Bioprocessing of Wheat Bran in Whole Wheat Bread Increases the Bioavailability of Phenolic Acids in Men and Exerts Antiinflammatory Effects ex Vivo

Abstract

Whole grain consumption has been linked to a lower risk of metabolic syndrome, which is normally associated with a low-grade chronic inflammation. The benefits of whole grain are in part related to the inclusion of the bran, rich in phenolic acids and fiber. However, the phenols are poorly bioaccessible from the cereal matrix. The aim of the present study was to investigate the effect of bioprocessing of the bran in whole wheat bread on the bioavailability of phenolic acids, the postprandial plasma antioxidant capacity, and ex vivo antiinflammatory properties. After consumption of a low phenolic acid diet for 3 d and overnight fasting, 8 healthy men consumed 300 g of whole wheat bread containing native bran (control bread) or bioprocessed bran (bioprocessed bread) in a cross-over design. Urine and blood samples were collected for 24 h to analyze the phenolic acids and metabolites. Trolox equivalent antioxidant capacity was measured in plasma. Cytokines were measured in blood after ex vivo stimulation with LPS. The bioavailabilities of ferulic acid, vanillic acid, sinapic acid, and 3,4-dimethoxybenzoic acid from the bioprocessed bread were 2- to 3-fold those from the control bread. Phenylpropionic acid and 3-hydroxyphenylpropionic acid were the main colonic metabolites of the nonbioaccessible phenols. The ratios of pro-:antiinflammatory cytokines were significantly lower in LPS-stimulated blood after the consumption of the bioprocessed bread. In conclusion, bioprocessing can remarkably increase the bioavailability of phenolic acids and their circulating metabolites, compounds which have immunomodulatory effects ex vivo.

A Review on: Antioxidant and Its Impact during the Bread Making Process

“…[17] found that baking had a negative impact on antioxidant properties of gluten-free breads, and polyphenol content was generally found to be reduced in the bread samples when compared in original seeds. They showed that, in the case of wheat bread 40% replaced with barley flour, the amount of free phenolic decreased by up to 23.5% during the baking process, while the amount of bound phenolic increased [18] [22]. At the same time, the measured antioxidant activities were relatively stable during the baking process.…”

“…There are a number of clinical studies suggesting that the antioxidants in fruits, vegetables, tea and red wine are the main factors for the observed efficacy of these foods in reducing the incidence of chronic diseases including heart disease and some cancers [1].Cereal grains are also a good source of antioxidants. Phenolic acids are the main antioxidants in cereal grains, which seem to have the greatest potential to be beneficial to our health as a result of their scavenging free radicals, inhibition of lipid peroxidation, and thus their anticancer activity [22] [26]. Phenolic compounds in cereals exist in free, soluble conjugated and bound forms, where the bound form represents the major proportion of phenolic acids [26] [27].The Bread and bakery products have an important role in human nutrition.…”

The Bioavailability and Metabolism of Phenolics, a Class of Antioxidants Found in Grains

“…A major factor affecting bioavailability is the type of food in which it is consumed. For example, Mateo Anson et al (40) investigated differences in the bioavailability of ferulic acid in eight men who had consumed a control bread (bran in its original state) or bioprocessed bread (bran bioprocessed via yeast fermentation combined with enzyme treatment for 20 hr at 20°C). The ferulic acid in the bioprocessed bread was significantly more bioavailable (average C max of 2,700 nM versus 880 nM for the control bread).…”

Anti-Inflammatory Role of Natural Polyphenols and Their Degradation Products

“…In addition, caffeic acid is an effective ABTS radical scavenging, DPPH radical scavenging, superoxide anion radical scavenging and it has total reducing power and metal chelating on ferrous ions activities (Gulcin, 2006). In wheat grain ferulic acid is the most abundant phenolic compounds and a correlation between changes in the plasma ferulic acid concentration and changes in the plasma antioxidant capacity was reported in a human ex vivo study (Mateo Anson et al, 2011). The antioxidant potential of ferulic acid can usually be attributed to its structural characteristic.…”

“…The other large family of phenolic acids: ferulic acid and its derivatives were also attributed as potent inhibitors of inflammatory mediators. Indeed, ferulic acid decreased the levels of inflammatory cytokines, e.g., TNF- (Han et al, 2007) in LPS-stimulated macrophages and lowered pro-:anti-inflammatory cytokine ratios (IL-6:IL-10 and IL-1 :IL-10) in the ex vivo LPS-stimulated blood (Mateo Anson et al, 2011). Ferulaldehyde decreased the levels of early pro-inflammatory cytokines such as TNF-, IL-1β and increased the anti-inflammatory IL-10 in the sera of the LPS-treated mice (Radnai et al, 2009;Tucsek et al, 2011) supporting further the importance of these compounds as potential anti-inflammatory agents.…”