Evaluation of the antimicrobial activity of pecan nut [Carya illinoinensis (Wangenh) C. Koch] shell aqueous extract on minimally processed lettuce leaves

Abstract

Pecan nutshell is a residue from food industry that has potential to be used as biopreservative in foods. The objective of this study was to evaluate the antimicrobial activity of pecan nutshell aqueous extract in vitro and its effectiveness to inhibit spoilage microorganisms on lettuce leaves. The results indicate that the aqueous extract presents inhibitory activity against important foodborne pathogenic bacteria such as Listeria monocytogenes, Salmonella Enteritidis, Staphylococcus aureus, Bacillus cereus, Aeromonas hydrophila and Pseudomonas aeruginosa. Antimicrobial activity was not observed against Corynebacterium fimi, Clostridium perfringens, Escherichia coli, and the phytopathogenic fungi tested. When applied onto lettuce leaves, pecan nutshell extract reduced the counts of mesophilic and psychrotrophic bacteria in 2 and 4 log CFU/g, respectively, during storage of leafy for 5 days at refrigeration temperature (5 °C). The extract was not effective to inhibit yeast on lettuce leaves. Thus, the aqueous extract of pecan shell showed great potential to be used as a natural preservative in foods, acting mainly in the inhibition of spoilage and pathogenic bacteria.

Bioactive components and health effects of pecan nuts and their by-products: a review

“…Ethnobotanical uses of pecan by-products include the consumption of infusions made from the leaves or nutshells for the treatment and prevention of diabetes, obesity, hypertension, hypercholesterolemia, cancer, tuberculosis, and other oxidative stress-related diseases (Caxambú et al, 2016;Gad et al, 2007;Hilbig et al, 2018;Trevisan et al, 2014). Several studies have been carried out using pecan by-products, mainly as antimicrobial, antidiabetic and cell protective ( Table 7).…”

“…Authors attributed this high antifungal activity to the high concentration of hydrolysable and condensed tannins. Caxambú et al (2016) evaluated the effectiveness of a water pecan nutshell extract against Gram+ and Gram-bacteria, and food pathogens. No inhibition was observed for E. coli or fungi.…”

Optimization of ultrasound-assisted extraction of phenolic compounds, antioxidants and rosmarinic acid from perilla leaves using response surface methodology

“…Several methods are available for extraction of phenolic compounds from plants, including solvent extraction, ultrasound-assisted extraction, microwave-assisted extraction, and supercritical fluid extraction (Glisic et al, 2011;Hossain et al, 2012;Caxambu et al, 2016). Of these methods, ultrasound-assisted extraction (UAE) technology has gained increasing popularity due to its advantageous properties, including high extraction efficiency, good reproducibility, low solvent consumption, speed, low cost, environmental friendliness and easy scale up for industrial applications (Tao et al, 2014;Cravotto et al, 2008;Vinatoru, 2001;Vuong et al, 2014).…”

Sugarcane Bagasse: Analysis of Polyphenols, Compounds With Antioxidant and Antimicrobial Activities

“…Similar results were observed previously by Sant'Anna et al [22] when spent coffee ground was evaluated. The disability of sugarcane extract to show antimicrobial activity in the present work may be related to a reduced concentration of compounds with antibacterial activity due to the extraction methodology, although Caxambú et al [14], using the same methodology found antibacterial capacity of aqueous extract from pecan nutshell. Also, different phenolic compounds may have different susceptibility to be extracted to the liquid system [9], and, in the present work, possibly not present in the extract to act as an antimicrobial agent.…”

“…The extraction of antimicrobial substances was performed by maintaining 10 g of dried sugarcane bagasse with 1 L of boiling distilled water for 10 min under constant stirring (model 754A, Fisatom, Brazil), and then filtered through Whatman filter paper nº1 and immediately used [ 14]. Suspensions of 10 7 CFU/mL of Staphylococcus aureus ATCC25923, Listeria monocytogenes ATCC7644, Listeria innocua, Salmonella Enteritidis ATCC13076 and Escherichia coli ATCC25922 were spread onto Plate Count Agar (PCA) with a sterile swab and aliquots of 0,02 mL of the extract were applied.…”