Ascorbic Acid Equivalent Antioxidant Capacity Research Articles

Lectin from seeds of a Brazilian lima bean variety (Phaseolus lunatus L. var. cascavel) presents antioxidant, antitumour and gastroprotective activities

Lectins are proteins able to interact specifically and reversibly with carbohydrates. They are present in all living beings, particularly in legume seeds, which have many biological functions. The aim of this study was to isolate, characterize and verify antioxidant, anti-hemolytic, antitumor and gastroprotective activities in a lectin present in seeds of Phaseolus lunatus L. var. cascavel (PLUN). The isolation of lectin was performed by size exclusion chromatography on Sephadex G-100, which was isolated from a protein capable of agglutinating only human erythrocytes type A, being this the only inhibited haemagglutination n-acetyl-d-galactosamine. Its weight was estimated by PAGE is 128kDa. The lectin is thermostable up to 80°C and is active between pH 2–11. As 8M urea was able to denature the lectin. PLUN is a glycoprotein consisting of 2% carbohydrate and has antioxidant action with ascorbic acid equivalent antioxidant capacity (μMAA/g) of 418.20, 326 and 82.9 for total antioxidant activity, ABTS radical capture and capture of DPPH radical, respectively. The lectin has antitumor activity against melanoma derived cells at doses of 100 and 50mg/ml, reducing up to 83% tumor cells, and gastroprotective action, reducing up to 63% damaged area of ​​the stomach induced by ethanol.

Antioxidant properties of selected fruit cultivars grown in Sri Lanka

Extracts of twenty locally available Sri Lankan fruits were analysed for 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferrous reducing antioxidant power (FRAP), total phenolic content (TPC), total flavonoid content (TFC) and vitamin C content. The results showed that gooseberry (Phyllanthus emblica ‘local’) exhibited the highest DPPH scavenging activity (111.25mg ascorbic acid equivalent antioxidant capacity (AEAC)/g), FRAP (1022.05μmol FeSO4/g), TPC (915.7mg gallic acid equivalents (GAE)/100g), TFC (873.2mg catechin equivalents (CE)/100g) and vitamin C (136.8mg ascorbic acid equivalents (AAE)/100g), respectively. Sugar apple (Annona squamosa ‘local’) and star fruit (Averrhoa carambola ‘Honey Sweet’) obtained the second and third highest antioxidant activities in terms of rankings of FRAP, DPPH activities, TPC, TFC and vitamin C content. Strong correlation between vitamin C, TPC and TFC with FRAP and DPPH showed their contribution to antioxidant capacity. Among the selected fruits, underutilized fruit cultivar gooseberry showed the highest overall antioxidant potential.

ANTI-OXIDATIVE POTENTIAL OF HONEY AND ASCORBIC ACID IN YOGHURT FORTIFIED WITH OMEGA-3 FATTY ACIDS

Processing of Nile perch (Lates niloticus), a commercial fish in Eastern Africa; results in omega-3 polyunsaturated fatty acids (PUFA) rich by-products. Oil derived from such by-products can be incorporated in commonly consumed foods; however, these fatty acids are highly susceptible to oxidation. Honey and ascorbic acid are natural anti-oxidants that could play a role in preventing lipid oxidation. In the current study, omega-3 rich oil was extracted from L. niloticus viscera and added to yoghurt samples. The aim of the study was to investigate the biochemical and anti-oxidative parameters in honey and lemon juice and use them as antioxidants in the fortified yoghurt samples. Stability of the fortified yoghurt was monitored over one month storage period. Ascorbic acid Equivalent Antioxidant Capacity (AEAC) of lemon juice and honey were 312 ± 2.34 and 197 ± 3.65 mg/L, respectively. The DPPH radical scavenging activity showed that honey (86.16± 1.43%) tended to be highly active in the reaction with DPPH compared to lemon juice (71.29± 3.52%).After four weeks of storage, the peroxide value (PV), anisidine value (AV) and (free fatty acid) (FFA) contents were within the acceptable range with the honey fortified sample being most stable. The ascorbic acid content was highest in lemon juice fortified samples (30 mg/100g) while in honey fortified samples were below 1mg/100g. The pH in all the samples decreased slightly over time. Honey and lemon juice are therefore good natural anti-oxidants and their anti-oxidative potential can be utilized in the prevention of lipid oxidation in omega-3 fortified yoghurts.

