DEHULLING OF CANOLA BY HYDROTHERMAL TREATMENTS

Hydrothermal pretreatments for loosening the hull of Westar canola (Br assica napus L.) to promote dehulling of the seeds were investigated. The samples tested had on average 14.5% hull on a mass basis. Conditio ning treatments involved soaking the seeds in distilled water or expos ing the seeds to saturated steam. The moistened seed was treated with one of the following drying methods: unheated-air drying, infrared dry ing, and fluidized-bed drying. The dried grain was milled in an abrasi ve dehuller to break the hulls loose. The hulls were removed from the mix by aspiration. The treated seeds yielded a minimum of 11.4% to a m aximum of 14.9% of the seed mass as the hull fraction. Nontreated seed s yielded 9.4% of the seed mass in hull fraction after abrasive dehull ing and aspiration. Among treatments, raising the moisture content of the whole seed from 6 to 15% by exposure to steam, followed by drying in a fluidized bed, resulted in the maximum percent dehulling efficien cy. The hull fraction contained about 24% crude fiber, 18% oil, and 18 % protein on a dry-mass basis.