The effect of drying temperature and sodium caseinate concentration on the functional and physical properties of spray-dried coconut milk

This study investigated the effect of drying temperature on the stability and quality of spray-dried coconut milk. A low concentration (1-2% w/w) of sodium caseinate (SC) was used as emulsifying agent with 8-9% of maltodextrin. The spray drying temperature was varied from 140 to 180 degrees C. Emulsions prepared at different SC concentration remained stable without phase separation for 24 h. Higher the SC concentration produced smaller-sized of droplet and powder particles. The spray dried coconut milk has a skin-forming structure. Emulsion with low concentration of SC (1% w/w) is unstable during atomisation process due to re-coalescence of fat. Adding SC to the emulsion reduce the moisture content to less than 5%. However, drying the emulsions at 180 degrees C gave negative impact to the powder properties. Some particles rupture and lead to high free fat content, high insolubility and larger fat droplet size. Presence of fleck is also noticed in the powder.

Automated summary

This study found that a low concentration of SC emulsifier can improve the stability and fineness of spray-dried coconut milk, but high temperature treatment may result in a decrease in powder quality, with fat coalescence and particle rupture observed.