• Korean Journal of Food Science and Technology
• /
• v.28 no.6
• /
• pp.1078-1083
• /
• 1996

During the pearling process of hull-less barley, protein, lipid, ash and insoluble dietary fiber (IDF) contents decreased, while soluble dietary fiber (SDF) and ${\beta}-glucan$ contents slightly increased. Depending on milling methods and types of grinding mills used, there were differences in particle size distribution of barley flour. Flour particle size was smaller in the following order of Fitz mill, Ball mill, Pin mill, Cyclotec sample mill and Jet mill. Color (brightness) was closely related to the particle size of barley flour. Damaged starch (%) in pearled barley flour was the highest in Jet mill among different mills. Flours prepared with Cyclone mill and Pin mill had a reasonable amount of damaged starch. Flour produced by Fitz mill showed the lowest amount of damaged starch. Scanning electron microscopy (SEM) of the flour samples demonstrated different sizes and shapes of particles consisting of starch granules and cell wall materials. Damaged starch tended to increase water absorption index (WAI), water solubility index (WSI), and water retention capacity (WRC). Pasting viscosity determined by amylograph was relatively high in Pin-milled and Cyclone-milled flours. Viscosity was the lowest in coarsely ground flour by Fits mill.

• Economic and Environmental Geology
• /
• v.36 no.4
• /
• pp.285-293
• /
• 2003

Tailings of Dukum mine in the vadose and saturated zone were investigated to reveal the mobility of metal elements and the condition of mineralogical solubility according to redox environments throughout the geochemical analysis, thermodynamic modelling, and mineralogical study for solid-samples and water samples(vadose zone; distilled water: tailings=5 : 1 reacted, saturated zone; pore-water extracted). In the vadose zone, sulfide oxidation has generated low-pH(2.72∼6.91) condition and high concentration levels of S $O_4$$^{2-}$(561∼1430mg/L) and other metals(Zn : 0.12∼l57 mg/L, Pb : 0.06∼0.83 mg/L, Cd : 0.06∼l.35 mg/L). Jarosite$(KFe_3(SO_4)_2(OH)_6)$ and gypsum$(CaSO_4{\cdot}2H_2O$) were identified on XRD patterns and thermodynamics modelling. In the saturated zone, concentration of metal ions decreased because pH values were neutral(7.25∼8.10). But Fe and Mn susceptible to redox potential increased by low-pe values(7.40∼3.40) as the depth increased. Rhodochrosite$(MnCO_3)$ identified by XRD and thermodynamics modelling suggested that $Mn^{4+}$ or $Mn^{3+}$ was reduced to $Mn^{2+}$. Along pH conditions, concentrations of dissolved metal ions has been most abundant in vadose zone throughout borehole samples. It was observed that pH had more effect on metal solubilities than redox potential. How-ever, the release of co-precipitated heavy metals following the dissolution of Fe-Mn oxyhydroxides could be the mechanism by which reduced condition affected heavy metal solubility considering the decrease of pe as depth increased in tile saturated zone.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.12
• /
• pp.1797-1801
• /
• 2011

Two brown rice samples differing in amylose content, 20.1 (normal) and 7.3% (low amylose) were milled by different milling methods, and their physicochemical properties were tested. Particle size of brown rice flour prepared by dry milling using a pin mill (DM) was lower than that prepared by wet milling using a roll mill (WM). Particle size was further reduced by successive dry milling of the flour after wet milling and drying (WM/DM). Damaged starch contents in the wet milled brown rice flour were 14.6 and 15.6% for the normal and low amylose samples, respectively, whereas they were only 4.2 and 4.8% for the dry milled samples. WM/DM method resulted in a lower damaged starch (%) than DM, despite a reduced flour particle size. Water absorption index (WAI) of the brown rice flour was the lowest after WM/DM, and the water solubility index (WAI) was higher in the order of DM, WM/DM, and WM. Brown rice flour with normal amylose content appeared to have significantly higher pasting viscosities, as determined using a Rapid Visco Analyzer (RVA). Compared to dry milled brown rice flour, wet milled brown rice flour showed lower peak viscosity and higher final viscosity, resulting in increased setback value.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.11
• /
• pp.1451-1457
• /
• 2007

