## 2 Uses of Avocado Agro-Industrial Residues: Seed, Peel, and Leaves  
Driven by the environmental concern of the large amount of residue generated by the avocado industry, numerous studies have been dedicated to finding valuable chemical compounds in avocado seeds (ASs), peel (AP), and leaves (ALs) and their potential application in other industrial sectors (See Figure 1). The high content of flavonoids and phenolic acids in these residues have been studied as potential antioxidants, particularly for the food and pharmaceutical industry [19]. [PERSON] et al. observed that ground ASs produce a bright orange color (\(\lambda_{\text{max visible}}=480\) nm) in water. Furthermore, the authors obtained a phenolic content of approximately 219.4 mg/g gallic acid equivalent (GAE) for the AS extract, which shows potential applications in the food industry as a source of natural pigments [20]. Later on, [PERSON] et al. identified the main-colored compound in the AS extract using HPLC-UV/Vis and named it perseorangin, a yellow-orange solid compound that contains glycosylated benzotropone and absorbs at \(\lambda_{\text{max}}=445\)[21]. Other studies delved into the potential of avocado peel extracts as an antioxidant and functional food ingredient. [PERSON] et al. used dried avocado peel in tea formulations, resulting in a beverage with notable antioxidant activity of 1954.24 uM Trollox equivalent (TE), and a total phenolic and flavonoid content of 123.57 mg GAE/L and 14.09 mgquercetin equivalent (QE)/L, respectively, showing no statistical difference after 45 days of storage, showcasing the stability of AP teas and potentially developing high antioxidant functional beverages [22]. Another approach by [PERSON] et al. developed highly antioxidant bioplastic films from AP and AS for food packaging applications. The films were processed by three different methods, and it was shown that using hydrolysis and plasticization followed by blending with pectin polymers obtained the materials with the most competitive properties and notable antioxidant activity, ranging from 3.3 to 4.7 umol TE/g dried sample, developing a sustainable alternative to traditional food packaging [7]. [PERSON] et al. incorporated an AP extract into gelatin/carboxymethylcellulose active films, enhancing their mechanical properties without affecting their integrity. The incorporation of AP extract also significantly decreased the moisture and solubility in the films, from 12.48 to 11.02% and 40.13 to 35.39%, respectively. The DPPH scavenging activity increased significantly, from 24.16 to 63.47%. Fresh berries were stored in the films, and a perseveration study showed no fungal activity in over six days of storage [23]. In pharmaceutics, avocado leaves are widely used due to their therapeutical properties [24]. ALs have been studied as potential antihypertensives, demonstrating an inhibition of the angiotensin-converting enzyme of 73.3%, which causes a decrease in both systolic and diastolic blood pressure [25]. Similar work observed anticonvulsant properties, delaying the onset of pentylenetetrazole-, picrotoxin -, and bicuculline-seizures in mice [26]. Another pertinent study showed anticholinergic activity in AL. The hydroalcoholic extracts of the leaves demonstrated strong inhibition of acetylcholine and butyrylcholine enzymes, ranging from 0.0168 to 0.0171 and 0.0214 to 0.0226 IC50, \(\mu\)g/mL, respectively, which could be potentially used to treat neurodegenerative diseases. AL extracts also showed strong antioxidant activity ranging from 240 to 601 IC50, \(\mu\)g/mL [15]. [PERSON] et al. studied the potential antioxidant, antibacterial and anti-inflammatory activity of aqueous AL extracts. The extract showed a lower antioxidant activity than the ascorbic acid reference, 11.3-52.3% and 28.0-90.7%, respectively. However, it still represents the potential to act as a free radical scavenger in the protection of biomolecules and the prevention of various diseases.