Comparative Evaluation of Bioactive Compounds and Functional Activities in Thai Honeys from Different Floral Origins

The study compares the biological potential of six varieties of honey from different floral origins in Thailand, including longan, premium longan (raw honey), Siam weed, lychee, coffee, and Manuka. Antioxidant activities were evaluated using FRAP, DPPH, and AEAC assays, while total phenolic content (TPC) and total flavonoid content (TFC) were determined. Quantitative analysis of phenolic and flavonoid compounds, antimicrobial activity (MIC), and basic physicochemical parameters were conducted. Multivariate analyses (PCA and Pearson correlation) were applied to link the biochemical composition of honeys with biological activities. Manuka and premium longan honeys exhibited the highest phenolic and flavonoid levels and strong antioxidant capacities. Major compounds-gallic acid, caffeic acid, quercetin, and catechin-showed significant correlations with TPC, TFC, and both antioxidant and antimicrobial effects. PCA grouped Manuka and premium longan honeys in a high-bioactivity cluster, closely associated with antioxidant variables and low MIC values, particularly against Staphylococcus aureus (7.5% w/v). Lychee honey showed high flavonoid content but limited antimicrobial activity, while coffee and conventional longan honeys displayed moderate activities. In contrast, Siam weed honey exhibited the lowest bioactive levels, consistent with its weak antioxidant and antimicrobial properties. Multivariate analyses confirmed that phenolics and flavonoids are the main drivers of honey bioactivities. These findings highlight premium longan honey as a promising valuable bioresource for functional food and cosmeceutical development, supporting its potential to enhance local economic value.