The effect of the natural antioxidants extracted from Glycyrrhiza glabra (licorice) on the cryopreservation of chicken breast meat
Authors: Almuharib Omar , Jameel Firas , Yaakop Marina 
Published: January 2025

Background: Chicken meat is highly nutritious, valued for its unique properties and versatility in culinary applications. Also, preparation methods and natural additives to its diet play an important role in estimating the nutritional value of its meat by increasing consumer acceptance of it from health, nutritional, and material aspects.
Objective: This study was conducted to determine the effect of licorice as a natural antioxidant on cold-preserved chicken meat.
Methods: Phenolic compounds were quantified using the colorimetric method with Folin's reagent, measuring absorbance at 765 nm, and results were expressed in terms of gallic acid equivalents per gram of dry weight. Gallic acid was used as a reference solution to prepare the standard curve with concentrations ranging between 20-120 μg/mL to determine the quantity of phenolic compounds. Determination of antioxidant activity was done using the DPPH method by taking 0.5 mL of the extract solution at concentrations ranging from 50-300 μg/mL and mixing with 3 mL of methanolic DPPH solution. The mixture was mixed for 1 min with a vortex mixer, and samples were measured by spectrophotometer at 517 nm. Moisture, ash, fat, protein, and pH were determined according to the methods mentioned by AOAC. Thiobarbituric acid-reactive substances (TBARS) were estimated by mixing 0.5 g of the sample with 2.5 mL of TBA solution. The mixture was heated in a boiling water bath for 10 min to orange color, chilled by adding 1 mL of chloroform and centrifuged at 5000 rpm for 25 min, and the absorbance was read at 532 nm wavelength. Total microorganisms, molds, and yeast were counted.
Results: Protein content increased proportionally with higher concentrations of ethanolic licorice root extract. The gradual increase in protein content in samples is attributed to their antimicrobial effect, which leads to the preservation of meat from microbial growth and the action of proteolytic enzymes. The increase in protein during refrigerated storage is due to the decrease in moisture and increase in dry matter reflected in the increase in protein. The reduced acidity in chicken meat treated with licorice root ethanolic extract is attributed to its antimicrobial effects, which limit the growth of microorganisms responsible for metabolizing nitrogenous compounds. Licorice extracts, rich in phenolic compounds, reduce lipid oxidation. The observed decrease in thiobarbituric acid-reactive substances with increasing extract concentration is due to the antioxidant properties of these phenolics with the hydroxyl group attached to the aromatic ring capable of giving hydrogen atoms and inhibiting free radicals. This study found that the growth of microorganisms could be lowered by licorice extract containing phenolic compounds, flavonoids, tannins, and alkaloids, which showed a significant antimicrobial effect.
Conclusion: This study examined how natural antioxidants, like licorice Glycyrrhiza glabra, affected the cryopreservation of chicken breast. 
Keywords: Licorice root extract, chicken breast, antioxidants, total phenol, Meat science