Antimicrobial and antioxidant activities of three Euphorbia species

Three toxic plants belonging to Euphorbia genus, namely Euphorbia biumbellata, Euphorbia terracina and Euphorbia dendroides were phytochemically screened and their total phenolic compounds (TPC) and total flavonoid compounds (TFC) were measured and antioxidant capacities were evaluated by DPPH test expressed by Vitamin C Equivalent Antioxidant Capacity (VCEAC). The VCEAC values for the three medicinal plants ranged from 1.0655 g to 0.7285 g of vitamin C equivalents (VCEAC)/100 g of dry matter. The concentrations of TPC and TFC in three plants were respectively 15.13 g to 7.55g of gallic acid equivalents (GAE)/100 g of dry matter and 7.06 g to 5.8 g of quercetin equivalents (QE)/100 g of dry matter. The methanolic extracts of these plants were used to determine their antibacterial activity with the disc diffusion method. The results showed that the three plants were active with the inhibition zones obtained varying from 8 to 22 mm. The highest inhibition zones reached was 22 mm for Euphorbia biumbellata leaves against Staphylococcus aureus. Phytochemical analysis of the total extract showed the presence of biologically active compound groups such as polyphenols, flavonoids, glycosides and tannins.

Study of antioxidant capacity of different parts of two south Algerian eggplant cultivars

In this study the antioxidant capacity of ethanolic EE and water WE extracts from different parts (calyx, peel, and pulp) of eggplant (Solanum melongena L) were evaluated using cyclic voltammetry. The antioxidant capacity of different parts of eggplant was measured using ascorbic acid equivalent antioxidant capacity assays. The peel extracts of both dark purple and white samples showed the highest antioxidant capacity (66.78 and 75.62 mg/g) followed by pulp (16.54 and 30.56 mg/g), and calyx (14.82 and 21.27 mg/g). These results indicate that antioxidant capacity of eggplant varied by parts and solvents.Keywords: Eggplant, Solanum melongena L, antioxidant capacity, cyclic voltammtry, ascorbic acid.

Characteristics of the Thermal Degradation of Glucose and Maltose Solutions.

In order to investigate the thermal degradation of glucose and maltose solutions after high temperature and high pressure (HTHP) treatment, the samples were treated at temperatures of 110, 120, 130, 140, and 150°C for 1, 2, 3, 4, and 5 h in an apparatus for HTHP treatment. Glucose and maltose solutions (20% w/w) were prepared by weighing glucose and maltose and adding distilled water in the desired proportion. Chromaticity, pH, organic acids, 5-hydroxymethylfurfural (HMF), free sugar contents, electron donating ability (EDA), and ascorbic acid equivalent antioxidant capacity (AEAC) were evaluated. With increasing heating temperatures and times, the L-, a-, and b-values decreased. The pH and free sugar contents decreased, and organic acids and HMF contents increased with greater temperatures and times. EDA (%) and the AEAC of the heating sugars increased with the increases in temperatures and times.

Antioxidant capacity and vitamin E in barley: Effect of genotype and storage

Antioxidants, including vitamin E, may have a positive effect on human health and prolong storage of food items. Vitamin E content and antioxidant capacity were measured in 25 barley genotypes before and after 4months storage at 10°C using high performance liquid chromatography (HPLC) and ability to scavenge DPPH radicals, respectively. As expected, α-tocotrienol (α-T3) and α-tocopherol (α-T) were the predominant tocol isomers. Vitamin E content and antioxidant capacity varied significantly among genotypes. Vitamin E ranged from 8.5 to 31.5μg/g dry weight (DW) while ascorbic acid equivalent antioxidant capacity (AEAC) varied from 57.2 to 158.1mg AEAC/100g fresh weight (FW). Generally, lower vitamin E content or antioxidant capacity was observed in hulless or coloured genotypes. These results suggest that some genotypes are potential candidates for breeding of barley cultivars with high vitamin E content or antioxidant capacity at harvest, even after storage.

