8. Conclusion and future trends
Sachets and pads are one of the most successful applications of ac- tive food packaging systems. Antimicrobial compounds incorporated in emitting sachets and absorbent pads include ethanol, ClO2, a variety of plant EOs and their main active compounds, and antimicrobial nano- particles. The technologies involving antimicrobial emitting sachets and absorbent pads are being continuously improved as new antimicrobial compounds are found or produced. Taking into account the increasing demands for less synthetic preservative, natural compounds have been widely exploited by the scientific community all over the world. The application of bio-based and/or biodegradable materials is also urged as environmentally friendly alternatives for carrier, sachet, and external packaging materials.
The literature has reported sachets capable of emitting carbon dioxide and scavenging oxygen, emitting ethanol vapor and scavenging oxygen, absorbing moisture and scavenging oxygen, and scavenging both oxygen and carbon dioxide (Day, 2008; Smith et al., 1995). The development of novel dual-action sachets is encouraged in an effort to optimize the efficiency of emitting sachets and absorbent pads.
Overall, researchers are more concerned about the release/absorp- tion of antimicrobials/undesirable compounds as well as the antimicro- bial performance of these systems either in vitro or in vivo. When real foods are tested, even though their physicochemical attributes are widely evaluated, the studies lack data on the sensory impact led by the use of emitting sachets and absorbent pads. The residual contents of antimicrobial impregnated into food and/or volatilized within pack- aging headspace are not often regarded, even if they can provide valu- able information regarding the acceptability of this packaging system, help overcome the hurdle of its resistance by consumers, and make its commercial application easier.
Finally, the use of emitting sachets and absorbent pads is no lon- ger limited for antimicrobial purposes. Continuous developments are being made in flavoring, antioxidant, nutrient-releasing, and anti-insect activity.
Acknowledgments