Effect of ultrasound and fibre enrichment on aroma profile and texture characteristics of pea protein-based yoghurt alternatives
Julia Matysek, Anne Kathrin Baier, Ann-Marie Kalla-Bertholdt, Sandra Grebenteuch, Sascha Rohn, Cornelia Rauh
Abstract
The impacts of ultrasound application and fibre enrichment on the aroma profile and texture characteristics of a pea protein-based yoghurt alternative were studied. Stable yoghurt alternative gels were produced in formulations with and without 3% fibre enrichment using ultrasound or high-pressure homogenisation prior to lactic acid bacteria fermentation. Fibre enrichment had an increasing effect on gel strength, but a decreasing effect on water-holding capacity. Ultrasound significantly reduced off-flavour-related compounds, whereas yoghurt-related compounds were significantly increased. The effects on aroma profile were attributed to cavitation. Effects of cavitation might have increased the availability of substrate for the fermentation and might have altered the proteins' surface and surface hydrophobicity, resulting in detachment of hydrophobic, reversibly bound off-flavour compounds. No major effects of 3% fibre enrichment on off-flavours were detected. To maintain the physical and mental health during aging, nutritional recommendations favour a more intense incorporation of plant proteins, dietary fibres, and unsaturated fatty acids into the diet. However, adding plant proteins and fibres to food products is challenging due to techno-functional and sensorial limitations. Pea protein is a promising, but challenging ingredient as it impairs consumer acceptance due to its off-flavours. Off-flavours diminish foods' organoleptic qualities and consequently their economic value. Therefore, ultrasound treatment as an alternative to conventional high-pressure homogenisation proves to be a promising tool to improve the aroma profile and thus, increase consumer acceptance for healthier and fibre-enriched plant protein-based products.