• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.820-825
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• 1989

Yukwa (one of most popular Korean traditional popped rice snacks) was made by four different varieties of rice, Shinsun (Japonica) and Hangang $(Japonica{\times}Indica)$ which are waxy rice and Dongjin (Japonica) and Samgang $(Japonica{\times}Indica)$ which are non waxy rice, for their quality by total expansion volume, hardness and brittleness. It was notified that hydration rate of waxy and non waxy rice for preparation of Yukwa were different by 30% and 42% in moisture content respectively soaked at $12^{\circ}C$ for 12 hours and the gelatinization temperature of their starch was $64.5-67.5^{\circ}C$ with no big difference by varieties. The quality of Yukwa was deeply related with amylose contents ranging from 18.5% of non waxy rice to 2-3% of waxy rice. Superior quality (p<0.05) was got from waxy rice. Lactic acid bacterial fermentation didn't improve the quality, and soybean and rice bran oil can be used for popping in even value.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.385-391
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• 2006

Physicochemical properties of hydroxypropylated waxy rice starches were investigated to reduce steeping-time of yukwa (Korean oil-puffed rice snack) processing. Swelling power of hydroxypropylated waxy rice starch increased at relatively higher temperature $(60^{\circ}C)$ than native waxy rice starch $(70^{\circ}C)$. Solubility of hydroxypropylated waxy rice starches increased with increasing propylene oxide content. Pasting temperature $(66.3-66.9^{\circ}C)$ and peak viscosity (216-232 RVU) of hydroxypropylated waxy rice starch were higher than those of native starch (179 RVU) and increased with increasing propylene oxide content. DSC thermal transitions of hydroxypropylated waxy rice starches shifted toward higher temperature. Amylopectin melting enthalpy of hydroxypropylated waxy rice starch (8.4-9.2 J/g) was similar to native starch (9.0 J/g). X-ray diffraction patterns of native and hydroxypropylated waxy rice starches showed typical A-type pattern with no significant differences between them, suggesting hydroxypropylation only affected amorphous region. Results suggest hydroxypropylated waxy rice starch is not applicable for yukwa due to low puffing efficiency and dark color.

• Korean journal of food and cookery science
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• v.22 no.3 s.93
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• pp.363-369
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• 2006

The aim of this study was to determine the optimum addition amount of waxy sorghum flour to rice flour in the preparation of Sulgidduk(waxy sorghum rice cake). The moisture content of Sulgidduk with added wary sorghum flour was $37{\sim}41%$. With increasing waxy sorghum (lour content over the range from 10% to 50%, the L-value decreased, whereas the a-and b-values increased. In the mechanical evaluation of waxy sorghum Sulgidduk, the hardness, gumminess and brittleness increased with increasing waxy sorghum flour content above 20%. The adhesiveness increased with increasing waxy sorghum flour content. The cohesiveness and springiness did not differ significantly with the addition of waxy sorghum flour. In the sensory evaluation of waxy sorghum Sulgidduk, the evaluation of the softness, moistness and chewiness was the best at 20% content. Sulgidduk made with the addition of 20% waxy sorghum flour to rice flour was found to be the best recipe in terms of overall acceptability and the sensory qualities of softness, moistness and chewiness.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.187-189
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• 1991

Gelatinization temperatures of upland and lowland waxy brown rice starches annealed at $25^{\circ}C$ and $60^{\circ}C$ for 24hr were investigated with differential scanning calorimetry No annealing effect was observed at low temperature. The upland rice starch showed narrower range of gelatinization temperature upon annealing treatment at $60\circ}C$ compared with the lowland rice starch. The enthalpy of gelatinization was not changed in case of the upland rice starch but was increased in case of the lowland one upon annealing.

• Culinary science and hospitality research
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• v.17 no.1
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• pp.248-258
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• 2011

To analyze die quality characteristics of loaf bread added with waxy black rice flour by its storage period, this study stored loaf bread made of wheat flour added with 10% 20% 30% and 40% of waxy black rice flour for 4 days while measuring water activity, pH, chromaticity and texture. The results of die study are as follows. Based on die results of measurements of water activity of loaf bread added with waxy black rice flour by storage period, die control group and die groups added with 10% and 20% of waxy black rice flour showed significantly low water activity from the $3_{rd}$ day of storage and die groups added with 30% and 40% of waxy black rice flour from the $2_{nd}$ day of storage. As for pH changes over the storage period, only die group added with 40% of waxy black rice flour showed significant pH decreases from die $3_{rd}$ day of storage while the control group and the groups added with 10% and 30% of waxy black rice flour showed significant pH decreases from die $2_{nd}$day of storage. As for the pH of each group of loaf bread by storage days, die loaf bread added with 40% of waxy black rice flour showed significantly higher pH compared to the control group. Brightness decreased significantly from the 2nd day of storage and die yellowness from the $3_{rd}$ day of storage. As for chromaticity changes by storage days, as die amount of added waxy black rice flour increased, L values and b values decreased while redness values significantly increased. Over die storage period, hardness, gumminess and chewiness increased and die waxy black rice flour added groups showed lower increase rates compared to die control group. Especially, die groups added with 30% and 40% of waxy black rice flour showed low hardness changes. Springiness level was decreased as die addition rate of waxy black rice flour was increased, and the group added with 40% of waxy balck rice flour showed die lowest springiness level. It also showed lower cohesiveness up to the 3rd day of storage compared to die day of manufacturing. Therefore, it could be seen that die loaf bread made from wheat flour added with 30% of waxy black rice flour showed better quality feature until die $3_{rd}$ day of storage than die other experimental groups.

