• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.1
• /
• pp.12-16
• /
• 2002

In this study, the physicochemical properties of warty black and glutinous rice flours were compared. Crude protein content of waxy black rice flour (9.01%) was higher than than of glutinous rice flour (7.54%). Most mineral contents of waxy black rice flour were higher than those of glutinous rice flour. The major fatty acids in the waxy black and glutinous rice flours were oleic acid (38.57% and 36.95%) and linoleic acid (38.60% and 39.10%). The major detected amino acids of both samples were aspartic acid, glutamic acid and arginine. Water binding capacity of waxy black rice flour (93.26%) was higher than that of glutinous rice flour (87.42%) . Swelling powers and solubilities of waxy black rice flour were lower than those of glutinous rice flour in according to increasing temperatures. Maximum absorbance wavelength (λ$_{max}$) and absorbance at 625 nm were similar between both samples. X-ray diffraction patterns of both samples showed traditional A type as Peaks 2$\theta$ at 15.1$^{\circ}$, 17.1$^{\circ}$, 18.0$^{\circ}$and 23.2$^{\circ}$. The relative crystallinities of waxy black and glutinous rice flours were 0.40 and 0.41, respectively.

• Korean Journal of Food Science and Technology
• /
• v.14 no.3
• /
• pp.210-218
• /
• 1982

Correlation between the sensory quality characteristics of commercial ice creams and chemical properties of fat extracted from those was studied. The results of evaluation of preference for appearance, flavor, texture and total quality of four commercial ice cream samples by multiple paired comparison test indicated that sample C was the best among samples in both type of carton and cone. There was some correlation between the sensory quality characteristics of commercial ice creams and chemical properties of fat extracted from those in carton, but that was not shown in cone. The results showed that flavor of ice cream in carton and appearance and flavor of ice cream in cone affected total quality, but texture did not.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.6
• /
• pp.944-950
• /
• 1996

The purpose of our study is to investigate the changes of physico-chemical properties according to packaging methods(vacuum packaged with polyamide/polyethylene, air packaged with polyvynyl-chloride) and illumination on the properties of Hanwoo beef. pH value in vacuum packaged beef tended to be decreased, but pH value in air packaged beef tended to be increased during storage for 21 days, irrespective of illumination. Contents of volatile basic nitrogen(VBN) and thiobarbituric acid(TBA) values were increased, regardless of packaging methods. However, vacuum packaged beef showed lower VBN, TBA values than those of air packaged beef. Red color(CIE a value) was also decreased. Regardless of packaging method, saturated fatty acids(SFAs) were increased, but unsaturated fatty acids(UFAs) were relatively decreased. And in the ratio of the UFA/SFA, vacuum packaged beef had lower UFA/SFA ratio than that of air packaged beef. In this study, the effect of illumination did not change on physico-chemical properties in Hanwoo beef. In conclusion, the results indicate that the vacuum packaging treatment was more important to prolong the shelf-life of Hanwoo beef than air packaging method.

• The Korean Journal of Food And Nutrition
• /
• v.6 no.4
• /
• pp.307-313
• /
• 1993

Bacillus cereus $\beta$-amylase was purified by Sephadex G-100 gel filtration, CM Sephadex C-50 ion exchange chromatography and CM Sephadex C-50 ion exchange rechromatography The purified enzyme showed 871 unit/mg of specific activity. The purified enzyme was identified as homogenious by disc PAGE, SDS-PAGE and analysis of reaction product. The purified enzyme showed optimum pH 7.0. optimum temperature 5$0^{\circ}C$, and was stable at 0~5$0^{\circ}C$ and at pH range of 6~10.

• Korean Journal of Food Science and Technology
• /
• v.10 no.4
• /
• pp.376-379
• /
• 1978

Three Korean leading wheat varieties and three imported ones were tested to compare the domestic wheat varieties with imported ones for their grain and Sour quality. The domestic varieties were generally inferior to the imported ones in milling characteristics. The milling rate of the Korean varieties was $66{\sim}68%$, while the imported one was 70%. But Jogwang, one of the Korean varieties had relatively high milling rate, 68%. Jogwang had a protein conten of 9.5%, sedimentation value of 30 ㏄ and Pelshenke value of 35 minutes. Jogwang seems likely to have a suitable quality as a soft variety and it showed somewhat better flour quality than white soft wheat, the imported soft wheat on farinogram.

