• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.886-895
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• 2013

This study was conducted to explore the antioxidant potential and functional value of guava (Psidium guajava L.) powder in muscle foods. Guava powder was used as a source of antioxidant dietary fibre in sheep meat nuggets at two different levels i.e., 0.5% (Treatment I) and 1.0% (Treatment II) and its effect was evaluated against control. Guava powder is rich in dietary fibre (43.21%), phenolics (44.04 mg GAE/g) and possesses good radical scavenging activity as well as reducing power. Incorporation of guava powder resulted in significant decrease (p<0.05) in pH of emulsion and nuggets, emulsion stability, cooking yield and moisture content of nuggets while ash and moisture content of emulsion were increased. Total phenolics, total dietary fibre (TDF) and ash content significantly increased (p<0.05) in nuggets with added guava powder. Product redness value was significantly improved (p<0.05) due to guava powder. Textural properties did not differ significantly except, springiness and shear force values. Guava powder was found to retard lipid peroxidation of cooked sheep meat nuggets as measured by TBARS number during refrigerated storage. Guava powder did not affect sensory characteristics of the products and can be used as source of antioxidant dietary fibre in meat foods.

• 한국식품영양학회지
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• 제25권2호
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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.

• 한국식품조리과학회지
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• 제26권2호
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• pp.171-179
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• 2010

The objectives of this study were to investigate the antioxidative activity of crackers made with a guava(Psidium guajava Linn.) leaf extract harvested in Korea. Guava leaf extraction using boiling water showed significantly higher antioxidative activities than extracting using 70% ethanol based on the higher total phenolic contents, FRAP, and ABTS assays(p<0.05). The crackers containing 1% guava leaf extract, and 0.075% BHT were stored at $63^{\circ}C$ for 7 days for the Schaal oven test, and the oxidative stability(AV, POV), antioxidative activity(DPPH, FRAP, ABTS assay), and sensory evaluation were compared. The crackers containing 1% guava leaf extract were found to have a higher oxidative stability than the control due to a lower acid value and peroxide value after 7 days of storage. The antioxidative activities of the crackers containing 1% guava leaf extract was the highest after 7 days as determined in the DPPH and ABTS assay, and was lower than crackers containing 0.075% BHT after 4 days as assessed by the FRAP assay. In the sensory evaluation, the crackers containing the 1% guava leaf extract had the highest scores in terms of taste, texture, and overall palatability than others at increasing storage time. As a result, the addition of 1% guava leaf extract harvested in Korea increased the antioxidative effect as well as the sensory acceptability of crackers.

• 한국식품저장유통학회지
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• 제14권6호
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• pp.605-610
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• 2007

구아바 잎을 이용한 가공제품개발의 기초자료를 마련하고자 구아바 잎을 발효, 증숙 및 볶음 처리하여 품질특성을 살펴보았다. 그 결과 총 페놀성 화합물 함량의 경우 볶음 처리한 것이 높게 나타났으며, tyrosinase 저해활성 및 전자공여능은 증숙 처리한 것이 우수한 것으로 나타났다. 또한 전반적인 기호도에 있어서는 발효 및 증숙 처리한 것이 우수한 것으로 나타났다. 한편 데침 및 증숙 처리 시간에 따른 품질특성을 살펴본 결과, 총 페놀성 화합물 함량, tyrosinase 저해활성 및 전자공여능은 처리시간이 길어질수록 전반적으로 감소하는 경향이었으며, 증숙 처리한 것이 데침 처리한 것에 비해 우수한 것으로 나타났다. 데침 및 증숙 처리된 구아바 잎의 관능검사 결과, 통계적으로 유의적인 차이가 없었으나, 구아바 잎의 떫은맛으로 인해 전반적으로 관능평점이 낮게 나타났다. 따라서 구아바 잎을 사용한 가공제품 개발에서는 떫은맛을 감소시킬 수 있는 방안의 연구가 필요한 것으로 나타났다.

• 한국식품영양과학회지
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• 제38권12호
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• pp.1773-1778
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• 2009

본 연구는 인공합성보존료를 대체할 수 있는 천연보존료의 개발을 위한 방안으로 대표적인 세균성 식중독 미생물로서 그람 음성균인 Escherichia coli O157:H7과 Salmonella Typhimurium, 그리고 그람 양성균인 Staphylococcus aureus와 Listeria monocytogenes에 대한 항균 특성을 조사하였다. 구아바 가지와 잎의 메탄올과 에탄올 추출물 S. aureus의 생육을 저해하였으며, 아울러 가지와 잎의 아세톤 추출물은 200 ppm 농도의 첨가에서 식중독 원인균 S. aureus균을 전혀 자라지 못하는 결과를 확인하였다. 이러한 결과는 구아바 잎과 가지의 추출물에 그람 양성균에 대한 높은 항균활성이 있음을 의미하며, 구아바 가지를 항균력을 가지는 소재로 이용될 수 있음을 시사한다.

