**1. Introduction**

Avocado (*Persea americana*) is native to central and southern Mexico but consumed globally [1]. The main problem for avocado growers, marketers and consumers is the short shelf life of avocados. Therefore, it is necessary to develop natural environmentally friendly products to improve the shelf life of avocados [2].

Xoconostle (*Opuntia oligacantha*) is a fruit from the central area of Mexico. Several reports have indicated that this fruit contains bioactive compounds such as phenolic compounds with antioxidant and antimicrobial properties [3]. However, these bioactive compounds are affected by pH, oxygen, and exposure to light or temperature, limiting their use in the food industry [4]. Cenobio-Galindo et al. [5] encapsulated *Opuntia oligacantha* extract and then incorporated it into starch films, finding that the encapsulated bioactive compounds were protected and available to act when released.

Orange essential oil (*Citrus sinensis*) is one of the most used essential oils in various industries, such as the food industry. It contains volatile monoterpenes with limonene identified as the major constituent, but its low solubility, volatility and instability during processing and storage makes it difficult to use. Therefore, it is necessary to incorporate this oil in a stable system that allows it to maintain its characteristics [6,7].

Nanoemulsions are encapsulation systems with characteristics of small particles (*r* < 100 nm), allowing excellent stability against separation and aggregation [8] and they also exhibit increased bioavailability of the encapsulated ingredients [9]. A potential advantage of these dispersions is that they have high compatibility with the components of foods and can even cross biological membranes without difficulty [8,10]. Nanoemulsions have been used mainly in the development of some foods and beverages to contribute to the stability of the foods that contain them [11]. Zambrano-Zaragoza et al. [12] studied the effect of a coating with α-tocopherol and cactus mucilage that were applied on apples and found that the nanoemulsion helped to maintain the firmness of the apples and decreased the activity of certain enzymes in the fruits. Oh et al. [13] developed a nanoemulsion with lemongrass oil and chitosan, finding an antimicrobial effect that contributes to colour retention and to maintaining the antioxidant activity of fruits. The objective of this study was to evaluate the effect of the application of a nanoemulsion based on orange essential oil and xoconostle extract on the physiological parameters, bioactive compounds and antioxidant activity of avocado fruits (*Persea americana*) during postharvest.

#### **2. Materials and Methods**
