Ascorbic Acid Equivalent Antioxidant Capacity Research Articles

Flavonoids, Phenolics, and Antioxidant Capacity in the Flower of Eriobotrya japonica Lindl.

Flavonoids and phenolics are abundant in loquat flowers. Methanol had the highest extraction efficiency among five solvents, followed by ethanol. Considering the safety and residue, ethanol is better as extraction solvent. The average content of flavonoids and phenolics of loquat flower of five cultivars were 1.59 ± 0.24 and 7.86 ± 0.87 mg/g DW, respectively, when using ethanol as extraction solvent. The contents of both bioactive components in flowers at different developmental stages and in the various flower tissues clearly differed, with the highest flavonoids and phenolics content in flowers of stage 3 (flower fully open) and petal, respectively. The antioxidant capacity was measured using FRAP, DPPH, and ABTS methods. The values of ABTS method was highest, followed by DPPH, the lowest was FRAP, when using vitamin C equivalent antioxidant capacity (VCEAC) as unit. Correlation analysis showed that the ABTS method showed the highest correlation coefficients with flavonoids and phenolics, i.e., 0.886 and 0.973, respectively.

Bioactive compounds and antioxidant activity of fresh exotic fruits from northeastern Brazil

Foods rich in antioxidants play an essential role in the prevention of diseases. The present study compared contents of phenolics, vitamin C, anthocyanin and antioxidant activity of 11 fresh exotic fruits, cultivated in the northeastern part of Brazil. The antioxidant activities were evaluated using two antioxidant systems 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), expressed as TEAC (Trolox Equivalent Antioxidant Capacity) and VCEAC (Vitamin C Equivalent Antioxidant Capacity) values. The results indicated that the above fruits, such as murici and mangaba, were good sources of antioxidants. The phenolic contents showed positive correlations with total antioxidant by ABTS (R=0.94, P≤0.001) and DPPH (R=0.88, P≤0.001) assays. However, this correlation was not noticed when examining vitamin C and anthocyanins contents. The 11 fruits studied had comparable antioxidant activity in both, ABTS and DPPH assays. These methods are recommended as useful tools for the evaluation of the total activity antioxidant in fruits. Our results indicated promising perspectives for the development and usage of fruits species studied with considerable levels of antioxidant activity.

Neuronal cell protection and acetylcholinesterase inhibitory effect of the phenolics in chestnut inner skin

Chestnut inner skin was known to contain various phenolics as a potential antioxidant, and 3 phenolics (catechin, epicatechin, and gallic acid) were isolated. The relative antioxidant capacity of 3 phenolics in vitamin C equivalent antioxidant capacity (VCEAC) evaluated by ABTS assay was in decreasing order as follows: gallic acid>catechin>epicatechin>vitamin C. Gallic acid showed the highest inhibitory effect against acetylcholinesterase (AChE) in a dose-dependent manner and competitive inhibition. However catechins presented neuroprotective effects on amyloid β-induced neurotoxicity by MTT, lactate dehydrogenase (LDH) release, and neutral red uptake assays. Considering above data, it was supposed that gallic acid, catechin, and epicatechin have various antiamnesic effect in neurodegenerative diseases such as Alzheimer’s disease (AD). Therefore, it was strongly suggested that chestnut inner skin as phenolics-rich substance can be used in functional food supplement or pharmaceutical industry by utilization of wastage from valuable resources.

Dietary total antioxidant capacity reflects dietary and plasma antioxidant status in healthy college students

Dietary total antioxidant capacity (TAC), based on the cumulative protective activities of all the antioxidants present in food, has been shown to be inversely associated with risks of chronic diseases. However, it has not been validated for its relevance in healthy young population or for reliability and predictability for antioxidant status in vivo. This study was conducted to validate TAC as a dietary tool in assessing antioxidant intake status and to investigate its predictability for plasma antioxidant status in healthy young population. Sixty healthy, non-smoking college students at the University of Connecticut aged 18–25 y were recruited. Thirty-day diet recalls and twice 12-h fasting blood samples were collected for dietary and plasma antioxidant assessments. After multivariate adjustment, dietary TAC was positively associated with intakes of dietary antioxidants, including α-tocopherol, vitamin C, carotenoids, flavonoids, and proanthocyanidins (p<0.01); it was also positively associated with plasma TAC determined by vitamin-C equivalent antioxidant capacity (VCEAC) (p<0.001). The findings indicate that dietary TAC is associated with dietary and plasma antioxidant status of healthy young population. Grant Funding Source: USDA Hatch Grant

