Effect of temperature on antibacterial activity and fatty acid methyl esters of Carica Papaya seed extract

This chapter addresses the antibacterial activity of Carica papaya seeds due to their abundance in bioactive compounds and these seeds contain high levels of fatty acid methyl esters (FAMEs). However, no report is available to indicate (1) which FAMEs are potent against pathogens and (2) the effect of temperature on the distribution of FAMEs. Therefore, this study aims to evaluate the effect of temperature against the antibacterial activity of Carica papaya seed extract (CPSE) and its FAME profile via extraction of the seeds using methanol and the extract was subjected to test of antibacterial activity against Salmonella enteritidis, Bacillus cereus, Vibrio vulnificus, and Proteus mirabilis. FAME profiling was done using GC/MS incorporated with principal component analysis (PCA). The CPSE at 5.63 mg/mL was potent against these pathogens at < 40 °C. Although the CPSE was rich with FAMEs, the PCA result had identified individual FAMEs that inhibited the pathogen growth. Palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid (C18:1n9c), and cis-vaccenic acid (C18:1n11c) had strongly inhibited V. vulnificus and P. mirabilis growths and moderately inhibit S. enteritidis growth. To avoid the formation of trans FAMEs, this study also suggested that the CPSE temperature should be held at < 150 °C.