The physical and chemical characteristics of powders from hot air and freeze dried leaves and roots of Acorous calamus L. were investigated. Two parts, upper and lower, of leaves, and two kinds of roots, 4 and 6 years old, were dried at 30 and $40^{\circ}C$, freeze-dried, and ground to make powder. Contents of moisture, ash, crude fat, and crude protein in freeze dried powder of upper leaf were 4.87%, 6.73%, 2.22%, and 3.57%, respectively. Water absorption index (WAI) and water solubility index (WSI) in freeze dried powder of lower and upper leaves were 8.476 and 0.077 g/mL. Contents of chlorophyll a, chlorophyll b and total chlorophyll in freeze dried powder of upper leaves were 12.18, 16.86, and 29.11 mg/100 g, respectively. Contents of total and reducing sugar in freeze dried powder of 4 and 6 years roots were $111.89{\sim}119.21$ ppm and $5.02{\sim}5.22$ ppm, $109.92{\sim}114.65$ ppm and $5.21{\sim}5.32ppm$. Contents of total polyphenols and flavonoids in freeze dried powder of upper leaf were 125.02 and $21.02{\mu}g/mg$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.7
• /
• pp.900-907
• /
• 2008

The physicochemical properties of black rice flours produced from dry and wet milling were carried out to investigate their applications in food processing industry. The dry milled black rice flours showed lower fat, protein, ash, and anthocyanin contents than those of wet milled black rice flours with no effect due to number of millings. Average particle sizes ($379{\sim}288\;{\mu}m$) of dry milled flours were bigger than those ($336{\sim}253\;{\mu}m$) of wet milled flours. Particles with 60 mesh or more increased with increasing milling times. Wet milled flours had higher damaged starch, water solubility index (WSI), and water absorption index (WAI) compared to dry milled flours. Pasting properties measured by rapid visco analyzer (RVA) resulted in higher pasting temperatures in dry milled flours ($62.5{\sim}69.4^{\circ}C$) than wet milled flours ($46.1{\sim}46.4^{\circ}C$). As the number of milling times increased, pasting temperature of wet milled flours were not effected. Dry and wet milling resulted in reduced trough, final viscosity, and consistency with increasing milling times.

• Food Science and Preservation
• /
• v.23 no.3
• /
• pp.355-360
• /
• 2016

In this study, the quality characteristics of spray dried powders from unripe fig extract were investigated. The protease activities of unripe fig and peeled unripe fig extract were 0.11 unit/mL and 0.28 unit/mL, respectively. The spray dried powder of unripe fig extracts was analzed using different maltodextrin ratios (F-MD 5, 5% maltodextrin; F-MD 10, 10% maltodextrin; and F-MD 20, 20% maltodextrin). The spray-dried powder showed the highest protease activity with F-MD 10 (0.84 unit/g). The moisture content and L value of the spray-dried powder were higher than those of the freeze-dried powder. The particle diameter of the freeze-dried powder ($209.67{\mu}m$) was higher than that of the spray-dried powders ($22.18{\sim}37.33{\mu}m$). The water absorption index ranged from 0.18 to 0.40, while the water solubility index ranged from 94.40% to 98.80%. In the in vitro digestion study, spray-dried powders of the unripe fig showed a protease survival range of 16.47%~24.80%. In conclusion, it is considered appropriate to use the spray-dried powder (F-MD 10) of unripe fig as a meat tenderizer for processing food.

• Food Science and Preservation
• /
• v.22 no.4
• /
• pp.591-597
• /
• 2015

In this study, extracts of chlorella using different extraction methods were compared for antioxidant activities and spray-dried chlorella powders were investigated for their physicochemical characteristics. The DPPH radical scavenging activity and superoxide radical scavenging activity of 50% ethanol extract were 29.19%, and 48.91%, respectively. The oxygen radical absorbance capacity (ORAC) of the 50% ethanol extract ($150.44{\mu}M/g$) was higher than those of other extracts. The total chlorophyll content of the 50% ethanol extract (542.89 mg/100 g) was higher than those of other extracts. The microencapsulation of the 50% ethanol extract was manufactured by spray-drying with 10 % maltodextrin (SD-C10), 20% maltodextrin (SD-C20), and 30% maltodextrin (SD-C30). The particle size of the freeze-dried powder ($454.47{\mu}m$) was higher than those of the spray-dried powders ($24.15{\sim}32.49{\mu}m$). Scanning electron microscope images showed that the spray-dried chlorella powders using SD-C10, SD-C20, and SD-C30 had an uniform particle distribution. The water absorption index and water solubility index (WSI) of powders were 0.31~0.45, and 96.96~98.28%, respectively. The spray-dried powders showed the stability in total chlorophyll content for 40 days storage. Based on these results, spray-dried chlorella powders could be used in various types of food processes.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.9
• /
• pp.1407-1414
• /
• 2014

