The addition of yerba mate leaves on bread dough has influences on fermentation time and the availability of phenolic compounds?

Phenolic mapping and associated antioxidant activities through the annual growth cycle of sugar maple leaves

Concentrations of antioxidant components (analyzed by HPLC-UV) and antioxidant attributes (assayed by radical scavenging and non-radical redox potential methods) of sugar maple leaves (SML) from different harvesting times were investigated. Moreover, measurements of colorimetry, SEM, and FTIR spectroscopy-based characterization of leaves composition, throughout the growth cycle, were performed. Results showed that the antioxidant activities of SML are strongly correlated with phenolic contents and significantly (p < 0.05) varied with harvesting time where minimum amount of total phenolics (105.67 ± 13.16 mg GAE/g DM) and total flavonoids (3.27 ± 0.26 mg CTE/g DM) were found to be concentrated in Fall leaves. The absorption bands obtained from FTIR spectra revealed the presence of functional groups that have great significance towards the antioxidant activity of SML. Principal component analysis revealed that biosynthesis of maximum phenolic compounds in SML mostly occurs during the leaf expansion and growth phases. The obtained data provided a better understanding towards the effect of harvesting time on the phenolic mapping of SML in favor of its valorization into functional food ingredients.

The Influence of Flavonoid Dihydroquercetin on the Enzymatic Processes of Dough Ripening and the Antioxidant Properties of Bread

Bread is an integral part of the diet of the world population. Development of bread enriched with biologically active substances, including antioxidants, could be good nutritional support for human health. Among well-studied antioxidants, we can highlight dihydroquercetin, a flavonoid with outstanding antioxidant properties, such as anti-inflammatory activity, immunostimulatory properties, anti-cancer properties, and others. At the same time, the technology of bread enrichment must consider the possible negative effects of the additive on the technological processes and properties of the final product. The present work was carried out to evaluate the effect of dihydroquercetin on the enzymatic processes occurring during dough maturation and the antioxidant properties of the finished bread. Dihydroquercetin was added in amounts of 0.05 g, 0.07 g, and 0.1 g per 100 g of wheat flour and fermented with commercial baker’s yeast (Saccharomyces cerevisiae). The kinetics of pH and total titratable acidity (TTA) during dough fermentation showed that dihydroquercetin caused slight slowing of enzymatic processes. However, the dosage of dihydroquercetin did not cause statistically significant changes in the yeast concentration, which reached a level of 108 KOU/g after 2 h in all dough samples. Loss of dihydroquercetin during fermentation was established at a level of 20–25%. At the same time, an increase in the total amount of flavonoids in the dough after 2 h of fermentation and an increase in values of antioxidant activity were noted. The antioxidant properties of the bread also increased when it was enriched with dihydroquercetin (about 3.5–4 times) despite the fact that the total quantitative loss of antioxidant in the technological process was considerable (about 40%). A protective effect of the bread matrix on flavonoids during digestion was shown. Dihydroquercetin loss was about 25% regardless of the amount applied. This work clearly showed that addition of dihydroquercetin to a bread formulation represents a promising strategy for increasing the antioxidant properties of bread.

Antioxidant effect of blueberry flour on the digestibility and storage of Bologna-type mortadella

The aim of the study was to add blueberry flour (BF) to Bologna-type mortadella as a natural antioxidant and to evaluate its activity during in vitro digestion and refrigerated storage. Five treatments of mortadella were prepared: without antioxidant, with sodium erythorbate and with the addition of three levels of BF: 0.05 %, 0.075 % and 0.1 %. Twenty-three phenolic compounds were quantified in blueberry fruits and twenty-eight in BF, with prevalence of chlorogenic acid. The presence of BF did not affect the proximal composition of the mortadella, but it had a small effect on pH, hardness (texture profile) and instrumental color, as well as reduced lipid oxidation during refrigerated storage (2-8 °C) for 90 days. During in vitro digestion, the addition of BF increased the content of total phenolic compounds and the antioxidant activity of mortadella (p < 0.05), among all simulated stages. At a concentration of 0.05 %, BF can be used as a synthetic antioxidant substitute in Bologna-type mortadella, enhancing the use of blueberry fruits in the form of flour and enriching the product with natural antioxidants.

The Effect of Stabilized Rice Bran Addition on Physicochemical, Sensory, and Techno-Functional Properties of Bread

Rice bran (RB) is a valuable byproduct derived from rice milling that represents an excellent opportunity for dietary inclusion. Bioactive components with antioxidant potential have been reported in RB, gaining the considerable attention of researchers. However, RB requires a stabilization process after milling to prevent it from becoming rancid and promote its commercial consumption. The aim of this study was to evaluate the effects of substituting stabilized rice bran (SRB) for wheat flour at levels of 10, 15, 20 and 25% on the proximate composition, dietary fiber, dough rheology, antioxidant properties, content of bioactive compounds, and sensory attributes of white wheat-based bread. Results indicated that the incorporation of SRB increased the bread’s insoluble dietary fiber, phytic acid, total polyphenol content, γ-oryzanol, γ-aminobutyric acid, and antioxidant properties, while decreased its water absorption capacity, elasticity, volume, β-glucans, and soluble dietary fiber content. Moreover, substituting wheat flour for SRB at levels higher than 15% affected sensory attributes, such as color, odor, flavor, and softness. This study highlights the potential application of SRB flour in bread-making to increase nutritional, and functional properties of white wheat bread.

Effect of yerba mate (Ilex paraguariensis) leaves on dough properties, antioxidant activity, and bread quality using whole wheat flour

This study investigated the effects of different yerba mate (YM) proportions (1.5, 2.5, and 4.5 g YM/100 g whole wheat flour (WWF) and particle sizes (245, 415.5, and 623.9 µm) on dough rheological properties, antioxidant activity, and bread characteristics. The addition of YM leaves led to a possible interaction between its phenolic compounds and the gluten network within the dough, without negative effects on dough formation. However, the larger YM particle size (623.9 µm) caused a weakening of the protein network, resulting in lower quality product compared to the other samples. Improved bread quality was found when the YM leaves were added at 2.5 g YM/100 g WWF. The total amount of phenolic compounds and the antioxidant activity increased as the proportion of YM increased in both flour and bread. Moreover, the phenolic compounds in 2.5 g YM/100 g WWF breads were stable during baking, showing no significant losses in the amount of phenolic compounds and antioxidant activity. These results suggest the YM can be successfully incorporated into baked product, improving its functional characteristics. PRACTICAL APPLICATION: This study evaluates the technological quality of bakery product made by incorporating yerba mate leaves in whole wheat flour. The results will contribute to the production of a bread with greater functional properties due to the presence of polyphenols and phytochemicals.