Nutritional Composition, Glycemic Index, Antioxidant and Anti-Inflammatory Activities of Five Monofloral Honeys from Qassim, Saudi Arabia: A Component–Effect Relationship Study

Background: Honey possesses anti-inflammatory, antimicrobial, and wound-healing properties due to its complex mixture of carbohydrates, phenolics, flavonoids, vitamins, and minerals. However, comprehensive data on monofloral honeys from Saudi Arabia’s Qassim region are lacking. Objective: This study evaluated the nutritional composition, glycemic index, antioxidant and anti-inflammatory activities of five Qassim honeys (Talh, Keina, Samr, Berseem, Ashr) and identified chemical components responsible for their therapeutic potential. Methods: Physicochemical parameters, sugar profiles, minerals, vitamins, total phenolic content (TPC), total flavonoid content (TFC), diastase activity, and HMF were analyzed. Antioxidant activity was assessed by DPPH and ABTS assays, anti-inflammatory activity by BSA denaturation inhibition, and in vitro glycemic index by simulated digestion. Statistical comparisons used one-way ANOVA with Fisher’s LSD (n = 5). Results: All honeys met international quality standards (moisture < 20%, HMF < 40 mg/kg, F + G > 60 g/100 g). Samr honey showed the highest TPC (890 mg GAE/kg) and TFC (226 mg QE/kg). Ashr and Berseem exhibited the highest DPPH scavenging (92% and 91%). Samr was the most potent ABTS scavenger (IC50 26.7 μg/mL). Ashr displayed the strongest anti-inflammatory activity (86.9%), followed by Berseem (72.0%). All honeys had low glycemic index (51–55). Talh and Samr (Acacia-derived) were richest in K, Mg, P, Fe, and Zn; Keina (Eucalyptus) was highest in Ca; Berseem (clover) had the lowest mineral content. Samr honey contained the highest levels of vitamin C and B vitamins. Conclusions: The five Qassim monofloral honeys possess distinct nutritional and bioactive profiles. Samr honey is exceptionally rich in phenolics, flavonoids, and B vitamins, contributing to high antioxidant capacity. Ashr and Berseem honeys showed remarkable anti-inflammatory activity. All honeys are low-glycemic and meet quality standards. These findings support their use as functional foods and provide a basis for botanical authentication and quality control.