Biscuits Polyphenol Content Fortification through Herbs and Grape Seed Flour Addition

Abstract

The study aimed to verify whether the addition of selected herbs and spices will affect the content of polyphenols in biscuits and their antioxidant capacity, as well as what impact it will have on their sensory properties and attractiveness to consumers. Ground cloves, cinnamon, mint, and grape flour were added to the biscuits in concentrations of 1.0, 3.0, 5.0, and 10.0%. The total content of polyphenols in spices and biscuit samples was determined using the Folin–Ciocalteau solution and, subsequently, the antioxidant capacity was measured by FRAP (ferric ion reducing antioxidant power) and DPPH (2,2-diphenyl-1-picrylhydrazyl inhibition). Polyphenols were transferred through spices and herbs into the biscuits in all samples and thus their antioxidant capacity was increased. The antioxidant capacity of the control sample measured by the DPPH method was 15.41%, and by the FRAP method 1.02 μmol Trolox/g. There was an increase in antioxidant capacity in all samples with the addition of spices and herbs. The highest increase was recorded in the sample with cloves, namely with the addition of 10% of cloves there was an increase measured by the DPPH method to 92.6% and by the FRAP method to 208.42 μmol Trolox/g. This also corresponds to the measured TPC (Total Polyphenol Content) in the pure clove, which was 219.09 mg GAE/g, and in the samples where the content gradually grew up to 4.51 mg GAE/g in the sample with the addition of 10%, while the polyphenol content of the control sample was 0.2 mg GAE/g. For other parameters, changes were also observed, depending on the addition of spices/herbs. There was a reduction in both texture parameters, hardness and fracturability, depending on the addition of spices/herbs, which was confirmed by both instrumental measurements and sensory analysis. Colour measurements clearly separated the control from the fortified samples, thus confirming the colour changes. The addition of grape flour shows the smallest difference from the control when the overall impression does not change with the addition. In terms of the combination of increased antioxidant capacity and overall consumer acceptability, the addition of cloves at a concentration of 3.0% appears to be the best option.

Research on the Potential Use of Grape Seed Flour in the Bakery Industry

“…Král et al [ 46 ] studied the addition of selected herbs and spices (ground cloves, cinnamon, mint, and grape flour) to biscuits, and the content of polyphenols and antioxidant capacity was measured, as well as their sensory properties and attractiveness to consumers. The results showed an increased antioxidant capacity for all samples, as well as for polyphenols.…”

Special Issue: Phenolic Profiling and Antioxidant Capacity in Agrifood Products

“…Král et al [2] studied the addition to biscuits of different concentrations (1-10%) of a selected herb (mint), spices (cinnamon and cloves) or fruit (grape) extracts and their influence on the content of polyphenols (TPC by Folin-Ciocateau), antioxidant capacity (FRAP and DPPH), and their sensory properties and attractiveness to consumers. The results showed that the use of appropriate spices and herbs in the elaboration of the biscuits increased their polyphenol content and thus their antioxidant capacity, with the highest values found in biscuits elaborated with the highest amount of cloves.…”