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Bioprospecting of cyanobacteria from Thai karstic caves as potential producers of phenolic compounds with antioxidant capacity
(2026-04-01)
Suphan, Sutthawan
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Kula, Kasinee
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Lomthong, Thanasak
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Sujarit, Kanaporn
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Maneeruttanarungroj, Cherdsak
Cyanobacteria are highly adaptable microorganisms that can survive in extreme environments. Survival of cyanobacteria in assorted habitats has positively impelled them to produce a range of bioactive compounds, which show a variety of beneficial biological activities. The karstic caves are harsh environments with low light and nutrient input and serve as a unique habitat for exploring cyanobacterial biodiversity as producers of natural products of economic and ecological importance. A total of 86 cyanobacterial strains isolated from 23 karstic caves in four regions of Thailand showed photosynthetic pigments correlated with growth performance and exhibited potential for producing phenolic compounds with significant antioxidant capacity. Based on DPPH scavenging efficiency per unit concentration of crude extract, Leptolyngbya sp. LKK14, Nostoc sp. SW02, and Leptolyngbya sp. LP01 exhibited the superior antioxidant potency. The highest contents of total phenolics (42.10 mgGAE/gCE) and flavonoids (395.90 mgQE/gCE) were found in Leptolyngbya sp. LP01 extract. The presence of phenolic compounds correlated with antioxidant activity; Leptolyngbya sp. LP01 showed the highest antioxidant activity, as measured by DPPH, ABTS, and FRAP assays, with respective values of 15.79, 20.87, and 42.69 mgAAE/gCE. Nine phenolic compounds were tentatively identified based on MS/MS fragmentation patterns compared with library data by LC-ESI-QTOF-MS/MS approach, suggesting that the extract of Leptolyngbya sp. LP01 contains valuable biological antioxidants. This study contributes to our current understanding of cyanobacterial biodiversity in poorly studied habitats, particularly in terms of their biotechnological potential as producers of secondary metabolites suitable for application in the food, pharmaceutical, and cosmetic industries.
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Impact of chilling stress on quality and bioactive compounds in young and mature leaves of kratom [Mitragyna speciosa (Korth.) Havil.]
(2024-09-01)
Supapvanich, Suriyan
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Raruang, Yenjit
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Promyou, Surassawadee
Importance of the work: There has been much attention paid to kratom (Mitragyna speciosa [Korth.] Havil.) since it was declared a legal plant in Thailand. Recently, the demand for fresh leaves has increased; nevertheless, only a few studies have investigated the postharvest quality management of the leaves. Objectives: To examine the impact of chilling stress on the quality and alteration of bioactive compounds in young and mature leaves of two cultivars of commercial kratom leaves: ‘kan khiao’ and ‘hang kang’. Materials and Methods: Fresh kratom leaves of both the kan khiao and hang kang types were sampled from the young and mature leaf stages and stored for 12 d with 85% relative humidity at: 1) 10°C or 2) at room temperature (RT;30°C) . Every 3 d throughout storage, monitoring occurred of the fresh weight loss, superficial leaf color, browning score, electrolyte leakage (EL), malondialdehyde (MDA) content and bioactive compounds (ascorbic acid, antioxidant activity, total phenolic compounds and mitragynine contents). Results: Chilling injury (CI; based on brown stain on the leaf) was discovered in both types of kratom leaves refrigerated at 10°C. In both types, RT storage resulted in less weight loss and browning. Yong leaves lost less weight loss and CI than mature leaves. CI was positively associated with increased EL and MDA levels in leaves kept at 10°C. In both types, the mitragynine content in the mature leaves was higher than in the young leaves. Both types lost mitragynine, ascorbic acid, antioxidant activity and phenolic compounds due to the cold storage condition. Main finding: Cold storage induced chilling stress that resulted in leaf browning due to membrane dysfunction, as well as the loss of bioactive compounds and medicinal components, including mitragynine.
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Physicochemical properties and bioactive compounds of purple rice (Oryza sativa L.) seedlings grown under light-emitting diodes
(2022-03-01)
Techavuthiporn, Chairat
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Potaros, Treesin
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Jarerat, Amnat
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Nimitkeatkai, Hataitip
Importance of the work: There has been increasing interest in using light-emitting diodes (LEDs) to aid in the development of bioactive compounds in a variety of plants to enhance crop nutritional quality. Objectives: To investigate the effects of LEDs on the physicochemical properties and bioactive compounds of rice seedlings. Materials & Methods: Purple rice seeds of Oryza sativa L. were grown under LEDs at different wavelengths (white, red, blue, and red+blue LEDs) for 12 hr/d, while the other 12 hr were in darkness. The physical properties, chemical properties and free-radical scavenging activity of the purple rice seedlings were investigated. Results: Applying exposure to LEDs during the seedling stage significantly (p < 0.05) affected the growth and physicochemical quality of the rice seedlings. Seedlings grown under the red LEDs developed an increased plant height and reducing sugar accumulation. The leaf width, total soluble solids content, chlorophyll content (22.70 mg/g), total phenolic content (5.73 mg gallic acid equivalents/g), and free-radical scavenging activity (79.41%) were significantly higher in rice seedlings grown under the blue LEDs than those under the other LED conditions. The red, blue and red+blue LEDs had no significant effects on the hue angle, ascorbic acid content, titratable acidity or pH. Main finding: Blue LEDs can be considered as an abiotic elicitor for growing purple rice seedlings, with the advantage of an increase in the secondary metabolites.
