The profile of phenolic compounds and their concentration depends on a diversity of factors such as fruit variety, ripeness, agronomic growing conditions, and so on. Additionally, as the phenolic compounds and other antioxidants compounds must be extracted previously to their determination, the recovery from the products will depend on the solubility in the solvent employed [18]. Considering all these variables it is not strange to find a great variability in results in the literature concerning TPC and antioxidant capacity. Nevertheless, this methodology is widely employed as it is based on colorimetric methods such as the Folin-Ciocalteu method that are very common and easy to use to compare sample processes under the same experimental conditions [19]. Related to pineapple samples, extraction procedures have been carried out by using different solvents. The results showed that the polyphenol content of the extracts was higher when carrying out the extraction in methanol, followed using ethyl acetate and the aqueous extract [20; 21]. Other studies have analyzed the content of polyphenols present in the total pineapple by-products [22], while, in the specific case of pineapple peel, the value obtained was around 150 mg GAE 100 g\({}^{-1}\) of by-product in fresh weight [21]. There are a great variety of antioxidant capacity determination methods in food samples such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), the antioxidant capacity to reduce the ferric ion (FRAP), and the method that uses 2,2'-azinobis (3-ethylbenzothazoline-6-sulfonate) (ABTS). Studies carried out on pineapple by-products have been obtained for each 0.1 mg mL\({}^{-1}\) of extract analyzed, an inhibition between 20-70% using the DPPH method [21; 22]. On the other hand, by using the FRAP methodology, freshly cut pineapple without treatment presented a value of 7.91 mmol kg\({}^{-1}\) while the samples treated with chitosan and procydianine showed slightly higher FRAP values of 8.49 and 8.97 mmol kg\({}^{-1}\), respectively, due to the production of antioxidant coatings on the surface of the sample [20; 21]. Finally, values between 63.66-64.02 mM TROLOX g\({}^{-1}\) of fresh weight were obtained after the application of the ABTS method for the analysis of different pineapple samples treated with different ultrasound power [23]. Based on this background, the aim of this work is the extraction and characterization of the volatile compounds present in two different pineapple by-products (core and peel) and the subsequent evaluation of their antioxidant capacity. For this, the evaluation of the antioxidant content in the two pineapple wastes has been performed employing different methods, analysis of the total phenolic content (TPC) in addition to analysis of the antioxidant capacity by using the antioxidant capacity to reduce the ferric ion (FRAP), the 2,2-diphenyl-1-picrylhydrazyl (DPPH) procedure and the method that uses 2,2'-azinobis (3-ethylbenzothazoline-6-sulfonate) (ABTS). Additionally, the volatile profile analysis of both by-products has been carried out through the headspace solid-phase microextraction technique coupled to gas chromatography with a mass spectrometry detector (HS-SPME-GC-MS). The optimization of the extraction conditions of volatile compounds has been validated using a Box-Behnken (BBD) experimental design. In addition, a quantitative analysis has been carried out to determine the content of ethyl acetate and isopentyl acetate, as characteristic compounds of pineapple, in both by-products.