• Journal of the East Asian Society of Dietary Life
• /
• v.25 no.5
• /
• pp.830-841
• /
• 2015

This study compared the physicochemical characteristics, proximate composition, taste compound and antioxidant properties of Sikhye prepared with pigmented rice. Proximate composition showed a significant difference depending on the type of pigmented rice except crude fat contents and pH, color was a significant difference depending on the type of pigmented rice. The highest brix degree was $15.07^{\circ}Brix$ in red and black rice Sikhye. Each highest value of reducing sugar and free sugar content showed milled rice and brown rice Sikhye. Titratable acidity and total acidity of the pigmented rice Sikhye were highest for black rice Sikhye, free sugar content were highest for green rice Sikhye. Analysis of their relative antioxidative properties indicated that black rice Sikhye had the highest total polyphenol, flavonoid, and anthocyanin content, the highest levels of DPPH radical scavenging ability, and the highest level of reducing power and ferric reducing ability of plasma scores. Principal component analysis suggested that black rice Sikhye had a strong association with antioxidant properties, brown and red rice Sikhye had the strongest association with the sweetness and unique flavor.

• Korean Journal of Food Science and Technology
• /
• v.44 no.5
• /
• pp.553-558
• /
• 2012

The pH, turbidity, color, brix, reducing sugar, total sugar, ketose, amino acid, protein and organoleptic characteristics of sikhye prepared with puffed rice powder (0, 25, 50, 75 and 100% (w/w)) were investigated during saccharification. A higher concentration of puffed rice powder and longer saccharification time resulted in pH reduction (p<0.05) and tended to increase turbidity. A higher Hunter "L" value was observed with higher puffed rice powder content, except for the addition of 25% at 0 h. The Hunter "L" value peaked at hour 1 and slowly declined thereafter. Elevations in brix, reducing sugar, total sugar and sucrose were observed with higher puffed rice powder content and longer duration of saccharification (p<0.05). The sucrose content ranged from 0.79-0.86% (w/w) at hour 6, which was markedly lower than that of commercial sikhye. With time, levels of amino acid and protein increased (p<0.05). Sensory evaluation revealed moderate differences between 0% and both 75 and 100% (p<0.001), with 75 and 100% preferred over 0% (p<0.05).

• Food Science and Preservation
• /
• v.24 no.2
• /
• pp.196-205
• /
• 2017

This study was conducted to increase the functionality of Korean traditional beverage, Sikhye. The Sikhye were prepared by supplementation up to 20% of Seomaeyaksuk extract (SE) and saccharification for five hours (h). During the saccharification, turbidity of SE-added Sikhye (SES) was the highest at two hours of saccharification and then lowered gradually. L vlaue of SES did not show significant difference feduring saccharification, and both a and b value of Sikhye were increased as saccharification time passed and SE addition ratio was increased. The pH before saccharification was not significantly different by SE addition ratio but it was increased to 5.68-5.73 at 5 h saccharification. Soluble solid, total sugar and reducing sugar contents were enhanced as saccharification time and SE addition ratio were increased. The total phenolic compounds contents and DPPH radical scavenging activity showed a similar trend by saccharification time and SE addition. In sensory test, the evaluations of 5% SES and control were not significant different, but 20% SES group showed significant lower evaluation than other groups because strong color and mugwort flavor. From all of these results, physicochemical characteristics and antioxidant activity of SES was improved by SE addition but sensory characteristics was lower. Acceptable addition ratio of SE in Sikhye is determined to be within 15%.

• The Korean Journal of Food And Nutrition
• /
• v.37 no.1
• /
• pp.9-16
• /
• 2024

To produce super sweet corn sikhye, substituted for sweetener, the ratio of rice and super sweet corn was adjusted and processed with complex enzymes during saccharification, and their physicochemical and sensory properties were analyzed. The soluble solid content of the control and Corn-5 showed significantly high content at 13.50 °Brix, and the reducing sugar content of Corn-5 showed the highest content at 9.45%. The control showed the lowest free sugar content among all the experimental groups, excluding maltose content. In the enzyme-treated corn sikhye group, as the amount of super sweet corn increased, the content of sucrose decreased and the contents of glucose and fructose increased. The content of ascorbic acid and polyphenol compounds increased as the amount of super sweet corn increased. DPPH and ABTS radical scavenging abilities increased with increasing ratio of super sweet corn and enzyme treatment compared to the control. In the case of sensory evaluation, Corn-3, which substituted 30% of super sweet corn for rice and treated with enzymes, showed higher evaluations in taste, sweetness, and overall preference than those of the control.

• Korean Journal of Food Science and Technology
• /
• v.21 no.2
• /
• pp.197-202
• /
• 1989

This study was conducted to investigate the characteristics of Sikhye as affected by different amount of cooked rice and malt, and by different kinds of sweeteners. In the various Sikhyes made with the different amount of cooked rice and malt, the degree of such sensory properties as color and malt odor significantly increased with the increased amount of malt. As the amount of cooked rice increased, sensory properties such as turbidity, sweetness and viscosity increased. Reducing sugar content in Sikhye was consistent with those of sensory evaluation on sweetness. Sikhyes containing aspartame, saccharin, sorbitol or sucrose at equisweet levels to Sikhyes containing 10% sucrose showed different sensory characteristics except sweetness. Sikhye sweetened with mixtures of substituted sweeteners showed increase in sweetness and differences in bitterness and astringency compared with Sikhye containing 10% sucrose.

