Effects of starch type and concentration on the physicochemical properties of bilayer-stabilized o/w emulsion gels enriched with β-1,3/1,6-D-glucans

Background: In recent years, consumer interest in low-fat foodstuff while having a clean label and potential benefits over physiological functions has shown a growing trend. β-1,3/1,6-D-glucans (BGs) from Saccharomyces cerevisiae have been recognized as excellent immune-modulating compounds. Bilayer-stabilized o/w emulsion gels (BEGs) containing oil droplets covered by myofibrillar proteins-gum arabic membranes were used for entrapping BGs in the inner phase. This study investigated the effects of starch type (waxy maize starch, WMS; potato starch, PS) and concentration (0.0-50 g kg^-1 ) on the physicochemical properties of BEGs composed of: 200 g kg^-1 rapeseed oil, 40 g kg^-1 myofibrillar proteins, 14 g kg^-1 gum arabic, 15 g kg^-1 β-1,3/1,6-D-glucans, 1 g kg^-1 citric acid.

Results: The studies proved that BGs were successfully incorporated into the inner phase of BEGs and stability test showed no separated oil and sediment layer. BEGs were characterized by droplet diameter of d_3,2 = 3.62 ± 0.209 μm and electrical charge of the outer membrane of -27.4 ± 0.257 mV. The increasing starch concentration significantly (p < 0.05) affected values of the studied rheological parameters, but to a greater extent in relation to PS than WMS. Sensory analysis showed that BEGs were most desirable at WMS and PS concentrations of 40-50 g kg^-1 and 30-40 g kg^-1 , respectively.

Conclusion: Bilayer-stabilized o/w emulsion gels containing oil droplets covered by myofibrillar proteins-gum arabic membranes can be used as carriers for insoluble β-glucans and manufactured in a wide range of rheological properties and sensory features desired by the consumers. This article is protected by copyright. All rights reserved.

Keywords: bilayer emulsion; myofibrillar proteins; rheological properties; sensory analysis; starch; β-1,3/1,6-D-glucan.