The experiment was based on a 2 × 3 factorial design, where the treatments of maturity (EHF and MHF) and extraction method (acid, water and enzyme) were combined to evaluate the significance of the main effects (maturity and extraction method) or interactions of maturity and extraction method. The data were analyzed by two-way analysis of variance (ANOVA) using SAS (version 9.1). The significance of differences among the treatments was determined by Duncan’s multiple range test (P ⩽ 0.05).