Impregnated Nostoc sphaeroids Kützing Crisp Grain Conditioning Processing Technologies

Abstract:

In this study，pre-drying vacuum impregnation technology was applied in the first stage，when some flavor substances such as butter，sugars were impregnated to the Nostoc sphaeroides kützing（N. sphaeroides），thus there were butter flavor in raw products. After that，though drying for the second stage，the rest water in impregnated materials was removed，and best drying process was necessary for keeping maters' shape and nutrition value.Firstly，pulse-spouted microwave-freeze drying（PSMVD），which was developed by our team was selected as the pre-drying process. Secondly，according to the quality of impregnated N. sphaeroides，different vacuum level，different impregnating time in vacuum and atmospheric pressure were researched，thus best vacuum impregnating process was realized，when the parameters were selected as：impregnating temperature was 75 ℃，vacuum pressure was -0.08 MPa，both vacuum and atmospheric pressure impregnating time was 30 min. Finally，according to the quality of impregnated N. sphaeroides，hot airflow drying and microwave vacuum drying were analyzed in comparison，and the drying process in second stage was confirmed，which was microwave vacuum drying with the power of 150 W.