The individual influence of glucose, sucrose and milk powder on the determination of β-glucan in oat products by the AOAC 995.16 method was studied. The absorption response increased as the glucose amount increased. The detected amounts of β-glucan in oat products had significant differences when more than 5% glucose was added. In this situation, pretreatment with 50% ethanol resulted in steadier data. Added sucrose or milk powder in oat products did not influence the determination of β-glucan.