GC/MS analysis & biological activities of mulberry leaf extract and formulation of instant freeze-dried functional beverages following encapsulation in protein-rich skim milk powder

Abstract

This study examines the volatile constituents and bioactive potential of mulberry leaf extract (MLE). Gas chromatography-mass spectrometry (GC-MS) identified key compounds such as gibberellic acid, 9,12,15-octadecatrienoic acid, and 5,7-dihydroxy isoflavone (mefenamic acid). MLE was then encapsulated in skim milk powder, and enhanced with rose flavour and sea-buckthorn anthocyanins, to create an instant freeze-dried beverage. The powder was evaluated for physical, structural, and biological properties, including antioxidant, antidiabetic, and anti-obesity activities under simulated gastrointestinal conditions. Scanning electron microscopy (SEM) revealed microcapsules with enclosed particles, while Fourier-transform infrared spectroscopy (FTIR) indicated phenolic compounds via increased –OH stretching in the 3000–3500 cm⁻¹ range. The beverage powder showed 75–81 mgQE per g phenolic content, 40–61% antidiabetic activity and 45–67% anti-obesity activity. Both bioactivity and consumer acceptability were increased with the addition of rose flavour and anthocyanins. This beverage powder could be considered a sustainable healthy food to manage the lifestyles of diabetic and obese groups of the population.