S. Kaewsuksaeng

Thaksin University, Badalung, Phatthalung, Thailand

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Publications (15)8.58 Total impact

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    ABSTRACT: Postharvest heat treatments by using hot water were applied to Thai lime fruit (Citrus aurantifolia Swingle cv. Paan) to investigate their effect on chlorophyll (Chl)-degradation and postharvest quality during storage. Mature green lime fruit were treated with water at ambient temperature (control) or with hot water at 50 °C for 3 and 5 min and then kept at 25 °C in darkness. The results showed that hot water treatment at 50 °C for 5 min efficiently delayed the decrease of hue angle values and the contents of Chl a. Activities of Chl-degrading enzymes including chlorophyllase, Chl-degrading peroxidase and pheophytinase as well as Mg-dechelation activity in lime fruit were reduced by hot water treatments. This reduction was more pronounced in fruit treated by hot water for 5 min than in those treated for 3 min. Moreover, heat treatments prolonged storage life by 5 days in fruit treated for 3 min and by 10 days in fruit treated for 5 min. Hot water treatment at 50 °C for 5 min maintained the highest total acidity and delayed the increase of total soluble solids contents during storage. Respiration rate and ethylene production were also reduced by the heat treatments. In conclusion, these results suggest that hot water treatment at 50 °C for 5 min could be a useful method to delay Chl degradation and to maintain postharvest quality in mature green lime during storage at 25 °C.
    Full-text · Article · Feb 2015 · Postharvest Biology and Technology
  • N. Tatmala · S. Kaewsuksaeng · S. Kanlayanarat · M. Buanong
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    ABSTRACT: Effect of Thidiazuron (TDZ) treatments on delaying the senescence of rabbit's foot ferns (Davallia spp.) was investigated by holding fern stems in 0 (control), 5 and 10 μM TDZ, respectively, in an observation room (21 ± 2°C, 70-80% RH, cool-white fluorescence lights for 12 h) throughout experimental period. The results showed that 10 μM TDZ holding treatment significantly delayed the decrease of fresh weight, water uptake and chlorophyll a and b contents, as compared to the control. However, the leaves treated by TDZ exhibited a significantly higher leakage of electrolytes than the control leaves. In addition, holding treatment of 10 μM TDZ significantly prolonged the vase life to 7.3 d while the control stems had the shortest vase life of 5.8 d. In conclusion, the senescence of rabbit's foot ferns was significantly delayed by the holding treatment of 10 μM TDZ.
    No preview · Article · Sep 2012 · Acta horticulturae
  • S. Kaewsuksaeng · S. Aiamla-Or · M. Shigyo · N. Yamauchi
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    ABSTRACT: UV-B irradiation was applied to lime fruit to investigate its effect on chlorophyll degradation and chlorophyll-degrading enzyme activities in stored limes. Lime fruits at the green mature stage were irradiated with UV-B at the dose of 0 (control) and 19.0 kJ m-2. Then, the treated fruits were stored at 25°C in a relative humidity (RH) of 85-90%. UV-B treatment efficiently delayed the decrease of the hue angle value and the contents of chlorophylls a and b. In treated fruits, chlorophyllase, chlorophyll-degrading peroxidase and pheophytinase activities as well as the Mg-dechelation were suppressed. Moreover, the weight loss and the opening of stomata were reduced by UV-B treatment. We concluded that UV-B treatment effectively suppressed chlorophyll degradation in mature green lime during storage, suggesting that this effect could be due to the suppression of chlorophyll-degrading enzyme activities.
    No preview · Article · Apr 2012 · Acta horticulturae
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    ABSTRACT: UV-B irradiation was applied to lime fruit to investigate its effect on chlorophyll (Chl)-degrading enzyme activities and postharvest quality during storage. Mature green lime fruit were irradiated with or without UV-B doses at 19.0 kJ m−2 and then stored at 25 °C in darkness. UV-B treatment efficiently delayed the decrease of hue angle values and Chl a contents. The activities of the Chl-degrading enzymes, chlorophyllase, Chl-degrading peroxidase and pheophytinase in the fruit with UV-B treatment were suppressed and Mg-dechelation activity was also retarded by the treatment. UV-B treatment induced a gradual increase in citric acid and suppressed the increase of sugar contents during storage. In addition, the ascorbic acid content with or without UV-B treatment decreased during storage, but the decrease in the control was faster than that with UV-B treatment. We concluded that UV-B treatment effectively suppressed chlorophyll degradation through the control of chlorophyll-degrading enzyme action and the changes in quality in mature green lime during storage.Highlights► UV-B treatment was effective in retarding degreening in green lime fruit during storage. ► UV-B treatment suppressed chlorophyll degradation through the control of activities of the chlorophyll-degrading enzymes, chlorophyllase, chlorophyll-degrading peroxidase, pheophytinase and Mg-dechelation. ► Quality of lime fruit treated with UV-B was maintained during storage.