Physicochemical properties of rice-based expanded snacks extruded with rice flour, high amylose starch, and isolated soy protein were investigated using a twin-screw extruder. The ingredients were extruded at various feed moisture contents (19~23%) and screw speeds (200~400 rpm) at a constant feed rate (43.4 kg/hr). Bulk density and apparent density of rice snacks were 0.06~0.21, and 0.55~0.65 respectively. Bulk density, apparent density, water absorption index, and breaking strength of rice snacks increased with increasing feed moisture content and decreasing screw speed. However, expansion and water solubility index of rice snacks increased with decreasing feed moisture content and increasing screw speed. Hunter's color L values of rice snacks was lower with increasing screw speed at feed moisture contents of 19% and 21%, but was not significantly different from a feed moisture content of 23%. On the other hand, a and b values of rice snacks were higher with increasing screw speed a feed moisture content of 19%. X-ray diffraction intensity of rice snacks decreased with decreasing feed moisture content and increasing screw speed. X-ray diffraction of rice snacks was V-type at feed moisture contents of 19% and 21% and screw speeds of 300, and 400 rpm. In the microstructure of the cross section of rice snacks, air cells in rice snacks were not well formed, and cell walls were thicker with increasing feed moisture content and decreasing screw speed.

• The Korean Journal of Food And Nutrition
• /
• v.29 no.1
• /
• pp.134-143
• /
• 2016

We evaluated the antioxidant properties of adzuki beans and the quality characteristics of sediment using various cultivation methods. There were significant differences in total polyphenol and flavonoid contents in beans grown using different methods of cultivation (p<0.05). Also, DPPH and ABTS radical-scavenging activities were significantly different depending on cultivation method (p<0.05). The sediment yield before drying of Chungju-pat, Hongeon, and Arari was 296.64~339.01, 271.36~282.24, and 268.21~292.32%, respectively, and the sediment yield after drying was 71.68~85.41, 77.90~85.19, and 74.15~78.65%, respectively. The L-value of Chungju-pat and Arari sediments revealed a significant difference given different cultivation methods (p<0.05), but Hongeon sediment did not show a significant difference. There was a significant difference in the a- and b-value of adzuki bean sediments cultivated using different methods (p<0.05). The particle size of Chungju-pat, Hongeon, and Arari sediments was 66.21~98.80, 61.62~97.07, and $82.96{\sim}106.71{\mu}m$, respectively, and all were significantly different depending on cultivation method (p<0.05). There were also significant differences in the water absorption index, water solubility index, and swelling power when different cultivation methods were used (p<0.05).

• Korean Journal of Food Science and Technology
• /
• v.16 no.4
• /
• pp.429-436
• /
• 1984

To expand the utility of barley the experiments on the extrusion characteristics of barley flour for snack processing were carried out and the effects of the extrusion conditions on the quality of the extrudates were investigated. The optimum moisture content of barley flour for snack processing was 20%. The moisture content and the density of the extrudates decreased with increasing extrusion temperature and decreasing die size. The die swell ranged from 0.98 to 2.18 according to various extrusion conditions and decreased with increasing temperature above $150^{\circ}C$. The lightness, redness and yellowness increased at higher temperature. The water absorption index and the water solubility index showed their maximum values at $180^{\circ}C$.The gelatinization degree of the extrudates increased with increasing temperature. The fracture fore, Young's modulus and maximum fiber stress decreased, but the deformation to fracture increased, with increasing temperature and decreasing die size. The yield force in puncture test showed lower values at higher temperature. The size and the fraction of the air cells increased with increasing temperature and decreasing die size. The optimum extrusion conditions of barley for snack processing were at the temperature of $180^{\circ}C$, with the die size of 4.5mm when processed at 160 rpm.