• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.11
• /
• pp.1603-1610
• /
• 2012

The effects of moisture content on the physical properties of cereal extrudates were investigated. Cereal flours (rice, wheat, corn, barley, and oat) were extruded at a barrel temperature of $130^{\circ}C$, feed rate of 120 g/min, and various moisture contents (20, 22.5, 25, 27.5, and 30%). Proximate content, expansion index, specific length, bulk density, breaking strength, apparent elastic modulus, water absorption index (WAI), water solubility index (WSI), specific mechanical energy (SME) input, paste viscosity, and color values were analyzed. Expansion ratio of extruded corn flour was higher than that of other extrudates at low moisture content. Bulk density, specific length, and elastic modulus in all cereals decreased with an increase in moisture content. The WAI increased with an increase in moisture content, whereas WSI decreased. SME input of extruded corn flour was higher than those of other cereal flours at lower moisture content, whereas that of oat flour extrudate was lower than those of other cereals at higher moisture content. Lightness of extruded rice flour was lighter than those of other cereals while that of extruded barley flour was darker.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.6
• /
• pp.846-852
• /
• 2012

The physical properties of instant puffed rice snacks with non-glutinous, glutinous, and steamed non-glutinous rice were evaluated at different moisture content and puffing temperatures. Raw materials were tempered to 9%, 12%, 15%, and 18% moisture content and puffed at $200^{\circ}C$, $210^{\circ}C$ and $220^{\circ}C$. With the increase in moisture content and puffing temperature, puffed snacks were less bulky. As the moisture content decreased and puffing temperature increased, the whiteness (L) value of puffed snacks decreased, while the redness (a) and yellowness (b) values increased. WSI and WAI were higher with an increase in moisture content and puffing temperature. Instant puffed rice snacks made from non-glutinous, glutinous, and steamed non-glutinous rice showed differences in bulk density, WSI, and WAI, while no difference was found in color values. When the moisture content increased from 9% to 15%, the cells within the products became more uniform and smaller. The instant puffed rice snacks made from glutinous rice showed the smallest and most uniform cell structure.

• Korean Journal of Food Science and Technology
• /
• v.27 no.5
• /
• pp.640-645
• /
• 1995

Job's-tears(Coix lachryma-jobi L. var. Ma-yuen Stapf) seeds were processed to flakes by soaking, heat treatment, intermediate-moisture drying, flaking, drying, and cooking. Some functional properties of job's-tears flakes subjected to varing degree of heating were characterized by specific volume, texture, water absorption index(WAI), water solubility index(WSI), and viscosity. As degree of gelitinization increased within the intermediate range of $60{\sim}70%$, steam-cooked Job's-tears demonstrated appropriate rheological properties for further processes, resulting in increased specific volume and decreased breaking strength. However, excessive heat treatment rendered Job's-tears undesirably sticky for flaking, which caused adverse effects on the functional properties of flakes such as specific volume and breaking strength. Increasing steaming time$(5{\sim}30\;min)$ caused an increase in WAI and WSI values. Apparent viscosity of powdered flakes was increased with the extent of gelitinization as a function of heat processing. Viscosity of powdered flakes determined using the amylograph increased with the degree of heating applied to Job's-tears at low pasting temperatures, accompanied by a decrease in maximum viscosity as the pasting temperature increased.

• Korean Journal of Food Science and Technology
• /
• v.33 no.6
• /
• pp.686-692
• /
• 2001

The effects of extrusion on solubilization of brown rice, glutinuous rice, barley and job's tear were analyzed by response surface methodology (RSM). Solubilization of whole grains by extrusion was characterized in terms of water solubility index (WSI), concentration of water soluble polysaccharides (C) and intrinsic viscosity $([\eta])$. Considering both concentration and intrinsic viscosity, a dimensionless target parameter $([\eta])$ was also included for analysing the extrusion effects on cereal extrusion. Response surface methodology analysis showed that the moisture content was the most significant contributor among screw speed, temperature and moisture content affecting the solubilizing phenomena of cereals processed with extrusion. Brown rice was not showed the significant relationship on $([\eta])$ because $([\eta])$ was more affected by intrinsic viscosity. The critical point of whole grains extrusion except brown rice was corresponded to screw speed of 300 rpm, moisture content of 20% and temperature of $120^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.37 no.5
• /
• pp.757-762
• /
• 2005

Characteristics of cereals prepared by extrusion-cooking and freeze-drying were compared. Parameters used were water solubility index (WSI), water absorption index (WAI), paste viscosity, and sterilization. Variables for extrusion process were barrel temperature at die section (70, 90, and $110^{\circ}C$) and moisture content (25 and 30%). WAI and WSI of extruded cereals were higher, whereas trough, breakdown, and final viscosity were lower than those of raw and freeze-dried cereals. Plate counting revealed no microbes in extruded cereals, whereas microbe colony was observed in freeze-dried cereals. Extrusion-cooking at low temperature resulted in better sterilization of microbes than freeze-drying for preparation of instant cereal drinks.

