Changes in carotenoids, phenolic acids and antioxidant capacity in bread wheat doughs fermented with different lactic acid bacteria strains

Amongst the processing technologies able to improve the functional features of cereal-based foods, sourdough fermentation using Lactic Acid Bacteria (LAB) has been recently rediscovered for its beneficial effects. Wheat (Triticum aestivum L.) bread doughs were prepared using LAB strains belonging to different Lactobacillus species and changes in phenolic acid, carotenoid content and antioxidant capacity were evaluated. Two L. plantarum strains out of six were able to significantly increase carotenoid content in the dough, suggesting that a higher mobilization/solubilisation of these antioxidant compounds occurs. Within different fractions (free, soluble-conjugated, insoluble-bound), the relative distribution of ferulic acid and antioxidant activity changes depending on the specific strain. Overall, results indicate that some LAB strains cause in situ changes, significantly increasing the content of functional compounds in doughs during fermentation. This, in turn, could improve the functional features of bakery foods characterised by a high content in carotenoids and other bioactive compounds

Microbial fermentation of industrial rice-starch byproduct as valuable source of peptide fractions with health-related activity

The rice-starch processing industry produces large amounts of a protein-rich byproducts during the conversion of broken rice to powder and crystal starch. Given the poor protein solubility, this material is currently discarded or used as animal feed. To fully exploit rice’s nutritional properties and reduce this waste, a biotechnological approach was adopted, inducing fermentation with selected microorganisms capable of converting the substrate into peptide fractions with health-related bioactivity. Lactic acid bacteria were preferred to other microorganisms for their safety, efficient proteolytic system, and adaptability to different environments. Peptide fractions with different molecular weight ranges were recovered from the fermented substrate by means of cross-flow membrane filtration. The fractions displayed in vitro antioxidant, antihypertensive, and anti-tyrosinase activities as well as cell-based anti-inflammatory and anti-aging effects. In the future, the peptide fractions isolated from this rice byproduct could be directly exploited as health-promoting functional foods, dietary supplements, and pharmaceutical preparations. The suggested biotechnological process harnessing microbial bioconversion may represent a potential solution for many different protein-containing substrates currently treated as byproducts (or worse, waste) by the food industry

In vitro bioaccessibility and bioavailability of iron from breads fortified with microencapsulated iron

Iron deficiency is the most prevalent mineral deficiency in the world. Food fortification offers an alternative to standard oral iron therapy, which often causes unpleasant side effects. In this study, bread was fortified with either ferrous sulphate or ferrous fumarate. To prevent undesired organoleptic changes in colour, odour and taste, iron compounds were introduced in the form of microcapsules. Eight types of bread were prepared using conventional fermentation or sourdough and fortified with one of four types of microcapsule. The in vitro bioaccessibility and bioavailability of the iron were determined using the human epithelial adenocarcinoma cell line Caco-2, preceded by digestion in a dynamic gastrointestinal digester, which mimics the upper gastrointestinal tract of an adult human. The bioaccessibility of the iron after digestion of the fortified breads varied from 41.45 to 99.31%. The iron transport efficiency varied widely, from 1.16 to 13.78%. Generally, both bioaccessibility and transport efficiency were higher in the samples of breads prepared by conventional fermentation. The mRNA expression of DMT1 and IREG1, cellular iron transporters which serve as molecular markers of iron movement across the intestinal border, was not statistically significant