Studies On Moulding Rice Hull Bowl And Its Zein Film Coating

Rice hull is a wast coproduct of the rice industry. There is no effective solution to utilize rice hull in the rice industry. In this paper, rice hull was used to mould single use bowl and it turned to be a success.A analysis about chemical composition of different size of rice hull powder was performed. The factors which affected moulding rice hull bowl were studied and optimum processing condition and recipe were obtained. Zein was used as the water-resistant film coating material of rice hull bowl. The process of preparing zein was studied from corn gluten and optimum processing condition was obtained. Finally water-resistant zein film coating was studied. Main results were described as follows :1. Single use rice hull bowl has been mould successfully . The optimum recipe is as follows :size of rice hull is 0.167mm, 62.5%rice hull powder, 20.8%starch , 12.5%CMC , 2.5%siloxane fluid and the others 1.7%.The optimum processing condition is as follow : moulding temperature 200 , moulding pressure 30Mpa, moulding time 40s, percent moisture 45%.2. Moulding process was used to make single use rice hull bowl . Properties of rice hull bowl are very well . The W value of rice hull bowl is under 2.5 better than the requirements of general specification for single use and degradable lunch container and drinking set. Microbe growth test has shown the rate of microbe coverage on the pieces of rice hull bowl was 100% after 15 days.3.Zein was prepared from corm gluten, the zein production rate can be up to 28%, the products contain about 91.53% protein. The optimum processing condition is:decolour: in the ethanol boil point temperature for 4hextraction: 70% ethanol at a ratio of liquid to liquid to solid as 10:l(w/v) andat60 ,pH9 for 2h precipitation: The supernatant of zein was dropped into twice the volume of2% Nacl solution.4.No. 1 waterproofing agent can improve water resistance of zein film coatings significantly, The T100 value of rice hull bowl with zein coating(containing 9%(w/v)No.l waterproofing agent) is up to 50 minutes better than the requirements of general specification for single use and degradable lunch container and drink set.