• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.12
• /
• pp.1656-1663
• /
• 2009

The antioxidant activities of water extracts from wild vegetables such as Ligularia fischeri (GC), Capsicum annuum L. (GCY), Aster scaber (CNM), Petasites japonicus S. et Z. Max (MYD), Ipomoea batatas L. (Lam) (GGM) were evaluated and compared with water extracts from freeze dried block. The antioxidant properties of water extracts from wild vegetables and their freeze dried block were evaluated using different antioxidant tests; 2.2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, hydroxyl radical scavenging and nitrite scavenging activities. The water extracts from wild vegetables were found to have a higher total phenolic content than water extracts from freeze dried block. Total phenolic contents of water extracts from GC, GCY, CNM, MYD, and GGM were $471.66{\pm}3.52\;{\mu}g/mg,\;141.33{\pm}2.51\;{\mu}g/mg,\;177.33{\pm}2.88\;{\mu}g/mg,\;238.66{\pm}9.50\;{\mu}g/mg\;and\;122.67{\pm}3.51\;{\mu}g/mg$, respectively. At the concentrations of 1000 ppm, water extracts from GC, GCY, CNM, and GGM showed higher activities than water extracts from their freeze dried block on DPPH radical scavenger activity. The activity of water extracts from CNM, GC, GCY, MYD, and GGM were 90.9%, 89.9%, 76.6%, 71.1%, and 57.4%, respectively. When 10000 ppm of GC, GCY, CNM, MYD, and GGM water extracts tested for hydroxyl radical scavenging activity, activities were increased by 38.8%, 33.4%, 35.9%, 34.3%, and 33.8%, respectively and a similar effect was found with water extracts from GCY, CNM, and GGM freeze dried block at 10000 ppm concentration. However, the water extracts from GC and MYD was slightly more effective than freeze dried block extracts. The water extracts from wild vegetables and their freeze dried block had effective DPPH radical scavenger activity and hydroxyl radical scavenging activity at all tested concentrations. Nitrite scavenging activity of GC water extract significantly increased in a dose-dependent manner and the extract had higher nitrite scavenging activity than extracts freeze dried block extracts. We found that freeze dried block maintained antioxidant activities of the wild vegetables.

• Korean Journal of Food Science and Technology
• /
• v.23 no.5
• /
• pp.554-560
• /
• 1991

The physicochemical properties of Korean yam starches (D. aimadoimo, D. batatas and D. japonica) were investigated. The mean granular size of starches were 23.5 μm for D. aimadoimo, 23.9 μm for D. batatas and 18.2 μm for D. japonica. Amylose content, blue value and water binding capacity was $29{\sim}33%,\;0.42{\sim}0.51%\;and\;109.9{\sim}118.3%$, respectively. The optical transmittance of 0.3% (dry basis) yam starch suspensions were increased at $70{\sim}75^{\circ}C$ and D. japonica showed typical two-step transmittance curve. The swelling power and solubility patterns increased over $60^{\circ}C$, and D. aimadoimo was the highest values. Amylogram patterns of 5% (dry basis) yam starch suspensions, determined by Brabender amylograph, were similar to that of yam flours and the viscosity of D. aimadoimo had 630 BU, which was about 5 times higher than 130 BU for D. batatas and D. japonica. Observation under scanning electron microscope lefted marks of resistance to glucoamylase because these surfaces were similar to the natural granules. In rates of solubiliazation by dimethyl sulfoxide, D. aimadoimo showed the highest value. (3-Amylolysis limits of yam starches and their amylose were $71.8%{\sim}75.5%\;and\;90.2{\sim}92.1%$, respectively. Gel filtration patterns of debranched amylopectin by pullulanase were divided into 3 peaks. The weight ratios of peak III to peak II in yam starches were $2.15%{\sim}2.42%$.

• KSBB Journal
• /
• v.19 no.2
• /
• pp.93-97
• /
• 2004

We investigate the effect of enzyme pretreatment using protease, carbohydrase, and lipase on improvement of sludge treatment efficiency by measuring SCOD and TCOD. The enzyme-pretreatment increases SCOD of excess sludge. In addition, the amount of sludge reduction during digestion, in terms of SCOD and TCOD, are enhanced by enzyme-pretreatment. Among pretense, carbohydrase, and lipase, pretense showed the best enhancement of the sludge treatment efficiency. Sludge digestion followed by ozone and enzyme treatments showed more effective sludge treatment when compared with ozone treatment alone. Therefore, we expect that enzyme pretreatment can be used as a useful tool for enhancing the sludge treatment efficiency.