|Abbott dr, Thomas|
Submitted to: Industrial Crops and Products International Conference Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 6/1/1997
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Meadowfoam (MF) seeds (e.g., Limnanthes alba) contain an active thioglucosidase, which interacts with m-methoxybenzyl glucosinolate to release m-methoxybenzylisothiocyanate, an unstable aglucon that readily liberates thiocyanate ion as a detectable product. There is potential for sulfur-containing products to chemically or thermally decompose during processing and deposit contaminants in the oil, and these may poison hydrogenation catalysts and/or cause odor problems. Thus, we sought cooking conditions that would destroy thioglucosidase during processing prior to oil extraction. Whole-seed inactivation is preferred because enzyme and glucosinolate may interact in flake transit or flake cooking. Whole MF seeds sealed in screw-capped vials were moisture equilibrated (6-16%) before being heated at 180-230 F for 15-60 min. These "cooked" seeds were then air dried, ground in a coffee mill, and the meal slurried with pH 7 phosphate buffer. The slurried meals were then checked for glucose using a glucose sensitive TesTapeR procedure. A positive test indicated that thioglucosidase was still active in the cooked seed meal. A negative test showed that enzyme had been inactivated. In our experiments, the effective levels of moisture, temperature and time during cooking to inactivate MF thioglucosidase were >10% moisture, >210 F, and 45-60 min. These results were confirmed in field experiments and resulted in high-quality oil.