• Food Engineering Progress
• /
• v.14 no.2
• /
• pp.127-134
• /
• 2010

This study was to develop high-nutritious energy bar from extruded hemp obtained by extrusion process. Mixture of rice flour and defatted hemp was extruded at a barrel temperature of 110 and 130$^{\circ}C$, and moisture content of 20 and 25%. Properties of extrudates such as bulk density, expansion index, breaking strength, apparent elastic modulus, water absorption index (WAI), water solubility index (WSI) have been analyzed. The antioxidant potential was determined by the DPPH-radical scavenging assay. The expansion index was the highest in rice-hemp extrudate at 130$^{\circ}C$ barrel temperature and 20% moisture content among the other hemp-added extrudates. The WAI was increased with increase in moisture content, while the WSI was increased with increase in barrel temperature. The peak viscosity of rice extrudate had higher valule than those of extrudate added with hemp. DPPH scavenging activity of rice-hemp extrudate at 130$^{\circ}C$ barrel temperature and 20% moisture content showed the highest value. Sensory properties, moisture content and color were assessed for quality of energy bar. The color values of the energy bar indicated decreasing L (lightness) and b (yellowness), and increasing a (redness) after 30 days storage at ambient condition. The highest overall acceptable was the energy bar added with rice-hemp extrudate at 130$^{\circ}C$ barrel temperature and 20% moisture content.

• Food Engineering Progress
• /
• v.21 no.3
• /
• pp.292-298
• /
• 2017

The aim of this study was to evaluate the effects of microencapsulation on the water absorption, DPPH radical scavenging activity (DRSA), hydroxyl radical scavenging activity (HRSA) and tyrosinase inhibition activity (TIA) in corn silk extracts. The lowest value (0.20) of water absorption index (WAI) and the highest value (95.23%) of water solubility index (WSI) were maltodextrin+cyclodextrin microencapulated corn silk extracts (MD+CD) and cyclodextrin encapulated corn silk extracts (CD), respectively. The 18.60% for DRSA value of control was increased to 89.25% for that of CD. The 16.89% for HRSA value of control was increased to 47.46%, and 7.16% for TIA value of control was increased to 39.35% for that of MD+CD, respectively. The MD+CD would be used for functional food and cosmetics materials as antioxidant and skin whitening agents. All investigated responses between control and treatment were statistically significant (p<0.05).

• Food Engineering Progress
• /
• v.22 no.4
• /
• pp.344-352
• /
• 2018

The effects of chemical compositions (protein, lipid, and dietary fiber) on the physical properties of dried biji powders were investigated. The raw biji was freeze-dried (control) and hot-air dried (untreated). The untreated biji was further defatted and deproteinated. The prepared biji powders were analyzed for the proximate composition, total dietary fiber (TDF), water absorption index (WAI), water solubility index (WSI), swelling power, solubility (including the quantification of soluble carbohydrate and protein fractions), and final viscosity (using a rapid visco analyzer). Control and untreated biji powders exhibited the similar chemical compositions. The defatted biji possessed higher TDF, although its protein content did not significantly differ for control and untreated ones. The deproteinated biji consisted mainly of TDF. WAI and swelling power increased in the order: deproteinated > defatted > control > untreated biji powders. WSI and solubility increased in the order: control > untreated > defatted > deproteinated biji powders. The similar patterns were observed for soluble carbohydrate and protein fractions. The deproteinated biji revealed the highest viscosity over applied temperatures, while the untreated one was lowest. Overall results suggested that the physical properties of the dried biji powder were reduced by protein and fat, but enhanced by dietary fiber.

• Journal of Ginseng Research
• /
• v.38 no.2
• /
• pp.146-153
• /
• 2014

A systematic comparison of the physicochemical properties of white ginseng (WG), extruded white ginseng (EWG), red ginseng (RG), and extruded red ginseng (ERG) was performed. The aim of the present study was to identify the effects of the physicochemical properties of ginseng by extrusion cooking. The highest value of the water absorption index (WAI) was 3.64 g/g obtained from EWG, and the highest value of the water solubility index (WSI) was 45.27% obtained from ERG. The ERG had a better dispersibility compared with other samples. Extrusion cooking led to a significant increase in acidic polysaccharide and total sugar content but resulted in a decrease in crude fat and reducing sugar contents. Enzyme treatment led to a sharp increase in acidic polysaccharide content, especially the cellulose enzyme. Extrusion cooking led to a significant increase in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power, and the increases in WG and RG were 13.56% (0.038) and 3.56% (0.026), respectively. The data of this study provide valuable information about the effects of extrusion on quality changes of EWG and ERG.

• Journal of Pharmacopuncture
• /
• v.9 no.3 s.21
• /
• pp.117-129
• /
• 2006

Objectives : The aim of this study was to find optimal conditions for producing red ginseng from cultivated wild ginseng using the Turbo Mill. Methods : Characteristics of powdered cultivated wild ginseng based on various temperature settings of the Turbo Mill were observed, and changes in the content was measured by HPLC for various ginsenosides. Results : 1. The diameter of cultivated wild ginseng powder ground by the Turbo Mill was around 10${\mu}m$. 2. As the temperature rose, pressure, Specific Mechanical Energy(SME), and density decreased, whileas Water Solubility Index(WSI) increased. 3. As the temperature rose, super fine powder showed tendency to turn into dark brown. 4. Measuring content changes by HPLC, there was no detection of ginsenoside Rg3 and ginsenosideRg1, Rb1, and Rh2 concentrations decreased with increase in temperature. Conclusions : Super fine powder of cultivated wild ginseng produced by the Turbo Mill promotes easy absorption of effective ingredients by breaking the cell walls. Using this mechanism to produce red ginseng from cultivated wild ginseng, it yielded less than satisfactory results under the current experiment setup. Further researches are needed to verify more suitable condition for the production of red ginseng.