Abstract:

This study aimed to investigate the cause of generation and transformation of trans fatty acids in tea seed
oil production. Crude tea seed oil was prepared by cold press technology followed by degumming, deacidification and
bleaching. The oil sample was further subjected to esterification using potassium hydroxide-methanol solution methyl before
deodorization and dehydration. The changes of fatty acid composition and the content of trans fatty acids in the final oil
products were determined by gas chromatography in comparison with 37 kinds of fatty acids standards. The results showed
that no trans fatty acids were detected in cold pressed crude oil, deacidificated or decolored oil. High temperatures (≥ 250 ℃)
could result in the generation of trans fatty acids while they were undetectable in the oil samples deodorized and dehydrated
at low temperature (≤ 150 ℃) for less than 3 hours.

Key words: tea seed oil, processing, trans fatty acids, gas chromatography (GC)