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Effects of maltodextrin on physicochemical properties of freeze-dried avocado powder
(2021-12-01)
Chuacharoen, T.
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Moolwong, J.
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Chysirichote, T.
The effect of maltodextrin on the moisture sorption isotherm, glass transition temperature (T<inf>g</inf>), and degree of caking of freeze-dried avocado samples at room temperature (25°C) was investigated. The incorporation of maltodextrin reduced the water sorption capacity of the powder due to its less hygroscopic nature. Parameters derived from the Guggenheim, Anderson, and de Boer (GAB) model describing the properties of absorbed water are discussed. The water absorption isotherm possessed the characteristic sigmoid-shaped type II isotherm curves and the model gave the best fit over the whole range of a<inf>w</inf> tested. The differential scanning calorimetric method was used to measure the T<inf>g</inf> of freeze-dried avocado samples. Increasing the water content decreased the T<inf>g</inf>, and T<inf>g</inf> was increased with increasing maltodextrin content. Increased maltodextrin content to solid material in the freeze-dried sample was associated with less sensitivity to caking as evidenced by T<inf>g</inf> values. In addition, increased maltodextrin content in the powders caused brighter, less yellowish, and more greenish coloration and protected color change including browning index. The antioxidant capacity was significantly decreased with increasing maltodextrin content. Thus, the effect of maltodextrin concentration on physicochemical properties was a promising way to preserve the physical property and chemical compounds in freeze-dried avocado powder.
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Effects of salicylic acid immersion on physicochemical quality of Thai papaya fruit 'Kaek Dam' during storage
(2016-02-29)
Promyou, S.
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Supapvanich, S.
This study addressed the effects of salicylic acid (SA) immersion on physicochemical quality of a Thai papaya fruit 'Kaek Dam' during refrigerated storage. Ripening index (RI), total soluble solids (TSS), peel and flesh colour (L∗ and hue values), firmness, electrolyte leakage (EL), pectin substances (total, EDTA-soluble and Na<inf>2</inf>CO<inf>3</inf>-soluble pectins), antioxidant capacity and total phenols of the fruit immersed in 0, 1.0 and 2.0 mM SA were monitored. SA had no effect on the changes in colour and total pectin content but significantly delayed the increases in RI, TSS, softening, EL, EDTA- and Na<inf>2</inf>CO<inf>3</inf>-soluble pectins during storage (P≤0.05). The papaya fruit immersed in 2 mM SA showed the best in delaying the loss of firmness and enhancing antioxidant capacity and total phenols. Thus, this study shows that SA immersion maintains postharvest quality and enhances bioactive compounds of the papaya fruit during storage.
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A feasibility study on organic lotus pollen tea as consumer product
(2015-01-01)
Hongsamoot, Duangtip
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Bumroongsook, Suvarin
Lotus pollen tea, in particular, contains potent antioxidants. The first step of this study was the screening for 3 desired qualities of 4 varieties of lotus (Nelumbonucifera Gaertn): Sattabongkutt, Buntharik, Sattabutt, and Patum. The 3 desired qualities were as follows: High pollen yield; potent antioxidant activity; and favorable aroma, flavor, and color to a panel of testers. The results of the screening were the following: one, the pollen productions of a flower of each of the 4 varieties stated above were 1.28, 3.11, 0.43, and 1.83 gm, respectively; two, Buntharik had the highest antioxidant capacity at a trolox equivalent of 499.48 μg/ml or 59.94 mg/serving and at a total polyphenol equivalent of gallic acid of 63.26 μg/ml or 7.59 mg/serving; and three, the highest-rated variety in a hedonic test of overall preference was Buntharik. Thus, the Buntharik tea was chosen for the consumer acceptance studies conducted with 90 tea testers with equal number of males and females. The finding was found that males preferred this tea over females; panelists over 30 years old gave the highest score on overall preference; their level of acceptance was fairly acceptable, at 50%, but their purchase intention was lower, at 27.78%.