• Applied Biological Chemistry
• /
• v.30 no.3
• /
• pp.242-249
• /
• 1987

Physicochemical properties on heat-moisture treatment of sweet potato starch were investigated. Starch granules of sweet potato observed by photomicroscope, polarized-light microscope and scanning electron microscope were round and polygonal. X-ray diffraction pattern was changed from Ca-pattern to A-pattern upon heat-moisture treatment. Water binding capacity was drastically increased as the moisture level was increased. The swelling power and solubility at the same temperature were decreased by heat-moisture treatment. Transmittance of 0.1% starch suspensions was increased rapidly from $65^{\circ}C$ in case of untreated starch and from $70^{\circ}C$ in case of treated starch. The starch on heat-moisture treatment was gelatinized over higher temperature range than the untreated starch.

• Korean Journal of Food Science and Technology
• /
• v.10 no.2
• /
• pp.157-161
• /
• 1978

Physicochemical properties of rice starches from Paldal(japonica type) and Tongil(indica type) were investigated. There were no significant differences in water-binding capacity, blue value and amylose content between the two starches. Paldal starch showed a higher value for-swelling power than Tongil starch. Amylograph data showed that both Paldal and Tongil starches had similar paste viscosities except setback in which Tongil starch showed a higher value. No significant differences were observed for intrinsic viscosity and glucose units per segment between Paldal and Tongil amylopectin fractions. However, the intrinsic viscosity for Tongil amylose was considerably higher than Paldal amylose. The rate of retrogradation of Tongil starch gels at $21^{\circ}C$ was faster than Paldal starch gels.

• Korean Journal of Food Science and Technology
• /
• v.25 no.4
• /
• pp.355-359
• /
• 1993

The effects of alum un the physicochemical properties of non-waxy and waxy rice starches were investigated. The swelling powers of non-waxy and waxy rice starches with $0.05{\sim}1.0%(w/w)$ alum were increased remarkably in comparison with rice starches without alum, but those of rice starches with alum above 1.0%(w/w) concentration were decreased slowly with the increasing amount of alum. While solubility of the non-waxy starch with $0.05{\sim}1.0%(w/w)$ alum was elevated gradually with the increasing temperature. that of the waxy starch was decreased regardless temperature. But solubilities of both rice starches with alum concentration above 1.0%(w/w) exhibited no significant changes. The more alum in the system, the higher and the lower blue value were resulted in non-waxy rice starch and waxy rice starch, respectively. From amylograms, it was found that alum increased breakdown and initial pasting temperatures for both rice starches, but reduced setback.

• Applied Biological Chemistry
• /
• v.34 no.2
• /
• pp.94-101
• /
• 1991

Physicochemical properties of waxy and non-waxy naked barley starches were investigated. The starch granules observed by photomicroscope, polarized-light microscope and scanning electron microscope were round. The starch showed a typical A type by X-ray diffraction pattern. Water binding capacity, swelling power and solubility of waxy naked barley starch were higher than non-waxy naked barley starch at the same temperature. Transmittance of 0.1% starch suspension was increased rapidly from $60^{\circ}C$ in case of waxy naked barley starch and from $65^{\circ}C$ in case of non-waxy naked barley starch. Amylogram revealed that the non-waxy naked barley starches had higher initial pasting temperature than waxy naked barley starch. Enthalpy for gelatinization of non-waxy and waxy naked barley starches were 1.12-1.58 and 0.85 cal/g, respectively.

• Korean Journal of Food Science and Technology
• /
• v.22 no.6
• /
• pp.651-658
• /
• 1990

Starch phosphates were prepared by dry heating, gelatinizing method and extrusion process using sodium tripolyphosphote (STPP) as a substitution reagent and their physicochemical properities were compared. In the preparation of starch phosphate by dry heating method(DSP), the effect of reaction temperature was the most significant to the DS(Degree of substitution). In the phosphorylation reaction with gelatinized starch(GSP), the substitution ratio was increased with increasing the reaction temperature, but the increase was insignificant above $85^{\circ}C$. By extrusion with the corn starch containing 2.0% STPP at various moisture contents of 20, 25 and 30%, the DS values of extrudate(WESP) were within the range of between 0.0066 and 0.0083. The starch phosphate(DSP) products showed lowering the gelatinization temperature, increasing the clarity of the starch paste. However, WESP showed higher gelatinization temperature than that of raw starch. The starch phosphate prepared by extrusion process showed lower apparent viscosity of paste than that of the DSP at same condition. All of starch phosphates showed reducing the tendency of the paste retrogradation.