A Novel Niosome-Encapsulated Essential Oil Formulation to Prevent Aspergillus flavus Growth and Aflatoxin Contamination of Maize Grains During Storage

Abstract

Aflatoxin (AF) contamination of maize is a major concern for food safety. The use of chemical fungicides is controversial, and it is necessary to develop new effective methods to control Aspergillus flavus growth and, therefore, to avoid the presence of AFs in grains. In this work, we tested in vitro the effect of six essential oils (EOs) extracted from aromatic plants. We selected those from Satureja montana and Origanum virens because they show high levels of antifungal and antitoxigenic activity at low concentrations against A. flavus. EOs are highly volatile compounds and we have developed a new niosome-based encapsulation method to extend their shelf life and activity. These new formulations have been successfully applied to reduce fungal growth and AF accumulation in maize grains in a small-scale test, as well as placing the maize into polypropylene woven bags to simulate common storage conditions. In this latter case, the antifungal properties lasted up to 75 days after the first application.

Assessment of the Effect of Satureja montana and Origanum virens Essential Oils on Aspergillus flavus Growth and Aflatoxin Production at Different Water Activities

“…In this study, we have demonstrated that SM EO was able to retard fungal growth and reduce AF production, mainly at the highest a w levels tested. The results obtained regarding the effect of SM EO on fungal growth and AF production by A. flavus at 0.98 a w using Bioscreen C are similar to those reported in previous in vitro studies in our laboratory [25]. The most significant results in this case were observed at 0.96 a w , which is coincident with the conditions in which both isolates reached the highest levels of AF production.…”

“…Recent consumer trends towards safer foodstuffs, produced using sustainable and ecofriendly methods, have sparked great interest in new alternatives to traditional chemical food preservatives or synthetic fungicides [13]. In a recently published work carried out by our group, the EOs extracted from Satureja montana (SM) and Origanum virens (OV) were demonstrated to be effective to controlling A. flavus growth and its ability to produce aflatoxins (AF) in vitro or in maize grains when humidity was maintained at high levels [25]. Considering the influence of environmental factors on the effectiveness of EOs, the objective of the present work was to determine if they were able to control fungal growth and AF production at three different water activity (a w ) levels.…”

“…The essential oils (EOs) tested from Satureja montana L. (SM) and Origanum virens Hoffmanns and Link (OV) were provided by The Agricultural Research Centre of Albaladejito (Cuenca, Spain). Extraction was previously described by García-Díaz et al (2019) [25]. Briefly, each plant species was extracted by hydrodistillation of the dried aerial parts of aromatic plants, following the methodology proposed by the European Pharmacopoeia in a Clevenger-type apparatus for 2 h. The chromatograms are shown in Appendix B.…”

Antifungal, antitoxigenic, and antioxidant activities of the essential oil from laurel (Laurus nobilis L.): Potential use as wheat preservative

“…EOs are volatile, so vapors can easily be removed from fumigated foods after drying in the sun. In this regard, active packaging and microencapsulation technologies can be used with EOs for the storage of foodstuffs (Bouzidi, Lakhlef, Hellal, & Djenane, 2019; Djenane et al., 2019; García‐Díaz, Patiño, Vázquez, & Gil‐Serna, 2019; Li et al., 2019).…”

Novel Approaches to Minimizing Mycotoxin Contamination

“…In addition, the treatment improves the qualities of crisp biscuits made from processed wheat. García-Díaz et al [15] proposed a novel niosome-based encapsulated essential oil product applied to polypropylene bags that significantly reduced the development of A. flavus and aflatoxin contamination in maize up to 75 days. Thus, the correct application of this product may be a sustainable way to avoid the occurrence of aflatoxins in stored maize.…”