Response surface methodology was used to optimize spray-drying process for concentrated orange juice. Independent variables were: inlet air temperature (130-170 ºC) and maltodextrin 12DE content (60-75% wet basis (wb)). Responses variables were powder yield, moisture, and ascorbic acid retention. Moisture content was negatively affected by inlet air temperature, while ascorbic acid retention was directly related. Powder yield and ascorbic acid retention increased with the rise in maltodextrin content, while moisture content was negatively affected by maltodextrin content. Multiple response optimisation indicated that an inlet air temperature of 155 ºC and maltodextrin content of 74% wb were predicted to provide 77% powder yield, 3.7% wb moisture content, and 89% ascorbic acid retention.

Spray‐drying process for guava pulp was optimized by response surface methodology. The factors were inlet air temperature (130–170°C) and maltodextrin DE 10 content (60–75% wb pulp solids basis), while powder yield, moisture, ascorbic acid retention, rehydration, and hygroscopicity were the responses variables. Inlet air temperature caused a positive effect on powder yield and ascorbic acid retention, while moisture content, rehydration, and hygroscopicity were negatively affected by maltodextrin content. The optimal conditions for drying guava pulp were an inlet air temperature of 148°C and maltodextrin content of 75% wb pulp solids basis; these parameters led to 67.9% powder yield, 4.2% wb moisture content, 90% ascorbic acid retention, 60 s rehydration time, hygroscopicity 21.7 g of water/100 g of dry matter and 9.2 μm of particle mean diameter. Practical application Nowadays an increase in the use of foods that are easy to make or ready for direct consumption has received a significant attention. Guava fruit has many health benefits potential, but it has short shelf life and seasonal crop. This research give the information about the effect of inlet air temperature and maltodextrin content on spray drying process and physicochemical properties of the developed guava powder. It is important for dehydrated pulp and juice producers to avoid production problems, such as stickiness and low yield.

Los aceites vegetales son buenas fuentes de ácidos grasos esenciales y compuestos antioxidantes, pero son sensibles a condiciones ambientales como el calor, luz, humedad y oxígeno. La microencapsulación de aceites representa una buena alternativa en su protección contra el deterioro oxidativo y en el mejoramiento de sus características sensoriales y de manejo, sin afectar significativamente sus propiedades biológicas y funcionales. El secado por aspersión es la técnica de microencapsulación más usada gracias a sus ventajas económicas y fácil aplicación del proceso. Esta revisión describe los beneficios de la microencapsulación de aceites vegetales mediante el secado por aspersión, los aspectos más generales relacionados con esta técnica de microencapsulación y una recopilación de los trabajos más sobresalientes en los últimos 10 años. Además, puede proporcionar información a investigadores que trabajan en el campo de los alimentos y nutrición que estén interesados en el microencapsulación de aceites vegetales.