Antioxidant properties of tropical juices and their effects on in vitro hemoglobin and low density lipoprotein (LDL) oxidations

Antioxidant properties of tropical juices, namely bambangan (Mangifera pajang), cocoa (Theobroma cacao) pulp and guava (Psidium guajava) juices and their effects on in vitro hemoglobin and low density lipoprotein (LDL) oxidations were determined. Total phenolics and its compounds in selected juices were determined using Folin-Ciocalteu assay and high performance liquid chromatography (HPLC), respectively. Evaluation of antioxidant properties was done using in vitro assays namely as diphenyl-1-picrylhydrazyl (DPPH) scavenging, β-carotene bleaching (BCB), hemoglobin and LDL oxidation assays. Guava and bambangan juices had the highest and lowest of total phenolic content (TPC), respectively. Nevertheless, bambangan juice showed the greatest scavenging activity on DPPH radical. Furthermore, antioxidant activity (AA) in BCB assay was in the order of cocoa pulp (79%) > bambangan (76%) > guava (47%) juices. Interestingly, the highest inhibition of malondialdehyde (MDA) formation was exhibited by bambangan juice (0.31 µM MDA) in hemoglobin oxidation, while guava juice (0.27 µM MDA) in LDL oxidation systems. The study indicated that bambangan juice may have a potential to be introduced as functional foods product because of its antioxidant propertie

Optimization of oven drying conditions for lycopene content and lipophilic antioxidant capacity in a by-product of the pink guava puree industry using response surface methodology.

Response surface methodology (RSM) was applied to optimize the oven drying conditions for lycopene content (Y1) and lipophilic antioxidant capacity (Y2) in decanter, a by-product of the pink guava puree industry. Two-factor central composite design was employed to determine the effects of two independent variables, namely temperature (X1: 50-80 °C) and drying time (X2: 4-6 h). Lycopene content and lipophilic antioxidant capacity were measured using high-performance liquid chromatography (HPLC) and the ABTS radicals scavenging assay, respectively. A β-carotene bleaching assay was also applied to measure the antioxidant activity. Response surface plots showed that an increase in temperature and time significantly reduced the response variables. The optimum oven conditions for drying of decanter with minimum lycopene degradation were 43.8 °C for 6.4 h, with a predicted lycopene content of 14 mg/100 g and antioxidant capacity of 21 μmol LE/100 g. To validate the optimized model, the experimental values were compared with the predicted values to check the adequacy of the model. The experimental values were found to be in agreement with those predicted, indicating the suitability of the model for optimizing the oven drying conditions for decanter

Determination and optimization of flavonoid and extract yield from brown mango using response surface methodology.

The optimum extraction conditions to obtain the highest flavonoid content and extract yield from Mangifera pajang pericarp (MPP) were analyzed using response surface methodology (RSM). A full factorial central composite design was used to investigate the effects of ethanol concentration (20-80%), temperature (30-65°C) and liquid to solid ratio (20-50 mL/g) on the recovery of extract yield and flavonoids. A second order polynomial model produced a satisfactory fitting of the experimental data with regard to extract yield (R 2 = 0.9890, p < 0.0001) and flavonoids (R 2 = 0.9652, p < 0.0001). The optimum conditions to obtain higher extract yield, were 54%, 50°C, and 42.4 mL/g, while for flavonoids were 68%, 57°C, and 20.2 mL/g, respectively. The experimental values agreed with those predicted with 99% and 96% confidence interval for extract yield and flavonoids respectively. This indicates the suitability of RSM in optimizing the extraction of flavonoids and extract yield from MPP

Total phenolic and antioxidant activities of Pouteria campechiana fruit parts

This study aimed to evaluate the total phenolics and antioxidant capacities of the seeds, pulp and peel of Pouteria campechiana fruit using three extraction solvents (water, 70% methanol and 70% ethanol). Among them, 70% ethanol exhibited the best solvent for yielding highest total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activities. The results showed that 70% ethanol extract from the peel contained the highest TPC(2304.7 mg gallic acid equivalent/100 g dw) while the pulp has the highest TFC(6414.03 mg rutin equivalent/100 g dw). The antioxidant activities of the pulp and peel ethanolic extracts were high as determined using 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation assay (49.60 and 49.56 mmoL TE/100 g dw) and ferric reducing antioxidant power assay (43.88 and 42.94 Fe2+/100 g dw) but not for seeds. However, their diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities were ~88%. Thus, the pulp and peel of P. campechiana fruit can be utilized as natural source for antioxidant components

Effect of steam blanching on lycopene and total phenolics in pink guava puree industry by-products

Lycopene and total phenolics of pink guava puree industry by-products (refiner, siever and decanter) were evaluated after steam blanching at selected temperatures and times. Lycopene content was in the order of decanter > siever > refiner (7.3, 6.3 and 1.5 mg/100 g, respectively), and the content of total phenolics was in the order of refiner > siever > decanter (4434.1, 2881.3 and 1529.3 mg GAE/100 g, respectively). Regression coefficients for temperatures (x1) and times (x2) from multiple linear regression models of siever and decanter showed significant (p<0.05) negative relationships with lycopene (y1) and total phenolics (y2). Nevertheless, lycopene content in decanter increased significantly about 13% from the control when steam blanching at 60 °C for 20-60 min. More than 27% of total phenolics were lost in blanched refiner. Regression analysis revealed the increasing loss of lycopene and total phenolics during steam blanching could occur when increasing in temperature and time

