Optimization of process parameters on hydroxymethylfurfural content, diastase and invertase activity of coriander honey

Floral authenticity of coriander ( Coriandrum sativum ) honey samples was confirmed by melissopalynology. Effect of temperature, time and pH on quality parameters i.e. hydroxymethylfurfural (HMF) content, diastase and invertase activity of coriander honey was analysed using response surface methodology. Central composite rotatable design was adopted for optimization of process variables. An increased in HMF content was observed with increase in temperature and pH whereas diastase activity decreased with increase in temperature and with a pH value other than the optimum value of 4.6–5.6. Invertase activity was maximum at 4.8 pH. Interaction effect of temperature and pH was significant for HMF whereas interaction effect of temperature and time was significant for HMF, diastase and invertase activity. Optimization of variables was done by the mathematical method, and optimized values of HMF content, diastase, and invertase activity were obtained as 7.78 (mg/kg), 17.95 DN and 13.96 IN, respectively at 47.5 °C (temperature), 4.7 (pH) and 9 min (time).