Various minerals in Kelulut honey possess a high value in human health and are crucial in regulating multiple biological metabolisms. However, each mineral from different honey sources needs to be monitored to avoid contamination and food poisoning. In addition, the amount of minerals content varies based on geographical region and nectar sources. This study aims to identify and determine the minerals content in Kelulut honey samples collected from different locations on the West Coast of Sabah. The samples were analyzed using ICP-OES, and a total of 20 minerals elements (Ag, Al, As, Ca, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Rb, Se, Sr, Ti, V, and Zn) were presented. The most abundant minerals which are categorized as macro minerals present in all the samples are K (1821.253 ± 35.16 mg/kg), followed by Na (371.00±5.06 mg/kg), Ca (338.643±3.07 mg/kg), and Mg (98.899±1.77 mg/kg). While from the group of minor minerals, Zn had the highest amount with a mean concentration of 6.38±10.35 mg/kg, followed by Mn (2.04±1.61 mg/kg), Cu (1.26±2.97mg/kg). No toxic elements were detected except for Ag (0.06±0.01 mg/kg), considered unbeneficial minerals, and the concentration was considered no harmful effect on the biological system.

Heavy metals pollution has now become a serious environmental problem worldwide especially in Malaysia River. As a precaution, continuous environmental monitoring is needed to minimize heavy metal to the ecosystem. Inhibitive enzyme assay based on enzyme including cholinesterase has been introduced as a rapid, cheap and reliable method to assess the level of contamination in the river. In this study, the Asian swamp eel, Monopterus albus, was selected and determined of the sensitivity level towards heavy metals. The liver of M. albus was extracted and purified using ion exchange chromatography of which DEAE sepharose as the matrix of the column. Based on the Ellman assay, cholinesterase was obtained at 4.86 purification fold with the percentage recovery of 30.32 %. The enzyme works optimally at pH 9 (0.1 M Tris-HCl buffer) and 25 °C, while BTC; 369×103 U.mg−1 was selected as the preferable substrate which shows highest catalytic efficiencies compared to ATC and BTC at 1457 × 103, 1220 × 103 and 488 × 103 Vmax.Km−1, respectively, Cholinesterase was tested with eight metal ions at the concentration of 5 ppm and the ascending order of inhibition is as followed; arsenic = chromium ⩽ plumbum ⩽ copper ⩽ argentum = nickel < mercury. From this study, the ability of cholinesterase partially purified from the liver tissue of M. albus has the potential to be an assay for heavy metals.

Affinity chromatography for acetylcholinesterase; AChE namely Procainamide Sepharose CL-6B was synthesised through the coupling method between soluble procainamide hydrochloride immobilised by a cross-linked agarose size exclusion, sepharose CL-6B. 1, 4-butanediol diglycidyl ether plays a role in building up a productive and rigid connecting of a biospecific ligand (Procainamide hydrochloride) to an insoluble matrix (Sephacryl CL-6B). Local freshwater eel brain was extracted and centrifuge at high speed. The supernatant was collected, and seven different volumes were separately loaded on to the column for isocratic purification where 12 fractions were collected at the end of elution stage. This study shows 1000 μL of extractant; considered as the maximum volume to load onto the column. Lastly, a stepwise elution was performed with five different concentrations of NaCl, and each of 1 mL fraction was collected then assay for determination of enzyme activity and protein content. The data shows AChE was successfully purified with percentage recovery of 38 % after 21 purification fold. Kinetic study strengthens the data where the efficient coefficient ratio of ATCi was much higher compared to PTCi and BTCi at 3.03, 2.67 and 1.52 Vmax⋅Km −1, respectively, prove that the collected fraction predominantly contained with AChE, which is a targeted enzyme to be used as a sensitive biosensor to detect the presence of carbamate and organophosphate contamination in the environment.

Over the centuries, honey is known for its superior usage in culinary, and for its rich nutrition and therapeutic values which are scientifically proven in the medical field. The chemical composition of honey varies depending on its botanical sources and environment. Therefore, the nutrition content in honey is highly likely to be affected by contaminants, such as heavy metals and pesticides. To ensure the quality of honey, parameters such as the heavy metal content should be within the safe range of total standard mineral and trace elements as defined by the International Food Standard (Codex Alimentarius), and pesticides should not be present at all. The high concentration of heavy metal and pesticides not only deteriorates the quality and quantity of honey, but also causes harm to the bee colony itself. In the agriculture sector, the excessive usage of pesticides and fertilizer negatively impacts the overall honey production process. Bees, a pollinating agent, bring the polluted nectar back to their beehives, eventually contaminating the honey and depreciating its value. Hence, this article will comprehensively review the activities that contribute to heavy metal and pesticide contamination, the interactions of bees as a pollinating agent, the impact of the pollutant to the colonies, and subsequently to the honey production.