Extraction and Partial Purification of Thaumatin from Arils of Thaumatococcus daniellii Fruit

Abstract

Thaumatococcus daniellii is a large flowering herb with rhizomatous rootstock, commonly found mostly in the western part of Nigeria. Thaumatococcus daniellii fruit arils that contain the sweetener, are embedded within a gel-like fluid that is richly composed of polysaccharide. The extraction and partial purification of thaumatin (protein) was undertaken to devise simpler means to extract and purify the protein, following the difficulty associated with the extraction due to the presence of the gel that encapsulates the protein. The research was carried out in department of biochemistry laboratory, covenant university Ota, Nigeria, between 10 August 2015 and 13 November 2018. In attempt to determine the optimal pH and temperature for extraction of crude thaumatin in different media from 4,000mg of the sample. Extraction was carried out at different pH values (2, 3, 4 and 5) in varied temperatures (25oC, 30oC, 40oC, 45oC, 50oC, 55oC, 60oC, 70oC, 80oC and 90oC). Maximum concentration of crude thaumatin extracted in 50ml of distilled water was 13.40mg/ml at pH 3 and temperature of 50oC while 28.17mg/ml at pH 3 and temperature of 55oC was extracted in 50ml of 0.85M of aqueous sodium chloride (dilute sodium chloride). Each extracted crude thaumatin was subjected to centrifugation at 10,000rpm for 1800secs, the decanted extracted crude thaumatin (supernatant) formed were assayed for protein via lowry method. Having pooled each decanted supernatant, the extracted crude thaumatin were precipitated with ammonium sulphate, dialyzed and subjected to column chromatography while the eluent were collected, tested for protein then freeze dried and stored as partially purified thaumatin. From the above findings, the extraction and partial purification of thaumatin can be optimized in dilute sodium chloride at optimal pH and temperature thereby making protein more readily available. Thaumatin a protein with very low calorie is an excellent alternative to other sweeteners with high calories especially sucrose, consequently will go a long way to reducing health challenges associated with sucrose such as obesity, hyperglycaemia, dental cares and even diabetes.