Efficacy of pectin-based caproic acid, caprylic acid, linalool and cuminaldehyde coatings in reducing Salmonella Heidelberg on chicken eggs

Authors: PELLSSERY, ABRAHAM - University Of Connecticut; VINAYAMOHAN, POONAM - The Ohio State University; XUE, JINGYI - University Of Connecticut; WANG, XINHAO - University Of Connecticut; VIJU, LEYA - University Of Connecticut; JOSEPH, DIVYA - University Of Connecticut; LUO, YANGCHAO - University Of Connecticut; Donoghue, Ann - Annie; VENKITANARAYANAN, KUMAR - University Of Connecticut

Submitted to: Frontiers in Sustainable Food Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/2022
Publication Date: 7/27/2022
Citation: Pellssery, A.J., Vinayamohan, P., Donoghue, A.M., Venkitanarayanan, K. 2022. Efficacy of pectin-based caproic acid, caprylic acid, linalool and cuminaldehyde coatings in reducing Salmonella Heidelberg on chicken eggs. Frontiers in Sustainable Food Systems. 6. Article 874219. https://doi.org/10.3389/fsufs.2022.874219.
DOI: https://doi.org/10.3389/fsufs.2022.874219

Interpretive Summary: Phytochemicals represent a group of compounds that have traditionally been used as antimicrobials, flavor enhancers and food preservatives. As natural and environmentally friendly option for a biocontrol agent, phytochemicals have gained acceptance and are preferred for use over chemical disinfectants that raise toxicity concerns and resistance development. A significant amount of research has been conducted in developing edible composite coatings incorporated with antimicrobial agents as a postharvest food safety measure on a variety of food products. The objective to this study was to investigate the efficacy of pectin-based coating incorporated with phytochemicals, including caprylic acid, caproic acid, cuminaldehyde, and linalool, either individually or in combination for reducing Salmonella Heidelberg on refrigerated shell eggs. Salmonella was spot-inoculated on surface sterilized white-shelled eggs. Eggs were evenly coated with either pectin-based treatments individually, or a combination of the 4 phytochemicals. The treated eggs were stored at 4°C and Salmonella counts were evaluated on days 0, 1, 3, 5, 7, 14 and 21 of storage. At the end of refrigerated storage (day 21), the individual phytochemicals reduced Salmonella when compared to controls. However, some of the treatments using phytochemical combinations, were most effective in reducing Salmonella counts from day 0 through day 14, and by the end of storage period (day 21) compared to untreated controls. Results indicate the potential efficacy of these phytochemicals in reducing SH on shell eggs; however, further studies investigating their industrial feasibility and effects on sensory attributes of eggs are warranted.

Technical Abstract: The current study investigated the efficacy of four GRAS (Generally Recognized as Safe)-status compounds, namely, caproic acid (CAO), caprylic acid (CAY), linalool (LIN) and cuminaldehyde (CUM), as pectin-based coating treatments, individually or in combination, for reducing Salmonella Heidelberg (SH) on shell eggs. A three-strain mixture of SH (~8.0 log CFU in 50 µL inoculum) was spot-inoculated on surface sterilized white-shelled eggs. Eggs were evenly coated with either pectin-based treatments of CAO (1%), CAY (1%), LIN (1%) and CUM (1%), individually, or a combination of 4 phytochemicals (COMB- each phytochemical at 0.5% v/v level of inclusion). The treated eggs were stored at 4°C and SH counts were enumerated on days 0, 1, 3, 5, 7, 14 and 21 of storage. The study was replicated thrice, 3 eggs/treatment/day time point, and the data were analyzed using two-way ANOVA. On day 0, pectin-coated control eggs had ~ 7.6 log CFU of SH/egg. At the end of refrigerated storage (day 21), pectin-based coating of CAO and CAY at 1% level reduced SH by 2.0-2.5 log CFU/egg (P<0.05) when compared to controls. In addition, the CUM and LIN based coatings produced 3.0 log and 3.9 log reduction, respectively, in SH counts on eggs by day 21 of storage. However, among the treatments with the phytochemical combinations, COMB1 was found to be most effective, reducing SH counts to 2.5-3.3 log CFU/egg from day 0 through day 14, and by the end of storage period (day 21) a 3.5 log CFU reduction/egg (p<0.05) compared to untreated controls. Results indicate the potential efficacy of these phytochemicals in reducing SH on shell eggs; however, further studies investigating their industrial feasibility and effects on sensory attributes of eggs are warranted.