Production of xyloglucan component extracted from tamarind ( <i>Tamarindus indica</i> ) seeds using microwave treatment for seed decortication

Abstract

Microwave treatment was applied for tamarind seed decortication and the decorticated seeds were milled and used for xyloglucan extraction. The aims were: (1) to determine a treatment for efficiently decorticating tamarind seeds with the specified moisture content and color of decorticated seeds and (2) to develop extraction and purification techniques for producing high-purity xyloglucan component powder from tamarind seeds. The results revealed that the application of microwave treatment produced high decortication yield and satisfactory color of decorticated seeds. Defatting tamarind kernel powder (TKP) using TKP:hexane ratio of 1:10 (wt/vol) was preferable for reducing fat to 0.5%. The xyloglucan component powder extracted from defatted TKP using 95% ethanol in precipitation process with protease enzyme application for 3 hr had comparable glucose, xylose, and galactose contents to the commercial xyloglucan standard. Overall production yields were 45.6%, 40.2%, and 25.8% for TKP, defatted TKP, and xyloglucan component powder with high purity, respectively. Practical applications The xyloglucan in tamarind seeds is a natural, nontoxic, and edible polysaccharide. Xyloglucan normally forms a gel in the presence of alcohol, sugar, and polyphenols. It is an interesting gelling agent for use in the food industry because it can form a gel over a wide pH range and is rather heat stable. Although a number of companies in some countries such as Japan and China have manufactured and exported xyloglucan powder extracted from tamarind seeds for many years, their processing techniques have not been disseminated. In this study, a microwave treatment was applied for tamarind seed decortication. The decorticated seeds were milled and used for xyloglucan extraction. The processes for xyloglucan extraction and purification were investigated. The xyloglucan component powder produced in this study had comparable glucose, xylose, and galactose contents to the commercial xyloglucan standard. The xyloglucan component powder produced in this study could be sold as a food additive.