Jing Ning

Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School


First Advisor

Duane Matthees


Tocols are naturally occurring vitamin E isomers. Corn is one of the rich sources of tocopherols and tocotrienols. Currently, corn is mostly processed by wet-milling. The first critical step of corn wet-milling is steeping---the soaking of the corn in water under controlled conditions of time, temperature and SO2 concentration. It was reported that only 27% of total tocols was recovered after wet-milling process. However, it was not clear which processing steps were detrimental to the tocols. The objective of this study is to develop a method for HPLC analysis of tocols in steeped corn and to study the effect of processing conditions on retention of different isomers. In this investigation, the extractions with saponification and without saponification were compared. The results indicated that steeped corn samples must be saponified with ethanolic KOH prior to determination of tocols. The optimal conditions for saponification were found to be 70 degrees for 15 minutes. The steeping conditions have different effects on retention of individual isomers.

Library of Congress Subject Headings

Corn - Processing
Corn -- Analysis
Vitamin E
High performance liquid chromatography




South Dakota State University



Rights Statement

In Copyright