytryptophan (5-HTP), would be associated with a reduction of the caffeine effect on sleep behavior and behavioral patterns, which was investigated in a Drosophila model. The effects of feeding roasted coffee beans (RB), explosion-puffed coffee beans puffed at 0.75MPa and 0.9MPa (PB 7.5 and PB 9.0, respectively), or decaffeinated coffee beans (DeRB) on locomotor activity and behavioral patterns of Drosophila was analyzed. In the decreasing order, the total chlorogenic acid (caffeoylquinic acids, CQA) content was PB 7.5>PB 9.0>RB. PB content analysis showed high levels of GABA and 5-HTP, compared with that of RB, which corresponded with the sleep-wake behavior of Drosophila. The RB and PB (PB 7.5 and PB 9.0) groups were not significantly different with respect to an activity count during the subjective night and day period compared with the normal controls. Sleep bout numbers of the normal, PB, and DeRB groups showed significant differences as compared with the caffeine and RB groups (p<0.05). The PB and DePB groups showed a significantly increased transcript levels for the GABA receptors compared to the caffeine group. The caffeine and RB groups displayed better climbing ability than the other groups, covering an average distance 6cm in the related test; the average distance covered by the normal, PB 7.5, and DeRB groups was <4cm. The normal and DeRB groups showed similar behavior patterns with respect to total distance, velocity, moving, not moving, and meander. However, the PB 7.5 group significantly regulated not moving and meander of flies compared to flies receiving only caffeine and RB. Suppression of the stimulating effect of caffeine by explosion-puffed coffee administration was indicated in the above results, which can be attributed to the increased content of GABA and 5-HTP with explosive puffing process carried out at 0.75MPa. Results of the underlying mechanism of the behavioral change patterns of explosive puffed with or without caffeine in Drosophila models, transcript level for the Dop1-R1 receptor in caffeine group was significantly higher than normal, PB, and DePB groups. Flies exposed to the caffeine had significantly decreased transcript levels for the GABA receptors. PB 7.5 and DePB showed higher level of GABA content than RB.

Thermal stability of yeast hydrolysate as a novel anti-obesity material

We examined the thermal stability of yeast hydrolysates before and after ultrafiltration (UF) in vitro, and the anti-obesity activity of yeast hydrolysates before and after heat treatment in vivo. Yeast hydrolysate after UF showed significantly higher thermal stability than before UF. Yeast hydrolysates before and after UF showed 3 and 4 thermal transition peaks in their thermograms, respectively, and the total thermal denaturation enthalpies of yeast hydrolysates before and after UF were 69.5 and 36.5 J/g, respectively. For the anti-obesity activity study, yeast hydrolysates before and after heating were administered ad libitum with water to 7-week-old male SD rats. The administration of yeast hydrolysate (YH-control; no heat treatment, YH-1; heat treatment at 140°C, and YH-2; heat treatment at 160°C) significantly increased mRNA expression of cocaine- and amphetamine-regulated transcript (CART) compared with control rats (saline administration). However, there was no significant difference between the heat-treated groups and YH-control and there was no significant difference in neuropeptide Y expression between the heat-treated groups and YH-control. These results suggest that yeast hydrolysate can be use an anti-obesity material after heat treatment.