# Antimicrobial Effect of Clove Against Foodborne Pathogens in Ground Buffalo Meat During Refrigerated Storage

## TL;DR

This study shows that clove oil and extract can safely extend the shelf life of buffalo meatballs by reducing harmful bacteria and improving sensory qualities during refrigeration.

## Contribution

The study evaluates the antimicrobial efficacy of different clove forms and concentrations in preserving buffalo meatballs.

## Key findings

- Clove oil at 1.0 g/kg achieved the highest log reductions in S. aureus, S. enterica, and E. coli O157:H7.
- Clove oil and extract improved sensory attributes like flavor and juiciness, unlike clove powder.
- Clove treatments extended the shelf life of buffalo meatballs to 9–12 days compared to 6 days for the control.

## Abstract

Ground meat is highly perishable and has a short shelf life due to microbial contamination with food spoilage bacteria along with foodborne pathogens, which increases the risk of food poisoning. Controlling microbial growth by using chemical or synthetic food additives or preservatives is of great health concern. Natural, plant-derived antimicrobial food additives are safer alternatives. Therefore, the main objective of this study was to evaluate the antimicrobial efficacy of different forms and concentrations of clove against food spoilage and foodborne pathogens and to determine their ability to enhance sensory quality and extend the shelf life of buffalo meatballs during refrigerated storage. Clove oil (0.25, 0.50, and 1.0 g/kg), clove extract (0.5, 1.0, and 1.5 g/kg), and clove powder (2.5, 5.0, and 7.5 g/kg) were assessed against aerobic plate counts (APCs), psychotropic counts (PCs), and foodborne pathogens such as Staphylococcus aureus, Salmonella enterica serovar Typhimurium, and Escherichia coli O157:H7, artificially inoculated in buffalo meatballs. Clove oil, clove extract, and clove powder treatments showed a significant (p < 0.01) reduction in the counts of S. aureus, S. enterica serovar Typhimurium, and E. coli O157:H7 compared to control samples. Among all tested forms and concentrations of clove, clove oil at 1.0 g/kg proved to be the most effective against the tested pathogens, as by the end of storage (day 12), it achieved 5.3 and 5.56 log reductions in S. aureus and S. enterica serovar Typhimurium, respectively, along with complete reduction in E. coli O157:H7, followed by clove extract at 1.5 g/kg, which produced 4.2, 4.92, and 7.01 log reductions in the corresponding three foodborne pathogens. The results showed that different concentrations of clove oil and extract treatments applied effectively improved the sensory attributes (flavor, tenderness, juiciness, and overall acceptability) of buffalo meatballs, while the sensory properties of clove powder were considered unacceptable, as it alters the taste and smell of meat. The ground buffalo meat treated with different concentrations of clove oil, clove extract, and clove powder significantly reduced the growth of APCs and PCs during refrigerated storage, resulting in 1.5 to 2.6 log reductions with a prolonged shelf life ranging from 9 to 12 days. Overall effects on shelf life and meat quality showed that all clove forms significantly slowed microbial growth and extended the shelf life of buffalo meatballs to 9–12 days, in contrast to 6 days or less for the control. The findings indicate that clove oil and clove extract are promising natural preservatives capable of improving microbial safety, maintaining sensory attributes, and enhancing the overall quality of buffalo meatballs during refrigerated storage.