• Food Engineering Progress
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• v.15 no.1
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• pp.80-84
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• 2011

The effects of incorporating hot water extract of Schisandra chinensis fruit on the physicochemical and sensory properties of Sikhe were investigated. The extract was incorporated at 5 levels (0, 10, 20, 30, 40, and 50%, v/v) by replacing equivalent amount of distilled water. The pH decreased while the soluble solids content increased significantly with the increase in the extract replacement (p<0.05). Redness ($a^*$-value) increased significantly as the extract concentration increased (p<0.05); on the other hand, lightness ($L^*$-value) and yellowness ($b^*$-value) did not show any direct relationships with the extract replacement. Color, sour taste, and sweet taste except for Sikhe flavor were distinctively classified by the sensory analyses (p<0.05). Correlation analysis indicated that level of extract incorporation was well-correlated with all the physicochemical and sensory properties studied except for $L^*$- and $a^*-$ value. Finally, the consumer test based on Friedman-type statistic, suggested that 10% incorporation of the hot water extract of Omija fruit was recommended for making Sikhe.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.417-421
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• 1997

Quality of Sikhe, the Korean conventional rice beverage depended on the characteristics of saccharifying activities of various amylases, intrinsic flavour, budding rate and so on. To improve the quality of Sikhe, characteristics of malt produced with wheat, covered barley and naked barley were evaluated. The germination rate of wheat was 82%, but those of naked and covered barley were 69% and 56% for 6 days, respectively. Malt prepared from germinated grains with 1.5~2.0 times length of buds had the highest saccharifying power. when the extraction of enzyme and reducing sugar was carried out at 5$0^{\circ}C$ for 4 hr, saccarifying power and reducing sugar contents were the highest. Malt of wheat had the highest saccharifying power. Malt of naked barley had higher saccharifying power than that of covered barley. The amylase types of wheat, covered barley and naked barley were similar to $\beta$-amylase.

• Korean journal of food and cookery science
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• v.23 no.6
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• pp.848-857
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• 2007

Sikhe, a traditional Korean drink, was prepared with Hovenia dulcis extract (HDE), and its quality and storage characteristics were evaluated through sensory and microbial analyses. In the color analysis, the lightness of the Sikhe showed a decreasing tendency according to the addition of HDE, while redness and yellowness increased. The Sikhe prepared with 20% HDE had the highest sugar concentration at 12days of storage ($4^{\circ}C$). Interms of sensory quality, both the 20% and 40% HDE-added Sikhes had the highest overall preference. The microbial cell counts presented no distinct differences early in the storage. period, but the general bacteria counts of the Sikhe made with the increasing concentrations of extracts decreased with a longer storage period. The coliform counts of the Sikhe prepared without HDE (control) was 10.5 CFU/g at 10 days of storage, but the 100% HDE-added Sikhe had a level of 7.9 CFU/g at 16 days of storage. These results indicates that Hovenia dulcis may inhibit normal microbial growth and extend the shelf-life on Sikhe.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.345-352
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• 2001

The volatile compounds of traditional Kyungsando squid sikhe were identified by GC-MS. The amount of ${\alpha}-zingibirene$ among identified volatile compounds was 19.73 mg/kg. The major volatile compounds of sikhe were (Z)-Di-2-propenyl disulfide, ${\alpha}-curcumene$, methyl allyl disulfide, (E, E)-a-farnesene, pentanol, z-citral, 3-ethyl-1,2-dithi-5-ene-${\beta}-elemene$, ${\beta}-elemene$, acetic acid, and ${\beta}-phellandrene$. The volatile compounds of sikhe were compose of 49 including hydrocarbone groups, 15 aldehydes groups, 33 alcohol groups kinds, 11 ketone and ester groups. The fraction obtained from sikhe were tested for electron donating ability, angiotensin converting enzyme inhibitory activity and xanthine oxidase inhibitory activity. There were no electron donating abilities$(SC_{50})$ in hexane and water soluble fractions. On the other hand, the angiotensin converting enzyme abilities of ethylacetate and butanol soluble fractions were $310.64\;{\mu}g/mL$ and $1096.49\;{\mu}g/mL$, respectively. Angiotensin converting enzyme inhibitory activities$(IC_{50})$ of ethylacetate butanol soluble fractions were 1.623 mg/mL and 1.303 mg/mL, respectively. Xanthine oxidase inhibitory activities$(IC_{50})$ of ethylacetate fraction and butanol soluble fractions were 3.591 mg/mL and 2.083 mg/mL, respectively.