Microbial bioconversion and processing methods enhance the phenolic acid and flavonoids and the radical scavenging capacity of Smilax china L. leaf.

It has been reported that Smilax china L. leaf (SCL) provided various biological functions owing to polyphenols. The objective of the current study was to assess the enhancing effect of processing methods and microbial conversions on phenolic acid and flavonoid content and radical scavenging capacity of SCL for potential applications of diverse food products. Targeted phenolic acid (chlorogenic acid) and flavonoids (piceid and quercetin) were identified in fresh SCL using liquid chromatography-mass spectrometry. The total amount of identified phenolic acid and flavonoids was highest in steamed SCL (12.70 ± 0.12 mg g(-1) on a dry matter basis, dmb). A substantial amount of chlorogenic acid (5.81 ± 0.16 mg g(-1) dmb), piceid (3.96 ± 0.04 mg g(-1) dmb) and quercetin (6.06 ± 0.12 mg g(-1) dmb) were quantified in SCL fermented by Bacillus species, roasted and steamed, respectively (P < 0.05). The oxygen radical absorbance capacity (ORAC) value was greater in microbial fermented SCL than in others, with the exception of Saccharomyces cerevisiae and Aspergillus oryzae. However, vitamin C equivalent antioxidant capacity (VCEAC) was highest in SCL fermented by Aspergillus oryzae. Results from our study suggest that the microbial fermentation processing method could improve accessibility to extraction of phenolic acids and flavonoid content and radical scavenging capacity.

Determination of Caffeine Content and Antioxidant Activity of Coffee

Attempt has been made to look into caffeine contents and antioxidant activity of coffee grown at Wembera, Goncha, Zegie, and Burie localities of North-West Ethiopia. The caffeine content of the extracts in % w/w has been found to be 1.53 ± 0.003 for Wembera coffee, 1.41 ± 0.040 for Goncha coffee, 1.29 ± 0.033 for Zegie coffee and 0.97 ± 0.049 for Burie coffee. The antioxidant activities of the coffee extracts were measured by using ferric reducing power assay and Rancimat assay. Ferric reducing power assay was used to measure the total antioxidant power of water soluble components of coffee and is expressed as ascorbic acid equivalent antioxidant capacity in milligram per gram of the dried coffee samples. The ferric reducing power values of the extracts were 9.532 ± 0.201, 9.159 ± 0.441, 8.955 ± 0.180, 6.751 ± 0.284 for Wembera, Burie, Goncha and Zegie coffees, respectively. The Rancimat assay was also used to measure antioxidant activity of lipid soluble portions of coffee extracts using sunflower oil as the oxidizable substrate. It was found that all the coffee extracts improved the oxidative stability of sunflower oil. The protection factors were 1.36 ± 0.027, 1.31 ± 0.027, 1.26 ± 0.069 and 1.17 ± 0.015 for Wembera, Burie, Goncha and Zegie coffees respectively. Based on these results, it is suggested that Wembera coffee has the higher caffeine content and antioxidant activities than Burie, Goncha and Zegie coffee varieties.

