Pongphen Jitareerat

The application of plasma-activated water and biostimulants offers a sustainable approach to supporting plant growth under reduced-nutrient conditions by supplying bioavailable nitrogen. This study investigated the growth and postharvest performance of hydroponically grown cos lettuce (Lactuca sativa L.) supplied with three Hoagland-based nutrient treatments: half-strength solution prepared with tap water (HS), half-strength solution with plasma-activated water (HS+PAW), and half-strength solution with plasma-activated water containing 1 mL L⁻¹ milk protein hydrolysate (HS+PAW+MPH). Plants treated with PAW, particularly those in the HS+PAW+MPH, exhibited increases in growth, biomass accumulation, and mineral composition, with reduced nitrate content compared to controls. At harvest, lettuce under HS+PAW+MPH exhibited nearly double fresh yield and enhanced dry matter, protein, lipid, phenolic, and flavonoid profiles as well as increased antioxidant capacity, indicating improved nitrogen utilization and nutritional quality under reduced nutrient input. Postharvest quality was evaluated by packing samples in polypropylene bags and storing them at 10 ± 1 °C and 95–98% relative humidity for 21 days. The HS+PAW+MPH treatment substantially suppressed respiration and production of ethylene, limited weight loss and color change, and better preserved pigments, bioactive compounds, and antioxidant stability compared to HS and HS+PAW, indicating HS+PAW+MPH as a sustainable nutrient management approach for hydroponic systems.

Protein hydrolysates (PHs), including milk‐derived PH (MPH), are sustainable biostimulants that can enhance crop yield, quality, and stress tolerance in hydroponic systems while reducing chemical fertilizer dependance. The MPH tested was produced by acid hydrolysis, giving a high degree of hydrolysis and a profile dominated by free amino acids, principally glutamic acid, aspartic acid, proline, leucine, and valine, with organically bound nitrogen and minerals. Cos lettuce ( Lactuca sativa L.) was grown across cool, summer, and rainy seasons under a half‐strength control (HS), HS with 1 mL L ⁻¹ MPH (HS + MPH1), and full‐strength with 1 mL L ⁻¹ MPH (FS + MPH1). HS + MPH1 increased fresh yield over HS in all seasons (+13% cool, +25% summer, +46% rainy); the largest relative gain occurred in the rainy season, whereas the highest absolute yield and strongest overall response occurred in the cool season. In the cool season, HS + MPH1 raised total phenolics and flavonoids (+61%–62%), enriched hydroxycinnamic and hydroxybenzoic acid derivatives and flavonoids, and markedly increased catalase (CAT, +496%), peroxidase (POD, both +137%), and superoxide dismutase (SOD, +60%). All minerals increased, particularly calcium, magnesium, iron, phosphorus, and potassium (+19%–56%), along with the dominant amino acids aspartic, glutamic, and leucine (+52%–59%). HS + MPH1 also lowered nitrate (−15% to −22%) and bitterness‐associated sesquiterpene lactones (SL, −48% to −62%), while FS + MPH1 added minerals but did not exceed HS + MPH1 for growth or quality. The summer and rainy seasons retained quality under suboptimal conditions, with HS + MPH1 showing the greatest relative gain in protective metabolites in summer (flavonoids + 135%). Our findings support MPH as a nitrogen‐centered biostimulant, with its readily assimilable amino acids serving as organic nitrogen reservoirs and protein‐synthesis substrates, supporting nitrogen assimilation, osmoprotection, and phenylpropanoid pathways. Multivariate analysis supported HS + MPH1 as the most effective treatment, an environmentally friendly strategy to optimize Cos lettuce yield, quality, and seasonal adaptability under reduced nutrient input.

