Development of prototype sensor for sugar adulteration detection in malaysian stingless bee honey /
Wan Nadja Julika Binti Wan Hamizan
- Pahang : UMP, 2022
- xvi,156 pages : Illustration ; 30 cm.+ 1-CD ROM
Faculty of Chemical and Process Engineering Technology
Thesis (Doctor of Philosophy) -- Universiti Malaysia Pahang – 2023
The growing demand for honey in the market has resulted in tampering honey with foreign substances and increased production of artificial honey. There are lots of laboratory tests for honey adulteration. However, most of the tests are tedious, costly, and complicated. As a result, alternative approaches for faster and simpler detection of honey adulteration should be developed and conducted regularly. Herein, this research attempts to develop paper-based analytical devices (PADs) as a simple, rapid, and inexpensive method for simultaneously detecting glucose and sucrose adulteration in stingless bee honey. Prior to developing the PADs, eight stingless bee honey samples were characterized, including the physicochemical, enzymatic, and microbiological analyses. Based on the results, the properties of the honey samples are pH (pH 2.52–4.03), free acidity (61.1–257.8 meq/kg), moisture content (19.4–31.4%), electrical conductivity (0.03–1.08 mS/cm), ash content (0.34–0.83 g/100 g), hydroxymethylfurfural (35.4–456.6 mg/kg), diastase activity (2.78–6.25 DN), invertase activity (0.16–3.68 IN), fructose (2.21–54.6 g/100 g), glucose (2.66–14.1 g/100 g), and sucrose (0.39–22.9 g/100 g). For microbiological analyses, several honey samples were positive with several microbes, but the results still comply with the Malaysian Kelulut Standard. In order to develop the PADs, two approaches were used: paper-based electrochemical devices (PEDs) and colorimetric paper-based analytical devices (C-PADs). Both PADs only used a small amount of sample solution (1 and 8 μL) for both glucose-sucrose analyses. Furthermore, no interfering compound was obtained for both PEDs and C-PADs. The storage stability was further investigated, and after 30 days, the stability of glucose and sucrose PEDs decreased to 57.2% and 85.2% from their initial response, respectively. The C-PADs are more stable than the PEDs as the performance of glucose and sucrose for C-PADs only decreased by 60% and 40% from their initial values, respectively. Finally, the glucose and sucrose content of eight stingless bee honey samples was measured using the PEDs and C-PADs and compared with high-performance liquid chromatography (HPLC). The results for both PADs corroborated well with HPLC as most of the results are not significantly different at the 95% confidence level. For glucose PADs, the highest glucose levels were observed in H5, H6, and H7. Meanwhile, for sucrose PADs, the commercial samples H4, H5, and H8 were positive for honey adulteration. From this research, it can be concluded that the prototype PADs have been successfully developed to determine sugar adulteration in stingless bee honey.
THE0009667 (Local)
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