The influence of lactic acid fermentation on functional properties of narrow-leaved lupine protein as functional additive for higher value wheat bread

•Lacto-fermentation markedly improved lupin protein functional properties.•Supplementation with fermented lupin flour improved the texture of wheat-lupine bread.•Facial expressions are able to explain introspective liking ratings on hedonic scale.

The effect of solid state fermentation (SSF) with Pediococcus pentosaceus KTU05-9 on narrow-leaved lupine (Lupinus angustifolius L.) protein functional properties was evaluated. Analysis of the texture and sensory characteristics of bread produced by wheat flour supplementation with non-fermented (NLF) and fermented (FLF) lupine flours was performed. For the assessment of wheat-lupine bread acceptability the professional software for analysis of facial expressions was used. The SSF treatment of lupine flour resulted in an increase of soluble protein content and improvement of lupine protein functional properties at pH 8. NLF reduced the quality and acceptability of wheat-lupine bread compared to control. The supplementation of wheat flour with 3 g/100 g of FLF resulted in a reduction of bread hardness and chewiness on average by 46%, reduction in resilience by 21%, and slight increase in springiness (by 5%). Higher amount of FLF had no significant influence on bread texture, but gave the most intensive colour, flavour and acidity. Sensory analysis showed significant differences between facial expressions elicited by the different samples. The measurement reflected the introspective liking ratings, especially “happy” and “sad” showed a high correlation with liking and were good indicators for liked and disliked samples, respectively.