• Korean Journal of Human Ecology
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• v.5 no.2
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• pp.23-31
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• 2002

Effects of autoclaving-cooling cycled waxy rice(Hwasunchalbyeo) starch(ACW) on textural and sensory properties of Injulmi were investigated. The protein, ash and lipid contents of waxy rice flour were higher than those of waxy rice starch and ACW. The RS level of ACW was 8.21%. By increasing ACW content added to Injulmi, hardness and adhesiveness of Injulmi decreased, Hunter color L and a values increased and b values decreased. The sensory test showed that the hardness of Injulmi decreased, but springiness and adhesiveness increased by increasing ACW content to Injulmi. Overall Qualities of injulmi added with ACW up to 20% were similar to the non-added Injulmi.

• Culinary science and hospitality research
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• v.13 no.4
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• pp.178-185
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• 2007

The antioxidant activities of the bread made from waxy black rice flour(WBRF) and wheat flour were investigated. The waxy black rice bread was manufactured with 10, 20, 30, or 40% waxy black rice flour(w/w). As the additive amount of WBRF were increased, DPPH(1,1-diphenyl-2-picryl-hydrazyl) radical scavenging activity and TEAC(trolox equivalent antioxidant capacity) were also increased. WBRF group showed the higher activity than the control group in DPPH radical scavenging activity and TEAC. The group with 10% WBRF added was not significantly different from the control group in metal chelating activity, but over 20% of addition, it had the higher metal chelating activity than that of the control group.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.241-246
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• 2000

In order to investigate structural properties of Chindo black rice(grown in Chindo, Chonnam) starch and its amylopectin, Chindo black rice was investigated in comparison to Shinsun waxy rice. The maximum absorbance wave and intrinsic viscosity of Chindo black rice starch and Shinsun waxy rice starch were 523 nm, 521 nm and 183 ml/g, 178 ml/g, respectively. ${\beta}-amylolysis$ limit(%) of Chindo black rice and Shinsun waxy rice starch were 62.8% and 60.3%, respectively. Chindo black rice was determined to be a waxy rice due to the results of iodine reaction and elution profile on Sephroce CL-2B. The chain of amylopectins in Chindo black rice distributed fraction 1$(F_1)$ of above degree of polymerization$({\overline{DP}})$ 55, fraction 2$(F_2)$ of ${\overline{DP}} $40{\sim}50$ and fraction 3$(F_3)$ of ${\overline{DP}} $15{\sim}20$, and the ratio of $F_3$ to $F_2$ for Chindo black rice was higher than that for Shinsun waxy rice. The super long chain of amylopectin in Chindo black rice was consisted much more than that of Shinsun waxy rice. ${\beta}-limit$ dextrins in Chindo black rice amylopectin distributed $F_1$ of above ${\overline{DP}} 55, $F_2$ of ${\overline{DP}} $30{\sim}45$ and $F_3$ of ${\overline{DP}} $10{\sim}20$. Little difference was shown between elution patterns of the pullulanase treated ${\beta}-limit$ dextrins of Chindo black rice amylopectin and Shinsun waxy rice amylopectin. These results suggest that Chindo black rice starch was similar to Shinsun waxy rice starch.

• Korean journal of food and cookery science
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• v.12 no.4
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• pp.557-561
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• 1996

Physicochemical properties of nonwaxy (Dongjin byeo) and waxy (Sin-seunchal byeo) brown rice flour were investigated. The proximate composition of nonwaxy brown rice flour was 7.02% of protein, 1.14％ of ash, 3.2% of lipid and that of wfny brown rice was 7.74% of protein, 1.48% of ash,4.83% of lipid. X-ray dif- fraction patterns were A types, and relatives crystallinity of nonwaxy brown rice flour was higher than that of waxy brown rice flour. Swelling power and solubility increased with the increase of temperature, waxy brown rice flour showed higher than nonwaxy rice flour until 70$^{\circ}C$, but lower after 80$^{\circ}C$. The gelatinization temperature, breakdown and consistency of nonwaxy brown rice flour by amylogram were higher than those of the waxy brown rice flour but setback was same. The initial gelatinization temperature and the enthalpy of nonwaxy brown rice flour by DSC were higher than those of the waxy brown rice flour.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.343-345
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• 2002

The study was investigated hot-water soluble on waxy black and waxy rice flours according to gelatinization temperatures and heating time. The hot-water soluble contents of both samples were increased during heating time at $90^{\circ}C$. The waxy black and waxy rice flours solutions according to gelatinization temperatures ($80^{\circ}C,\;90^{\circ}C,\;95^{\circ}C\;and\;98^{\circ}C$) were heated for 10, 20 and 30 min. Determination of elution patterns of rice flours was used by Sepharose CL-2B column. As a result, the elution patterns were eluted the most in void volume ($V_0$) and the elution patterns of the hot-water solubles were increased according to heating time and gelatinization temperatures.