Process Optimisation and Quality Evaluation of Preservative-free Spray-dried Lime Juice Powder Using Maltodextrin as a Carrier Agent

Abstract

Lime juice is highly perishable because of its high moisture content, while its sugar and organic acid composition can cause stickiness, wall deposition and low powder recovery during spray drying. This study optimised the spray-drying process for producing preservative-free lime juice powder using maltodextrin as a carrier agent and evaluated the quality attributes of the resulting powder. A three-level factorial design was applied using inlet air temperatures of 150, 160 and 170 °C and maltodextrin concentrations of 20, 30 and 40% (w/v). The spray-dried powders were assessed for product yield, physicochemical composition, reconstitution and flow properties, colour characteristics, microstructure, sensory quality and economic feasibility. Increasing maltodextrin concentration improved powder recovery and reduced hygroscopicity, while the optimised condition of 20% maltodextrin at 160 °C provided a balanced response across the measured quality attributes. Under this condition, the powder showed high solubility (95.73%), acceptable flow behaviour and good colour retention. Scanning electron microscopy showed predominantly spherical particles with slight surface dents and limited irregularities. The optimised powder contained 3.39% moisture, 94.80% carbohydrate and 46.72 mg vitamin C per 100 g, and the total plate count was 0.3 × 10^4 CFU/g. Sensory evaluation of the reconstituted powder indicated high acceptability, with an overall acceptability score of 8.5 on a nine-point hedonic scale, comparable to the commercial control. The estimated production cost was INR 275 per kg, with a benefit-cost ratio of 1.5. The findings indicate that controlled spray drying with maltodextrin can produce a stable, preservative-free lime juice powder with desirable functional, sensory and economic attributes.