Citral is an essential oil with antimicrobial activity against a broad range of microorganisms. However, its low solubility and susceptibility to environmental conditions difficult the use of citral in the food industry. In this study, the formulation of an eco-friendly emulsion of citral obtained by ultrasound was optimized using a Box-Behnken design. The effect of arabic gum (AG), sodium alginate (SA), maltodextrin (MD), and their concentration on the droplet size of the emulsion was evaluated. Based on the droplet size (1 μm), the emulsion formulated using 7.5% of AG and 0.4% of SA was selected as optimal with viscosity 34.63 cP, pH 5.76, and conductivity 1.426 mS. This emulsion retains the 92% volatile fraction of citral and contributes to increase the thermal stability of the essential oil from 37 to 185 °C. Besides, it has antifungal properties against Fusarium sp., contributing to reduce in 66% of the disease incidence caused by this fungus in bananas. Therefore, the optimal emulsion formulated in this research can be used to control the postharvest decay in fruits. Moreover, it can be used to obtain microcapsules and microfibers that can be used as edible coatings in the food industry. Graphical Abstract

Jackfruit seeds (Artocarpus heterophyllus Lam.) are a viable option for supporting a sustainable protein supply. The objective was to obtain protein powder from jackfruit seeds protein concentrate (JSPC) by spray drying. A central composite design was used; the independent variables were inlet temperature (110, 115, and 120 °C) and the solids of the JSPC solution (5, 7.5, and 10%). With the desirability function, the optimal drying parameters to maximize the process yield and achieve a low moisture content were 7.5% solids in the JSPC solution and an inlet temperature of 115 °C, resulting in a process yield of 71.51 ± 1.21%. Moisture (5.33 ± 0.11%), water activity (0.15 ± 0.02), bulk density (0.40 ± 0.01 g/mL), and color (L*: 70.56 ± 0.38, a*: 7.80 ± 0.11 and b*: 15.18 ± 0.15) were measured; these parameters are within the allowed ranges for stable food powders. Hydrosolubility (82.46 ± 1.68%), foaming capacity (48.33 ± 1.66%), and emulsifying activity (105.74 ± 10.20 m²/g) were evaluated. Glass transition temperature (129.49 °C) of the JSPC powder enables the establishment of optimal storage and processing conditions for the protein. JSPC powder could be applied to the elaboration of food products with nutritional and functional value.

Mango leaves (Mangifera indica), an underutilized residue, represent a promising source of functional proteins with potential applications in emulsion-based delivery systems. Leaf protein concentrate (LPC) was extracted and modified by high-intensity ultrasound (HIU) to enhance its techno-functional properties. The modified protein was subsequently used as a natural emulsifier to develop oil-in-water (O/W) emulsions enriched with Curatella americana leaf extract, a phenolic-rich source of antioxidant bioactive compounds. Ultrasound-assisted emulsification (UAEm) conditions were optimized using a Box–Behnken experimental design, evaluating the effects of protein concentration (0.5, 1, and 1.5%), oil-to-water ratio (1:4, 1:4.5, and 1:5, mL:mL), and sonication time (2.5, 5, and 7.5 min) on droplet size (D_[4,3], µm). The optimized formulation consisted of 1.5% protein, an O/W ratio of 1:4 mL, and a time of 7.5 min, producing an emulsion with a droplet diameter of 7.23 µm. The emulsions exhibited high resistance to storage, pH variation (2–10), ionic strength (100–500 mM NaCl), and thermal treatments up to 50 °C. Additionally, incorporating C. americana extract enhanced thermal stability, photostability, and antioxidant retention under UV exposure, suggesting the formation of reinforcing protein–polyphenol interactions. These findings demonstrate the potential of mango leaf protein as a sustainable emulsifier and protective carrier for sensitive bioactive compounds, supporting its application in functional food and nutraceutical formulations.