Purple sweetcorn – something tasty and healthy?

Abstract

Anthocyanins are a group of red and purple plant pigments found in a range of fruit and vegetables, but seldom associated with sweetcorn. Anthocyanins have been shown to possess various potential health benefits such as antihypertensive and anti-inflammatory activities. Although yellow/white sweetcorn does not normally contain anthocyanins, purple Peruvian maize can contain considerable concentrations in the kernel pericarp. The current study reports the anthocyanin profile of purple 'supersweet' sweetcorn, recently developed from purple Peruvian maize, and the effect of kernel maturity on anthocyanin accumulation. A total of 13 anthocyanin compounds, mainly cyanidin- peonidin- and pelargonidin-based glycosides, were identified and quantified in purple sweetcorn samples ranging in physiological maturity from 20 to 40 days after pollination. Total anthocyanin concentration increased with increasing physiological maturity, reaching a maximum 5-6 days after optimum sweetcorn eating stage. Anthocyanin pigmentation is only present in the pericarp layer of the kernel and is absent from the endosperm. As kernels matured, the coverage of purple pigment increased from a small spot at the stigma end of the kernel, gradually spreading toward the base of the kernel, and eventually covering the entire kernel. These results are important in regards to the development of strategies to improve the natural anthocyanin content and nutritional quality of purple sweetcorn.