Active Food Packaging Based on Biopolymers and Aroma Compounds: How to Design and Control the Release

Abstract

Aroma compounds are known to be efficient active agents for a broad range of applications (antimicrobial, anti-oxidant, insect repellent…) that are highly sought when aiming at extending shelf life of food or biological products. However, they are intrinsically odorant and volatile at ambient temperature, which restricts the processing routes used to introduce them in a polymeric matrix and can affect their mode of action and limit efficiency. Indeed, due to their high sensitivity toward temperature they can be lost or transformed during processing. Acting after being released in the headspace, their concentration has to be controlled to avoid any odorant contamination of the targeted products. Hence, the ability for an aroma compound to be retained in a polymeric matrix, and then released when submitted to a triggering effect, are the two main requirements that should be satisfied. The volatile nature of the aroma compound offer the possibility when introduce in the packaging to act by direct or indirect contact with the product and thus to be used in different ways; as a coating layer directly applied on the product surface, as a self-supported film or as coated paper when associated with a paper sheet, as well as an object that could be inserted in the package. As biopolymers such as proteins and polysaccharides are able to retain aroma compounds but also to favor their release by modification of their structure when the relative humidity (RH) and temperature change, they are relevant carriers of these specific aroma compounds. Examples of how active packaging systems with limonene, eugenol and carvacrol as active agents were designed and elaborated. These examples will be presented with a special focus on the processing conditions and the way to improve their aroma compound retention and the release control (biopolymer nature, cyclodextrin clay addition…). Avrami's equation has been used to model the transfer of aroma compound and to advantageously compare it taking into account the mechanism in relation to the biopolymer structural changes.

Cyclodextrins, Natural Compounds, and Plant Bioactives—A Nutritional Perspective

“…CDs have been used in food and pharmaceutical products for many years, largely to form inclusion complexes with problematic drugs to enhance their solubility [ 55 ]. In addition, previous studies have shown that CDs are useful as an antibacterial food packaging material when forming inclusion complexes with natural antimicrobial agents such as thymol and carvacrol [ 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ]. This embedment of an antibacterial agent into food packaging material is one strategy to inhibit bacterial growth.…”

New Trends in the Use of Volatile Compounds in Food Packaging

“…In relation to food packaging containing volatile compounds, the mechanism of action is based on the release of these compounds from the polymer matrix to the food sample to perform their technological function [ 4 ]. For this reason, the compatibility of the volatile compound with the polymer matrix and its capacity to be retained during processing are key parameters for the final validation of the active packaging for a specific food application.…”

“…Volatile compounds such as aldehydes, terpenes, and sulfur compounds, among others, are efficient active agents for a broad range of food applications due to their intrinsic antimicrobial, antioxidant, insect repellent, and other properties that can be suitable to extend the shelf-life of food that degrade under different mechanisms. However, they are also odorant and volatile at ambient temperature, properties that difficult their successful incorporation into a polymer matrix leading to high losses of the volatile compound and the formation of degradation products after processing and drying of the new developed materials [ 4 ]. In order to solve this limitation, in recent years, different processing methods have been designed and implemented apart from the conventional ones such as extrusion or injection molding, the main processing techniques used in the packaging industry in which high temperatures are needed causing losses of volatile compounds near to 30 wt% [ 5 ].…”

“…They can also form complexes with a large group of molecules, changing their chemical composition or biological behavior as they have been modified to improve their reactivity with the compound to be encapsulated. The incorporation of volatile compounds/cyclodextrin complexes in different matrices has been evaluated such as the addition of cyclodextrins containing carvacrol in coated papers [ 4 ].…”

Sustainable Active PET Films by Functionalization With Antimicrobial Bio-Coatings

“…At the same time, the selection of the proper antimicrobial, as well as the choice of its optimal loading, is an important and not an easy task in the design and application of antimicrobial packaging (Becerril et al, 2013;Wicochea-Rodríguez et al, 2019). Some of these substances can modify the organoleptic profile of the packaged foodstuff, or can be used only for a small variety of foods, or can affect the functional properties (i.e., gas permeability, tensile strength, transparency, thermal stability, etc.)…”