Comparison of Anthocyanin Extraction Methods from High Anthocyanin Purple Corn Cob Hybrid: KPSC 901, and Quality of the Extract Powder

Abstract

Anthocyanins are compounds extracted from natural origins, and can be use as a natural colorant. The high anthocyanin corn hybrid Kasetsart Purple Corn Single Cross (KPSC) 901 (Zea mays L.) is a new purple corn single cross-hybrid in Thailand. Anthocyanin extraction from KPSC 901 purple corn cob by new extraction methods, including microwave-assisted, ultrasound-assisted and ohmic heating techniques were studied and compared with the conventional heating method (solid : liquid ratio = 1:20) to select the best method for upscaling extraction. The extract was later concentrated and freeze-dried before quantity analysis. The optimal process for anthocyanin extraction was microwave-assisted extraction which gave a total anthocyanin content (TAC) of 397.1 mg/100 g corn cob powder. The extract powder had TAC and total phenolics content values of 3,446 and 20,915 mg/100 g powder, respectively. Practical Applications In this research, microwave-assisted extraction is the optimized method, which can help to efficiently extract anthocyanins and phenolic compounds from purple corn cob by using only water as a solvent for producing colorant powder. The powder dissolved in water and had a deep red color so it could be used in functional foods as a natural colorant and/or a source of active ingredients, depending on the concentration used.