English

Pseuderanthemum palatiferum (Nees) Radlk. has been used extensively as a medicinal plant for the treatment of diabetes mellitus in various parts of Southeast Asia. However, the mechanism of its anti-diabetic action has not been fully characterized yet. The objectives of this study were to investigate the in vitro effects of P. palatiferum leaf ethanolic extract (PPE extract) on adipocyte lipolysis, α-amylase enzyme activity and antioxidant activity. The PPE extract at every concentration tested (10, 25, 50, 100, 250, 500 µg/ml) caused a significant inhibition on basal lipolysis in adipocytes of the high fat diet-fed rats. The PPE extract also produced a concentration-dependent anti-lipolytic action against isoprenaline (0.1 µM)-induced lipolysis in the normal pellet diet-fed rat derived adipocytes. Inhibition of α-amylase was detected using the 3,5-dinitrosalicylic acid assay, the PPE extract having an IC50 of 4.99 mg/ml. An antioxidant activity, as evaluated by the DPPH assay (IC50), was 58.13 µg/ml. In the ferric reducing power assay, the extract exerted antioxidant activity with a vitamin C equivalent antioxidant capacity (VCEAC) and a trolox equivalent antioxidant capacity (TEAC) of 2.33 and 2.04 g/100 g extract, respectively. The anti-lipolytic, α-amylase inhibitory and antioxidant activities of PPE extract detected here help justify the traditional use of this plant in the treatment of diabetes mellitus. Key words: Pseuderanthemum palatiferum, diabetes mellitus, adipocyte lipolysis, α-amylase, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, ferric reducing power assay.

미국 고추케찹 및 국내산 고추케찹의 생리활성 성분 및 관능특성 분석

미국인이 즐겨먹는 기능성 고추케찹과 한국산 고추케찹의 생리활성 특성을 비교하고, 한국산 고추케찹의 외국인 관능평가를 진행하여 고추케찹의 특성과의 상관관계를 분석하여 고부가 가치 고추가공품의 기초자료를 마련하고자 연구를 진행하였다. 미국산 고추케찹 4종과 한국산 고추케찹의 총당, 염도, 당도의 이화학적 분석과 ASTA 값, 총 캡사이시노이드, 총 카로티노이드, 총 페놀, 총 항산화력의 생리활성 성분을 분석하고, 관능평가를 실시하였다. 한국산 고추케찹은 미국 고추케찹보다 생리활성 성분이 모두 높게 나타났으며, 관능평가 결과, 미국 고추케찹에 비하여 단맛과 짠맛이 약하고, 종합적 기호도가 높은 것으로 평가되었다. 생리활성 성분과 관능평가 결과의 상관관계 분석을 통하여 ASTA 값, 총 캡사이시노이드, 총 카로티노이드 함량과는 통계적으로 서로 양(positive)의 상관관계를 갖는 것으로 분석되었고, 이 3가지 생리활성 성분은 종합적 기호도와 높은 상관관계가 있는 것으로 나타났다. The purpose of this study is to analyze the Korean chili (Capsicum annuum L.) ketchup and American chili ketchup for their comparative bioactive components and then conduct a sensory evaluation. American chili ketchups are collected from Americans' local favorites, and then the American chili ketchups and Korean chili ketchups are analyzed based on their physiological compositions. Bioactive analysis of the Korean chili ketchups show : total capsaicinoids of <TEX>$2.59{\pm}1.00mg/100g$</TEX>, total carotenoids of <TEX>$33.28{\pm}1.52mg/100g$</TEX>, total phenol of <TEX>$61.17{\pm}8.08mg/GAE/100g$</TEX>, and vitamin C equivalent antioxidant capacity (VCEAC) of <TEX>$187.04{\pm}3.22mg/100g$</TEX>. The Korean chili ketchups show higher overall acceptability when being compared to Americans' local favorite chili ketchups. In the sensory evaluation, there are significant differences (p<0.05) in sour, sweet, hot, salty taste, and the overall acceptability in two groups.