    No preview · Article · Aug 2011 · Postharvest Biology and Technology
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    ABSTRACT: Involvement of Mg-dechelatase in relation to chlorophyll (Chl) degradation of stored broccoli (Brassica oleracea L. Italica Group) florets was investigated to clarify the mechanism of Chl degradation. Mg-dechelation activity in floret extracts was found in two different molecular weight fractions - a low molecular weight (<5,000) fraction (LMWF) and a high molecular weight (>5,000) fraction (HMWF), which seemed to be Mg-dechelatase, using chlorophyllin (Chlin) a or chlorophyllide (Chlide) a as a substrate. Mg-dechelation activity of the extract from broccoli florets, which were stored for 4 days at 15°C, was higher than that of extracts from fresh broccoli florets using Chlin a or Chlide a as a substrate. High molecular weight substance (HMWS), which has a Mg-dechelation activity, was purified by (NH4)2SO 4 precipitation (20-60% saturation), molecular exclusion chromatography (Sephacryl S-200), anionic exchange chromatography (DEAE-650M), hydrophobic interaction chromatography (Butyl-650M) and molecular exclusion chromatography (HW-55F). Only one peak of the activity was detected in fresh broccoli extract and no other isozyme with Mg-dechelating action was found in the yellow broccoli extract and molecular mass was about 70 KDa. This high-molecular weight substance shows strong activity with artificial substrate, Chlin a, but hardly have an activity with native substrates, Chlide a. Moreover, low molecular weight substance from 5,000 to 10,000 also had a Mg-dechelation activity. This means that HMWS does not have an activity with Chlide a. It is interpreted by the results obtained in this study that HMWS is not involved in Chl degradation of broccoli florets.
    No preview · Conference Paper · Oct 2010
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    Sukanya Aiamla-ora · Samak Kaewsuksaeng · Masayoshi Shigyo · Naoki Yamauchi
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    ABSTRACT: UV-B irradiation was applied to broccoli florets to investigate its effect on chlorophyll degradation and chlorophyll-degrading enzyme activities in stored broccoli. Broccoli florets were irradiated with UV-B doses at 4.4, 8.8, and 13.1kJm−2 and then kept at 15°C in darkness. We found that a UV-B dose of at least 8.8kJm−2 efficiently delayed the decrease of the hue angle value and the contents of chlorophylls a and b. Chlorophyllide a and 132-hydroxychlorohyll a gradually decreased with senescence. Pheophorbide a and pyropheophorbide a levels were significantly higher in broccoli without UV-B treatment. Chlorophyllase and chlorophyll-degrading peroxidase activities with UV-B treatment were suppressed, as well as the activity of Mg-dechelatase. Mg-dechelating substance activity was also suppressed with this treatment. We concluded that UV-B treatment effectively suppressed chlorophyll degradation in broccoli florets during storage, suggesting that the effect could be due to the suppression of chlorophyll-degrading enzyme activities.
    Full-text · Article · Jun 2010 · Food Chemistry
  • S. Kaewsuksaeng · A. Uthairatanakij · S. Kanlayanarat
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    ABSTRACT: The effects of high O2 atmosphere (HOA) on peel browning and phenolic metabolism in longan were examined. Fruit cv. Daw at the commercial ripe stage were held in controlled atmosphere (CA) chambers flushed with 50, 60, 70 or 80 kPa O2 (balance nitrogen) or air (control) at 4°C and 95% relative humidity. Pericarp browning rapidly increased during storage accompanied by an increase in polyphenol oxidase (PPO) activity. In contrast, phenylalanine ammonia lyase (PAL) activity decreased during storage. The decrease in PAL activity in HOA was greater than in air. CA storage in 70 kPa O2 reduced browning and PPO activity. The phenolics content of HOA stored fruit was higher than in fruit stored in air as a consequence of the reduction in PPO activity.
