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Eco-friendly pectin/BCG film sensor: a smartphone-compatible platform for gamma-aminobutyric acid detection
(2026-05-01)
Niamlaoong, Rungthiwa
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Teerasong, Saowapak
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Phengdaam, Apichat
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Tantirungrotechai, Yuthana
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Wattanasin, Panwadee
This work introduces a biodegradable pectin–bromocresol green (BCG) film integrated into a microplate platform for the colorimetric determination of gamma-aminobutyric acid (GABA). The sensing mechanism relies on electrostatic ion-pair formation between the protonated amine group of GABA (-NH₃+) and the sulfonate group of BCG, producing a distinct color transition from yellow to green. The resulting colorimetric response was quantitatively analyzed using a smartphone-assisted RGB system coupled with ImageJ software. Molecular modelling provided insight into the interaction mechanism and indicated that the GABA-BCG association is dominated by electrostatic interactions. Under optimized conditions, the developed assay exhibited a wide linear range (0.1–1000 mg L−1) with detection and quantification limits of 0.07 mg L−1 and 0.22 mg L−1, respectively. Good analytical precision was achieved (%RSD ≤ 5%), while negligible interference from common amino acids, vitamins and food additives was observed. The method was successfully applied to beverage and dietary supplement samples, demonstrating good agreement with HPLC analysis. The biodegradable BCG–pectin film platform provides a rapid, low-cost, and portable approach for GABA determination and represents a promising sensing strategy aligned with the principles of green analytical chemistry.
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Genomic comparison of gamma-aminobutyric acid-producing Levilactobacillus brevis and Companilactobacillus zhachilii strains from Thai fermented foods
(2025-01-01)
Pakdeeto, Amnat
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Phuengjayaem, Sukanya
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Kingkaew, Engkarat
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Tungkajiwangkoon, Santhita
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Phitchayaphon, Chantharat
Importance of the work: The GABA-producing Companilactobacillus zhachilii isolated from fermented pork (‘nham’) demonstrates both efficacy and safety in GABA production. Objectives: To identify the GABA-producing strains ASK-1 and ANB-1 to compare their genomes with those of Levilactobacillus brevis and Companilactobacillus zhachilii strains. Materials and Methods: Two fermented food samples were collected and used for the isolation of lactic acid bacteria. The strains obtained were evaluated for GABA production. The selected strains were identified based on their phenotypic and genotypic characteristics. Genomic comparisons of the GABA-producing strains were performed using genome sequencing, assembly, annotation and comparative analysis. This analysis included the examination of CRISPR regions, antimicrobial genes, functional attributes and genome visualization. Results: The GABA-producing lactic acid bacteria (ASK-1 and ANB-1) were isolated from traditional Thai fermented foods (‘sai-krog-prieo’ and ‘nham’). The strains ASK-1 and ANB-1 produced 9.12 ± 0.51 g/L GABA and 12.73 ± 0.57 g/L GABA, respectively. On the basis of phenotypic characteristics and 16S rRNA gene sequencing, strain ASK-1 presented 100% sequence similarity to Levilactobacillus brevis ATCC 14687T, whereas ANB-1 presented 99.93% similarity to Companilactobacillus zhachilii HBUAS52074T. Genome analysis identified ASK-1 as L. brevis ATCC 367, with an average nucleotide identity based on a BLAST (ANIb) value of 98.86% and ANB-1 with an ANIb value of 96.92%, to C. zhachilii HBUAS52074T. Additionally, genomic studies revealed GABA-producing genes (gadA and gadB) via the KofamKOALA-KEGG Orthology database. Main finding: Levilactobacillus brevisASK-1 and Companilactobacillus zhachiliiANB-1 efficiently and safely produced GABA and exhibited probiotic properties, making them promising starter cultures for functional food production in both local food and industrial fermentation processes.
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The decoration of ZnO nanoparticles by gamma aminobutyric acid, curcumin derivative and silver nanoparticles: Synthesis, characterization and antibacterial evaluation
(2021-02-01)
Talodthaisong, Chanon
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Plaeyao, Kittiya
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Mongseetong, Chatariga
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Boonta, Wissuta
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Srichaiyapol, Oranee
Zinc oxide nanoparticles (ZnO NPs) are applied in various applications in catalysis, bio-sensing, imaging, and as antibacterial agents. Here we to prepare ZnO nanomaterials decorated by γ-amino butyric acid (GABA), curcumin derivatives (CurBF2) and silver nanoparticles (CurBF2-AgNPs). The structures of all ZnO nanostructures were characterized using Fourier transform in-frared (FT-IR) spectroscopy, X-ray diffraction (XRD), UV–VIS spectrophotometry, fluorescence spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HR-TEM). Further, their antibacterial activities against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria were investigated through analysis of minimum inhibitory concentration (MIC) method. Among the prepared nanostructures, the ZnO NPs-GABA/CurBF2-AgNPs showed excellent antibacterial activity against both Gram-positive and-negative bacteria. ZnO NPs fabricated here may have potential use in future anti-bacterial compositions and coatings technologies.
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Influence of geographical and genetic variation on GABA content in Annona muricata grown in Thailand
(2020-12-08)
Deewatthanawong, R.
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Tontiworachai, B.
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Kongchinda, P.
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Chanapan, S.
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Sriwilaiwan, S.
Annona is a genus of tropical fruit trees in the family Annonaceae. Fruit pulp of Annona muricata contained the highest amount of gamma-aminobutyric acid (GABA) among Annona species. GABA content results from many factors including genetic makeup and environment. Influences of genetic variation and geographical environment on GABA content in fruit pulp of A. muricata were determined. To study genetic variation, sequences of ITS2 and psbA-trnH were used to construct phylogenetic trees. Young leaves of A. muricata were collected from different geographical locations including Chumphon, Trang, Nakhon Ratchasima, Nakhon Si Thammarat, Buriram, Nong Khai, Udon Thani, and Prachuap Khiri Khan Provinces in Thailand. Sequences of ITS2 and psbA-tmH were aligned and data sets were analyzed using maximum likelihood (ML) and neighbor-joining (NJ) methods. ITS2 sequence variations were observed within and among samples from different locations. A. muricata fruit harvested from eight provinces, namely Chumpon, Trang, Nakhon Ratchasima, Nakhon Si Thammarat, Buriram, Nong Khai, Udon Thani, and Prachuap Khiri Khan contained 19.75, 35.02, 32.91, 28.18, 42.37, 32.17, 65.02, and 31.58 mg 100 g-1 FW GABA, respectively. Findings indicated that both geographical environment and genetic variation had significant effects on GABA content in A. muricata fruit.

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