Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Nutritional Composition of Stevia rebaudiana Bertoni Leaf: Effect of Drying Method

Mohammed Abdalbasit A Gasmalla^1,2, Ruijin Yang¹ , Issoufou Amadou¹, Xiao Hua¹

¹State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China; ²Department of Nutrition & Food Technology, Faculty of Science and Technology, Omdurman Islamic University, PO Box 382, 14415, Khartoum, Sudan.

For correspondence:- Ruijin Yang Email: Yrj@jiangnan.edu.cn Tel:+8651085919150

Received: 18 October 2013 Accepted: 14 November 2013 Published: 25 January 2014

Citation: Gasmalla MA, Yang R, Amadou I, Hua X. Nutritional Composition of Stevia rebaudiana Bertoni Leaf: Effect of Drying Method. Trop J Pharm Res 2014; 13(1):61-65 doi: 10.4314/tjpr.v13i1.9

© 2014 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To determine the effect of three methods of drying, viz, sun, oven and microwave, on Stevia rebaudiana Bertoni leaf’s nutritional composition.

Methods: Fresh Stevia rebaudian bertoni leaves were dried separately by sun, oven and microwave. The chemical composition was determined by Association of Official Agricultural Chemists (AOAC) method. Tannin content was measured by titrimetric method while heavy metals were analyzed by atomic absorption spectrometry.

Results: The following data were obtained for the plant when the three drying methods were employed: moisture content, 4.45 – 10.73 %; ash, 4.65 – 12.06 %; protein, 12.44 – 13.68 %; fat, 4.18 – 6.13 %; total dietary @257;ber, 4.35 – 5.26 % and total carbohydrates, 63.10 – 73.99 %. The pH value was 5.96, 5.95 and 6.24 for sun, oven and microwave drying, respectively. Total energy of the plant material was in the range 362.3 – 384.2 kcal/100 g while tannin content was in the range 5.43 – 5.91 %. Moreover, reducing sugar was 4.5, 4.8 and 5.3 %, respectively, for sun, oven and microwave drying. Heavy metals content varied in stevia leaves, with lead was detected in high concentration in sun-, oven- and microwave–dried materials with values of 4.77, 0.14 and 2.16 µg/g, respectively, while the corresponding values for cadmium were 0.49, 0.44 and 0.33 µg/g, Arsenic level was 0.30, 0.09 and 0.10 µg/g for sun, oven and microwave drying, respectively. Mercury level was the same (0.1 µg/g) irrespective of the drying method.

Conclusion: The results obtained indicate that Stevia leaves is a good source of carbohydrate and other nutrients and hence a substitute for sugar in processed drinks. Furthermore, drying reduces nutritional values with the exception to fiber content.

Keywords: Stevia rebaudiana Bertoni , Nutritional composition, Protein, Heavy metals, Drying, Total energy