By-product of green pea canning as a substrate for Propionibacterium freudenreichii fermentation to fortify bread with vitamin B12

This study focused on upcycling the industrial by-product of canned green peas for the production of vitamin B12 by in-situ fermentation and subsequent bread fortification. The by-product, rich in protein (24.3 g/100 g dry matter, DM) and dietary fibre (33.2 g/100 g DM), was fermented with Propionibacterium freudenreichii DSM 20271, resulting in a significant vitamin B12 production (1374–1535 ng/g DM). The fermented material was then incorporated into wheat bread at two levels (15 and 20 % on the dough weight), aiming to address the deficiency of vitamin B12 in strictly plant-based diets. From 40 to 70 g of fortified bread provided the recommended daily allowance of vitamin B12 (2.4 μg/day for adults), along with minimal losses in volume development and no significant differences in texture when compared to the controls. The addition of non-fermented or fermented pea by-product batter in breads increased only the content of soluble conjugated and insoluble bound p-coumaric acid. The study underscores the potential of using food-grade by-products for enhancing the nutritional value of plant-based products, while also contributing to food-waste reduction.