Antioxidant and antibacterial properties of green, black, and herbal teas of Camellia sinensis

Background:The role of non-polymeric phenolic (NP) and polymeric tannin (PT) constituents in the antioxidant and antibacterial properties of six brands of green, black, and herbal teas of Camellia sinensis were investigated.Materials and Methods:Total phenolic content (TPC) and ascorbic acid equivalent antioxidant capacity (AEAC) were assessed using the Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, respectively. Minimum inhibitory dose (MID) against Gram-positive Micrococcus luteus, Staphylococcus aureus, and Bacillus cereus, and Gram-negative. Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa was assessed using the disc-diffusion method. Teas were extracted with hot water successively three times for one hour each time. The extracts were fractionated using Sephadex LH-20 column chromatography to obtain the NP and PT constituents.Results:Extraction yields ranged from 12 to 23%. Yields of NP fractions (70–81%) were much higher than those of PT fractions (1–11%), suggesting that the former are the major tea components. Ranking of antioxidant properties of extracts was green tea>black tea>herbal tea. For all six teas, antioxidant properties of PT fractions were significantly higher than extracts and NP fractions. Extracts and fractions of all six teas showed no activity against the three Gram-negative bacteria. Green teas inhibited all three Gram-positive bacteria with S. aureus being the least susceptible. Black and herbal teas inhibited the growth of M. luteus and B. cereus, but not S. aureus. The most potent were the PT fractions of Boh Cameron Highlands and Ho Yan Hor with MID of 0.01 and 0.03 mg/disc against M. luteus.Conclusion:Results suggested that NP constituents are major contributors to the antioxidant and antibacterial properties of teas of C. sinensis. Although PT constituents have stronger antioxidant and antibacterial properties, they constitute only a minor component of the teas.

Bioactive compounds from flesh and by-product of fresh-cut watermelon cultivars

The fresh-cut industry produces thousands of tons of waste in non-edible portions that present an environmental and management problem. These by-products could be reused, in particular, to obtain bioactive compounds. In this study, five different fresh-cut watermelon cultivars were assessed for their flesh and by-product bioactive contents. The amount of by-product varied between 31.27 and 40.61% of initial fresh weight (f.w.) depending on the cultivar. Watermelon cultivars were poor sources of total antioxidant, and the content was similar between rind and flesh samples (46.96 vs 43.46 mg ascorbic acid equivalent antioxidant capacity kg(-1) f.w.). However, the rind had a moderate total phenolic content higher than that of the flesh (458 vs 389 mg chlorogenic acid equivalent kg(-1) f.w.) and a much higher content of the amino acid citrulline (3.34 vs 2.33 g kg(-1) f.w.), which has potential bioactive properties. Watermelon rind offers quantitative interest as a natural source of citrulline, particularly Fashion, a dark-skinned, seedless cultivar. More research is required on the efficient extraction of citrulline from watermelon rind and its suitability as an additive to drinks, juices or others products to produce new functional food products with valid health claims.

Thermal Degradation Characteristics and Antioxidant Activity of Fructose Solution with Heating Temperature and Time

