Characterisation and antimicrobial activity of active polypropylene films containing oregano essential oil and Allium extract to be used in packaging for meat products

Abstract

Cooked ham is more prone to spoilage than other meat products, making preservation a key step in its commercialisation. One of the most promising preservation strategies is the use of active packaging. Oregano essential oil (OEO) and Proallium® (an Allium extract) have previously been shown to be useful in polylactic acid (PLA)-active films for ready-to-eat salads. The present work aims to study the suitability of polypropylene (PP) films containing OEO and Proallium® in the preservation of cooked ham. Concerning the technological features of the studied material, no significant changes in the mechanical or optical properties of PP films containing the active substances were recorded in comparison to the PP film without extracts. However, films containing both active substances were more flexible than the control film and less strong, highlighting the plasticisation effect of the natural extracts. Moreover, physical properties changed when active substances were added to the film. Incorporation of 4% Proallium® affected the transparency of the film to a higher extent compared to 8% OEO, undergoing decreases in transparency of 40% and 45%, respectively. Moreover, only the film containing the highest amount of OEO (8%) significantly decreased the thickness. Both active substances showed antibacterial properties; however, Proallium®-active films seemed to be more effective against Brochothrix thermosphacta than PP films containing OEO, with all percentages of Proallium® killing the bacterial population present in the ham after 60 days. In addition, materials containing the lowest Proallium® content exhibited higher acceptability by consumers in the sensory analyses with 63-100% willing to purchase, better even than the control package (56-89%). In fact, 2% of Proallium® obtained the best results in the odour study performed by the panellists.

Antioxidant active packaging systems to extend the shelf life of sliced cooked ham

“…CON at the end of storage. The bioactive compounds present in oregano essential oils as carvacrol, thymol, ρ-cymene, γ-terpinene could be responsible for the antimicrobial activity of ATRX ( Pateiro et al., 2018a , Mahmoudzadeh et al., 2017 , Ramos et al., 2012 ), and specifically against Brochothrix thermosphacta ( Llana-Ruiz-Cabello et al., 2018 , Paparella et al., 2016 ).…”

“…Recently there is a growing interest in the use of natural active compounds (as essential oils or polyphenol-rich extracts) in the production of active films, which limit the use of synthetic additives and extending the shelf life through controlled migration of the active substances into the food ( Ramos et al., 2012 ). Several studies have demonstrated the effectiveness in the use of plant extracts and essential oils as part of the packaging material ( Lorenzo et al., 2014 , Camo et al., 2008 , Llana-Ruiz-Cabello et al., 2018 ). Additionally, it is well known that some natural extracts presented both, antimicrobial and antioxidant activities, which allows double protective function.…”

New Tricks for Old Guys: Recent Developments in the Chemistry, Biochemistry, Applications and Exploitation of Selected Species from the Lamiaceae Family

“…Several studies have been conducted in this field sometimes also considering the final acceptance of consumers, which remains a fundamental variable for the large‐scale application of these materials. Incorporation of oregano EO into polypropylene film gave a material with similar thermal and mechanical properties of polypropylene with a higher antimicrobial activity in a food model of ready‐to‐eat salad but with ‘negative impact on consumers’ purchase intentions . Rosemary oil was incorporated on a packaging film of bilayer structure based on low‐density polyethylene for maintaining the freshness and extending the shelf life of packaged shrimps up to four days .…”

“…Incorporation of oregano EO into polypropylene film gave a material with similar thermal and mechanical properties of polypropylene with a higher antimicrobial activity in a food model of ready-to-eat salad but with 'negative impact on consumers' purchase intentions. [330] Rosemary oil was incorporated on a packaging film of bilayer structure based on lowdensity polyethylene for maintaining the freshness and extending the shelf life of packaged shrimps up to four days. [331] A polyvinyl alcohol film containing oregano essential oil as an active packaging application for fresh tomatoes without significant changes in the hardness, weight, and color of the product during storage was developed.…”

Biodegradable Antimicrobial Food Packaging: Trends and Perspectives

“…The sachets will slowly release the natural antimicrobial agent and help preserve the food. This is an easy, low-cost method to confer antibacterial activity to the packaging materials already in the market and can be classified as modified atmosphere packaging (MAP), and can be seen as an intermediate step toward obtaining antimicrobial packaging without addressing the problem of plastics pollution [ 92 ].…”