Evaluation of Phenolic Content and Antioxidant Property of &amp;lt;i&amp;gt;Crossandra infundibuliformis&amp;lt;/i&amp;gt; Leaves Extracts

The present study was aimed to investigate the phenolic content and antioxidant property of Crossandra infundibuliformis leaves. Shade dried leaves were successively extracted and determined phenolic and flavonol content of the extracts. Six different in vitro antioxidant assays such as 1, 1’-diphenyl-2-picrylhydrazyl (DPPH), lipid peroxidation (LPO), nitric oxide, hydrogen peroxide radical scavenging, reducing power of the extracts and total antioxidant capacity (values were expressed as mg ascorbic acid (vitamin C) equivalent antioxidant capacity per gram of extracts) assays were followed to determine the antioxidant capacity of the extracts. The results of this study indicated that methanol extract possess higher level of phenolic (98.52 mg of gallic acid/g of extract) and flavonol (84.59 mg of rutin/g of extract) constituents. The antioxidant property of ethyl acetate extract was significantly higher than other extracts in DPPH method. Moreover, methanol extract has significantly higher antioxidant activity in LPO inhibition (IC50 value of 70.66 μg/ml), hydrogen peroxide (IC50 value 130.33 μg/ml) and reducing capacity of the extract (1.19) than other chloroform and ethyl acetate extracts. The strong correlation was observed for phenolic content and antioxidant activities of the extracts ensuring the involvement of phenols in antioxidant activity. However, results suggests that Crossandra infundibuliformis leaves possess antioxidant activity.

Antioxidant activity and polyphenol content of methanol extracts from Arisarum vulgare

Arisarum vulgare is generally known as a toxic plant but it has some medicinal uses. The plant collected from National Park of El-Kala (north-east of Algeria), is phytochemically screened [1], and the total phenolic [2] and flavonoids [3] compounds were measured for its methanolic extract. In addition, the antioxidant capacity of the methanolic extract of this plant is evaluated by ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic)) and DPPH (2,2-diphenyl-1-picrylhydrazyl) tests expressed by vitamin C Equivalent Antioxidant Capacity (VCEAC) [4]. The VCEAC values are 0.3472 g and 0.2768 g of VCEAC/100 g of dry weight; as determined by ABTS and DPPH tests respectively. The total phenolic and total flavonoids contents are, respectively: 2.138 g of gallic acid equivalent/100 g of dry weight, and 7.126 g of quercetin equivalents/100 g of dry weight. A direct correlation between phenolic compounds and antioxidant activity was observed (R2= 0.95). According to the results, it is observed that the Arisarum vulgare possess a considerable antioxidant and antiradical capacity, therefore the antioxidant properties might increase the therapeutic value of this medicinal plant. Key words:Arisarum vulgare, antioxidant, polyphenols, flavonoids, ABTS, DPPH.

Antioxidant and antiproliferation activities of winter cereal crops before and after germination

This study investigated the changes in antioxidant and antiproliferation activities of germinated winter cereal crops, including oats, barley, rye, and wheat, to develop functional materials. The highest total polyphenol content was found post-germination at 3.97 mg gallic acid equiv./g, which was 1.61-fold higher than the 2.46 mg gallic acid equiv./g in pre-germination barley. The flavonoid content was highly increased in wheat, which was 2.25-fold higher than 0.28 mg catechin equiv./g sample in pre-germination. The DPPH free radical scavenging activity (IC50) was the greatest in the post-germination barley at 1.67 mg/mL. The highest ascorbic acid equivalent antioxidant capacity (7.43 mg AA eq/g sample) was obtained from post-germination barley, while its pre-germination capacity was 5.44 mg AA eq/g sample. The post-germination oats ethanol extract had a higher antiproliferation effect on HepG2 and HCT-116 cell lines than the pre-germination extract. The cell viability of the HepG2 and HCT-116 cell lines exposed to the post-germination oats was 19.98 and 11.81% at 3.0 mg/mL, respectively.

