Rambutan (Nephelium lappaceum) peel extract:Antimicrobial and antioxidant activities and its applicationas a bioactive compound in whey protein isolate film

Enhanced antimicrobial effectiveness of synergistic mixtures of rambutan peel extract and cinnamon essential oil on food spoilage bacteria and bio‐based food packaging

“…Our previous study found that ethanolic rambutan peel extract (RPE) was rich in phenolic compounds such as corilagin, ellagic acid, geraniin, and gallic acid and exhibited strong antioxidant activity, and showed moderate antibacterial activity to inhibit spoilage and foodborne pathogenic bacteria such as Escherichia coli, Pseudomonas fluorescens, Salmonella typhimurium, Staphylococcus aureus, and Enterococcus faecalis. Moreover, RPE were successfully introduced into whey protein isolate (WPI) film to improve the antibacterial activity, but the feasibility of WPI film with a high amount of RPE was restricted due to its lower distribution within the film matrix, and the weak mechanical properties and the dark brown color of the film degraded the general appearance and consumer acceptance (Sukatta et al, 2021).…”

“…The paler color appearance of the film is attributed to the natural slightly yellow color of CEO. Our previous study reported that the use of RPE in food packaging film might have limited consumer acceptance due to the dark brown color of WPI/RPE film(Sukatta et al, 2021). The incorporation of RPE with CEO resulted in paler color of the bioactive films, which might enhance consumer acceptance of this WPI bioactive film.…”

“…The antimicrobial activity of the mixture was more pronounced against Gram-positive bacteria as compared with the Gram-negative, due to the presence of cell-wall lipopolysaccharides or outer membrane proteins of Gram-negative bacteria could protect their cell from the attack of bioactive compounds(Chouhan, Sharma, & Guleria, 2017). The inhibitory efficacy of the WPI based films is mainly due to the major chemical components of RPE (Corilagin, Ellagic acid, Gallic acid, and Geraniin)(Sukatta et al, 2021) and CEO (trans-Cinnamaldehyde, α-Pinene, Borneol acetate, 1,8-Cineole, and Benzaldehyde) (Cardoso-Ugarte et al, 2016) and the synergistic effect of both.4 | CONCLUSIONThis study revealed the antimicrobial activity of RPE/CEO mixtures inhibiting nine bacterial strains of pathogenic and meat spoilage bacteria, for both Gram-positive and Gram-negative bacteria. The combination of RPE and CEO at a weight ratio of 5:5 (w/w) (RPE/CEO (5:5) ) exhibited the highest effective activity, due to additive and synergistic effects of those mixtures.…”