• The Korean Journal of Food And Nutrition
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• v.19 no.2
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• pp.227-233
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• 2006

The effects of adding green tea powder(GTP) on the quality and storage characteristics of sikhe, Korean traditional sweet rice drink, were studied, The values of sweetness and pH of the sikhe with GTP were $18.40{\sim}18.50%\;and\;5.81{\sim}5.85$, respectively. The L and a values were decreased, but the b value was highly increased when the amounts of GTP were increased. Sensory evaluation showed that color and flavor of sikhe made of GTP were the highest among the treatments. However, sweetness of sikhe with GTP was lowered as the addition of GTP was increased. Sensory attributes such as taste, tenderness, aftertaste and overall acceptability were significantly higher in sikhe perpared with 2% GTP than those of control group(p<0.05). During the storage, pH of the sikhe with GTP was not significantly changed at the nineteenth day of storage, but pH of control group was markedly decreased. The L, a and b values showed no significant changes during storage.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.980-985
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• 2000

Influences of Japanese green tea powder (GTP) supplementation to commercial diet on laying performance and egg quality were studied by using 60 laying hens. The experimental diet with or without 0.6% GTP was given ad libitum to the birds during the period from 6 to 71 weeks of age. The birds started egg production from 21 wk of age regardless GTP feeding. Body weight, feed intake, egg weight tended to decrease with GTP supplementation, while egg production rate tended to increase. Haugh unit score was significantly increased with GTP, which accompanied with the increased albumen height. These were observed almost throughout the laying period over 50 wk. Gel proportion in thick albumen was decreased as storage time is prolonged, then higher values of the gel proportion were recorded in the eggs from GTP group. Thick albumen of the eggs from GTP-fed layers had more carbohydrate than that from control layers. All these indicate physical stability of thick albumen in the eggs from GTP group. Thiobarbituric acid content of egg yolk tended to remain lower in the eggs from GTP group during 5-10 days of storage at room temperature. Levels of egg yolk cholesterol and yolk lipid were significantly reduced by GTP feeding. There were no significant differences in eggshell weight, shell thickness and shell strength between the two groups. Thyroid gland and liver from hens slaughtered at 71 wk of age did not differ in weight irrespective of GTP feeding. The present results suggest that GTP could modify components of edible part of egg, leading to the characteristics favourable to consumers such as high durability of thick albumen and less cholesterol in yolk, without altering general performance of the layers throughout this year round experiment.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.398-405
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• 2010

In this study, white bread was prepared containing 1.5, 3.0, 4.5 or 6.0% barley leaves tea powder (BLTP). The samples along with a control were then compared regarding their quality characteristics, including pH, total titratable acidity, fermentation power of dough expansion, specific volume, baking loss, moisture content, color, textural characteristics, internal surface appearances and sensory qualities, all to determine the optimal ratio of BLTP. As the BLTP content increased, the pH of the dough and bread and the lightness decreased, whereas the total titratable acidity increased. The fermentation power of dough expansion increased with a longer incubation time. The control group was evidenced by a significantly higher specific volume and baking loss than that observed in the BLTP samples. However, greenness and yellowness evidenced the opposite effect. Hardness was highest at a substitution level of 1.5% and lowest at a level of 4.5%. Fracturability and resilience were not significantly different among the samples. For the internal surface appearance, darkness and greenness increased both increased at higher BLTP content. In the sensory evaluation, color, flavor and overall acceptability were highest in the control bread samples but minimal at a substitution level of 6.0%. Softness was the highest at the 3.0% substitution level and lowest in the control bread samples. Barley leaf flavor, astringency, bitterness and off-flavor increased as the BLTP content increased. Delicious taste was not significantly different among the samples. In conclusion, the results demonstrated that 4.5% BLTP may prove quite useful as a substitute for wheat flour in the production of white bread and may provide favorable nutritional and functional properties.