• Korean journal of food and cookery science
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• v.14 no.1
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• pp.91-96
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• 1998

Growth of acrospire length from germinated covered barley with 1.5∼2.0 times length of buds had the highest amylase activity for 9 days at 15$^{\circ}C$. When the extraction of malt was carried out at 50$^{\circ}C$ for 3.5 hr., total sugar, reducing sugar, sweetness determined by refractometer and amylase activity were the highest, and 2.33%, 1.61%, 3.4 brix(%), 28,332 units, respectively. The sikhe saccharificated at 60$^{\circ}C$ for 8 hr. showed total sugar content increased to 3.90∼9.27% in nonwaxy rice, 4.19∼11.91% in waxy rice, and reducing sugar-content increased 3.30∼7.61% in nonwaxy rice, 3.31∼9.11% in waxy rice. Also, brix was increased to 3.6∼10.8 brix (%) in nonwaxy rice, 3.6∼12.8 brix(%) in waxy .ice, as saccharification time increased. The amylase activity was decreased as saccharification time was increased. And pH was gradually decreased according to time increase, however, it changed little after 4 hr. Morphology of cooked rice kernel during saccharification for sikhe gradually enlarged the oval for hydrolyzed starch granule by increasing saccharification time.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.101-106
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• 1997

This study was carried out to examine the possibility of using brown rice or paddy as raw materials for sikhe. Brown rice and paddy were soaked in water at $15^{\circ}C$ for 2 days and then germinated at $15,\;20,\;25,\;30^{\circ}C$ for upto 10 days. The higher the germination temperature, the higher the germination speed, the increase of ${\alpha}-amylase$ activity, and the increase of extract amount and its sugar content. The viscosity of extract rapidly decreased first and then slightly increased during germination. The activities of ${\alpha}-amylase$ of germinated brown rice and paddy were much smaller than those of germinated barley; however, the extract amount and its sugar content of germinated brown rice and paddy were similar to those of germinated barley. The germinated brown rice can be used for sikhe not as a saccharifying agent but as a substitute for white rice.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.65-72
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• 2002

This study was to determine the optimum conditions of malt extracting temperature, extracting time of malt in water, ratio of malt to water, and rice volume of malt extract water on saccharification in producing sikhe (sweet rice drink) using central composite design of response surface methodology. Glucose and maltose were analyzed by a biosensor having dual cathode system. The optimum temperatures of malt extracting for glucose and maltose were 60 and $55^{\circ}C$. The saccharification power for the two sugars was highest when malt powder soaked for 6.5 and 5.75 hour, respectively. And ratios of malt to water for optimum saccharification were 1 : 6.3 to 1 : 8.8, respectively. The optimum volumes of malt extracting to rice for the two sugars were 0.48% and 0.6%, respectively. The application of response surface methodology to sikhe processing showed a good correlation with high significance.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1092-1096
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• 1998

This work was to study the possibility of using germinated colored rice as a raw material for sikhe. Colored rice was soaked in water at $15^{\circ}C$ for 2 days and then germinated at 15, 20, 25 and $30^{\circ}C$ for upto 10 days. The higher the germination temperature, the higher the germination speed, the rate of increase in ${\alpha}-amylase$ activity, and the rate of increase in extract and its sugar content. The viscosity of extract rapidly decreased first and then slightly increased during germination. The germination speed of colored rice was lower than that of brown rice at $25^{\circ}C$. The germinated colored rice can be used for sikhe not as a saccharifying agent but as a substitute for white rice for the nutritional purpose.

• Korean journal of food and cookery science
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• v.18 no.2
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• pp.157-163
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• 2002

The gelatinization and retrogradation properties of rice starch added with dietary fibers from sikhe were investigated. The pasting temperature and setback of starch measured by using a rapid visco analyzer were increased by the addition of the fiber, whereas the peak viscosity, trough viscosity, end viscosity, breakdown and consistency were lowered. The onset temperature of starch measured by a DSC was increased, but the enthalpy of gelatinization of the starch was decreased as the addition of fiber increased. The melting peak temperature of the retrograded starch gels was 41∼46$\^{C}$ as measured by a DSC. The melting enthalpy of the control retrograded starch gel was increased while storing for 1, 3 and 7 days at 4$\^{C}$, but that of containing sikhe fiber showed no differences.

• Journal of the Korean Society of Food Culture
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• v.7 no.4
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• pp.329-338
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• 1992

This study was attempted aimed to prepare of Andong sikhe by pure culture inoculation and to improve storage stability by the addition of stabilizers to the product. Lactobacillus delbreuckii was selected for pure culture inoculation in the fermentation. The effect of stabilizers on the sedimentation, sensory evaluation and viscosity of Sikhe were investigated during the fermentation of traditional Andong Sikhe stored at $4^{\circ}C$ Morphological characteristics of Sikhe were determined by scanning electromicrograpy. Among the stabilizers added to the traditional Andong sikhe Na-alginate was found to be best stabilizers. When the product was evaluated by the sensory panel, the addition of stabilizers up to 0.1% level actually increased the acceptability of the product, while the concentration of more than 0.2% stabilizers affected the acceptability of the negatively. Sikhe added Na-carboxymethyl cellulose and Na-alginate showed highest viscosity on the 2nd day of fermentation, while homogenized Andong sikhe with Carrageenan showed the highest peak in viscosity on the first day of fermentation. Lactic acid bacterial count reached to $3.2{\times}10^8/ml$ after 20 days of storage. The surface and cross section of rice was observed by scanning electron microscope. As the fermentation proceeded holes on the surface increased, and nearly empty cell wall remained at the later stage of fermentation. Use of pure cultured inoculum of L. delbreuckii supported the rapid build up of the lactic acid bacteria and consequently the whole process of the fermentation was shortened. The acceptability and product quality were improved by use of L. delbreuckii inoculum.