Bread enriched with Chenopodium quinoa leaves powder - The procedures for assessing the fortification efficiency

- Antioxidant potential of bread was significantly improved by quinoa leaves addition.
- Supplementation up to 3% was optimal without compromising sensory quality.
- Large differences between chemical and in vitro physiological approaches were found.
- Universal protocol for evaluation of efficiency of fortificated food is proposed.

The objectives of the study were to investigate the effect of fortification with ground Chenopodium quinoa leaves (QL) on the sensory value and nutraceutical potential of breads and to compare an in vitro physiological and chemical procedure for determination their quality. By QL addition, breads were mainly enriched with rutin and gallic acid. The highest content of rutin was found in buffer extracts (from 73.55 μg/g DM to 209.89 μg/g DM depending from QL addition), whereas the highest gallic acid content was observed after simulated digestion (from 1527.81 μg/g DM (control bread) to 2214.60 (bread with 5 g/100 g QL addition)). Antioxidant potential of enriched breads was significantly higher than activity of control. Breads were especially fortificated with bioaccessible lipids preventers and reductive compounds. Essential differences between both used procedures were illustrated by extractability and fortification factors. Chemical extraction overestimates the ability to chelate metal ions, while underestimates the ability to lipids prevention and reducing power of potentially bioaccessible and mastication-extractable compounds. The sensory evaluation, antioxidant tests, extractability and fortification factors showed that the replacements of wheat flour with up to 3 g/100 g QL powder in breads gives satisfactory results. Additionally, we propose the universal protocol for preliminary evaluation of efficiency of fortificated food.