KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 5 of 5
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Valorization of freshwater crab shell residues to chitosan for postharvest quality of mango (Mangifera indica L.) by fruit coating
    (2024-12-01)
    Nimitkeatkai, Hataitip
    ;
    Apiwatanapiwat, Waraporn
    ;
    Janchai, Phornphimon
    ;
    Meelaksana, Jiraporn
    ;
    Vaithanomsat, Pilanee
    Freshwater crab shells (Somanniathelphusa dugasti) are abundant in inland areas and rich in chitosan, which can be extracted and utilized. This study investigated the characteristics of chitosan from freshwater crab shells (FC-chitosan) and its impact on extending the shelf life of Nam Dok Mai mangoes (Mangifera indica L.). The FC-chitosan had a high degree of deacetylation (99.15 %), thereby enhancing solubility and reactivity for a uniform coating, and a low ash content (0.75 %), minimizing the interference effects on mechanical strength and transparency, both of which could contribute to its potential use as a well-adhering coating material. The FC-chitosan film exhibited superior properties as a coating film, with relatively higher transparency (25.09 % T/mm), tensile strength (21.57 MPa), and elongation (76.09 %) compared to commercially available marine crab chitosan. Mango fruits coated with 2.0 % (w/v) FC-chitosan demonstrated appropriate postharvest quality, with lower weight loss and maintained peel color, fruit firmness, titratable acidity, and ascorbic acid during storage at room temperature (30 ± 5 °C) for up to 11 days. The results suggest that FC-chitosan is effective as a coating material for delaying ripening and extending the shelf life of mangoes. The novelty of using chitosan derived from freshwater crab shells lies in its unique properties and its sustainable use of underutilized byproducts.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Postharvest UV-C Treatment Affects Bioactive Compounds and Maintains Quality of Okra (Abelmoschus esculentus L.) during Storage
    (2024-01-01)
    Techavuthiporn, Chairat
    ;
    Jarerat, Amnat
    ;
    Singhkai, Chonlada
    ;
    Nimitkeatkai, Hataitip
    The effects of UV-C treatment on physicochemical quality, bioactive compounds and antioxidant activity of okra (Abelmoschus esculentus L.) during storage were investigated. Okra pods were exposed to UV-C irradiation dose at 1.5, 3.0 or 6.0 kJ·m<sup>−2</sup> before storage at 10 ± 2°C for 12 days. The results showed that UV-C treatment had a significant effect on okra bioactive compounds, such as ascorbic acid, total phenolic, flavonoid contents and antioxidant activity. The highest values of these compounds were observed in okra treated with 6.0 kJ·m<sup>−2</sup> UV-C irradiation. A statistical analysis of the data demonstrated that mucilage had a favorable association with antioxidant capabilities and bioactive substances in response to UV-C treatment. Moreover, UV-C treatment also effectively maintained the quality of okra during storage, as evidenced by lower weight loss and higher firmness without incidence of decay. Therefore, postharvest UV-C treatment can be a potential approach to enhance bioactive compounds and maintain the quality of okra during storage.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Short-term Anoxic Treatment of Litchi Fruit (Litchi chinensis Sonn. cv. Hong Huey) Delays Pericarp Browning and Maintains Physicochemical Quality During Storage
    (2023-01-01)
    Techavuthiporn, Chairat
    ;
    Jarerat, Amnat
    ;
    Nimitkeatkai, Hataitip
    The effect of short-term anoxic treatment prior to storage at ambient and cool temperatures on pericarp browning, fruit quality, secondary metabolites, antioxidant activity, and the browning enzyme of litchi (Litchi chinensis Sonn.) cv. Hong Huey were investigated. Litchi fruit were exposed to anoxic conditions for 6, 12, 18 and 24 h before storage at 28 ± 2°C for 5 days, or at 7 ± 2°C for 14 days. Anoxic treatment resulted in significantly decreases in electrical conductivity, weight loss, browning index, while maintaining the total soluble solids (TSS) and delaying increases in polyphenol oxidase (PPO) and peroxidase (POD) activities compared with control fruit. Furthermore, anoxic treatment increased litchi pericarp methanol extract antioxidant capacity, as measured by free-radical scavenging activity. This is associated with greater amounts of ascorbic acid, anthocyanins, and phenolic/flavonoid components as compared with control fruit. Additionally, anoxic treatment considerably delayed litchi fruit pericarp browning. This suggests that with adequate short-term anoxia duration, an enhanced non-enzymatic antioxidant process may directly or indirectly delay litchi pericarp browning. Thus, a short anoxic treatment enables harvested litchi quality to be sustained at ambient and cool temperatures. This non-chemical and inexpensive treatment deserves further development and application, especially in commercial distribution systems where cooling is insufficient.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Physicochemical properties and bioactive compounds of purple rice (Oryza sativa L.) seedlings grown under light-emitting diodes
    (2022-03-01)
    Techavuthiporn, Chairat
    ;
    Potaros, Treesin
    ;
    Jarerat, Amnat
    ;
    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.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Enhancement of Antioxidant Activity and Bioactive Compounds in Eggplants Using Postharvest LEDs Irradiation
    (2022-02-01)
    Jarerat, Amnat
    ;
    Techavuthiporn, Chairat
    ;
    Chanchomsuek, Chanthana
    ;
    Nimitkeatkai, Hataitip
    Eggplant (Solanum melongena L.), one of the major vegetable crops, is recognized for its availability of numerous bioactive compounds and antioxidant activity. The accumulation of these compounds in plant tissues can be increased by exogenous stimuli, including light exposure. This study aimed at enhancing the antioxidant activity and bioactive compounds of eggplant using light-emitting diode (LEDs) irradiation after harvest. For this purpose, eggplant fruits were irradiated under LEDs at different wavelengths, including red (650–660 nm), blue (450–460 nm), or the com-bination of red and blue (red + blue) LEDs, for 48 h. The results indicated that red + blue LED exposure during postharvest significantly (p < 0.05) elevated the accumulation of bioactive compounds and antioxidant activity. The accumulation of major phenolic compounds, chlorogenic acid (58.59 mg/100 g FW), and gallic acid (14.25 mg/100 g FW) in the eggplant fruits was increased significantly under red + blue irradiation when compared with the control (under dark condition). The total phenolic (821.86 mg GAE/100 g FW) and the total flavonoid (595.98 mg CE/100 g FW) contents were shown to have a considerably high accumulation in the peels of eggplant after irradiation under red + blue LEDs, whereas the total carotenoid content was relatively high in the flesh of eggplant fruits. Consequently, red + blue LED irradiation can be considered as a convenient tool used for the postharvest of eggplant, with a positive effect in the increasing of important secondary metabolites. The obtained eggplant fruits proved to be a promising source of bioactive and antioxidant compounds for functional food production.