Antioxidant and Antimicrobial Potential of Blackthorn and Red Cherry Extracts in Natural Sausage Casings

This study explores the use of natural plant extracts as a sustainable method to enhance the quality and safety of long-life sausages by incorporating them into natural edible casings. Ethanol (E) and aqueous (A) extracts of blackthorn (BT) and red cherry (RC), as well as their ethanol and water-based solutions, were prepared and analysed for their antioxidant and antimicrobial properties. The analyses included the quantification of total phenols, non-flavonoids, flavonoids, flavonols, and anthocyanins, along with antioxidant activity assessments using FRAP, DPPH, and ABTS assays. Antimicrobial efficacy was tested against Gram-positive and Gram-negative bacteria (Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Salmonella enterica) and mold Penicillium expansum via agar dilution methods to determine MIC and MBC/MFC. Results showed that ethanol extracts had higher antioxidant activity than aqueous ones (p<0.05), with the ethanol extract of blackthorn (EBT) containing the highest levels of phenolics (54.11 mg GAE/g d.e.) and exhibiting the strongest antioxidant, antimicrobial, and antifungal activities. Casings treated with EBTE (ethanol BT extract dissolved in ethanol) demonstrated significant antibacterial properties, particularly against Gram-negative bacteria. This study confirms that plant-extract-enriched natural casings can protect against oxidation and microbial spoilage, thereby enhancing the overall quality and safety of dry-cured sausages.