No abstract

No abstract

No abstract

No abstract

No abstract

The popularity of Malaysian stingless bee honey is rising among healthconscious individuals; thus, chemical and physical evaluations of Malaysian stingless bee honey are vital to ensure the honey has achieved the optimum limits set by Malaysian and international regulatory standards so that it can be commercialized locally and internationally. Therefore, in the present study, the physicochemical characteristics (moisture content, total dissolved solids, pH, free acidity, electrical conductivity, and ash content), antioxidant properties (total phenolic and flavonoid contents), and 5-hydroxymethylfurfural (5-HMF) of Heterotrigona itama (H. itama) honey from different sites in Peninsular Malaysia were investigated. Subsequently, the correlation between these chemical and physical parameters was studied using Spearman correlation coefficients. The significant difference between H. itama honey from different topographical origins was studied using univariate analysis (one-way ANOVA followed by post hoc Tukey's test). The discrimination pattern of 45 honey samples based on their topographical origins was evaluated using cluster analysis (heatmap and dendrogram) and chemometrics analysis (partial least squares-discriminant analysis). Results showed that some samples of certain parameters (electrical conductivity, free acidity, and moisture content) have exceeded the limit set by the international regulatory standard. However, the 5-HMF content of all samples was within the allowed range. A statistically significant difference (p < 0.05) has been observed for all the parameters except electrical conductivity and ash content in terms of inter-topographical origins. Although the profiles of H. itama honey from different origins were close, most of them were separated according to their topographical origins and were validated using a permutation test.

No abstract

Pressurised liquid extraction (PLE) method was utilised to extract eurycomanone from Tongkat Ali root (Eurycoma longifolia) using water as extraction solvent. Optimisation of PLE operating parameters was conducted using three-factor response surface experimental design to evaluate the interactive effects of temperature (90 -150 ºC), extraction time (10 -30 min) and pressure (850 -1700 psi) on the yield of eurycomanone. Online solid phase extraction -high performance liquid chromatography (SPE-HPLC) with a diode array detector (DAD) was used for the separation and detection of this compound. Extraction temperature was found significant in increasing the yield of eurycomanone. Based on maximum yield of eurycomanone, the optimum operating extraction conditions for PLE were set up at temperature (106 °C), pressure (870 psi) and static time (30 min). The amount of eurycomanone from Tongkat Ali root samples of various sources was analysed using the optimised PLE conditions. Keywords: pressurised liquid extraction, Eurycoma longifolia, eurycomanone, solid phase extraction -liquid chromatography Abstrak Kaedah pengekstrakan cecair tekanan tinggi (PLE) telah digunakan untuk mengekstrak eurikomanon daripada akar Tongkat Ali (Eurycoma longifolia) menggunakan air sebagai pelarut. Pengoptimuman parameter operasi PLE dijalankan dengan menggunakan reka bentuk eksperimen gerak balas permukaan tiga faktor untuk menilai kesan interaktif suhu (90 -150 °C), masa pengekstrakan (10 -30 min) dan tekanan (850 -1700 psi) ke atas hasil eurikomanon. Pengekstrakan fasa pepejalkromatografi cecair tekanan tinggi (SPE-HPLC) dengan pengesan diod (DAD) telah digunakan untuk pemisahan dan pengesanan sebatian ini. Suhu pengekstrakan didapati penting dalam meningkatkan hasil eurikomanon. Berdasarkan hasil maksimum eurikomanon, pengkstrakan optimum untuk PLE, ialah suhu (106 °C), tekanan (870 psi) dan masa static (30 minit). Amaun eurikomanon daripada pelbagai sampel akar Tongkat Ali telah dianalisis dengan menggunakan keadaan PLE yang telah dioptimumkan.