This study investigated the thermal degradation characteristics of fructose. A 20% fructose solution was heated to 110-150°C for 1-5 hours. Chromaticity, pH, organic acid, 5-hydroxymethylfurfural (HMF), fructose content, electron-donating ability (EDA) (as a percentage), and ascorbic acid (AA) equivalent antioxidant capacity (AEAC) of heated fructose solutions were evaluated. With increasing heating temperature and time, the L-value decreased, and the a- and b-values increased to 120°C for 4 hours and 2 hours, respectively, and then decreased thereafter; however, total color difference increased. The pH and fructose content decreased. Organic acids, such as formic acid, lactic acid, and levulinic acid, and HMF content increased with increasing heating temperature and time. Antioxidant activity increased with increasing heating temperature and time (no antioxidant activity in 20% fructose solution). The EDAs after heating at 130°C for 3 and 4 hours were 17.21% and 31.73%, respectively, and the highest antioxidant activity was 94.57% (150°C for 4 hours). The AEAC was 1.71 mg of AA eq/g before heating and 24.43 mg of AA eq/g after heating at 150°C for 4 hours. These results suggest that heat treatment may be a useful method for increasing the antioxidant activity of fluid foodstuffs such as fruit juices and fructose-containing foods.

Species Variability for Fruit Antioxidant and Radical Scavenging Abilities in Mulberry

Fruits from five accessions of mulberry (Morussp.) representing Morus nigra, Morus lavigeta, and Morus alba were evaluated for ferric reducing antioxidant potential, diphenyl picryl hydrazyl radical scavenging ability, total phenols, flavonoids, anthocyanins, and ascorbic acid contents. In fresh fruits, higher antioxidant capacity was found in M. nigra followed by M. lavigeta and the lowest capacity was observed in M. alba. Higher ferric reducing antioxidant potential and diphenyl picryl hydrazyl scavenging capacities were mainly due to higher anthocyanins. Among the black accessions evaluated, Acc. No. 362 and 497 recorded the highest ferric reducing antioxidant potential (4,515.75 and 4,224.24 mg ascorbic acid equivalent antioxidant capacity 100 g−1 dry wt, respectively), diphenyl picryl hydrazyl (IC50 values of 0.124 and 0.116 mg−1, respectively), and anthocyanin (4,255.65 and 4,103.93 mg/100 g−1 dry wt, respectively) content when compared to other accessions. Accession number 249 (M. alba) with white colored fruits recorded the lowest antioxidant capacity. A phenolic acid profile of fruits indicated that these accessions are rich in caffeic and gallic acids. Gentisic and protocatechuic acids were also found in fairly good quantities. Dried fruits also recorded very high antioxidant (0.18–2.32 g ascorbic acid equivalent antioxidant capacity 100 g−1 dry weight) and diphenyl picryl hydrazyl radical scavenging abilities (IC50 of 0.3–2.98 mg, quantity needed for removing 50% of diphenyl picryl hydrazyl radicals). Results indicated that black mulberry fruits could be used for preparation of high antioxidant postharvest products.

AKTIVITAS ANTIOKSIDAN BEKATUL LEBIH TINGGI DARIPADA JUS TOMAT DAN PENURUNAN AKTIVITAS ANTIOKSIDAN SERUM SETELAH INTERVENSI MINUMAN KAYA ANTIOKSIDAN

&lt;p class="MsoNormal" style="margin: 0cm 5.65pt 6pt 14.2pt; text-align: justify; text-indent: 1cm;"&gt;&lt;span style="font-size: 10pt;" lang="en-us" xml:lang="en-us"&gt;Recently, many foods were identified contain high antioxidant substances such as tomatoes and rice bran. The &lt;/span&gt;&lt;span style="font-size: 10pt;"&gt;objectives&lt;/span&gt;&lt;span style="font-size: 10pt;" lang="en-us" xml:lang="en-us"&gt; of this research &lt;/span&gt;&lt;span style="font-size: 10pt;"&gt;were&lt;/span&gt;&lt;span style="font-size: 10pt;" lang="en-us" xml:lang="en-us"&gt; to observe their total antioxidant activity values and the effect of intervention of high-antioxidant beverages (tomato juice and rice bran beverage) to total antioxidant activity on breast cyst women patient’s blood serum. Subject consumed each of the beverages for 14 days. Blood samples were taken before the intervention, at the end of tomato juice intervention period and at the end of rice bran bevera&lt;/span&gt;&lt;span style="font-size: 10pt;"&gt;g&lt;/span&gt;&lt;span style="font-size: 10pt;" lang="en-us" xml:lang="en-us"&gt;e intervention period. Total antioxidant activity on serum was determined by DPPH method. The ascorbic acid equivalent antioxidant capacity (AEAC) of rice bran greater than tomato juice is 28.74 mg/100g and 1.87 mg/100g respectively. The total antioxidant activity on serum was decreasing after tomato juice intervention (p&amp;gt;0.05) but the decreasing of it was significantly shown after rice bran intervention (p&amp;lt;0.05)&lt;/span&gt;&lt;span style="font-size: 10pt;"&gt;.&lt;/span&gt;&lt;/p&gt;

