• 한국자원식물학회지
• /
• 제28권6호
• /
• pp.734-742
• /
• 2015

The purpose of this research was to find the most appropriate process for making yacon leaf tea. We applied both green tea and black tea brewing and fermenting methods for producing yacon leaf tea. This research included consumer test and descriptive analysis of professional trained panel on yacon tea tastes and flavors. Both consumer test and descriptive evaluation preferred yacon tea produced by black tea brewing and fermenting methods because it tasted less bitter and had a sweet, delicate taste. According to orthogonal transformation resulting from varimax rotation, first principal component was positively affected by black tea brewing and fermenting methods, while it was negatively affected by green tea brewing and fermenting methods. As a result, the study concluded black tea brewing and fermenting methods were appropriate for producing yacon leaf tea.

• 동아시아식생활학회지
• /
• 제27권3호
• /
• pp.313-320
• /
• 2017

This study was conducted to investigate the intakes and preferences related to Korean traditional teas in each of the age groups. The survey was conducted from March $9^{th}$ to $23^{rd}$, 2015. The subjects in this study were 642 adults aged more than 20 years that resided in the Seoul and Gyeonggi areas. The health status score was 3.57, and the health concern score was 3.54. The reason for preferring traditional tea was 'health' (40.5%) and 'good taste, color, and aroma' (29.7%). The most important factor in drinking a traditional tea was health (37.1%). Acceptance of each type of traditional tea was ranked in order of 'grain tea', 'fruit tea', 'floral leaf tea', 'assorted tea', 'medical root tea', and 'tonic tea'. A total of 92.8% of respondents said traditional teas should be popularized. Regarding problems for popularization of traditional teas, the most common response was 'not popularized yet' (39.7%). Regarding the method for popularization of traditional teas, the most common response was 'convenience of purchase for ingredients'. As a result, preferences for traditional tea and popularization method were different according to age. It is thus necessary to develop traditional tea products considering the age range.

• 한국식품영양학회지
• /
• 제18권1호
• /
• pp.94-101
• /
• 2005

녹차와 발효 정도에 따른 발효차에 대한 이화학적 특성을 분석한 결과는 다음과 같다. 녹차의 수분함량은 2.04% 이었으며, 각각 발효된 차의 수분함량은 2.01∼2.02%로 나타났고, 총질소 함량은 3.49∼3.5%로 나타났다. 무기질 함량은 Ca, Mg이 가장 높게 나타났으며, Na, K, Al, Fe, Zn, Cu, Ni 등 대부분의 무기질이 홍차에서 가장 높은 함량을 보였다. Vitamin C 함량은 녹차가 670.62 mg으로 169.70∼85.03 mg을 보인 발효차에 비해 높은 함량을 보였다. Vitamin E와 β-carotene 함량은 녹차> 청차> 황차> 홍차 순으로 나타났다. Rutin함량은 녹차가 0.12%, 홍차가 1.37%로 발효가 많이 된 차일수록 함량이 증가되었다. 녹차에는 총 아미노산이 2,270.96 mg이 함유되어 있었으며, 주요 아미노산은 Glu, Asp, Leu로 각각 342.01 mg, 165.32 mg, 161.69 mg이 함유되었고, Glu 함량이 가장 높았다. 발효된 차의 총 아미노산 함량은 홍차가 2,219.08 mg으로 가장 높았고, 청차가 1,963.22 mg, 황차가 1,618.76mg으로 홍차> 청차> 황차 순으로 발효가 가장 많이 된 홍차가 가장 높았다. Caffeine 함량은 녹차 1.17%, 각각의 발효차는 1.15, 1.32, 1.05%로 발효에 따른 함량 변화는 일어나지 않았다. Theanine 함량은 녹차 0.95%, 발효차는 0.73∼l.42%를 나타내었다. 총 Catechin함량은 녹차 12.84%로 가장 높고, 발효를 많이 시킨 차일수록 현저하게 감소하였다. Flavonoid 함량은 녹차가 1.05%로 가장 높은 함량을 나타냈다. 항산화 활성의 지표인 DPPH radical 소거능은 녹차 4.73%, 청차 4.86%, 황차 19.5%, 홍차 8.43%로 나타나 황차가 항산화성이 가장 높은 경향을 보였다.

