Optimization of spray drying parameters for production of instant coconut milk powder

Abstract:

Can spray drying conditions be tuned so that coconut milk retains its characteristic flavour and nutritional value after conversion to an instant powder? This research examined how inlet air temperature, feed concentration, and atomizer disc speed affect the physical, chemical, and sensory traits of coconut milk powder prepared in a lab-scale co-current spray dryer. Five inlet temperatures (140, 150, 160, 170, and 180 °C), four feed total-solid levels (18, 22, 27, and 32%), and three atomizer speeds (18 000, 22 000, and 26 000 rpm) were tested in a full-factorial layout during the period March to September 2023 at Central Luzon State University, Science City of Muñoz. Responses measured included moisture content, bulk density, water solubility index, free-fat content, whiteness index, and overall acceptability scored by a trained sensory panel. Results pointed to an inlet temperature of 170 °C, a feed solid content of 27%, and an atomizer speed of 22 000 rpm as the best combination, yielding powder with 3.2% moisture, 89.4% solubility, and a sensory score of 8.1 out of 10. Higher inlet temperatures above 170 °C lowered moisture but raised free fat and off-flavours. These findings offer a workable set of conditions for small-scale processors interested in producing shelf-stable coconut milk powder with minimal quality loss.