Nutraceuticals in gummy candies form prepared from lacto-fermented lupine protein concentrates, as high-quality protein source, incorporated with Citrus paradise L. essential oil and xylitol

As an addition to a normal diet, the use of food enriched with functional compounds has become increasingly popular. Alternatively, functional ingredients can be incorporated into nutraceuticals in gummy candies (GC) form. This study aimed to adapt lacto-fermented lupine protein concentrates, as high-quality protein and genistein sources, with Citrus paradise essential oil (EO), an antimicrobial and bean taste masking agent, and xylitol, a low glycaemic index sweetener, for preparation of nutraceuticals in GC form. For GC preparation, submerged fermentation with Lactobacillus sakei lupine variety Vilniai protein concentrate was selected, which had the highest protein content (90.11%), protein digestibility (89.94%) and genistein content (30.93gg(-1)) and the lowest trypsin inhibitors activity (19.40%), among the concentrates assessed. GC formulated with xylitol, ascorbic acid, grapefruit EO (up to 0.2%) and lupine protein concentrate (up to 13.0%) allowed obtaining products that exhibited a good texture, high overall acceptability and contained desirable functional compounds.