MSc

The project entitled “Extraction and utilization of anthocyanin pigments from jamun (Syzygium cumini Skeels.)” was undertaken at the Department of Processing Technology, College of Horticulture, Vellanikkara during 2013-15. The objectives of the study were standardization of method of extraction of anthocyanin pigment and evaluation of pigment stability to pH, light, temperature, storage conditions and in processed products.
Method for extraction of anthocyanin pigments from jamun was standardized. Among the four extraction methods compared, highest content of anthocyanin (61.07mg/100g), recovery per cent (13.75), colour hue (1.30) and colour intensity (1.13) were obtained for acidified solvent extraction method (20% ethanol + 0.5% citric acid).
The effect of light and storage conditions on pigment stability was evaluated. Storage in amber coloured bottles under refrigerated conditions was found to be best for anthocyanin pigment due to lesser degradation of the pigment compared to that stored under ambient conditions.
The effect of temperature on the anthocyanin content was studied at 70, 80 and 900 C and anthocyanin content was measured at intervals 30 minutes, 45 minutes and one hour of incubation at each temperature. Anthocyanin content decreased from an initial value of 61.25mg/100g to 50.24mg/100g one hour of heating at 900 C.
The effect of pH on stability of anthocyanin pigment was studied at different pH ranging from 2.5 to 7 and incubating it for different intervals from one hour to 20 days at room temperature. Anthocyanin content was found to decrease with increase in pH and the least decrease was found at pH 2.5. Anthocyanin content was found to decrease from an initial value of 61.25mg/100g to 34.28mg/100g 20 days after incubation at a pH of 7.
Least changes in pH were observed in RTS beverage prepared with 0.3% citric acid and 0.01% ascorbic acid and stored at refrigerated condition (T10). Acidity of the RTS beverage followed an increasing trend during storage, greatest change in acidity was observed in T8 (product coloured with synthetic colour). Ascorbic acid was found to decrease with increase in duration of storage, minimum changes in ascorbic acid was observed in RTS beverage prepared with 0.4% citric acid and 0.02% ascorbic acid and stored at refrigerated condition (T14).
RTS beverage stored under refrigerated conditions retained colour throughout the storage period as compared to ambient condition where there was a greater loss of the colour. Addition of ascorbic acid was found to hasten the colour degradation of the beverage under ambient conditions, but under refrigerated conditions there was not much change in colour.
Pigment stability in mixed fruit jam was also studied by storing the prepared product under ambient and refrigerated conditions for a period of three months. pH of the mixed fruit jam followed a declining trend during storage, least change in pH was observed in T1 (control under refrigerated condition) during storage. There was no significant change in the colour of the mixed fruit jam stored under refrigerated conditions. A slight darkening of the colour was seen in the bottles stored at ambient condition.
Guava RTS beverage and mixed fruit jam was organoleptically evaluated by selected panel of judges. The products kept under refrigerated conditions recorded highest scores for flavour, texture, taste and overall acceptability compared to those kept at ambient conditions three months after storage.