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Khao-Mao producer group in Thailand’s Nakhon Phanom province’s Phon Sawan district, Na Hua Bo sub-district is a community that has produced Khao-Mao according to conventional wisdom, for a very long time. Khao-Mao has an emerald, green color, fragrant, delicate texture, and delicious taste, however the essential nutritional facts are not provided. Consequently, this study’s goal was to evaluate nutritional values by proximate analysis. All 6 types of young flattened rice-: Laos Wan, Kor Khor 6(RD6), Ai Lueng, San Pa Tong, Yee Pun, and Hom Nang Nuan have phenolic compounds by Folin-Ciocalteu method and antioxidant properties by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. According to the findings, rice's primary constituents are carbohydrates, which range from 69.76 to 73.07 %, protein, which ranges from 4.79 to 6.11 %, crude fat, which ranges from 1.68 to 2.22 %, fiber, which ranges from 0.00 to 0.03 % moisture, which ranges from 17.96 to 21.31 %, and ash, which ranges from 1.13 to 1.70 %. The San Pa Tong Khao-Mao has the highest 6.11% of protein content. Ai Lueng Khao-Mao has the greatest levels of total phenolic compounds, 0.79 mg/g dry weight. The DPPH radical scavenging assay test was used to measure the antioxidant activity. Their half-maximal inhibitory concentration (IC50) value falls between 1.18 and 2.00 mg/mL. The Hom Nang Nuan Khao-Mao has the lowest 1.18 mg/mL of IC50. According to the study’s findings, this community’s Khao-Mao has good nutritional and antioxidant properties. HIGHLIGHTS Khao-Mao has high proximate composition and high energy value Khao-Mao has relatively high quantities of protein and phenolic compounds Khao-Mao is a dish with a high-level antioxidant activity GRAPHICAL ABSTRACT

This study describes the preparation, characterization, and application of a new magnetic chitosan–graphene quantum dots (Fe 3 O 4 @Chi–GQDs) nanocomposite as an adsorbent for the preconcentration of Cu(II) in Thai food recipes or the so-called “Som Tam” (green papaya salad) prior to determination by inductively coupled plasma–optical emission spectrometry. The spectroscopic and magnetic properties along with the morphology and thermal property were analyzed using FTIR, EDX, XRD, TGA, VSM, and TEM. Preconcentration optimizations including pH, dosage of adsorbent, adsorption–desorption time, concentration and volume of elution solvent, sample volume and enrichment factor, and reusing time were investigated. Good linearity was obtained ranging from 0.05 to 1500 µg L −1 with correlation coefficient of 0.999. Limit of detection was 0.015 µg L −1 . Relative recoveries of 85.4–107.5% were satisfactorily obtained. This Fe 3 O 4 @Chi–GQDs has high potential to be used as preconcentration method and can be reused 7 times with high extraction efficiency.

For the extraction and determination of trace amounts of Sudan I–IV dyes in chili product samples, a simple and efficient liquid phase microextraction technique was developed using electrolyte-assisted microemulsion breaking in vortex-agitated solidified floating organic drop microextraction (VA-SFODME-EAMB) and high performance liquid chromatography. Under optimal conditions, 5.0 mL of sample solution yielded a pre-concentration factor of 62. Linearity (0.5–2500 ng mL−1, R2 > 0.99), the limit of detection (0.16–0.24 ng mL−1), and the limit of quantification (0.53–0.80 ng mL−1) were used to validate this method. The precision, expressed as relative standard deviation (% RSD), was calculated using seven and five experiments with mixed Sudan dyes at a concentration of 500 ng mL−1. Intra- and inter-day analyses validated the % RSD precision data (

A selective fluorescent sensor based on graphene quantum dots (GQDs) was developed for the determination of silver ions (Ag+). The GQDs were prepared by the citric acid pyrolysis method. In the presence of mercury ions (Hg2+), the fluorescence intensity of the GQDs decreased linearly and it was fully recovered by the hydrolysis of thioacetamide (TAA), giving hydrogen sulfide in the reaction system. This research study was aimed at using the fluorescence turn-off sensor for the selective determination of Ag+. Upon the addition of Ag+, the fluorescence intensity of the generated sulfide-(Hg2+ quenched GQDs) decreased as a linear function of the Ag+ concentration. Then, the acquired GQDs showed steady, selective, and highly sensitive detection of Ag+. The experimental parameters affecting the fluorescence turn-on/off sensor were investigated and optimized. The optimum conditions included 4 μM Hg2+ concentration, 70 μM TAA concentration, solution pH of 7 and a 5 min reaction time. Under the optimized conditions, the working linear concentration range, limit of detection and limit of quantification for Ag+ were 0.5–10.0, 0.18 and 0.60 μM, respectively. The proposed method was successfully applied for the selective determination of trace amounts of Ag+ in five real water samples with satisfying levels of recovery (89.31–114.08%).

This study describes the preparation, characterization, and application of a new magnetic chitosan-graphene quantum dots (Fe