Microdetermination of the major individual isothiocyanates and oxazolidinethione in rapeseed

Abstract

A method has been developed for the quantitative determination of the major individual thioglucosides (as their aglycones) in rapeseed on a micro scale. The thioglucosides in the meal were hydrolyzed with myrosinase (B.C. 3.2.3.1, thioglucoside glucohydrolase), and the released aglycones were extracted with methylene chloride. The 3‐butenyl and 4‐pentenyl isothiocyanates were determined by gas‐liquid chromatography. The 5‐vinyl‐2‐oxazolidinethione was determined on an aliquot of the same extract by ultraviolet absorption. Five to 20 milligrams of seed or meal were used, and one operator could analyze 24 samples per day. The standard deviation was ŷ3% for the isothiocyanates and ŷ6% for the oxazolidinethione. The limit of detection was 0.1 mg per gram of meal for the isothiocyanates and 0.3 mg per gram of meal for the oxazolidinethione. Small amounts of phenylethyl isothiocyanate and two unidentified isothiocyanates were also found.

A Nutritional Comparison of Various Rapeseed and Mustard Seed Solvent-Extracted Meals of Different Glucosinolate Composition

“…Such information should be useful in the seafch for improved rapeseed through plant breeding, especially in view of the differences in species, cultivars and environmental responses that have been observed (Clandinin et al, 1959;Josefsson and Appelqvist, 1968;Wetter and (Youngs and Wetter, 1967 Youngs and Wetter (1,967 (Youngs and Wetter, 1967) (Fig. 1), indicating that allyl-isothiocyanate may be less deleterious than the 3-butenyl form.…”

INHERITANCE OF THE MAJOR GLUCOSINOLATES OF RAPESEED (BRASSICA NAPUS) MEAL

“…However, differences between cultivars were relatively small and none of the cultivars was free or practically free of glucosinolates. Cultivars of B. campeslns from Japan and lndia were found to be free of PI and/or OZT, and were used in a genetic study of Canadian B. campestris cultivars (3) (8). RESULTS …”

The Feeding Value of Tower Rapeseed for Early-Weaned Pigs. I. Effects of Methods of Processing and of Dietary Levels

“…Erucic acid in Tower rapeseed oil was analyzed using Gas Liquid Chromatography (GLC). The oxazolidinethione contents of the processed and unprocessed seeds were determined by the method of Youngs and Wetter (1967). Myrosinase activity was determined by the method of Schwimmer (1961).…”