Plasma total antioxidant capacity is associated with dietary intake and plasma level of antioxidants in postmenopausal women

Increased plasma total antioxidant capacity (TAC) has been associated with a high consumption of fruits and vegetables. However, limited information is available on whether plasma TAC reflects the dietary intake of antioxidants and the levels of individual antioxidants in plasma. By using three different assays, the study aimed to determine if plasma TAC can effectively predict dietary intake of antioxidants and plasma antioxidant status. Forty overweight and apparently healthy postmenopausal women were recruited. Seven-day food records and 12-h fasting blood samples were collected for dietary and plasma antioxidant assessments. Plasma TAC was determined by vitamin C equivalent antioxidant capacity (VCEAC), ferric-reducing ability of plasma (FRAP) and oxygen radical absorbance capacity (ORAC) assays. TAC values determined by VCEAC were highly correlated with FRAP (r=0.79, P<.01) and moderately correlated with ORAC (r=0.34, P<.05). Pearson correlation analyses showed that plasma TAC values by VCEAC and ORAC had positive correlation with plasma uric acid (r=0.56 for VCEAC; r=0.49 for ORAC) and total phenolics (r=0.63 for VCEAC; r=0.36 for ORAC). However, TAC measured by FRAP was correlated only with uric acid (r=0.69). After multivariate adjustment, plasma TAC determined by VCEAC was positively associated with dietary intakes of γ-tocopherol (P<.001), β-carotene (P<.05), anthocyanidins (P<.05), flavones (P<.05), proanthocyanidins (P<.01) and TAC (P<.05), as well as with plasma total phenolics (P<.05), α-tocopherol (P<.001), β-cryptoxanthin (P<.05) and uric acid (P<.05). The findings indicate that plasma TAC measured by VCEAC reflects both dietary and plasma antioxidants and represents more closely the plasma antioxidant levels than ORAC and FRAP.

Screening of antioxidant activity, total phenolics and gas chromatography-mass spectrophotometer (GC-MS) study of ethanolic extract of Aporosa lindleyana Baill

The present study was carried out for the identification of phytochemicals present in the roots ofAporosa lindleyana and also to evaluate the total phenol, total flavonoids and antioxidant activity. Total phenol was carried out by Folin Ciocalteu method and the phenolic content was 31.20 mg/100 g of gallic acid equivalent (GE) and the flavonoid content was 203.10±0.9. Antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and the roots of A. lindleyana showed 19.91 mg/100 g of ascorbic acid equivalent antioxidant capacity (AEAC). The gas chromatography-mass spectrophotometer (GC-MS) study was also carried out and it showed the presence of phytochemicals like 1,2-benzenedicarboxylic acid, diphenyl ester (RT: 11.97), pthalic acid, bis (7 methylocytyl) ester (RT: 20.86) and squalene (RT: 24.70). Key words: Aporosa lindleyana, antioxidant, flavonoids, gas chromatography-mass spectrophotometer (GC-MS), 2,2-diphenyl-1-picrylhydrazyl (DPPH).

Screening of antioxidant activity, total phenolics and gas chromatography-mass spectrophotometer (GC-MS) study of ethanolic extract of Aporosa lindleyana Baill

The present study was carried out for the identification of phytochemicals present in the roots ofAporosa lindleyana and also to evaluate the total phenol, total flavonoids and antioxidant activity. Total phenol was carried out by Folin Ciocalteu method and the phenolic content was 31.20 mg/100 g of gallic acid equivalent (GE) and the flavonoid content was 203.10±0.9. Antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and the roots of A. lindleyana showed 19.91 mg/100 g of ascorbic acid equivalent antioxidant capacity (AEAC). The gas chromatography-mass spectrophotometer (GC-MS) study was also carried out and it showed the presence of phytochemicals like 1,2-benzenedicarboxylic acid, diphenyl ester (RT: 11.97), pthalic acid, bis (7 methylocytyl) ester (RT: 20.86) and squalene (RT: 24.70). Key words: Aporosa lindleyana, antioxidant, flavonoids, gas chromatography-mass spectrophotometer (GC-MS), 2,2-diphenyl-1-picrylhydrazyl (DPPH).