Screening of antioxidant activity, total phenolics and GC-MS study of Vitex negundo

The present study was carried out for identification of the phytochemicals present in the Vitex negundo leaves and also evaluate the total phenols, total flavonoids and antioxidant activity of the leaf extract. Total phenols was carried out by Folin Ciocalteu method and the phenolic content was 27.72 mg/100 of gallic acid equivalent (GE). Antioxidant activity was evaluated by DPPH method and the leaves of V. negundo showed 23.21 mg/100 of ascorbic acid equivalent antioxidant capacity (AEAC). The GC-MS study also carried out and it showed the presence of phytochemicals like 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-(RT:6.17), Phytol (RT:19.67) and Vitamin E (RT:25.11). Key words: Total Phenols, total flavonoids, antioxidant activity, DPPH, GC-MS.

Antioxidant activity of seed extracts of Annona squamosa and Carica papaya

PurposeThe purpose of this paper is to investigate various extracts of Annona squamosa L (Annonanceae) and Carica papaya L (Caricaceae) seeds for their antioxidant activity, free radical scavenging ability, total phenolic and flavonoid contents.Design/methodology/approachSamples from both the seeds were prepared by subjecting them to microwave‐assisted extraction. After determining their antioxidant properties and polyphenolic contents, correlation between them was also investigated.FindingsHighest antioxidant activity (3,179.66 g gallic acid equivalent/g of dry extract) and phenol content were registered by chloroform:methanol extract of C. papaya seeds. Maximum radical scavenging activity (3,201.63 ascorbic acid equivalent antioxidant capacity g/100 g of dry extract) was exerted by water extract of A. squamosa seeds, whereas acetone extract of C. papaya registered highest flavonoid content among all extracts. Polar extracts were found to be better free radical scavengers compared with those less polar. Hexane extracts showed least DPPH radical scavenging activity. Acetone proved efficient in extracting flavonoids, whereas phenols were best extracted in a mixture of chloroform and methanol. Phenolic metabolites seem to be contributing significantly towards antioxidant activity of the C. papaya extracts, but less so in the case of A. squamosa.Originality/valueThere have been few reports on antioxidant activity of non‐edible parts of commonly consumed fruits. The research indicates that seeds may be a promising source of antioxidants, which may have therapeutic implications.

Comparison of ABTS/DPPH assays for the detection of antioxidant capacity in foods

The present study aimed to evaluate two different spectrophotometric assays for detection of vitamin C equivalent antioxidant capacity (VCEAC) of foods. Fifty popular, antioxidant‐rich fruits, vegetables and beverages in the U.S. diet were analyzed for their 2,2′‐azino‐bis‐3‐ethylbenzthiazoline‐6‐sulphonic acid (ABTS) anion radical scavenging activity (ABTS assay) and their ability to reduce 1,1‐diphenyl‐2picrylhydrazyl (DPPH) radical (DPPH assay). The highest VCEAC was detected for strawberry with 520.7 ± 39.3 mg vitamin C equivalent (VCE)/100 g by DPPH assay and for blueberry with 476.6 ± 28.9 mg VCE/100 g by ABTS assay. Although the order differed slightly, both assays identified the same top ten VCEAC food items in the U.S. diet based on fresh weight as blueberry, plum, strawberry, red cabbage, red wine, grape, cherry, green tea, broccoli and apple. VCEAC of 50 food items detected by ABTS assay showed a strong positive relationship with VCEAC measured by DPPH assay (r = 0.886, p&lt;0.001). VCEAC detected by ABTS assay demonstrated a stronger positive association with the USDA database for the oxygen radical absorbance capacity (ORAC) (r = 0.473, p &lt; 0.01). ABTS assay was superior to DPPH assay in reflecting the antioxidant levels of foods containing hydrophilic, lipophilic, high‐moisture, or high‐pigmented nutrients. Hence, ABTS assay may be more useful than DPPH assay in detecting VCEAC in foods.Grant Funding Source: Supported by Beginning Grant in Aid (BGIA) No. 0865092E from the American Heart Association and University of Connecticut Faculty Large Grant