• 한국식품영양과학회지
• /
• 제34권6호
• /
• pp.869-874
• /
• 2005

녹차 및 발효정도에 따른 약발효차, 중발효차, 홍차 가루를 첨가하여 제조한 식빵의 일반성분, 수분결합력, 무게, 부피, 색도, texture 및 관능검사 측정한 결과는 다음과 같다. 차가루 첨가식빵의 수분함량은 $36.02\~36.44\%$로 대조구 $36.98\%$와 거의 차이가 없었다. 조단백질과 회분 함량은 대조구보다 차첨가구가 높게 나타났다 수분결합력은 녹차 첨가구가 가장 높았고, 발효차 첨가구, 대조구 순으로 높게 나타났다 식빵의 부피와 비용적은 대조구가 가장 높게 나타났고, 발효 차 첨가구, 녹차첨가구 순으로 높게 나타났다. 색도는 대조구에 비하여 발효가 많이 진행된 차가루를 첨가한 식빵일수록 L값은 낮고, a값과 b값은 높게 나타났다. 식빵의 견고성은 발효가 많이 진행된 차가루 첨가구일수록 높게 나타난 반면, 응집성은 발효가 많이 진행된 차가루를 첨가할수록 낮게 나타났다 접착성과 씹힘성은 홍차가루 첨가식빵이 가장 높았다. 관능검사 결과, 색깔, 외관, 질감은 대조구가 가장 높은 기호도를 보였고, 향미와 맛은 녹차 및 약발효차 가루 첨가구의 기호도가 높았으며, 전체적인 기호도는 약발효차 가루 첨가구의 선호도가 가장 높게 나타났다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제19권8호
• /
• pp.1190-1196
• /
• 2006

This experiment was carried out to investigate the effects of Korean, Japanese and Chinese green tea on laying performance and egg quality in hens. A total of 168 "Tetran Brown" hens aged 40 weeks were assigned to 7 treatments in a completely randomized design. Each treatment had 4 replicates accommodating 6 layers per replication. The seven dietary treatments were: 1) control diet with no green tea added, 2) diet containing 1.0% Korean green tea (1.0% KGT), 3) diet containing 2.0% Korean green tea (2.0% KGT), 4) diet containing 1.0% Japanese green tea (1.0% JGT), 5) diet containing 2.0% Japanese green tea (2.0% JGT), 6) diet containing 1.0% Chinese green tea (1.0% CGT), and 7) diet containing 2.0% Chinese green tea (2.0% CGT). Egg production rate of the layers fed diets containing 1.0 or 2.0% green tea powders were significantly increased compared to that of the control (p<0.05). The egg weight of layers was significantly reduced in layers fed 1.0% CGT (p<0.05). The feed intake was significantly decreased in KGT and CGT groups at 2.0% inclusion levels (p<0.05). The egg shell thickness and shape index of JGT treatment was significantly lower than that of the control (p<0.05). There were no significant differences in albumen index, yolk index and Haugh unit of eggs for layers fed diets containing green tea powders regardless of origin (p>0.05). Green tea feeding to layers tended to reduce the overall cholesterol content of egg yolk. Particularly, 1.0 or 2.0% CGT significantly depressed the total cholesterol content of egg yolk (p<0.05). In conclusion, incorporation of 1.0 or 2.0% Korean, Japanese and Chinese green tea into layer diets regardless of origin had favorable effects on laying performance and egg quality profiles. Among the three green tea sources, the Chinese green tea powder had the highest reducing effect on cholesterol content in egg yolk.

• Journal of Biosystems Engineering
• /
• 제41권4호
• /
• pp.365-372
• /
• 2016

Purpose: Tea is the most frequently consumed drink worldwide, next to water. About 75% of the total world tea production includes black tea, and withering is one of the major processing steps critical for the quality of black tea. There are two types of tea withering methods: physical and chemical withering. Withering can be achieved by using tat, tunnel, drum, and trough withering systems. Of these, the trough withering system is the most commonly used. This study focuses on the different types of withering, their effect on the various quality attributes of tea, and other aspects of withering methods that affect superior quality tea. Results: During physical withering, tea shoots loose moisture content that drops from approximately 70-80% to 60-70% (wet basis). This leads to increased sap concentration in tea leaf cells, and turgid leaves become flaccid. It also prevents tea shoots from damage during maceration or rolling. During chemical withering, complex chemical compounds break down into simpler ones volatile flavor compounds, amino acids, and simple sugars are formed. Withering increases enzymatic activities as well as the concentration of caffeine. Research indicates that about 15% of chlorophyll degradation occurs during withering. It is also reported that during withering lipids break down into simpler compounds and catechin levels decrease. Improper withering can cause adverse effects on subsequent manufacturing operations, such as maceration, rolling, fermentation, drying, and tea storage. Conclusion: Freshly harvested leaves are conditioned physically and chemically for subsequent processing. There is no specified withering duration, but 14-18 h is generally considered the optimum period. Proper and even withering of tea shoots greatly depends on the standards of plucking, handling, transportation, environmental conditions, time, and temperature. Thus, to ensure consumption of high quality tea, the withering step must be monitored carefully.

