Optimization of the measurement of the antioxidant power of spices for their use in brewery

Details

Supervisors

Collin, Sonia ; Willemart, Guillaume

Faculty

Faculté des bioingénieurs

Degree label

Master [120] : bioingénieur en sciences agronomiques, à finalité spécialisée

Abstract

enThe growing demand for natural ingredients has fostered increasing interest in spices as alternatives to synthetic additives. While spices are already used in some brewing practices, limited research has explored their antioxidant contributions. Beyond their flavor quality, spices represent a potential source of antioxidant compounds that could enhance beer preservation. This study aimed to evaluate the antioxidant capacity of eleven culinary spices and to assess their potential applications in brewing. Extracts were obtained with solvents of varying polarities (methanol, ethanol, ethanol/water mixtures, acetone, acetonitrile, water, and acetone/water/acetic acid mixture) and analyzed by ORAC assay. Extracts obtained with the acidified mixture were further analyzed for total polyphenols, flavanoids, flavonols, and flavones, while UPLC-MS enabled the identification and quantification of individual antioxidant molecules. Results showed large variability between spices. Clove exhibited the highest antioxidant capacity (11,805 μmol TE/g in water extracts), followed by cinnamon, which also displayed the highest polyphenol (60.2 mg/g) and flavanoid (15.3 mg CE/g) contents. Solvent polarity markedly influenced extraction efficiency, with the acidified acetone/water mixture proving most effective for most spices. Ultrasound further enhanced yields, particularly for peppermint and licorice, with increases exceeding three- and four-fold, respectively. Altogether, this work provides an integrated overview of the antioxidant potential of spices and their extractability. These findings highlight their relevance for beer stabilization.