Quality of fresh‐cut baby spinach grown under a floating trays system as affected by nitrogen fertilisation and innovative packaging treatments

Alternative techniques for cultivation of leafy vegetables such as a floating tray system and unconventional gas mixtures for post-harvest active modified atmosphere packaging (MAP) could be of interest in the minimally processed vegetable industry. The combined effect of three pre-harvest fertilisation doses (8, 12 or 16 mmol N L(-1)) and three post-harvest MAP conditions (passive, super-atmospheric or N2O-enriched) on the main quality attributes of fresh-cut baby spinach leaves throughout 10 days at 5 degrees C was studied. After 8 days of shelf life, spinach leaves fertilised with 8 and 16 mmol N L(-1) and stored under N2O-enriched MAP showed the lowest microbial growth, with good sensory quality. Such combined treatments also preserved the total antioxidant capacity sampled at harvest (8 g ascorbic acid equivalent antioxidant capacity kg(-1) f.w.). A decrease of 10-20% in total vitamin C content regardless of N fertilisation and packaging treatment was found during shelf life. Total phenolics content at harvest was 2 g gallic acid equivalents kg(-1) f.w., which was slightly decreased or preserved during shelf life while total chlorophylls were preserved for all treatments assayed around 550 mg kg(-1) f.w. No clear effect of fertilisation doses was observed during post-harvest storage on overall quality of fresh-cut baby spinach leaves, while N2O-enriched atmospheres seems to be a promising alternative to passive MAP for extending shelf life.

Gallic Thermosensitive Gel

Gallic acid (G) is a natural phenolic compound that has potent antioxidant and antityrosinase activities. The solubility of gallic acid in aqueous system is rather poor. The purpose of this research is to develop the thermosensitive gel containing G based on Lutrol® F127 (L) and the antioxidant of prepared gels was determined using modified ABTS.+ method expressed as Vitamin C Equivalent Antioxidant Capacity (VCEAC) method. N-methyl pyrrolidone (N) could be used to effectively solubilize G into L aqueous systems. This developed thermosensitive system could convert from solution in the cool place to the firm gel under physiological condition on the skin to delivery an anti-aging agent such as gallic acid. Gallic acid gel prepared from hydroxypropyl methyl cellulose (HPMC, H) was employed to compare with the developed system. The developed gel containing 25% L, 25% N and 5% G (L25N25G5) showed the good physical appearances. In vitro release study was performed using the membrane-less method. The release of G from L25N25G5 into citrate-phosphate buffer pH 5.5 was faster than that of the gel containing 3% H, 25% N and 5% G (H3N25G5). From rheology study, L25N25G5 exhibited as a Newtonian flow at 4 °C and plastic flow at 28°C and 35 °C whereas H3N25G5 demonstrated as a pseudoplastic flow at all the three temperatures. Additionally, from VCEAC method, L25N25G5 exhibited a good antioxidant activity.

