The study aimed to optimize an oil-in-water emulsion loaded with the antioxidant extract of Randia monantha using Coccoloba uvifera seed protein (CUSP) as emulsifier and ultrasound-assisted processing. Response surface methodology (RSM) was employed to evaluate the effects of protein concentration (2, 3, and 4%), oil amount (5, 15, and 25%), and ultrasound duration (3, 5, and 7 min) on the polydispersity index (PDI) and droplet size. A total of 21 mg of extract was added to each formulation. The optimal conditions were a 3% protein concentration, 20% oil content, and 7 min of ultrasound. Under these conditions, the emulsion showed low PDI (1.88), D_[3,2] (1.11 µm), and D_[4,3] (1.60 µm). It remained stable at 4 °C for 15 days within a pH range of 6−10, with NaCl concentrations < 200 mM and at temperatures between 25 and 50 °C. Thermal analysis of the emulsion revealed endothermic transitions and decomposition events at higher temperatures, achieving 100% entrapment efficiency and ~83% photoprotection for the extract. This plant protein stabilizes the extract at the oil/water interface, enhancing thermal stability and protecting against photodamage. These qualities are vital in the food industry for preserving thermolabile compounds. The emulsion can enhance antioxidant properties in semi-solid foods or be spray-dried into a powder for functional formulations.

The soft rot caused by Rhizopus stolonifer is the most important disease in jackfruits. Currently, the control of this phytopathogen is achieved with toxic fungicides. Due to this, the control of R. stolonifer is sought through natural alternatives such as plant extracts. This study aimed to identify the compounds in Dalea carthagenensis extract and evaluate its antifungal potential against important postharvest phytopathogens. The antioxidant activity of the extract and the in vitro activity against Penicillium italicum, Colletotrichum gloeosporioides, and R. stolonifer were evaluated. The chemical compounds were identified by HPLC-UV-Vis and the in vivo antifungal activity was assessed against R. stolonifer in jackfruit. The extract presented an antioxidant activity of 48.34 ± 1.3 mg TE/g dw and a total phenolic content of 52.23 ± 0.57 mg GAE/g dw. P. italicum, C. gloeosporioides, and R. stolonifer were inhibited between 11.50-55.6%, 22.16-53.88%, and 27.46-79.71%, respectively. The most sensitive fungus was R. stolonifer with a minimum inhibitory concentration of 11.08 mg/mL. D. carthagenensis extract reduced the severity of soft rot by 59% in jackfruits and gallic acid and vanillin were the main compounds identified. In conclusion, D. carthagenensis extract is a promising alternative for managing soft rot disease in jackfruit at postharvest stage. The extract offers an eco-friendly control solution for jackfruit growers.

La investigación de proteínas vegetales como emulsionantes ha ido en aumento considerablemente. La fracción de glutelina del concentrado proteico de hoja de yaca se muestra prometedora como emulsionante. Este estudio tuvo como objetivo evaluar la actividad de eliminación de radicales (RSA), el perfil térmico mediante análisis termogravimétrico y los parámetros cinéticos y termodinámicos de la fracción de glutelina. Se utilizó ultrasonido para crear emulsiones de aceite en agua (O/W), y se evaluó su estabilidad bajo diferentes condiciones simuladas. La fracción de glutenina exhibió 50% ABTS+ RSA a 0.377 ± 0.004 mg/mL y estabilidad térmica hasta 239.7 °C. Los parámetros cinéticos y termodinámicos indicaron que su descomposición térmica es un proceso endotérmico. La emulsión creada con glutelina al 0.5% (p/v) exhibió un tamaño promedio de gota de 2.4 µm. La emulsión se mantuvo estable durante 5 días tanto a 4 °C como a 25 °C, fue estable en un rango de pH de 6.0 a 8.0, con estabilidad moderada en presencia de NaCl. La glutelina puede ser un emulsionante que posee buena estabilidad térmica y RSA y eficaz para crear emulsiones O/W (en ciertas condiciones). Esta fracción proteica es una alternativa vegetal a los emulsionantes tradicionales.