Anti-aflatoxigenic nano-emulsions based on Monarda didyma and Neopallasia pectinata essential oils as novel green agent for food preservation

Abstract

Food-borne aflatoxins impede the path of current agriculture and worsened the food safety problem, thus researches on prevention and detoxification of aflatoxins by biological, chemical and physical technologies have become hot spots in food safety and agriculture fields. Recently, efficient preservative based on phytochemicals with nano formulation is considered a versatile and green approach to control aflatoxin contamination. In this study, fabrication of a series of nano-emulsions based on American mint and pectinata essential oils via high pressure homogenization is presented. Their morphology and stability via dynamic light scattering and scanning electron microscopy were explored. All these nano-emulsions, namely MNEO 1–5, exhibited obviously growth inhibition effect towards Aspergillus aflatoxiformans with ED50 values of 5.18 ± 0.56, 4.70 ± 0.83, 6.37 ± 0.55, 6.65 ± 0.79 and 8.89 ± 0.90 mg g−1, respectively. Moreover, cell membrane damage assays showed that interactions between MNEO and cell membrane of A. aflatoxiformans resulted in increased electronic conductivity and cell death. To demonstrate prevention effect, a storage simulation experiment was designed on peanut seeds to determine the AFB1 control efficacy of nano-emulsions in hot and wet environments, and both the nano-emulsions displayed remarkable prevention effect after the preservation with AFB1 protection at 86.06–94.00%. For realistic management of pathogens and mycotoxins, bio-active EOs with nano-formulation capable of adapting to complex environment may help to innovate important key source technologies for food processing and preservation in future.