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Durian (Durio zibethinus Murr.) cultivars as nutritional supplementation to rat's diets
(2008-02-01)
Leontowicz, Hanna
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Leontowicz, Maria
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Haruenkit, Ratiporn
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Poovarodom, Sumitra
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Jastrzebski, Zenon
The properties of Mon Thong, Chani and Kan Yao durian (Durio zibethinus Murr.) cultivars were compared in vitro and in vivo studies in order to find the best one as a supplement to antiatherosclerotic diet. Total polyphenols (361.4 ± 35.3 mgGAE/100 g FW), flavonoids (93.9 ± 8.9 mgCE/100 g FW) and total antioxidant capacity determined by DPPH and β-carotene-linoleic acid assays (261.3 ± 25.3 μMTE/100 g FW and 77.8 ± 7.8% of inhibition) were maximal in Mon Thong in comparison with Chani and Kan Yao and showed a good correlation between these three variables (R<sup>2</sup> = 0.9859). Five groups of rats were fed diets supplemented with cholesterol and different durian cultivars. Diets supplemented with Mon Thong and to a lesser degree with Chani and Kan Yao significantly hindered the rise in the plasma lipids (TC - 8.7%, 16.1% and 10.3% and (b) LDL-C - 20.1%, 31.3% and 23.5% for the Chol/Kan Yao, Chol/Mon Thong and Chol/Chani, respectively) and the decrease in plasma antioxidant activity (P < 0.05). Nitrogen retention remained significantly higher in Chol/Mon Thong than in other diet groups. Diet supplemented with Mon Thong affected the composition of plasma fibrinogen in rats and showed more intensity in protein bands around 47 kDa. No lesions were found in the examined tissue of heart and brains. Mon Thong cultivar is preferable for the supplementation of the diet as positively influenced the lipid, antioxidant, protein and metabolic status. The durian fruit till now was not investigated extensively, therefore based on the results of this study durian cultivars can be used as a relatively new source of antioxidants. © 2007 Elsevier Ltd. All rights reserved.
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The nutritional and metabolic indices in rats fed cholesterol-containing diets supplemented with durian at different stages of ripening
(2007-01-01)
Leontowicz, Maria
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Leontowicz, Hanna
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Jastrzebski, Zenon
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Jesion, Iwona
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Haruenkit, Ratiporn
The aim of this investigation was to assess the nutritional and health properties of Mon Thong durian cultivar at different stages of ripening. The assessment was carried out in vitro and in vivo. The contents of dietary fibers, minerals and trace metals at different stages of ripening were comparable. Total polyphenols (mgGAE/100 g FW) and flavonoids (mg CE/100 gFW) in ripe durian (358.8 ± 31.4 and 95.4 ± 9.3) were significantly higher (p < 0.05) than in mature (216.1 ± 1 and 39.9 ± 3.8) and overripe (283.3 ± 26.2 and 53.5 ± 4.9). Antioxidant capacity (μMTE/100 g FW) in total polyphenol extracts of ripe durian measured by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and [2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS) assays (259.4 ± 23.6 and 2341.8 ± 93.2) were significantly higher (p < 0.05) than that of mature (151.6 ± 15.2 and 1394.6 ± 41.5) and overripe (201.7 ± 19.4 and 1812.2 ± 61.4) samples. The correlation coefficients between the bioactive compounds in different stages of ripening and their antioxidant capacities were high (R<sup>2</sup> = 0.99). Then 35 male Wistar rats were divided into 5 dietary groups each of 7 and named Control, Chol, Chol/Mature, Chol/Ripe and Chol/Overripe. During 30 days of the experiment the rats of all 5 groups were fed basal diet (BD), which included wheat starch, casein, soybean oil, vitamin and mineral mixtures. The rats of the Control group were fed a BD only. To the BD of the Chol group was added 1% of cholesterol. The BD of the Chol/Mature, Chol/Ripe and Chol/Overripe groups was supplemented with 1% of cholesterol and 5% of the mature, ripe and overripe durian as freeze-dried powder, respectively. Diets containing ripe and to a lesser degree mature and overripe durian significantly hindered the rise in plasma lipids and also hindered a decrease in plasma antioxidant activity. The nitrogen retention in rats of the Chol/Ripe group was significantly higher (63.6%, P < 0.05) than in other diet groups and the level of the plasma glucose remained normal. A decrease in fibrinogen fraction with ripe durian included in rat's diets was shown by electrophoretic separation. These changes were detected mostly in the low molecular weight proteins of rat's serum. Histological examination of aorta showed only slight differences in the tissue. In conclusion, ripe durian contains higher quantity of bioactive compounds, has higher antioxidant capacity and nutritional value. It positively affects the plasma lipid profile, the plasma glucose and the antioxidant activity in rats fed cholesterol enriched diets. Therefore, the ripe durian supplemented diet could be beneficial for patient suffering from hypercholesterolemia and diabetes mellitus. © 2007 - IUBMB/IOS Press and the authors. All rights reserved.

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