Production and characterization of enzyme‐treated spray‐dried soursop (<i>Annona muricata</i> L.) powder

Abstract

Abstract Easily perishable soursop ( Annona muricata L.) fruit was converted into powder for value‐addition. Soursop puree obtained from fruit pulp that had been treated with different concentrations (0–2% v/w) of Celluclast 1.5 L at fixed (1.5% v/w) concentration of Pectinase Ultra SP‐L were spray‐dried at various inlet temperatures (130–160 °C) after mixing the puree with maltodextrin (20–40% w/w). Multiple responses optimization from Response Surface Methodology (RSM) indicated puree that was pretreated with 1.3% (v/w) cellulase and incorporated with 37% w/w maltodextrin and spray‐dried at an inlet temperature of 156 °C could be transformed into powder that had the following physicochemical properties: moisture content, 2.03% (wb); A w, 0.18; hygroscopicity, 29.02 g/100g; stickiness, 173.02 g and yield 70.56% of powder. The glass transition temperature ( T g ) was found to range between 46.53 and 58.25 °C, indicating the spray‐dried powder was an amorphous material. Surface morphology of the powder particles, viewed using Scanning Electron Microscopy, showed they exhibited spherical in shape and possessed a continuous wall (crust) without surface cracks. Practical applications This work offers an alternative way of reducing wastage in soursop plantation due to short shelf life and perishable properties of soursop fruit. Soursop fruit was transformed to soursop puree without the addition of water by enzymatic–liquefaction. The soursop puree produced by enzymatic pretreatment is suitable to be used as spray drying feed as the puree produced is smooth. This is significant especially to the food processing industry to understand the potential application of enzyme in pretreatment step to liquefy and reduce the viscosity in the production of puree instead of using conventional method (addition of water). Soursop powder was produced by spray drying which is a commercial method in the production of fruit powder. This indicates it is feasible with the spray drying to produce soursop powder that exhibited amorphous particle characteristic. Production of soursop powder also broadens its potential applications in food industry.