Edible bubbles: A delivery system for enhanced bioaccessibility of phenolic compounds in red fruits and edible flowers

Abstract

In this study, we developed edible bubbles as a delivery system for enhancing the bioaccessibility of phenolic compounds in red fruits and edible flowers. The bubbles were formed using a spherification method and characterized for their physical properties. The diameter of the bubbles ranged from 8.14 mm to 9.83 mm, and the mass varied from 0.346 g to 0.428 g, which was suitable for consumption with bubble teas. Compared to existing products, the spherification manufacturing method differentiated these bubbles. The addition of phenolic extracts influenced the internal structure of the bubbles, as observed through changes in roughness and elemental composition. Energy dispersive spectroscopy analysis confirmed the presence of carbon, oxygen, sodium, chlorine, and calcium in the bubbles. Silicon was detected in samples containing extracts. Atomic force microscopy images showed variations in roughness, suggesting an interaction between the internal wall and bioactive compounds. Edible bubbles exhibited a total phenolic compound concentration of up to 182 μg GAE/g, while antioxidant activity reached as high as 9748.54 μg TE/g as determined by the DPPH assay. Simulated gastrointestinal digestion demonstrated higher bioaccessibility and remaining antioxidant activity in the edible bubbles compared to isolated extracts. Chromatographic analysis revealed the presence of individual phenolic compounds before and after digestion, indicating the release of adsorbed compounds during in vitro gastrointestinal digestion of edible bubbles. In conclusion, these edible bubbles offer a novel delivery system for enhancing the bioaccessibility of phenolic compounds. Their unique physical and chemical properties and the spherification method make them promise for use in the functional food and beverage industries. Further research is needed to explore sensory attributes and product stability.