• 한국식품영양학회지
• /
• 제37권2호
• /
• pp.100-109
• /
• 2024

This study examined the quality characteristics and antioxidant properties of sword bean tea available in domestic markets. Each product of sword bean tea had distinct appearance characteristics. The color, pH, brownness, and turbidity of the tea varied significantly across different products, with tea bags showing higher levels of brownness and turbidity. The total polyphenol content of hot water extraction ranged from 165.13 to 517.69 mg gallic acid equivalents (GAE)/100 g sample for pod tea, 999.36 to 2,054.74 mg GAE/100 g sample for tea bag tea, and 74.62 to 275.00 mg GAE/100 g sample for grain tea, respectively. Similarly, the total flavonoid content, measured in terms of catechin equivalents (CE), ranged from 39.51 to 65.00 mg CE/100 g sample for pod tea, 86.57 to 253.63 mg CE/100 g sample for tea bag tea, and 32.94 to 38.63 mg CE/100 g sample for grain tea, for hot water extraction. The DPPH and ABTS radical scavenging activities of pod tea were 95.68 to 276.19 mg TE/100 g sample and 270.87 to 804.21 mg trolox equivalents/100 g sample, respectively, for hot water extraction. These results suggest the need to establish quality standards to ensure consistent quality of sword bean tea.

• 산업기술연구
• /
• 제31권B호
• /
• pp.113-117
• /
• 2011

The purpose of this study is to determine the antimicrobial effect of tea tree oil a against pathogens relate to acne. Tea tree oil extracted from Australian Melaleuca alterifolia has been studied extensively for their antimicrobial properties against different type of bacteria and fungi. Tea tree oil has been reported to have antibacterial, antiinflammatory and antitumor activities, among others. By evaluating the antibacterial effect of Tea Tree Oil of Australia, the MIC value of Tea Tree oil against P. acnes was 0.05% and 0.5% against aerobic bacteria. This study showed that Tea Tree Oil has antibacterial effect against bacteria which induce acne. Tea Tree Oil had better antibacterial effect against P. acnes compared to aerobic bacteria. It is promising to develop a nature-based functional material for makeup product, which can cure and prevent acne.

• 생명과학회지
• /
• 제7권4호
• /
• pp.309-315
• /
• 1997

The fermented black tea with tea fungus (FBTF) was prepared by culturing tea fungus biomass in black tea with 10% sucrose (BT) at 30$\circ$ for 14 days. The flavor quality of FBTF was investigated by sensory and chemical analysis, and the results were compared with BT. The data of sensory analysis indicated that fruity, wine-like, sharp-pungent, and vinegar-like flavor notes were increase, while earthy note was reduced during fermentation. GC-MS analysis of volatile compounds collected from FBTF and BT by Tenax trap showed that linalool, liinalool oxide other flavor compounds known as black tea flavor compounds were disappeared. Some major flavor compounds produced during fermentation were acetic acid, ethanol, limonene, $\alpha$-terpineol, and these volatiles may be attributed to the flavor of characteristic FBTF. Biosynthetic pathway for the formation of limonene and $\alpha$-terpineol are proposed through mevalonic acid pathway using acetic acid as precusor and/or through transformation of linalool and linalool oxide.

• 대한소아치과학회지
• /
• 제44권4호
• /
• pp.437-445
• /
• 2017

이 연구의 목적은 한국인들이 일상적으로 마시는 서로 다른 네 종류의 차 티백을 이용하여 차가운 생수나 뜨거운 생수로 5분 또는 10분 동안 우려내는 일상적인 방법으로 차를 추출하였을 때 각각의 추출물이 Streptococcus mutans 세균막 성장에 미치는 효과를 알아보고자 하였다. 균주는 S. mutans UA 159를 이용하였고 1%의 sucrose와 각각의 차 추출물을 웰 플레이트에 넣고 배양하였다. 추출 온도에 따른 세균막 형성을 비교 했을 때 녹차와 홍차에서 추출 온도가 높을 때 세균막 형성이 적었고 통계적으로 유의하였다(p < 0.05). 추출 시간을 달리 하고 $72^{\circ}C$ 온수로 많은 양을 추출 했을 경우 세균막 형성을 비교 했을 때는 네 종류 차 모두 추출 시간에 대해서 통계적으로 유의하지 않았다. 한편 추출량에 따른 비교에서는 녹차와 홍차의 경우 같은 시간, 같은 온도로 추출하였을 때 추출량이 적다면 오히려 세균막 성장이 증가하였다.