Screening of antioxidant activity, total phenolics and gas chromatograph and mass spectrometer (GC-MS) study of delonix regia

The present study was carried out for identification of the phytochemicals present in the Delonix regia leaves and also evaluates the total phenols, total flavonoids and antioxidant activity of the leaf extract. Total phenols were carried out by Folin Ciocalteu method and the phenolic content was 16.00 mg/100 g of gallic acid equivalent (GE). Antioxidant activity was evaluated by 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) method and the leaves of D. regia showed 10.73 mg/100 g of ascorbic acid equivalent antioxidant capacity (AEAC). The gas chromatograph and mass spectrometer (GC-MS) study was also carried out and it showed the presence of phytochemicals like phytol (RT: 15.49), Cumarin 7, 8-dihyddro-7-hydroxy-6-methoxy-8-oxo (RT: 15.92), Squalene (RT: 25.41) and Vitamine (RT: 29.97). Key words: Total phenols, total flavonoids, antioxidant activity, 2,2-Diphenyl-1-Picrylhydrazyl (DPPH), gas chromatograph and mass spectrometer (GC-MS), delonix regia.

English

The antibacterial and antioxidant activities of different parts of local seeded banana fruit were investigated&nbsp;in vitro. Dried peels, pulps and seeds of the fruit were extracted with hexane, ethyl acetate and ethanol. Antibacterial property of the extracts was evaluated against four Gram positive and four Gram negative bacteria using disc diffusion technique. Ethyl acetate and ethanol extract of both pulp and peel exhibited antibacterial activity with zone of inhibition ranging from 9 to 24 mm. On the other hand, only ethyl acetate extract of seeds showed antibacterial activity and the zone of inhibition ranged from 8.5 to 10 mm; interestingly, none of the hexane extracts of the three banana parts exhibited zone of inhibition. Antioxidant activity of the extracts was evaluated by total phenolic content determination and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. Total phenolic content expressed as gallic acid equivalents (GAE) was found to be highest in ethyl acetate extract of banana seed (19.46 mg GAE/g extract) followed by the same extract of banana pulp (15.78 mg GAE/g extract) and peel (11.23 mg GAE/g extract). High free radical scavenging activity was observed with ethyl acetate extracts of banana seed, peel and pulp with an ascorbic acid equivalent antioxidant capacity (AEAC) value of 1238.33, 1011.43 and 588.03 mg AA/ 100 g extract, respectively. &nbsp; Key words:&nbsp;Seedy banana, antibacterial, antioxidant, phenolic content.

미생물을 이용한 후발효차의 발효기간별 항산화 성분 및 활성의 변화

위생적으로 안전성이 확보된 후발효차를 제조하기 위해 Bacillus subtilis, Saccharomyces cerevisiae 및 Lactobacillus bulgaricus를 이용하여 후발효차를 제조한 후 발효시간에 따른 항산화 성분 및 활성의 변화를 측정하였다. 후발 효차의 ascorbic acid의 함량은 발효기간 내내 균종에 관계없이 녹차(66.74 ㎎%)에 비하여 비교적 낮은 함량(43.62～62.84 ㎎%)을 보였고 산소와의 접촉을 최소화한 L. bulgaricus 균에 의한 발효가 비교적 적은 변화를 보였다. Polyphenol 화합물의 함량은 녹차의 경우 14.88%였으며 후발효차는 11.54～14.12%로 세 균주 모두 발효가 진행됨에 따라 함량이 다소 감소하였다. 실험에 사용한 녹차의 flavonoid 함량은 7.78 ㎎%였으며 미생물을 이용한 후발효차의 경우에는 4.33～7.88 ㎎%로 대부분 녹차에서의 함량보다 적은 것으로 나타났다. 항산화 활성의 경우, 녹차의 DPPH 전자공 여능 및 ABTS 항산화 활성은 각각 87.47% 및 203.22 AEAC ㎎%였으나 발효기간에 따른 후발효차에서는 녹차에 비하여는 낮은 활성을 보여 후발효차 제조 시 어느 정도 항산화 성분의 함량 및 활성이 다소 감소하게 되지만 미생물을 이용하여 후발효차를 제조 시 위생적이고 기호도가 우수한 제품을 생산할 수 있는 것으로 판단되었다.