Introduction: This study focused on the discussion of effect of various extraction conditions for phlorotannin content and antioxidant activities extracted from brown algae Sargassum serratum. The algae was grown in the tropical coastal areas of Vietnam. Methods: The various extraction conditions include the following parameters: temperature (30-80 0 C), maceration time (1/2-2,5 hours; 8-48 hrs), the ratio of solvent to material (10:1-70:1 (v/w)), pH (2-8), various kind of solvents (ethanol, acetone, chloroform, ethyl acetate and n-hexan) and solvent concentrations. Phlorotannin content, antioxidant activities, and some phytochemical compositions of Sargassum serratum were evaluated. Results: The highest phlorotannin content and antioxidant activities was expressed when extracting in the following conditions: 100% ethanol solvent at 50 0 C in 32 hours with the ratio of solvent to material of 40/1 (v/w), pH 7 and one-step extraction. The extract contained flavonoid, terpenoid, alkaloid, fatty and oil. DPPH free radical scavenging of the extract was 87.53%. Conclusion:Phlorotannin content and antioxidant activities extracted from Sargassum serratum was depended on the extracting conditions. The condition of extraction for antioxidant phlorotannin and the chemical composition of extract was determined. Brown algae Sargassum serratum has high antioxidant phlorotannin content. A total of 6 compounds were identified from the extract of Sargassum serratum.Key words: Antioxidant, Brown algae, Extraction, Phlorotannin, Sargassum. Correspondence :Vu Ngoc Boi, Nhatrang University, Ministry of Training and Education Nguyen Dinh Chieu street, Nhatrang city, Khanhhoa province, VIETNAM. 100%; the ratio of ethanol solvent to sample of 10:1, 20:1, 30:1, 40:1, 50:, 60:1 and 70:1 (v/w); different temperatures of 30, 40, 50, 60, 70 and 80°C; different times 0.5, 1.0, 1.5, 2.0, 2.5, 8.0, 16.0, 24.0, 32.0, 40.0 and 48.0 h; pH of 2, 3, 4, 5, 6, 7 and 8; and the repeat of extracting times in choiced condition. The extract were then centrifuged at 2500 rpm for 10 mins at 4°C and filtered with Whatman no. 4 filter paper, and analysed. Determination of total phlorotannin content (PC)The total phlorotannin content (PC) of extracts was quantified according to the Folin-Ciocalteu's method. 20 300 μL of extracts was mixed with 1 mL of 10% Folin-Ciocalteu reagent. After keeping the mixture for 5 mins, 2 mL of 10% sodium carbonate was added. The samples were incubated for 1.5 h at room temperature in the dark. The absorbance was measured at 750 nm. Phloroglucinol was used as the standard. The results were expressed as milligrams of phloroglucinol equivalents (PGEs) per g dry weight of sample. Total antioxidant activityTotal antioxidant activity (TA) of extracts was determined according to the method of Prieto et al. (1999).21 100 µL of extracts was mixed with 3 mL of reagent (0.6 M sulfuric acid, 28 mM sodium phosphate and 4 mM ammonium molybdate) and 900 µL of distilled water. The samples were incubated at 95°C for 90 min in water ba...
The phlorotannin content and the total antioxidant, reducing power and DPPH free-radical-scavenging activities in relation to postharvest storage time of six Sargassum species (Sargassum mcclurei, Sargassum polycystum, Sargassum oligocystum, Sargassum serratum, Sargassum aquifolium, and Sargassum denticarpum) commonly found growing in the tropical marine area of Nhatrang, Khanhhoa Province, Viet Nam, were investigated. The results showed that phlorotannin content with total antioxidant and reducing power activity, and DPPH free radical scavenging of Sargassum aquifolium species were the highest, corresponding to 6.770± 0.001 mg phlorotannin g −1 DW, 6.1290±0.0200 mg ascorbic acid g −1 DW, 19.7210±0.0300 mg FeSO 4 g −1 DW and 76.28± 0.20 % of 25 μg DPPH mL −1 extract. The change (decline) of phlorotannin content with antioxidant activities in Sargassum polycystum occurs the fastest. The storage time of the algae descends in the following species order such as S. oligocystum>S. mcclurei, S. aquifolium>S. serratum> S. denticarpum>S. polycystum.
