Content and Molecular Weight of Extractable β-Glucan in American and Swedish Oat Samples

β-(1→3),(1→4)-d-Glucan (β-glucan) was extracted from 93 Swedish and 41 American oat samples using hot water containing CaCl2 and thermostable α-amylase. The samples showed a large variation in both the content of extractable β-glucan (0.76−3.68%) and the average molecular weight ((1.25−1.78) × 106 g mol-1). An analysis of the variance of β-glucan content and the molecular weight of Swedish oat samples grown in 2000 and 2001 was done with cultivar and harvest year as factors. It showed that the extractable β-glucan content was a heritable trait whereas molecular weight depended more on environmental factors. The American oat samples had a higher average content of extractable β-glucan (2.24%) and a somewhat higher average molecular weight (1.58 × 106 g mol-1) than the Swedish oat samples (1.43% and 1.49 × 106 g mol-1). Keywords: extractable β-glucan; molecular weight; oats