Enhanced functional properties and storage stability of spray-dried calamansi waste in maltodextrin/gum Arabic complex

Calamansi waste, rich in bioactive compounds (BCs), is prone to degradation when exposed to environmental factors. This study explores enhancing calamansi waste extract's functional properties and storage stability using spray-drying, with a mixture of maltodextrin and gum Arabic as encapsulating agents. Various core-to-encapsulating ratios (1:1, 1:1.5, 1:2) and drying temperatures (120, 140, 160 °C) were employed to produce microencapsulated calamansi waste extract powder (MCWEP). The results showed that all MCWEP samples demonstrated high encapsulation efficiency (89-91 %) for phenolic compounds, indicating strong compatibility between the phenolic compounds and the encapsulating agents. Encapsulation efficiency showed no significant variation across most temperature and ratio combinations (p > 0.05), except at 160 °C where core-to-encapsulating ratio had a significant effect (p < 0.05). The low moisture content (3.80-4.97 %), water activity (0.15-0.22), and porosity (0.22-0.40) of the samples suggest that the powders are less susceptible to microbial spoilage. The best production conditions for MCWEP, which were found to preserve significant BCs content (e.g., phenolic and flavonoids compounds) and exhibited enhanced antioxidant activities (e.g., DPPH radical scavenging activity, ferric reducing antioxidant power, and oxygen radical absorbance capacity), were at a core-to-encapsulating ratio of 1:1 and an inlet temperature of 140 °C. The storage stability results for MCWEP showed significant retention of BCs (76.27-93.81 %), with an estimated half-life of up to 55 weeks under conditions of 45 °C and 52.9 % relative humidity. This study demonstrates that microencapsulation significantly improves the functional properties and extends the shelf-life of calamansi waste, offering a potential strategy for producing functional food ingredients with prolonged shelf-life.