## 1 Introduction  
Avocado (_Persea americana_ Mill.) is a ubiquitous fruit with origins in Central America. The avocado fruit is known for its high nutritional value and health benefits [1]. Several varieties of avocado have been reported, including Bacon, Fuerte, Gwen, and Hass, with the latter being the most commercialized [2]. In 2022, the global avocado production was approximately 8.98 million metric tons, with the Dominican Republic being the fourth-largest producer of avocado, with 737,200 metric tons [3, 4]. In 2023, 21,875 hectares were dedicated to avocado production in the Dominican Republic. Different cultivars, such as Hass, Popenoe, Simmonds, Pollock, Doctor Dupoi, and Carla, are commercially available in different seasons. Regarding exportation, the most popular variety is Semil 34, which accounts for 58% of the total national avocado production [3; 5; 6]. Semil 34 is a hybrid between the Guatem and the West Indian varieties [7]. Previous studies have reported that, on average, the seed, pulp, and peel constitute 13.93, 79.07, and 7.00%, respectively, of the avocado, as well as an oil and dry matter percentage of approximately 9% and 20% [8]. However, there is limited information available about Semil 34. Throughout the industrialization process of avocados, the pulp is the only part of the fruit utilized, and its byproducts, such as the avocado seed (AS) and peel, are discarded into the environment, contributing to environmental concerns surrounding the produced waste. The AS represents approximately 13% of the fruit [9], which, according to the numbers previously mentioned, translates into 1.16-1.62 million metric tons of waste globally per year and 317,000-439,000 metric tons of AS annually in the Dominican Republic. In the Dominican Republic, initiatives have been undertaken to utilize the avocado residue to produce oil, and this has demonstrated remarkable effectiveness, utilizing approximately 1.5 million kilograms of discarded avocados between 2020 and 2021 [10]. Nevertheless, other management options are to be considered to drive more environmentally friendly production and meet the Sustainable Development Goals proposed by the United Nations, particularly the objectives of sustainable industrialization and production [11]. Numerous studies have explored the potential applications of AS residues in various industries, such as pharmaceuticals, food and cosmetics, highlighting its potential as a source of many bioactive compounds that can provide antioxidant, anticancer, anti-inflammatory, and antibacterial properties [12; 13]. AS also contains significant concentrations of carbohydrates, fiber, protein, lipids, and vitamins, such as A, B1, B2, B3, C, and E [14; 15; 16]. There are several methods available to recover bioactive compounds, including novel green technologies like ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and Ohmic heating-assisted extraction (OHAE), as well as conventional solid-liquid extractions (SLEs) like maceration, cooking, and infusion. Among these, UAE has been widely applied for the recovery of phytochemicals from plant material [17]. This method uses ultrasound waves to facilitate the rupture of cell walls and the release of compounds at moderate temperatures with little solvent, which enables the high recovery of compounds. The identification of these health-promoting phytonutrients in the AS extract often requires the utilization of sophisticated techniques such as nuclear magnetic resonance and, more recently, high-performance liquid chromatography-electrospray ionization-mass spectrometry in tandem (HPLC-ESI-MS/MS), which allows the separation and identification of molecules. With these techniques, various phenolic acids, including 3-O-caffeoylquinic acid, 3-p-coumarooylquinic acid, caffeoylquinic acid, and derivates of chlorogenic acid, have been characterized from different AS extracts, as well as terpenes and flavonoids like catechin, epicatech, procyanidins, luteolin, apigenin, kaempfer, and quercetin [18; 19; 20; 21].