KMITL

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

Browse

Search Results

Now showing 1 - 3 of 3
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Preharvest blue diode laser irradiation enhances betalain biosynthesis, antioxidant responses, and postharvest quality of red amaranth microgreens during storage
    (2026-12-01)
    Supapvanich, Suriyan
    ;
    Sripumimas, Sookmas
    ;
    Li, Man
    ;
    Kang, Chuankai
    ;
    Puisoongnoen, Nichaphat
    In recent years, light-based technologies have attracted growing interest as a postharvest strategy for maintaining the quality of leafy vegetables and microgreens. This study investigated the effects of blue diode laser irradiation (450 nm, 3 h) on the postharvest quality, antioxidant system, and betalain biosynthesis of red amaranth (Amaranthus tricolor) microgreens during storage at 4 ± 1 °C for 9 d. Blue laser treatment effectively maintained visual quality and reduced weight loss compared with untreated samples. Treated microgreens exhibited significantly lower accumulation of hydrogen peroxide (H₂O₂), superoxide anion (O₂⁻), and lipoxygenase (LOX) activity during storage, indicating reduced oxidative stress and membrane lipid peroxidation. In addition, laser-treated samples maintained higher antioxidant capacity, including ferric reducing antioxidant power (FRAP) and DPPH radical scavenging activity, together with greater retention of total phenolics, flavonoids, vitamin C, and glutathione. Activities of antioxidant-related enzymes, including phenylalanine ammonia-lyase (PAL), superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), were also significantly enhanced by laser irradiation. Furthermore, blue laser treatment effectively delayed chlorophyll degradation and increased betacyanin accumulation during storage. Gene expression analysis revealed significant upregulation of betalain biosynthesis-related genes, including AtrWRKY42–2, AtrCYP76AD1, AtrMYB72, AtrDODA1–1, and AtrB5-GT, particularly during the early storage period. Principal component analysis clearly separated laser-treated and control samples, confirming the positive association between laser irradiation, antioxidant defense, pigment retention, and overall quality maintenance. These findings demonstrate that short-term blue laser irradiation is a promising postharvest technology for enhancing antioxidant defense, regulating betalain biosynthesis, and extending the shelf life of red amaranth microgreens.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Stress response of fresh-cut potatoes to laser irradiation before processing can prevent discoloration and maintain overall quality
    (2023-03-01)
    Wen, Bo
    ;
    Cui, Shijiang
    ;
    Suo, Xiaoyu
    ;
    Supapvanich, Suriyan
    Browning is accepted as a main factor affecting quality of fresh cut products. Physical treatments maintaining quality of fresh-cut products have been recently considered by consumer safer than chemical treatments. This study investigated whether preprocess diode laser irradiation can improve the physicochemical quality of fresh-cut potatoes. Laser irradiation at a 450-nm wavelength for 30 min prevented the browning of potato slices during short-term storage at 25 °C. Compared with no treatment, preprocess laser irradiation preserved the appearance and whiteness and inhibited browning and delayed weight loss in potato slices when refrigerated at 4 °C for 96 h. The increases in the total phenol concentration and phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD) activities of fresh-cut potatoes were diminished after laser irradiation. Moreover, the laser irradiation also enhanced antioxidant activities in the samples. The expression of PAL, PPO and POD genes was suppressed by the laser treatment. Therefore, the laser irradiation at 450 nm wavelength for 30 min effectively eliminates discolouration and improves quality of sliced potatoes during cold storage.
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Ultraviolet-C treatment maintains physicochemical quality of water bamboo (Zizania latifolia) shoots during postharvest storage
    (2019-06-01)
    Wen, Bo
    ;
    Cheng, Zechao
    ;
    Hu, Yanmei
    ;
    Boon-Ek, Yaowapa
    ;
    Wongs-Aree, Chalermchai
    Ultraviolet-C (UV-C) treatment has been used as a method to maintain postharvest quality for many kinds of fruits and vegetables. In this study, we investigated the effects of UV-C treatment on physicochemical changes in water bamboo shoots (WBS) during storage. WBS were treated with UV-C at the doses of 0 (control), 1.06, 2.12, 3.18, 4.24, 5.30, and 6.36 kJ m <sup>−2</sup> at 20 °C ± 2 °C for 2 d. The increase in greenness of WBS was inhibited by all UV-C treatments, but the 4.24 kJ m <sup>−2</sup> UV-C treatment maintained lightness and whiteness index values of WBS better than other treatments. Thus, the 4.24 kJ m <sup>−2</sup> UV-C treatment was selected for use to determine the physicochemical quality of WBS during refrigeration at 10 °C. The UV-C treatment retarded the increases in greenness, chlorophyll a, chlorophyll b, and total chlorophyll content, resulting in maintenance of the whiteness index and colour attributes. It also prevented toughness by retarding lignin increase during storage. Moreover, it induced antioxidant activities and bioactive compounds, especially total phenol, and maintained the activities of antioxidant enzymes such as phenylalanine ammonia lyase and catalase during storage. However, the UV-C treatment did not affect ascorbic acid content and the activities of ascorbic acid peroxidase and guaiacol-peroxidase. These results indicated that UV-C treatment at the dose of 4.24 kJ m <sup>-2</sup> is a potential alternative for maintaining physicochemical quality and improving the nutritional quality of WBS during storage.