A pilot study on sterilization of functional Monascus red rice by steam explosion

Objective: To study the effect of steam explosion sterilization on functional Monascus red rice and its main active component Monacolin K.Methods: Functional Monascus red rice was sterilized by steam explosion.The effects of steam explosion residence time 0 min, 1 min, 3 min, 5 min on sterilization efficiency were investigated under 115 ℃, 125 ℃, 135 ℃, respectively.The change of Monatinlin K content, water content and aerobic plate count was investigated, and sterilization indicator tape was used to characterize the sterilization effect.Results: The results showed that the heat ( 3.92%) of Monacolin K sterilized by steam explosion at 135 ℃ for 3 min was lower than the loss ( 17.76%) of traditional sterilization at 121 ℃ for 20 min. And the water content of functional Monascus red rice sterilized by steam explosion was 13.07%, which was lower than the water content ( 18.49%) of traditional sterilization.Under this condition, the average gray value of the sensitive area in sterilization indicator tape was 62.77.Conclusion: Steam explosion was feasible and efficient for the sterilization of functional Monascus red rice, which could greatly reduce the product cost and energy of subsequent dry step. Steam explosion sterilization of functional Monascus red rice could provide the theoretical basis of retention of the active ingredient and reduction of the water content.