Functional and Physicochemical Properties of Turmeric Powder as Affected by Processing Methods

Abstract

Turmeric rhizomes are exposed to a variety of conditions during processing such as boiling, cooking, blanching and drying before being utilized. In this study, the effect of processing methods on the functional properties and physicochemical properties of turmeric powder was investigated. Fresh turmeric rhizomes were processed into powder and five samples generated from the turmeric powder: Sample A (oven drying), sample B (blanching + oven drying), sample C (sun drying), sample D (cooking + oven drying). The processed turmeric powders were subjected to functional and physicochemical analysis using standard methods. Results obtained showed that cooking/oven drying resulted to a significant (p<0.05) improvement in the bulk density, water and oil absorption capacities and swelling power of the turmeric powders as compared to other processing methods. Dispersibility and solubility were greatly improved on sun drying/oven drying. Among the processing methods employed, blanching/oven drying exhibited significantly (p<0.05) higher colour value and curcumin content whereas decreases in TTA and pH was observed for cooked/oven dried sample. It is therefore recommended from the study that blanching/oven drying be used in the processing of turmeric powder for better nutrient retention. For better functionality of the turmeric powder, cooking/oven drying method should be employed.