    No preview · Article · Apr 2010 · Acta horticulturae
  • S. Kaewsuksaeng · A. Uthairatanakij · S. Kanlayanarat
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    ABSTRACT: Longan (Dimocarpus longan Lour.) fruit cv. Daw harvested at the commercial stage were enclosed in controlled atmosphere (CA) chambers ventilated with 2 or 4% O2 combined with 5 and 15% CO2 (balance N2) or air (control) at 4°C and 95% relative humidity. The changes in respiration, ethylene production and weight loss were evaluated at 5 day interval. CA-stored fruits had lower rates of respiration than those fruits stored in air throughout storage. CA totally inhibited the rise in ethylene production as manifested by fruits in normal atmosphere. CA also reduced weight loss, with the CO2 level exerting a more dominant effect than low O2·Of the atmospheres applied, the combination of 2% O 2 and 15% CO2 had the greatest impact at reducing respiration, ethylene production and weight loss.
    No preview · Article · Apr 2010 · Acta horticulturae
  • S. Kaewsuksaeng · A. Uthairatanakij · V. Srilaong · S. Kanlayanarat
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    ABSTRACT: Longan fruit cv. Daw at the commercial ripe stage were held in controlled atmosphere (CA) chambers applied with 2 or 4 kPa O2 plus 5 or 15 kPa CO2 (balance nitrogen) or air (control) at 4°C with 95% relative humidity. CA levels in 2 kPa O2 treatments were effectively inhibited pericarp browning relative to the control, whilst 4 kPa O2 treatments were not consistently better than the control. Polyphenol oxidase (PPO) activity correspondingly decreased resulting to reduced phenolics oxidation indicated by retention of higher phenolics content than that in air. Phenylalanine ammonia lyase (PAL) also decreased and may have contributed to the reduction of browning. Most effective CA level was 2 kPa O2 plus 15 kPa CO2, retarding browning by 10 days. However, pulp ethanol content increased in CA-stored fruits.
    No preview · Article · Apr 2010 · Acta horticulturae

  • No preview · Article · Dec 2008 · Acta horticulturae
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    ABSTRACT: The effects of heat treatment on the formation of chlorophyll (Chl) derivatives and Chl-degrading enzyme activities in stored broccoli (Brassica oleracea L. Italica Group 'Ryokutei') florets were determined. The Chl a level barely changed during heat treatment, but each Chl a derivative level changed. Chlorophyllide (Chlide) a, pheophorbide (Pheide) a, C13 2 -hydroxychlorophyll (C13 2 -OHChl) a, Chl a', an isomer of Chl a, and pheophytin (Phy) a were detected as a Chl derivative during heat treatment and during storage after treatment. Chlide a, Pheide a, and C13 2 -OHChl a levels decreased during 2-h heat treatment (50°C), whereas Chl a' and Phy a levels increased. Chl-degrading enzyme activities, in particular, Mg-dechelation activity, were effectively suppressed after 2 h of heat treatment. The content of Chls a and b in control broccoli florets decreased greatly during storage at 15°C, while the content in heat-treated broccoli florets hardly changed at all. In Chl derivatives, the Pheide a level in broccoli florets treated with or without heat treatment, especially the former, increased appreciably during storage. The Chlide a level in control florets decreased markedly during storage. On the other hand, the Chlide a level in heat-treated broccoli florets did not change during storage. Mg-dechelation activity in control florets markedly increased after 4 days of storage at 15°C, but the enhancement of the activity was suppressed by heat treatment. These findings suggest that Chl derivatives, especially Pheide a, are accumulated as intermediates in heat-treated broccoli florets, and Mg-dechelating action, in conjunction with that of chlorophyllase and Chl-degrading peroxidase, could be involved in Chl degradation in stored broccoli florets.
    Full-text · Article · Oct 2007 · Journal- Japanese Society for Horticultural Science
  • S. Kaewsuksaeng · S. Kanlayanarat · N. Yamauchi · M. Shigyo
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    ABSTRACT: Effect of heat treatment on Mg-dechelation activity in stored broccoli (Brassica oleracea L. Italica Group) florets was determined. Chlorophylls (Chls) a and b contents in the control broccoli florets decreased greatly during storage at 15°C, while the content changed very little in heat-treated broccoli florets. Mg- dechelation activity was found in two different molecular weight fractions - a low molecular weight (5,000-10,000) fraction (LMWF) and a high molecular weight (more than 10,000) fraction (HMWF), which seemed to contain Mg-dechelatase. The activities of both fractions in the control broccoli florets increased during storage at 15°C, but the enhancement of the activity was suppressed by heat treatment. Thus, Mg-dechelation activities in LMWF and HMWF are involved in Chl degradation of stored broccoli florets, and the suppression of yellowing in heat- treated broccoli florets could be in part due to the inhibition of Mg-dechelating action by heat treatment.