To meet global food demand, agricultural systems must enhance crop performance, productivity, and sustainability. Biostimulants have emerged as a promising strategy, particularly in vegetable production, due to their ability to enhance plant growth and resilience. This study characterized milk-derived protein hydrolysates (MPH) produced from expired milk and evaluated their potential as biostimulants for hydroponic cos lettuce. Hydrolysis of expired milk with hydrochloric acid achieved 94.55% hydrolysis and yielded 80.77% free amino acids. MPH was applied at volumes of 0, 1, 3, and 5 mL L⁻¹ in combination with Hoagland and Arnon nutrient solution. The 1 mL L⁻¹ (MPH1) treatment significantly increased shoot and root biomass and canopy size while reducing nitrate accumulation and enhancing total flavonoid and ascorbic acid content, as well as antioxidant capacity. HPLC analysis showed that MPH1 treatment promoted the accumulation of key metabolites, including vanillic acid, para-coumaric acid, salicylic acid, ferulic acid, gallic acid, syringic acid, quercetin, myricetin, and naringenin. MPH1 improved uptake of phosphorus, potassium, calcium, magnesium, and iron, contributing to mineral biofortification and nutritional quality. These results demonstrate that MPH at 1 mL L⁻¹ is an effective biostimulant, improving yield and quality while reducing nitrate levels in hydroponically grown cos lettuce, offering a sustainable solution for food waste valorization.

Nitric oxide has been identified as a chemical compound that can prolong the vase life of various cut flowers. The effects of sodium nitroprusside, a nitric oxide donor, on 1-aminocyclopropane-1-carboxylate synthase and 1-aminocyclopropane-1-carboxylic Acid oxidase activities, ethylene production, respiration, bud opening, and electrolyte leakage and lipid peroxidation during post-harvest storage of cut inflorescences of Dendrobium cv. “Planty Fushia” orchid were evaluated. Inflorescences kept in 10 µmol L-1 sodium nitroprusside solution at room temperature (23±2°C) had longer vase life compared to controls in distilled water. Sodium nitroprusside increased vase life due to 1-aminocyclopropane-1-carboxylate synthase and 1-aminocyclopropane-1-carboxylic acid oxidase a activities in buds and open flowers, thereby reducing ethylene production. Electrolyte leakage, malondialdehyde and respiration were also lower in plants treated with sodium nitroprusside compared to controls. In addition, sodium nitroprusside treatment increased the percentage of buds that opened. Therefore, sodium nitroprusside can be used to prolong the vase life of cut inflorescences of Dendrobium for 4 days at room temperature. The results indicate that sodium nitroprusside solution significantly affected the vase life of cut inflorescences of Dendrobium, 10 µmol L-1 sodium nitroprusside could significantly increase bud opening and prolong vase life compared to the control.

Methyl bromide fumigation aims to control insect infestation in mangosteen fruit before export which leads to reduce the fruit quality. Thus, the objective of this study was to control the quality of methyl bromide fumigated mangosteen using integrated postharvest technology. Fruit were prepared by fumigating with 32 g m^-3 for 2 hours, washed with tap water, surfaced disinfestation with sodium hypochlorite. The prepared fruit samples were divided to treat with different methods as follows; 1) fruit were coated with ethanolic shellac-modified coconut oil (ES-MCO) and then packed in low density polyethylene (LDPE) bag containing ethylene inhibitor (1-MCP sachet), 2) fruit were coated with ES-MCO and packed in LDPE bag, 3) fruit were treated with ES-MCO and packed in nylon net bag, and 4) fruit were non-coated and packed in nylon net bag (control). All fruit samples were kept at 13ºC for 20 days (as the shipment stimulation) and then transferred to 25ºC for 2 days (as the shelf-life stimulation). The results revealed that after 15 days of storage fruit were treated with ES-MCO + LDPE bag + 1-MCP sachet showed the highest reduction of fruit rot disease and this treatment helped to delay the drying and browning of mangosteen calyx, chlorophyll degradation of the calyx, and reduce weight loss, the respiration rate and ethylene production. However after storage for 20 days, the pericarp of mangosteen in fruit treated with ES-MCO + LDPE bag + 1-MCP sachet became hard, and its shelf-life was 15 days.