In vitro antibacterial activity of nut by-products against foodborne pathogens and their application in fresh-cut fruit model

Abstract

Aqueous extract of nut by-products (cashewnut shell, coconut shell, and peanut hull) were studied for their physicochemical properties, antibacterial activity and food preservation potential in an artificially inoculated fresh-cut fruit (papaya) model. Physicochemical characteristics revealed the colour, odor, nearly neutral pH (6.67-6.83), high water solubility (69.18-82.63%) and total phenolic content (1130.54-2403.41 mg GAE/100 g) of the extracts. The antibacterial property of the extracts evaluated by zone of inhibition assay revealed that cashew nut shell extract had a strong inhibition effect on (18 mm), (18 mm), and (16 mm). Food preservative effect of extracts was examined in an artificially inoculated fresh-cut papaya model, and both cashewnut and coconut shell extracts significantly reduced the population of the above mentioned foodborne pathogens. However, when compared to coconut shell extract, the application of cashewnut shell extract was found to affect the sensory property of the fresh-cut fruit as darkening of the cut fruit was observed. So, the coconut shell extract could be considered as a natural source of antibacterial agent for food preservative applications. Phytochemical investigation through LC-MS/MS technique revealed that luteolin as the major constituent of coconut shell extract.

Fresh Cut Fruits - An Overview of Microbiological Conditions, Recent Outbreaks and Preventive Strategies

“…H2O2, ozone, organic acids (e.g. acetic, citric, succinic, malic, tartaric, benzoic, propanoic and sorbic acids) and peroxyacetic acids used as an alternative to chlorine also have limited effects in killing microorganisms (Prakash et al, 2018). Furthermore, biopreservation methods, defined as the "use of living organisms to suppress the population density or impact of a specific pest organism, making it less abundant or less damaging than it would otherwise be" (Eilenberg et al, 2001) are preferred in order to inhibit microbial growth and increase shelf life of FCFs.…”

Assessment of toxic effect ofCentella asiaticaextract and its application as natural preservative in fresh‐cut mango, pear and cabbage

“…The initial inoculum was confirmed by plating 100 µl from the appropriate dilution in triplicate before inoculating it into each sample. Inoculated FCFV were kept for 30 min in the laminar hood flow for air-dried and allowed complete microbial attachment on samples (Choi et al, 2015;Prakash et al, 2018). Therefore, the experiment conducted in 1 pathogen species × 1 produces type × 3 replicates = 3 treatment combinations.…”

“…After drying, all portions were aseptically transferred into a light density poly-ethylene (LDPE) zip-lock bag (15 × 22 cm) to prepared RTD-FCFV (22 ± 1℃), and plastic tray covered with stretchable cling film to prepare CS-FCFV (4 ± 0.5℃). One bag or tray of 25 g samples represented an experimental replicate and triplicate was done (Akbas & Ölmez, 2007;Prakash et al, 2018;Ramli et al, 2017). Microbiological analysis and flesh color measurement were conducted periodically on an hour basis (RTD-FCFV; 0 to 4 hr) and daily basis (CS-FCFV; day 0 to 4).…”

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Consuming fruits and vegetables are often recognized by human beings as the main micronutrient supply and prevents health diseases (Vivek et al, 2019). Due to the high demand of consumers for healthier food, fresh-cut fruits and vegetables (FCFV) sectors are getting developed and expanded worldwide (Prakash et al, 2018). In South-East Asian countries like Malaysia or Thailand, FCFV is easily found in supermarkets, street vendors and hawkers, or open-air markets (James & Ngarmsark, 2010).

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“…As RTE products, FCFV usually does not involve any effective pathogen decontamination or preservation treatments before consumption. Fresh produce is a leading vehicle in diversifications of virulent pathogen and illness outbreaks associated with FCFV such as Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes (Choi et al, 2015;Prakash et al, 2018).…”