Osmotic treatment for the impregnation of anthocyanin in candies from Indian gooseberry (Emblica officinalis)

Bioactive compound like anthocyanin can be infused into the solid food matrix like Indian gooseberry or
amla (Emblica officinalis) through osmotic treatment. When the surrounding solution concentration was
minimum (0 �Brix) the infusion of anthocyanin was higher (3.15 mg/100 g). The values of moisture, solids
and anthocyanins diffusion coefficients during infusion process were found to decrease with increase in
concentration from 0 �Brix to 20 �Brix from 2.71 � 10�9 to 1.06 � 10�9 m2/s, from 0.73 � 10�9 to
0.28 � 10�9 m2/s and from 1.14 � 10�9 to 0.71 � 10�9 m2/s, respectively. The infused amla pieces were
further subjected to higher osmotic solution concentration (30e70 �Brix) for candy making. The diffusion
coefficients for moisture and solid contents increased from 0.33 � 10�9 to 2.30 � 10�9 m2/s and
0.68 � 10�9 to 1.25 � 10�9 m2/s respectively. With an increase in the concentration of surrounding
solution, the time required to reach moisture and solid equilibrium was reduced. The entire process for
anthocyanin infused amla candy could be achieved in 24 h of immersion time compared to conventional
method of candy making 120 h (5 days). The resulting product had higher retention of nutrients like
vitamin C, with softer texture, reduced lightness and high anthocyanin content as a result of infusion. The
product was highly acceptable with higher sensory attributes compared to control sample. The present
study concluded that osmotic treatment could be a feasible technology for impregnation of bioactive
compounds for candy making without significantly altering the cellular integrity of the solid food matrix.