Phytochemicals and Medicinal Properties of Indigenous Tropical Fruits with Potential for Commercial Development

Hundreds of fruit-bearing trees are native to Southeast Asia, but many of them are considered as indigenous or underutilized. These species can be categorized as indigenous tropical fruits with potential for commercial development and those possible for commercial development. Many of these fruits are considered as underutilized unless the commercialization is being realized despite the fact that they have the developmental potential. This review discusses seven indigenous tropical fruits from 15 species that have been identified, in which their fruits are having potential for commercial development. As they are not as popular as the commercially available fruits, limited information is found. This paper is the first initiative to provide information on the phytochemicals and potential medicinal uses of these fruits. Phytochemicals detected in these fruits are mainly the phenolic compounds, carotenoids, and other terpenoids. Most of these phytochemicals are potent antioxidants and have corresponded to the free radical scavenging activities and other biological activities of the fruits. The scientific research that covered a broad range of in vitro to in vivo studies on the medicinal potentials of these fruits is also discussed in detail. The current review is an update for researchers to have a better understanding of the species, which simultaneously can provide awareness to enhance their commercial value and promote their utilization for better biodiversity conservation

Lycopene-rich fractions derived from pink guava by-product and their potential activity towards hydrogen peroxide-induced cellular and DNA damage.

Effects of solvent and supercritical carbon dioxide (SC-CO2) extraction on antioxidant and cytotoxic activities of lycopene-rich fractions of decanted pink guava by-product (decanter) were determined with lycopene-equivalent antioxidant capacity, β-carotene bleaching and MTT (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide) assays. Extraction with SC-CO2 gave a higher yield than solvent extraction (3.15 vs. 0.68mg/100g dried decanter, corresponding to 42.99 and 33.63mg of lycopene). No cytotoxicity was found in Chang liver cells supplemented with either extracts (6.25-200μg/ml). Solvent extract at 25μg/ml (2.32μM lycopene) and SC-CO2 extract at 200μg/ml (5.09μM lycopene) had protective effect against hydrogen peroxide-induced cytotoxicity. However, only high concentrations of solvent extract (200μg/ml; lycopene=18.65μM) or lycopene standard (10μM) protected cells against DNA damage. Supercritical fluid extraction demonstrated a higher yield in lycopene-rich fraction from decanter. These fractions have the potential to be developed as a functional ingredient to prevent oxidative stress and other related diseases

Antioxidant Capacities of Peel, Pulp, and Seed Fractions of Canarium odontophyllum Miq. Fruit

Antioxidant capacities of ethylacetate, butanol, and water fractions of peel, pulp, and seeds of Canarium odontophyllum Miq. (CO) were determined using various in vitro antioxidant models. Ethylacetate fraction of peel (EAFPE) exhibited the highest total phenolic (TPC), total flavonoid content (TFC), and antioxidant activities compared to pulp, seeds, and other solvent fractions. Antioxidant capacities were assayed by total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical activity, ferric reducing antioxidant power (FRAP), and hemoglobin oxidation assay. Total phenolic content of ethylacetate fractions was positively correlated with the antioxidant activity. This is the first report on the antioxidant activities from CO fruit fractions. Thus, EAFPE can be used potentially as a readily accessible source of natural antioxidants and as a possible pharmaceutical supplement

Carotenoids and their geometry isomers in selected tropical fruits

This study determined the carotenoids content in cherry tomato, pink guava, and red grapefruit pulps and juices. Cherry tomato pulp exhibited the highest β-carotene content whereas pink guava pulp had the highest lycopene content. However, β-carotene and lycopene contents in the studied fruit juices were lower than their pulps in the same sample portion. Interestingly, six to twelve cis-isomers of carotenoids were identified in the fruit pulps and juices studied. A higher number of trace amounts of cis-carotenoids was found in fruit pulps as compared to juices. Therefore, consumption of whole fruit is recommended as the studied fruit juices have lower carotenoids content

Response surface optimisation for the extraction of phenolic compounds and antioxidant capacities of underutilised Mangifera pajang Kosterm. peels.

The optimum extraction conditions for highest recovery of total phenolics content (TPC) and antioxidant capacities (AC) were analysed for Mangifera pajang peels (MPP), using response surface methodology. The effects of ethanol concentration (X1: 20-80%), extraction temperature (X2: 30-65°C) and liquid-to-solid ratio (X3: 20-50 mL/g) on the recovery of total phenolics (Y1) and antioxidant capacity (Y 2) were investigated. A second order polynomial model produced a satisfactory fitting of the experimental data with regard to total phenolic content (R2 = 0.9966, p < 0.0001) and antioxidant capacity (R 2 = 0.9953, p < 0.0001). The optimum extraction conditions for TPC were 68%, 55°C and 32.7 mL/g, and for AC were 68%, 56°C and 31.8 mL/g, respectively. Predicted values for extraction of TPC and AC agreed well with the experimental values. Liquid chromatography-mass spectrometry of the optimally obtained extracts from MPP revealed the major phytochemicals as mangiferin, gallic acid, catechin and epicatechin. © 2011 Elsevier Ltd. All rights reserved