Improvement in texture and cooking quality of black rice (Oryza sativa L.) using different pretreatments

In this work, three pretreatment methods enzymatic hydrolysis, microwave treatment, and soaking with soluble soybean polysaccharides (SSPS) were employed to improve the cooking and eating quality of black rice. Meanwhile, the effects of three pretreatments on polyphenol content and antioxidant activity of black rice were evaluated. The results indicated that three pretreatments improved the textural properties, cooking quality and sensory scores of black rice, especially the enzymatic hydrolysis treatment showed excellent effects in improving the textural properties and cooking quality of black rice: the hardness/adhesion ratio decreased from 107.72 (control group) to 26.03; the soaking water absorption (SWA) rate increased from 7.76% (control group) to 20.63% at 20 min and increased from 25.85% (control group) to 35.60% at 120 min, respectively; the optimal cooking time (OCT) decreased from 30.3 min (control group) to 23 min; the cooking water absorption (CWA) rate increased from 227% (control group) to 284%, The above parameters were significantly different from the control group (p < 0.05). Simultaneously, most of the antioxidant activity of black rice was retained. In addition, there was an obvious change in the surface microstructure observed by scanning electron microscopy.