Natural Gum from Flaxseed By-Product as a Potential Stabilizing and Thickening Agent for Acid Whey Fermented Beverages

Abstract

The valorization of food industry by-products is still a major challenge. Here, we report the production of acid whey fermented beverages stabilized with flaxseed gum (derived from oil industry by-product). Four variants of drinks were prepared: (1) fermented whey (W), (2) fermented whey with milk powder added (5% w/v) (WMP), (3) fermented whey with flaxseed gum added (0.5% w/v) (WFG1) and (4) fermented whey with flaxseed gum added (1.0 % w/v) (WFG2). The beverages were kept in refrigerated conditions (5 ± 1 °C) for 28 days. Alterations in lactic acid bacteria population, pH, titratable acidity, water activity, syneresis, viscosity, acetaldehyde content, color, consumer acceptance, bio-active compounds and antioxidant activity were identified. The findings revealed that flaxseed gum addition significantly enhanced bacteria survivability and improved the viscosity of acid whey at a level comparable with milk powder, meeting consumer acceptance criteria. The beverages were characterized by normative physicochemical properties and showed high antioxidant activity and free amino acids level. The use of valuable by-products from the dairy and oil industries opens up a promising route for the production of innovative beverages, which is in accordance with the principles of circular economy and the idea of zero waste.