• 한국조리학회지
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• 제19권3호
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• pp.248-258
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• 2013

본 연구에서는 쌀가루에 구아바 분말을 0%, 10%, 20%, 30%를 첨가하여 쿠키로 제조한 후 품질특성을 살펴보았다. 구아바 분말을 첨가한 쌀 쿠키의 수분함량은 $5.90{\pm}0.12{\sim}6.02{\pm}0.13$이었다. 구아바 분말을 첨가한 쌀 쿠키의 L 값과 b 값은 구아바 분말 첨가량이 증가함에 따라 유의적으로 감소하는 경향을 보였다(p<0.05). 구아바 분말을 첨가한 쌀 쿠키의 경우 구아바 분말의 첨가량이 증가할수록 퍼짐성은 작아지고 구아바 분말 쌀 쿠키의 경도는 유의적으로 증가하는 경향을 보였다(p<0.05). 구아바 분말을 첨가하지 않은 대조구보다 색(color), 맛(taste), 향(flavor), 조직감(texture), 전체적인 기호도(overall acceptability), Top grain score에 있어서 구아바 분말 20% 첨가구가 전반적으로 높게 평가되어 구아바 분말을 첨가한 쌀 쿠키 제조 시 구아바 분말 20%를 첨가하는 것이 가장 바람직할 것으로 사료된다.

• 한국식생활문화학회지
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• 제36권2호
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• pp.210-217
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• 2021

This study evaluated the biological activity and cytoprotective effect of guava (Psidium guajava L.) branch against oxidative stress. The contents of vitamin C, beta-carotene, total carotenoids, quercetin and catechin determined were 26.783, 43.676, 65.083, 58.245, and 8.309 mg/100 g, respectively. To measure antioxidant activity, the guava branch was extracted using various concentrations of ethanol (60, 80, or 100%) and water. The highest content of polyphenols (0.245 mg gallic acid equivalent/mg residue) and flavonoids (0.128 mg cathechin equivalent/mg residue) was found in the 100% ethanol extract of the branch (E100). Moreover, E100 also possessed the highest radical scavenging activities and showed the highest inhibition rate of α-glucosidase (77.692%). E100 was the most effective extract to impart cytoprotectant activity against oxidative stress in HepG2 cells. Taken together, our results determine the promising antioxidant activity of guava branch, and indicate the potential to be applied as a natural antioxidant.

• 한국의류산업학회지
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• 제13권5호
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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.

• 한국약용작물학회지
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• 제20권2호
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• pp.94-100
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• 2012

Guava ($Psidium$ $guajava$) contain a great deal of polyphenol compound and work on the treatment of $Diabetes$ $mellitus$ effectively. In this study, the bioactivities of aqueous extract (GLEx) of guava leaf were investigated. Total phenolic contents of GLEx was 266.9 mg tan/g. The effects of GLEx on digestive enzymes, ${\alpha}$-amylase, maltase and sucrase were investigated. $IC_{50}$ values of GLEx against ${\alpha}$-amylase, maltase and sucrase were 0.65 mg/$m{\ell}$, 2.0 mg/$m{\ell}$ and 3.5 mg/$m{\ell}$ respectively. The effect of GLEx on oral glucose tolerance test (OGTT) was performed in normal ICR mouse, control (dstilled water) and GLEx (aqueous extract of Guava leaf) were co-administered orally with glucose, showed reducing effect on the blood glucose level. The guava is likely to useful for prevention or improvement of hyperglycemia by lowering the blood glucose level and inhibiting glycoside hydrolase activity.

• 한국식품영양학회지
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• 제32권1호
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• pp.33-40
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• 2019

The purpose of this study was to evaluate the antioxidant and hepatocyte protective effects of guava (Psidium guajava L.) leaves cultivated in Korea. The contents of the total polyphenol of the extract was 271.57 mg gallic acid equivalent (GAE)/g residue. Antioxidant activities of leaf extract were evaluated by examining the free radical scavenging ability. 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ${\alpha}-{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) free radical scavenging activities of the extract were 1133.23 mg trolox equivalent antioxidant capacity (TEAC)/g residue and 721.68 mg TEAC/g residue, respectively. The hepatocyte protective effect of guava leaf extract was examined in HepG2 cells. Against tert-butyl hydroperoxide (TBHP), the viability of HepG2 cells were increased by the treatment of leaf extract. In addition, guava leaf extract led to the inhibition of reactive oxygen species (ROS) generated in HepG2 cells. The leaf extract increased the activity of glutathione (GSH), glutathione reductase (GR), and glutathione peroxidase (GPx) against oxidative stress. These results suggested that guava leaves might be regarded as a potential source natural antioxidant and a hepatoprotective material.