Prolonging the Post-Harvest Life of Strawberries with Chitosan and Limonene Pads

Strawberries are highly perishable with a short shelf life due to their high susceptibility to mechanical damage, water loss, texture deterioration, and microbiological decay, which quickly reduces their marketability. Rapid cooling after harvest and storage at 0?4 ?C extends the shelf life to approximately 5 days, but even under such conditions, the development of gray mold (Botrytis cinerea) can seriously damage the product. Synthetic fungicides are available for post-harvest control of B. cinerea, including in strawberries. However, this fungus is a "high-risk" pathogen due to its ability to develop resistance to various classes of fungicides. The application of an appropriate post-harvest treatment to prevent deterioration and restrict microbial contamination is a challenge for extending the shelf life of these fruits. In fact, in recent decades, consumer demand for products free from synthetic chemical preservatives has been growing. The development of innovative and ecological strategies capable of improving strawberry quality is a current challenge. Bioactive PackagingIn this context, bioactive packaging offers a good solution because it provides protection to products without affecting their quality and safety. One of the most innovative and flexible applications of bioactive packaging systems is antimicrobial food pads. They are based on classic cellulose pads, commonly used to absorb moisture and liquid from packaged fresh foods, improving aesthetics and protecting against harmful exudate. The latter is generally responsible for unwanted odors, foodborne pathogen propagation, and product deterioration. Antimicrobial food pads consist of a multilayer structure, with the intermediate layer primarily composed of cellulose fibers and active ingredients that absorb excess liquid and inhibit microbial growth. Chitosan and Essential OilsChitosan, a polymer derived from crustacean shells, is biocompatible, non-toxic, non-antigenic, and has drawn significant attention for its potential to act as an antibacterial and moisture-absorbing agent. Integrating chitosan as an active substance into the matrix of absorbent pad structures shows promise. Essential oils are natural compounds of plant origin with potential antioxidant and/or antimicrobial activity. They consist of a mixture of terpenes, terpenoids, and other aliphatic and aromatic constituents, with a composition that can significantly vary depending on the specific oil. Lemon essential oil is primarily composed of limonene, valencene, and ocimene. Limonene is used as a food additive or flavoring agent and is known for its fungicidal activity, including against Botrytis spp. and Aspergillus niger. Active Pads Based on Chitosan and LimoneneThe combination of chitosan and limonene has been studied for the development of active food packaging materials capable of increasing product safety and quality control for agricultural products. However, despite the antimicrobial activity of limonene incorporated into chitosan films, these films have poor mechanical properties that limit their use as active packaging materials; hence, the development of antimicrobial pads based on cellulose is recommended. Active absorbent pads have been developed, containing a layer of cellulose activated with chitosan and limonene to preserve fresh strawberries. The results show that strawberries stored at 8 ?C in containers containing these pads are marketable for an additional 3 to 6 days, comparable to fresh strawberries in the controls. Additionally, they reduce respiratory activity, mold count, and preserve the volatile compound profile. These results demonstrate a promising approach to preserving the quality of strawberries during refrigerated storage. SourcesCefola, M.; Caputo, L.; Quintieri, L.; Cervellieri, S.; Fancello, F.; Netti, T.; Lippolis, V.; Palumbo, M.; Ricci, I.; Sorrentino, A.; Pace, B.; Zara, Z. (2023). Innovative limonene and chitosan-based pads in improving shelf-life and preserving the volatile profile of fresh strawberries. Postharvest Biology and Technology,204: 112430. Wang, D.; Yang, H.; Lu, X.; Wu, Y.; Blasi, F. (2022). The Inhibitory Effect of Chitosan Based Films, Incorporated with Essential Oil of Perilla frutescens Leaves, against Botrytis cinerea during the Storage of Strawberries. Processes, 4:706. Picturehttps://doutorjairo.com.br/leia/morango-incrementa-saude-do-cerebro-aprenda-receitas-com-fruta/?