• Journal of the East Asian Society of Dietary Life
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• v.12 no.2
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• pp.135-140
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• 2002

Mungbean starch gels(MSG) was prepared by adding green tea powder(GP) in the ratio of 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% and tested for sensory characteristics, chromaticity and rheological properties. In sensory evaluation test, 1.5% GP added MSG gave the highest score in color, 1% GP added MSG in flavor and overall quality and 0.5% and 1.0% GP added MSG was evaluated higher than control in general. In chromaticity tests lightness(L) value of MSG decreased as the ratio of GP increased. In rheometer test, 2% and 2.5% GP added MSG showed the high values in hardness, cohesiveness, gumminess and brittlness.

• Food Science and Preservation
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• v.23 no.2
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• pp.188-193
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• 2016

Black tea is rich in phenolic antioxidants that has shown diverse health benefits such as protection against cardiovascular diseases and cancers. Thus, it is rational to incorporate black tea into suitable food products such as sponge cakes to enhance their nutritional and functional qualities. The aim of this study was to investigate the effect of the addition of black tea powder (BTP) on the quality of sponge cake. The pH of cakes ranged from 7.00~7.17, with no remarkable differences. Height decreased while baking loss rate and hardness significantly increased with increases in the content of BTP in the formulation (p<0.05). For crumb color values, $L^*-value$ decreased while $a^*$ and $b^*-values$ increased as a result of BTP substitution. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities were significantly increased (p<0.05) with increases in the content of BTP which were well correlated. Hedonic sensory results indicated that sponge cakes supplemented with 2~4% BTP obtained the most favorable acceptance scores. On the basis of the overall observations, sponge cakes supplemented with 2~4% BTP were found to be benefit from the functional properties of BTP, without compromising on consumer acceptance.

• Journal of the Korean Society of Food Culture
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• v.22 no.5
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• pp.615-620
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• 2007

Physicochemical and sensory characteristics of the green tea dasik varying the added value of oligosaccharide were investigated and the products were surveyed by elementary school students regarding the acceptability. Protein and ash contents were significantly higher and fat contents were significanlty lower in the samples with oligosaccharides compared to those in commercial ones(p<0.05). Commercial samples had significantly higher values in all of the textural characteristics using textural analyzer compared to those of the developed dasik sample groups. In analytical sensory evaluation, varying the amount of oligosaccharide, commercial samples had significantly higher values of sweetness, hardness, and cohesiveness and lower values of savory aroma and falvor compared to those of developed dasik(p<0.05). Savory aroma and flavor were highly negatively correlated with textural hardness, springiness, chewiness, gumminess, and cohesiveness(p<0.01), while sensory sweetness and hardness were significantly positively correlated with textural springiness(p<0.05), chewiness, gumminess, and cohesiveness(p<0.01). When surveying elementary school students regarding the acceptability of green tea dasik and commercial samples, green tea dasik 2 was the most preferred with significance in color. Regarding aroma, green tea dasik 1 received the highest acceptability (p<0.05). In the flavor, both dasik 1 and 2 received higher score than those of the commercial dasik. In overall acceptability, both green tea dasik 1 and 2 were preferred to the commercially sold ones with significance(p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.177-182
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• 2011

This study was designed to evaluate the effect of Yukwa prepared by addition of green tea powder on change of lipid composition and body weight in mouse model. Mice were fed with Yukwa containing the five different types of green tea powders such as Bucho-cha, Okro-cha, Yongjeong-cha, Oolong-cha and Hong-cha with a normal diet. Body weight changes of Yukwa fed mice were measured once in a week for seven weeks. After seven weeks, mice were sacrificed and serum and tissues were collected for the following: adipose tissue weight, liver morphology, adipose tissue size and cholesterol content. The Yukwa combination with green tea fed mice reduced all the parameters compared to Yukwa alone fed mice. In conclusion combination with green tea showed reducing effect of hypocholesterolemia, which suggests the possibility of application to green tea as a food ingredient.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1339-1347
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• 2008

