Optimization of Asafoetida gum extraction and assessments of emulsion stability

Abstract

Response surface methodology was applied for optimization of alcoholic extraction of Asafoetida gum from Ferula assa-foetida L. The effects of time, temperature, ethanol to gum ratio and pH on the purity and physico-chemical properties of that gum were investigated. Extraction parameters significantly affected purity (ranged from 55.5 to 76.4%), protein content (between 5.2 and 12.7%), solubility (19 to 96%), particle size (100 to 900 μm), particle size distribution (span) (0.6 to 5.4), foam capacity (20–115%) and foam stability (13–111%) of the gum. Effect of different concentration (5, 10, 15 and 20% w/v) of optimum extracted gum on stability and viscosity of emulsions was studied over 28 days. The concentrations below 20% w/v showed creaming after 4 weeks. Particle size, span and microscopic analysis confirmed droplet size reduction. No significant alteration in emulsion stability and droplet size was observed over storage due to viscosity enhancement.