• The Korean Journal of Food And Nutrition
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• v.25 no.2
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• pp.317-323
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• 2012

We investigated the quality characteristics of cookies prepared after the addition of various concentration of used guava leaf powder(0%, 1%, 3%, 5%, all w/w) as a substitute for flour. In this study, as guava leaf powder concentration rose, there was a decrease in the water content level. In addition, color, spread factor, hardness and sensory evaluation of the cookies were examined. The results showed that with an increase in guava leaf powder concentration, the L value decreased significantly, while the values for a and b of cookies increased when more guava leaf power was added to cookies. The spread factor of cookies decreased, but the hardness of cookies increased significantly, as guava leaf powder concentration increased. Cookies containing 0% and 3% of guava leaf powder showed a similar sensory evaluation score in terms of color, taste and flavor of the cookies. In the case of texture and overall consumer acceptability, cookies with 3% of guava leaf powder showed the highest score.

• Culinary science and hospitality research
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• v.19 no.4
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• pp.1-12
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• 2013

The purpose of this study was to find the effects of guava leaf powder as a natural tenderizing ingredient for low-fat pork seasoned with meat sauce, and to promote a consumer demand and practical use of low-fat pork. Moisture content, pH, color, texture, and sensory tests (quantitative descriptive sensory evaluations and acceptance) were conducted to the control and 5 samples of pork seasoned with 0.75, 1, 1.5, 2, 3% guava leaf powder) to determine the highest effectiveness on tenderizing pork. Moisture content and pH values were the highest in the samples with 1% and 1.5% of guava leaf powder added. L-value of cooked meat decreased, while a-value increased. In the texture test, most of the experiments showed the best values in the sample with 1.5% added. Based on quantitative descriptive sensory evaluations, the unpleasant smell of meat tended to decrease with more guava leaf powder, and the scores of the others were highest in the sample with 1.5% added. This sample also got the highest score in the acceptance test. These results can be used as primary data for research on the tenderizing effect of a functional ingredient and solutions to unbalanced consumption of pork.

• Fashion & Textile Research Journal
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• v.13 no.5
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• pp.778-789
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• 2011

The natural dyeing of silk fabrics with guava leaf extract was investigated. Mixed components of flavonoid and tannin seem to be the components of guava leaf extract. The temperature and time for dyeing of silk fabrics with guava leaf extract were $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. The dyeing equilibrium was shown at the fourth time of repeated dyeing. The highest K/S value was recorded at pH 3. Fe-mordanted fabrics showed the highest K/S value. High K/S values were shown in the post-mordanting of dyed fabrics at $40^{\circ}C$ and the pre-mordanting of dyed fabrics at $90^{\circ}C$. After repeated dyeing and mordanting, various color change occurred with mordant treatment. Surface colors were changed to YR color in alkaline water extract and to Y color in acidic water and ethanol extract, respectively. The washing fastness was level 3-4 for Sn-mordanted fabrics and level 4 for Fe-mordanted fabrics, and the dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness was satisfactory with level 3-4. The light fastness was above level 4 only when Fe-mordanting was conducted, and the rest of dyed fabrics was not fast enough. In the antibacterial activity, the powder of guva leaf extract showed 99.9% of high antibacterial activity and Staphylococcus aureus showed 99.6% in dyed fabric. All dyed fabrics showed higher deodorization and UV protection rate than control fabric.

• Fashion & Textile Research Journal
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• v.14 no.2
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• pp.320-330
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• 2012

The natural dyeing of cotton fabrics with guava leaf extract was investigated. The temperature and time of dyeing are $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. In addition, the dyebath has been set at pH 5. Sn pre-mordanted fabrics showed the highest K/S value. Regardless of dyeing temperature, K/S values were high when Al, Cu, Fe-mordanted fabrics were dyed in post-mordanting and Sn-mordanted fabrics were dyed in pre-mordanting. The K/S value of dyeing fabrics could be increased with repetitive dyeing and mordanting. Compared to untreated dyed fabrics, the K/ S values of fabrics which had been treated with soybean milk, chitosan and gall nut tannin were increased. The changed surface colors of fabrics that were treated with soybean milk, chitosan and gall nut tannin were Y, YR and achromatic colors. Fabrics dyed with alkaline water extract showed reddish color. Sn-mordanted fabrics dyed with acidic water extract showed vivid yellowish color, and Cu-mordanted fabrics dyed with ethanol extract showed yellowish green color. In case of Sn-mordanted fabrics, the washing fastness was level 4. The dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness was better in dry rubbing than in wet rubbing of the fabrics. For the light fastness, all dyed fabrics showed low fastness. For antibacterial activity, the powder of guava leaf extract and the dyed fabrics with guava leaf extract showed 99.9% of high antibacterial activity. All dyed fabrics showed higher deodorization and UV protection rate than control fabric.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.5
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• pp.585-592
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• 2012

This study was to investigate the quality characteristics and microbiological of simple preprocessed foods vege-ball with guava leaf powder (VB) for soup during storage at $4^{\circ}C$ and preparation of standard recipe. Lightness was increased during storage, but yellowness and redness were no significantly differences during storage, except for control. Hardness of VB increased with increasing guava leaves powder springness, cohesiveness significantly as a powder addition guava leaves was lower. DPPH, ABTS compared to the control showed higher levels in VB with increasing amounts significantly increased antioxidant activity (p<0.05). According to the sensory evaluation, VB 0.1% showed higher score in term of taste, flavor, overall preference. All the VB samples showed significantly lower values for acid, peroxide and than the control. Low level of total aerobic bacteria was detected during storage (<5.00 log CFU/g). Coliforms and yeast & mold were not detected during storage in VB samples. In conclusion, the addition of 0.1% with guava leaves powder would be useful way to enhance the anitoxidant quality and sensory characteristics of preprocessed food. The estimated storage was 8 days at $4^{\circ}C$.