CASSAVA STARCH NANOFIBERS INCORPORATED WITH OREGANO ESSENTIAL OIL AS AN ACTIVE PACKAGING SYSTEM FOR STRAWBERRY PRESERVATION

Essential oils (EOs) are natural compounds widely recognized for their antimicrobial, antifungal, and antioxidant activities, and are considered promising alternatives for application in food preservation systems. Among them, oregano essential oil (OEO) stands out due to the presence of phenolic monoterpenes, such as carvacrol, which are responsible for its high biological activity. However, its direct application is limited by high volatility, sensitivity to light, oxygen, and temperature, as well as its strong aroma. In this context, encapsulation in nanofibers produced by electrospinning emerges as an efficient strategy to protect these compounds and promote their controlled release. The use of the Nanospider^® system offers advantages such as high productivity and industrial feasibility, while cassava starch stands out as a wall material due to its biodegradability, abundance, and low cost. Therefore, this study aimed to produce cassava starch nanofibers containing OEO and to evaluate their application as an active packaging system for strawberry preservation. Nanofibers were produced from cassava starch solutions at 20% (w/v), without and with the addition of 60% (w/w) OEO, resulting in control and active nanofibers, respectively. Scanning electron microscopy (SEM) analysis revealed continuous and homogeneous structures, with average diameters of 250 nm for control nanofibers and 302 nm for those containing essential oil, with the increase attributed to the higher solute concentration. In situ assays showed significant fungal growth in control strawberries and in samples containing only nanofibers without OEO, reaching values on the order of 10⁸ CFU/g after 7 days of storage at room temperature. In contrast, strawberries packaged with OEO loaded nanofibers exhibited a significant reduction in fungal load, with values on the order of 10⁶ CFU/g, corresponding to a reduction of approximately 2 log cycles. The observed antifungal effect is associated with the gradual release of bioactive compounds from OEO, particularly carvacrol, and may have been favored by the larger nanofiber diameter, which contributes to improved compound retention. Thus, cassava starch nanofibers incorporated with OEO demonstrate potential as an active packaging system, representing a promising alternative for the preservation of strawberries and other fresh fruits.