수수가루 첨가에 따른 두부의 이화학적 특성

기능성 강화 두부의 제조와 수수의 이용성을 높이기 위해 수수가루를 첨가한 두부를 제조하여 이화학적 특성을 검토하였다. 수수가루 첨가 비율에 따라 제조된 두부의 수율은 약간 증가하는 경향을 보였으며, 5 및 7%(w/w) 첨가한 두부에서 무첨가 두부와 비슷한 수율을 보였다. 제조된 두부의 수분함량은 불린 후 볶은 수수가루를 첨가하였을 때 높은 수분함량을 보였고 단백질 및 회분 함량은 큰 차이가 없는 것으로 나타났다. 식이섬유 함량은 무첨가 두부보다 수수가루를 첨가한 두부가 높은 함량을 보였다. 칼륨의 함량은 증가하는 것으로 나타났으며, 칼슘 및 마그네슘 함량은 대체적으로 수수가루 첨가에 따라 감소하는 경향을 보였다. 경도는 수수가루 첨가량이 증가함에 따라 경도는 뚜렷하게 감소하는 경향을 보였다. 대체적으로 수수가루 첨가량에 따라 L 및 b값은 감소하는 경향을 보였으며, a값은 증가하는 경향을 보였다. 무첨가 두부의 총 폴리페놀, 플라보노이드 및 탄닌 함량은 0.955, 0.072 및 0.328 ㎎/g(dry basis)으로 나타났으며, 총 항산화력은 0.770 ㎎ AA eq/g sample(dry basis)으로 나타났다. 수수가루 첨가량에 따라 총 폴리페놀, 플라보노이드 및 탄닌 함량과 총 항산화력은 증가하는 경향을 보였으며, 불리지 않고 볶은 수수가루를 첨가한 두부 추출물이 불린 후 볶은 수수가루를 첨가한 두부 추출물보다 높은 경향을 보였다. 두부의 수분함량, 경도, 항산화활성 등을 고려할때 5～7%의 불리지 않고 불리지 않고 볶은 수수가루를 두부 제조 시 첨가하는 것이 바람직한 것으로 생각되었다.

Reliability of bond dissociation enthalpy calculated by the PM6 method and experimental TEAC values in antiradical QSAR of flavonoids

The applicability of the newly developed RM1 and PM6 methods implemented in the semiempirical quantum chemistry mopac2009™ software package in modeling free radical scavenging activity of flavonoids was examined. Bond dissociation enthalpy (BDE) of OH groups could be calculated much faster than with DFT method but with similar quality. Despite the known shortcomings of the Trolox equivalent antioxidant capacity (TEAC) assay, we show that taking into account the hydrogen atom transfer (HAT) mechanism of free radical scavenging of flavonoids encoded by minimal BDE values (BDE min) and the number of OH groups ( nOH), as well as experimental data, reasonable QSAR models could be developed. For TEAC values of 38 flavonoids measured by the ABTS free radical, a model based on BDE min and nOH was developed, having very good statistical parameters ( r = 0.983, r cv = 0.976). The applicability of this model to three different data sets of flavonoids and reliability of TEAC values measured in distinct laboratories were discussed. Finally, a reasonably good model of experimental vitamin C equivalent antioxidant capacity (VCEAC) of 36 flavonoids was obtained ( r = 0.954, r cv = 0.947), involving BDE min and nOH as descriptors. Additionally, all presented models have comparable fit and cross-validated statistical parameters, as well as significant regression coefficients.

Antioxidant activities and chemical composition of essential oil of Pistacia atlantica from Algeria

A total number of 34 samples of leaves of Pistacia atlantica Desf. collected randomly from four different locations in Algeria were submitted to hydrodistillation. The essential oils obtained at a yield range of 0.02–0.12% (v/w) were screened for theirs antioxidant activities in vitro using two different and complementary assays: the DPPH • (2,2-di-phenyl-1-picrilhydrazyl) free radical scavenging and the FRAP (Ferric Reducing Antioxidant Power). The result of the DPPH assay gives an IC 50 range value of (8.8–27.48) mg/mL for all the samples studied. BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene) and ascorbic acid were used for comparison purposes. The FRAP antioxidant activity test of the oil was expressed using ascorbic acid as standard reference antioxidant. Others synthetic antioxidants were used for comparison. The antioxidant expressed as Ascorbic acid Equivalent Antioxidant Capacity (AEAC) has a range value of (2.8–11.1) mg/mL, i.e. that the sample oils are almost 3–11 times much more active than ascorbic acid. The essential oils were analyzed by GC and GC–MS. The essential oil was rich in monoterpenes and oxygenated sesquiterpenes. Forty-seven compounds were identified. The main compounds were not the same in the all analysed samples. The percentages ranges of the major components identified from the different locations were α-pinene + α-thujene (5.54–66.61%), camphene (0.75–20.85%), β-pinene (1.09–13.12%), p-cymene (0.39–10.19%), terpinen-4,ol (0.42–15.97%) and spathulenol (0.46–32.64%).

