title: Kinetics and mechanism of free fatty acid formation on the surface of milled rice.
abstract: The presence of free fatty acid (FFA) is an important factor in determining rice quality for brewing. FFA formation in milled rice during storage was monitored, and a two-parameter semiempirical kinetic model giving product concentration as a function of time is proposed to describe FFA formation on milled rice during storage. The model was tested using sets of data obtained from partially milled rice samples stored at 24, 37, and 50 degrees C and fully milled rice stored at 37 degrees C and 70% relative humidity. The predicted values provide very good fits (R(2) >or= 97%) of the experimental data at all storage temperatures. A two-substrate reaction mechanism representing a two-phase process is also presented. Milled rice FFA at a given storage time varied with storage temperatures. The kinetic model and mechanisms proposed could be useful in describing and predicting FFA contents of milled rice during storage and transportation.
authors.affiliation: Department of Food Science, University of Arkansas, 2650 North Young Avenue, Fayetteville, Arkansas 72704, USA.
authors.forename: Henry S
authors.initials: HS
authors.lastname: Lam
authors.forename: Andrew
authors.initials: A
authors.lastname: Proctor
mesh_terms: D005230:Fatty Acids, Nonesterified / Q000032:analysis / Q000378:metabolism*; D005511:Food Handling; D005519:Food Preservation; D006813:Humidity; D007700:Kinetics; D012275:Oryza / Q000737:chemistry / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors
chemical_list: D005230:Fatty Acids, Nonesterified