Margaux Lim Ah Tock

Mrs. Margaux Lim Ah Tock

Tshwane University of Technology, Pretoria, Gauteng, South Africa
orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 July 2022 in Antibiotics
Verified
Journal Article
Open access
PDF file
MTMargaux Lim Ah Tock
Margaux Lim Ah Tock
SCSandra Combrinck
Sandra Combrinck
GKGuy P.P. Kamatou
Guy P.P. Kamatou
WCWeiyang Chen
Weiyang Chen
Sandy Van VuurenSandy Van Vuuren
Sandy Van Vuuren
AVAlvaro Viljoen
Alvaro Viljoen
Salvia africana-lutea L., S. lanceolata L., and S. chamelaeagnea L. are used in South Africa as traditional medicines to treat infections. This paper describes an in-depth investigation into their antibacterial activities to identify bioactive compounds. Methanol extracts from 81 samples were screened against seven bacterial pathogens, using the microdilution assay. Biochemometric models were constructed using data derived from minimum inhibitory concentration (MIC) and ultra-performance liquid chromatography-mass spectrometry data. Active molecules in selected extracts were tentatively identified using high-performance thin layer chromatography (HPTLC), combined with bioautography, and finally, by analysis of active zone eluates by mass spectrometry (MS) via a dedicated interface. Salvia chamelaeagnea displayed notable activity towards all seven pathogens, and the activity, reflected by MICs, was superior to that of the other two species, as confirmed through ANOVA. Biochemometric models highlighted potentially bioactive compounds, including rosmanol methyl ether, epiisorosmanol methyl ether and carnosic acid. Bioautography assays revealed inhibition zones against A. baumannii, an increasingly multidrug-resistant pathogen. Mass spectral data of the eluted zones correlated to those revealed through biochemometric analysis. The study demonstrates the application of a biochemometric approach, bioautography, and direct MS analysis as useful tools for the rapid identification of bioactive constituents in plant extracts.

4 May 2026 in Foods
Verified
Journal Article
Open access
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Kayise Hypercia MasekoKayise Hypercia Maseko
Kayise Hypercia Maseko
MTMargaux Lim Ah Tock
Margaux Lim Ah Tock
AVAlvaro Viljoen
Alvaro Viljoen
PBPaul Bartels
Paul Bartels
TRThierry Jean Claude Regnier
Thierry Jean Claude Regnier
Belinda MeiringBelinda Meiring
Belinda Meiring
The growing demand for sustainable alternative proteins has intensified interest in fungal mycelia as a nutrient-dense biomass for food applications. This study compared Pleurotus ostreatus fruiting bodies with mycelia grown in liquid state on amaranth seed- and Bambara groundnut-based media, evaluating aroma-active volatiles and amino acid composition. Across 52 identified volatiles, C8 oxylipin-derived compounds dominated all matrices, with exceptionally high odour activity values (OAVs) for 1-octen-3-one (~4.1 × 103), 3-octanone (~1.5 × 103), 1-octen-3-ol (~8.3 × 102) and 3-octanol (~5.3 × 102). Amaranth-grown mycelia showed intensified mushroom/green/fatty notes due to elevated C8 ketones and unsaturated aldehydes, whereas Bambara-grown mycelia exhibited reduced C8 prominence and stronger malty, nutty and fermented nuances driven by Ehrlich-pathway aldehydes (e.g., 3-methylbutanal ~2.0 × 103), with floral contributions from linalool (~3.8 × 102). Mycelial protein contents ranged from 35.8 to 36.1 g/100 g (amaranth) and up to 38.2 g/100 g (Bambara), compared with 39.5 g/100 g in the fruiting body. Amino acid scores (AAS) identified cystine + methionine as limiting; mycelia exhibited higher AAS, with more indispensable amino acids exceeding reference requirements. Elevated glutamic and aspartic acids underscore the umami potential of the mycelial biomass. Overall, these plant-based substrates can strategically modulate both flavour chemistry and amino acid balance in P. ostreatus mycelia, supporting their use as nutritionally relevant, flavour-active ingredients in alternative protein and hybrid food systems.

17 September 2026 in South African Journal of Botany
Verified
Journal Article
Open access
KMKoketso Mothobi
Koketso Mothobi
MTMargaux Lim Ah Tock
Margaux Lim Ah Tock
ENEfficient Ncube
Efficient Ncube
WCWeiyang Chen
Weiyang Chen
MSMaxleene Sandasi
Maxleene Sandasi
AVAlvaro Viljoen
Alvaro Viljoen