반응표면분석에 의한 건대추의 추출조건 최적화

중심합성계획법으로 조건을 설정하여 건대추를 각각의 조건에서 추출하여 수율 및 이화학적 특성을 분석하여 반응 표면분석을 실시한 결과 추출수율에 대한 최적조건은 추출온도 49℃, 추출시간 17시간 및 에탄올 농도 73%로 나타났다. 건대추 추출물의 지표성분인 c-AMP 함량은 50℃, 24시간, 80% 에탄올에서 8.92 ㎎/100 g으로 가장 높은 함량을 나타냈으며, 46℃, 15시간, 73% 에탄올에서 최적 추출조건을 가지는 것으로 나타났다. 건대추 추출물의 총 폴리페놀 및 플라보노이드 함량을 추출하는 최적의 조건은 16개의 실험구간에서 60℃, 24시간, 60% 에탄올에서 각각 18.42 및 0.94 ㎎/g으로 나타났으며, 통계처리 결과 65℃, 21시간, 67% 에탄올에서 최적조건을 가지는 것으로 나타났다. 건대추 추출물의 항산화활성(IC50)은 60℃, 12시간, 60% 에탄올에서 5.87 ㎎/mL로 가장 높은 활성을 보였다. 통계처리 결과 48℃, 16시간, 59% 에탄올에서 최적의 추출조건을 가지는 것으로 나타났으며, 총항산화력(AEAC)은 60℃, 24시간, 60% 에탄올에서 5.04 ㎎ AA eq/g으로 가장 높은 활성을 보였고 통계처리 결과 48℃, 16시간, 71% 에탄올이 최적조건으로 나타났다. 전체적으로 볼 때 건대추의 최적 추출조건은 추출온도 약 55℃, 추출시간 약 18시간, 에탄올 농도 약 72%의 조건으로 생각된다.

Evaluation of Heat Processing Temperature and Time on Functional Properties of Garlic Juice

To develop a functional juice using garlic (Allium sativum L.), heated garlic juice was investigated using a central composite design set with variables of treatment temperature (110, 115, 120, 125, and 130℃) and time (1, 2, 3, 4, and 5 hr) using high temperature and pressure treatment apparatuses. Total soluble solid, total acidity, reducing sugar, total pholyphenol contents, electron donating activity (EDA), and ascorbic acid equivalent antioxidant capacity (AEAC) in heated garlic juice were increased with increasing heating temperature and time. The highest total soluble solid content was 17.81 obrix at 123.10℃ for 1.10 hr. The highest total acidity was 1.43% at 127.35℃ for 4.35 hr. The highest reducing sugar content was 86.67 ㎎/mL at 119.90℃ for 4.35 hr. The highest total polyphenol content was 8.42 ㎎/mL at 127.75℃ for 4.26 hr. The highest EDA and AEAC were 60.09%, and 7.40 ㎎ AA eq/mL at 127.85℃ for 4.23 hr, and 128.10℃ for 4.18 hr, respectively.

Effects of different drying methods on the antioxidant properties of leaves and tea of ginger species

Effects of five different drying methods on the antioxidant properties (AOP) of leaves of Alpinia zerumbet, Etlingera elatior, Curcuma longa, and Kaempferia galanga were assessed. All methods of thermal drying (microwave-, oven-, and sun-drying) resulted in drastic declines in total phenolic content (TPC), ascorbic acid equivalent antioxidant capacity (AEAC), and ferric-reducing power (FRP), with minimal effects on ferrous ion-chelating ability and lipid peroxidation inhibition activity. Of the non-thermal drying methods, significant losses were observed in air-dried leaves. Freeze-drying resulted in significant gains in TPC, AEAC, and FRP for A. zerumbet and E. elatior leaves. After one week storage, AOP of freeze-dried E. elatior leaves remained significantly higher than those of fresh control leaves. Freeze-dried tea of A. zerumbet was superior to the commercial tea for all AOP studied.