Exploring the hydration promotion and cooking quality improvement of adlay seed by high hydrostatic pressure

Abstract

Adlay (Coix lacryma-jobi L. var. ma-yuen Stapf), a minor cereal, has long been consumed as both a food and a medicine. However, adlay seeds have a dense episperm and its tissue is hard, which makes water absorption difficult. High hydrostatic pressure (HHP), as a non-thermal processing technology, enables batch hydration of grains in a short time. In this work, the hydration promotion and cooking quality improvement of adlay seeds by HHP (300–600 MPa) were investigated. Results showed that HHP pretreatment promoted seed hydration by inducing cracks in the seed cross-section and disrupting the cell wall and ventral groove structure. HHP pretreatment increased the proportion of intracellular water and unbound water in the cooked adlay seeds, facilitated water infiltration from the seed grooves and increased the hydration rate by creating a water gradient between the soak water and seeds. After applying HHP during soaking, the cooking time of adlay seeds was reduced, and the cooked adlay seeds were softer, brighter in color.