Experimental results proved that the development of Colletotrichum capsici B4 is extremely sensitive to water-soluble chitosan (WSC) and inhibitory effects increase with increasing concentrations of WSC. In the in vitro test, the results showed that the entire prevention of conidial germination and mycelial diameter development are recognized in a potato dextrose agar medium containing 0.4% and 0.8% WSC, respectively. WSC was more efficient in a potato dextrose broth where it absolutely prevented the mycelial development of C. capsici B4 at a concentration of 0.32%. WSC treatments considerably decreased disease prevalence and the lesion diameter of anthracnose disease on chilli pepper fruits in the in vivo experiments. Experiments in biochemistry indicated that the activities of the key defense-related enzymes in peel, consisting of chitinase, b-1,3-glucanase and total phenolic content, were increased by both C. capsici B4 infection and C. capsici B4 treatment, and was further treated with a 0.5% WSC concentration. Practical applicationsFrom the present studies we conclude that water-soluble chitosan (WSC) can directly inhibit the development of C. capsici B4 isolated from infected chili pepper fruits showing typical symptoms of anthracnose in in vitro and effectively control anthracnose in chili pepper fruit in in vivo with concentration-dependent antifungal effects. These findings suggest that WSC may be recognized as a feasible effective alternative to artificial fungicides for postharvest disease control of chili pepper fruits. | I N TR ODU C TI ONChili pepper (Capsicum annuum L.) is a popular vegetable with medicinal and health-promoting properties (Howard, Talcott, Brenes, & Villalon, 2000). It is desired for its good natural colors, favor, spice and nutritional value, and is a plentiful source of antioxidant compounds. Chili pepper is susceptible to a range of postharvest diseases. Among them, anthracnose, caused by Colletotrichum capsici, can cause considerable economic losses during both the preharvest and postharvest stages.This pathogen commonly infects immature fruits in the field, then remains "quiescent" and resumes growth and development during ripening when symptoms like spots and decay (Than et al., 2008). Syn- | Fruit sample preparationsThe chili pepper fruits were obtained from a local farm in the Phu Vang District, Thua Thien Hue Province, Vietnam. Fruits were sorted for uniformity in size and freedom from defects such as physical injury or disease infection. The fruit samples were washed with tap-water, then decontaminated by 70% ethanol, and lastly rinsed with sterile water (Meng, Yang, Kennedy, & Tian, 2010). | Preparation of WSCWSC was prepared from food-grade chitosan powder (degree of deacetylation of 90 6 5%, ash content 1%, As 1 mg/kg, Pb 2 mg/ kg, Hg 0.5 mg/kg) purchased from Hung Tien Co. Ltd, Vietnam. The method of Long, Trung, and Boi (2015) was followed. | Effect of WSC on conidial germinationGermination of conidia was determined by the technique described by Cronin, Yo...
The fan-bellied leatherjacket skin was treated to extract collagen by chemical method. The non-collagenous substances and the pigment in the skin were removed with NaOH and H2O2, respectively. Collagen was extracted with acetic acid. The treatment and extraction conditions were optimized by response surface methodology. The concentrations, skin/solution ratios (g/ml) and times were surveyed. The optimum conditions to remove the non-collagenous substances were as follows: the concentration of NaOH at 0.15M, the ratio (g/ml) at 1/13.9, time at 56.9 hours. Using H2O2 with the concentration at6%, the skin/solution ratio (g/ml) at 1/2, time at 10 minutes were suitable values for skin pigmentation removal. For collagen extraction, the concentration of acetic acid at 0.53M, skin/solution ratio at 1/9.6 g/ml and time in 59.6 hours were optimal.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.