Determination of Glycaemic Responses of dairy yoghurt incorporated with spice oleoresins (Cinnamomum zeylanicum, Curcuma longa)

Diabetes mellitus, which is characterized by high levels of blood glucose, is one of the most common metabolic disorders. Blood glucose level of individuals can be controlled by the incorporation of spices in the diet. The main objective of this study was to manufacture spice oleoresin (Cinnamomum zeylanicum, Curcuma longa) incorporated, high quality, novel dairy yoghurts with reduced glycaemic impact. The developed yoghurt products were compared with typical dairy yoghurt as the control, mainly for the glycaemic impact after consumption, using 16 healthy volunteers in a randomized crossover study. The blood glucose concentration of individuals was measured using a blood glucose monitoring system at fasting state and at 30, 45, 60, 90, 120 min following ingestion. Glucose response curves were plotted for individuals, and control was used as the standard. In addition, shelf life, compositional and physiochemical properties were determined for the prepared yoghurt products. The developed novel and control yoghurt products were within the acceptable standards and significant differences were not observed in compositional and physiochemical properties. However, significant (p <; 0.05) reduction was observed in peak blood glucose concentration and area under the curve (AUC) of individuals for both novel yoghurt products compared to the control. Percentage peak glucose concentration reduction for cinnamon and turmeric yoghurt products were 9.61% and 9.26%, respectively compared to the control. Mean peak blood glucose concentration for control, cinnamon and turmeric yoghurt products were 113.38±6.39, 102.50±6.00, 102.88±5.38 mg/dL, respectively and mean AUC were 11951±523, 11012±611, 10941±530 ((mg/dL)min), respectively. Hence, incorporation of spice oleoresin (Cinnamomum zeylanicum, Curcuma longa) has significantly reduced the glycaemic impact of dairy yoghurt.