CARBOHYDRATES AND DIETARY FIBER COMPONENTS OF YELLOW-SEEDED AND BROWN-SEEDED CANOLA

Meal samples derived from a number of yellow- or partly yellow-seeded varieties/lines of canola were analyzed for carbohydrate and dietary f iber content and shown to contain 8-10% sucrose, 2-3% oligosaccharides , 20-22% nonstarch polysaccharides (NSP), and 5-8% lignin and polyphen ols. The sucrose content was positively correlated (r = 0.66) with the percentage of yellow seeds in canola samples and was higher by 3-4 pe rcentage points in fully yellow-seeded cultivars as opposed to brown-s eeded varieties. Approximately 15 and 40% of the NSP fractions were fo und to be soluble in water and neutral detergent fiber (NDF) solution, respectively. Due to the high solubility of NSP in the NDF solution a nd because of a low content of lignin and polyphenols, the NDF values for yellow-seeded canola averaged only 19% as compared to 26% for brow n-seeded canola. The total dietary fiber, however, was found to be 27% on average which is only slightly lower than that estimated for brown -seeded canola (30%). On average in comparison to brown-seeded canola, yellow-seeded canola was shown to contain more sucrose and much less lignin and polyphenols. Although the digestibility values were low, th e digestibility of NSP from yellow-seeded canola meal was higher than that for brown-seeded canola meal (8.6 vs 3.4%) when measured with lay ing hens fed semipurified diets. Dry matter and amino acid digestibili ties also tended to be higher for yellow-seeded canola meal.