The objective of this study was to determine the effects of green tea probiotics on growth performance, meat quality and immune response in finishing pigs, and to assess the possibility of substituting green tea probiotics for antibiotics in diets of finishing pigs. This green tea probiotics is made by mixing green tea powder and excipients (defatted rice bran and wheat bran) and fermenting the mixture with beneficial bacteria. A total of 90 crossbreed "Landrace$\times$Yorkshire" finishing pigs with an average body weight of $72.5{\pm}2.5kg$ were assigned to 5 dietary treatments in a completely randomized design. Each treatment had 3 replications with 6 pigs per replication. The five dietary treatments were control, antibiotic (0.003% chlortetracycline added) and 0.1, 0.5 and 1.0% of green tea probiotics. There were no significant differences in final body weight, daily weight gain, daily feed intake and feed conversion ratio in the green tea probiotics and antibiotic treatments (p>0.05). Crude protein content was significantly increased in the 0.1 and 1.0% green tea probiotics treatment groups (p<0.05) and there was no significant difference in crude fat content of the meat among the treatments. The TBA value of meat was significantly lowered with 0.5 and 1.0% green tea probiotics treatments compared to that of controls and statistically similar to the antibiotic treatment after 3 weeks of storage (p<0.05). The growth of spleen cells stimulated with Con A (0.1 and $1.0{\mu}g/ml$) was significantly increased with 1.0% green tea probiotics treatment compared to that of the control treatment (p<0.05). The growth of spleen cells stimulated with LPS (1.0, 3.0 and $10{\mu}g/ml$) was significantly increased in the 0.5% green tea probiotics group compared to the antibiotic group (p<0.05). In Con A ($1.0{\mu}g/ml$) medium, IL-6 production of spleen cells was significantly increased with 1.0% green tea probiotics treatment compared to that of the control (p<0.05). In LPS ($10.0{\mu}g/ml$) medium, TNF-${\alpha}$ production of spleen cells increased significantly in all green tea probiotics treatment groups compared to that of the control (p<0.05). Finally it can be summarized that addition of green tea probiotic has a positive effect similar to antibiotic and 0.5% is the suitable dietary supplementation dose for finishing pig production.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2003.10a
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• pp.43-43
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• 2003

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1079-1084
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• 2004

The present study was conducted to compare antioxidant activity of green teas, fermented teas and other related common teas by examining radical scavenging activity using DPPH (2,2 diphenyl l-picryl hydrazyl). Scavenging activity ($SC_{50}$/) of epigallocatechin gallate (EGCG) for 0.1 mM DPPH radical was 5.5 $\mu$M or 4.2 mg/L by weight, then catechin, 14 $\mu$M or 2.5 mg/L and vitamin C, 22 $\mu$M or 3.9 mg/L, respectively. Kyokuro tea (okro) powder of 24.2 mg/L or green tea powder of 25.2 mg/L was used to reach $SC_{50}$/ for 0.1 mM DPPH. One serving of 2 g green tea provides antioxidant activity equivalent to 109∼147 mg EGCG, 145∼185 mg catechin or 131∼168 mg vitamin C. Teas from the first harvest had the highest radical scavenging activity when compared with later harvest green teas grown in the same region, but there is virtually no difference by the harvest time. A Chinese green tea, Dragon well had the highest antioxidant activity among other green teas tested providing antioxidant capacity equivalent to 168 mg EGCG or 188 mg vitamin C per 2 g serving, but partially fermented Chinese teas had much lower antioxidant activity than any green tea tested. Black tea which is fully fermented showed as strong antioxidant activity as green teas (76.3 mg vs 86.7∼67.6 mg per tea bag). One tea bag of green teas from market provided antioxidant capacity equivalent to 52∼86 mg EGCG, 70∼105 mg catechin or 63-96 mg vitamin C. Teas made of persimmon leaf, pine needle, mulberry leaf had comparatively low anti-oxidant activity equivalent to 2.5∼4.8 mg EGCG or 15∼21 mg vitamin C per teabag. The third brewed green tea still had enough antioxidant activity, while tea from tea bag brewed for 3 min or 5 min did not have any difference in their antioxidant activity. More systemic studies are needed to clarify the relationship between tea catechins and antioxidant capacity focusing on how growing, harvest time, fermentation and other processes can influence on this.