Enzyme technology for oat milk production

¹ Department of Biochemistry and Nutrition, University of Food Technologies, 26 Maritza Blvd., 4002 Plovdiv, Bulgaria
² Department of Engineering Ecology, University of Food Technologies, 26 Maritza Blvd., 4002 Plovdiv, Bulgaria
³ Center of Competence AgriFoodSystems and Bioeconomy, 4000 Plovdiv, Bulgaria

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Oat milk production through enzymatic hydrolysis was investigated. The enzymatic hydrolysis involved liquefaction with α-amylase at 70 °C, and subsequent sacharification with glucoamylase or maltogenic amylase at 60 °C. The chemical composition of different oat flour fractions was studied and oat flour fraction with fine particles size (75-150 µm) was selected for oat milk production. The effect of hydromodule on chemical composition, dry matter yield and rheological behaviour of oat milk was investigated. The optimal hydromodule of the oat slurry was determined to be 1:6. At hydromodule 1:6 the largest relative viscosity decrease (Δη ≈ 90%), high dry matter yield (61-65 %) and homogeneous liquefaction of the slurry was achieved. Both investigated enzymes (glucoamylase and maltogenic amylase) were considered suitable for efficient hydrolysis of oat slurry. Based on the reducing sugars released, the most favorable conditions for enzyme hydrolysis were identified to be 0.10% glucoamylase for 60 min at 70 °C and 0.10% maltogenic amylase for 60 min at 60 °C. Under these conditions, oat milk, with balanced macronutrient composition (protein = 0.35-0.46 %, lipids = 0.47-0.48 %), high sugar content (6.6-14.2 mg/ml), and favorable rheological properties was produced.