• Journal of the East Asian Society of Dietary Life
• /
• v.25 no.6
• /
• pp.1007-1017
• /
• 2015

This study compared the physicochemical characteristics, proximate composition, taste compound, and antioxidant properties of Sikhye prepared with berries. Proximate composition and color were significantly different depending on the type of berry, whereas crude fat content and pH were not. The highest brix degree was $18.92^{\circ}Bx$ in strawberry Sikhye. Total free sugar, glucose, and fructose contents were highest in blueberry Sikhye. Titratable acidity, total acidity, and organic acid contents were highest in raspberry Sikhye. Analysis of relative antioxidative properties indicated that bokbunja Sikhye had the highest total polyphenol, flavonoid, and anthocyanin contents, highest DPPH radical scavenging ability, and highest reducing power and ferric reducing abilities in plasma. Principal component analysis suggests that bokbunja Sikhye has strong antioxidant and sweetness properties.

• Journal of the East Asian Society of Dietary Life
• /
• v.26 no.1
• /
• pp.44-54
• /
• 2016

This study compared the physicochemical characteristics, proximate composition, taste compounds, and antioxidant properties of Sikhye prepared with mulberry fruit concentrate. Analysis of the physicochemical characteristics of Sikhye added with mulberry indicated that sugar content and titratable acidity increased significantly with increasing mulberry concentration, whereas pH decreased significantly. The whiteness index (L) was 36.77~51.40, which significantly decreased with increasing mulberry concentrate. The redness index (a) was -0.90~1.97 and highest in Sikhye sample containing 4% mulberry concentrate. The yellow index (b) was 0.03~1.90 and highest in Sikhye sample containing 1% mulberry concentrate. Analysis of the antioxidant properties of Sikhye added with mulberry indicated that total polyphenol content and flavonoid content increased significantly as the amount of mulberry concentrate increased above 1%. Total anthocyanin color also increased significantly with increasing mulberry concentrate. The mulberry Sikhye sample containing 8% extract showed the strongest antioxidant properties based on DPPH radical scavenging activity, reducing power, and FRAP assay. Evaluation of the sensory properties of Sikhye added with mulberry revealed that the most preferred flavor, color, and taste were observed in Sikhye samples containing 2%, 4%, and 8% extract, respectively. However, the highest overall preference was observed in Sikhye sample containing 2% extract, indicating that 2% concentration was most suitable for Sikhye and that flavor and aftertaste were more critical than taste. Analysis of the storage characteristics of Sikhye added with mulberry indicated that total bacteria count increased across all samples with increased storage period. However, total bacteria count in the added mulberry concentration group decreased in comparison to the control group as the amount of added mulberry increased.

• Culinary science and hospitality research
• /
• v.19 no.3
• /
• pp.46-56
• /
• 2013

This study investigates the quality characteristics of Sikhye, a Korean traditional drink, made with different amounts of Monascus anka rice, or red yeast rice, and the results are as follows. During the saccharification process of red yeast rice, there was not significant change in pH, and its sugar content increased. It revealed that the optimal hours of saccharification for making Sikhye were four or five hours, which showed the highest in $^{\circ}Brix$. PH decreased significantly with increasing amounts of red yeast rice, and there was no change in sugar content and reducing sugar. Chromaticity L values decreased with increasing amounts of red yeast rice, and a value, b value and the turbidity increased. DPPH free radical scavenging activity of the samples showed significant differences in the samples with high scores as the amounts of red yeast rice increased. As a result of measuring the total microorganism number of the sample stored at $4^{\circ}C$, storability was improved with increasing amounts of red yeast rice. Preference was high in the order of 40%, 50%, 30%, 20%, 0%, and 10%, and the optimal amount of red yeast rice was less than 40-50%. Adding red yeast rice showed high scores in the sensory test, showing red color in Sikhye. In addition, its antioxidative activity effect and microbial growth inhibitory activity were considered to improve storability and preference.

• The Korean Journal of Food And Nutrition
• /
• v.11 no.2
• /
• pp.143-149
• /
• 1998

Sugars in Korean beer(3 brands) and Japanese beer(21 brands) were studied by HPLC and TLC. Total sugar of beer were estimated to 1.71∼3.93%(average 3.15%). Ethanol 4.5% class beers were estimated to 3.24% for Korean brands and 2.5% for Japanese brands. Ethanol 5% and 5.5% class beer were estimated to contain 3.2% for Japanese brands, respectively. Maltooligosaccharide series from glucose to maltodecaose were detected in the test of TLC and HPLC. No fermentable maltooligosaccarides and limit dextrin were estimated to 2.32%. But sugars in Korean Sikhye, rice drink saccharifide by malt, were not detected maltooligosaccharide series form maltotetraose to maltoheptaose.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.1
• /
• pp.82-86
• /
• 1997

A Korean traditional sweet rice drink "Sikye" was produced from the raw material of 20% of rice and 4% malt supplemented with 2l of tap water, by incubating the mixture at 6$0^{\circ}C$ for 7 hours. The product was found to contain 11.01% of maltose, 5.31% of isomaltooligosaccharides, 1.75% of maltotriose and 0.28% of glucose. Maltose, maltotriose and isomaltooligosaccharides in Sikye were seperated by ethanol (3 volume) precipitation repeated three times, followed by gel chromatography of Toyopearl HW-40S. 1H-NMR analysis revealed that the products of G2 and G3 size had only $\alpha$-1, 4-glucosidic linkage. but isomaltooligosaccharides showed both signal of $\alpha$-1, 4 and $\alpha$-1, 6-glucosidic linkage with its estimation ratio of 5:1. Isomaltooligosaccharides were hydrolyzed to produce maltooligosaccharide series from maltose to maltohexaose by pullulanase. These results, suggest that isomaltooligosaccharides were constructed by maltohexaose main chain with maltose or maltotriose and maltotetraose side chain.ide chain.