    No preview · Article · Aug 2007 · Acta horticulturae
  • S. Kaewsuksaeng · N. Yamauchi · Y. Funamoto · M. Shigyo · S. Kanlavanarat
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    ABSTRACT: The effect of storage temperature on Mg-dechelation activity and the formation of chlorophyll (Chl) derivatives in stored broccoli (Brassica oleracea L.) florets were determined. The hue angle levels of broccoli florets declined during storage at 15°C, whereas those levels showed almost no change at 4°C. Chls a and b contents in broccoli florets decreased greatly after 4 days of storage at 15°C, whereas the contents at 4°C hardly showed any change for the first 3 days of storage at 4°C and then decreased slightly. Chlorophyllide (Chlide) a, pheophorbide (Pheide) a, pyropheophorbide (Pyropheide) a, C132-hydroxychlorophyll (C132-OHChl) a and pheophytin (Phy) a as Chl a derivatives were detected during storage by HPLC analysis. Chlide a, C132-OHChl a and Phy a levels in broccoli florets decreased concomitantly with the enhancement of Pheide a and Pyropheide a levels during storage at 15°C. The Mg-dechelation activity increased after 4 days of storage at 15°C, while the activity at 4°C decreased. These findings suggest that Mg-dechelating action together with chlorophyllase could be involved in Chl degradation in stored broccoli florets.
    No preview · Article · Jun 2006 · Acta horticulturae
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    ABSTRACT: The effects of heat treatment on the formation of chlorophyll (Chl) derivatives and Chl-degrading enzyme activities in stored broccoli (Brassica oleracea L. Italica Group ‘Ryokutei’) florets were determined. The Chl a level barely changed during heat treatment, but each Chl a derivative level changed. Chlorophyllide (Chlide) a, pheophorbide (Pheide) a, C132-hydroxychlorophyll (C132-OHChl) a, Chl a′, an isomer of Chl a, and pheophytin (Phy) a were detected as a Chl derivative during heat treatment and during storage after treatment. Chlide a, Pheide a, and C132-OHChl a levels decreased during 2-h heat treatment (50°C), whereas Chl a′ and Phy a levels increased. Chl-degrading enzyme activities, in particular, Mg-dechelation activity, were effectively suppressed after 2 h of heat treatment. The content of Chls a and b in control broccoli florets decreased greatly during storage at 15°C, while the content in heat-treated broccoli florets hardly changed at all. In Chl derivatives, the Pheide a level in broccoli florets treated with or without heat treatment, especially the former, increased appreciably during storage. The Chlide a level in control florets decreased markedly during storage. On the other hand, the Chlide a level in heat-treated broccoli florets did not change during storage. Mg-dechelation activity in control florets markedly increased after 4 days of storage at 15°C, but the enhancement of the activity was suppressed by heat treatment. These findings suggest that Chl derivatives, especially Pheide a, are accumulated as intermediates in heat-treated broccoli florets, and Mg-dechelating action, in conjunction with that of chlorophyllase and Chl-degrading peroxidase, could be involved in Chl degradation in stored broccoli florets.
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    Samak Kaewsuksaeng
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    ABSTRACT: One of the symptoms of senescence in harvested horticultural crops is the loss of greenness that comes with the degradation of chlorophyll. With senescence, the chlorophyll-degrading enzyme activities such as chlorophyllase, Mg-dechelatase or Mg-dechelation activity, a new chlorophyll-degrading enzyme, pheophytinase, pheophorbidase and chlorophyll-degrading peroxidase, which are involved in chlorophyll degradation, affected greatly in stored horticultural crops. The chlorophyll derivatives, especially chlorophyllide, pheophytin, pheophorbide and C13 2 -hydroxychlorophyll are accumulated as intermediates of chlorophyll degradation. In addition, chlorophyll degradation by the chlorophyll-degrading enzymes seems to occur in the thylakoid and envelope membrane of chloroplast and/ or the vacuole. The involvement of chlorophyll-degrading enzymes in senescing horticultural crops is also discussed.
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