## 1 Introduction  
Postharvest abiotic stress influences the quality of fruits and vegetables in terms of their food and nutritional attributes, shelf life, and vulnerability to pathological and physiological disorders. All these factors will thus influence postharvest losses. Postharvest technologies often apply stress conditions to extend the storage and shelf life of fruits and vegetables [1]. Abiotic stress has a positive impact on the quality and nutritional conditions of fresh cut fruits and vegetables due to the abiotic stresses that occur throughout processing, packaging, and storage. The impact of abiotic stress can be assessed through colour change, increased respiration rates, ethylene evolution, loss of taste, and texture (softening of the tissues), weight loss, increase of off-odors, and rupture of the cell membrane [2; 3]. Postharvest treatments preserve the quality of fresh produce and control microbial growth through a secondary response that induces plant metabolic activity. Most postharvest treatments involve changing the natural conditions of the fruit and trigger mechanisms that develop, for example, the antioxidant activity of the fruit [4]. Fruits and vegetables immersed in hot-water baths showed improvements in quality, namely the reduction of diseases during the storage period [5]. Heat stress is likely to cause changes in biochemical pathways such as synthesis of heat shock proteins, suspension of protein synthesis, including quality-related enzymes (polyphenol oxidase, peroxidase, phenylalanine ammonia-lyase, and pectin methylesterase), as well as variations in kinetic characteristics of enzymes [5; 6]. Wounding in fresh-cut fruits and vegetables induces the synthesis of enzymes of phenylpropanol metabolism, and consequently the synthesis and accumulation of phenolic compounds [6]. Stress or damage in the plant cell can trigger the oxidation of phenolic compounds due to cell membrane rupture that causes contact between phenolic compounds and oxidative enzyme systems or promote phenolic synthesis to repair wound damage. The phenolic synthesis to repair wound damage is produced by variations in phenylalanine ammonia lyase activity (PAL, EC 4.3.1.5), since it is the metabolic enzyme responsible for the phenylpropanol pathway [7]. Some studies indicate that PAL enzymatic activity becomes significantly higher during the storage time after an abiotic stress has occurred [8]. Polyphenol oxidase (PPO; EC 1.14.18.1) is an oxidative enzyme existent in pineapple accountable for unwanted sensorial effects, such as darkening and deterioration of taste [9]. PPO catalyzes the hydroxylation of monophenol to diphenol and the oxidation of diphenol to \(o\)-quinones [10]. PPO is thus responsible for the breakdown of antioxidant compounds such as pigments, phenols, and flavonoids of pineapples, promoting darkening and devaluation of the fruit [11]. The industrial processing of pineapple generates a high quantity of by-products, which represent 42-59% of the pineapple fruit, where the shell is the principal fraction [12]. It is imperative to valorize these by-products and converting them into value-added products with the purpose of decreasing the environmental effect [13]. Pineapple has numerous beneficial properties such as the presence of phenolic compounds that can be a useful source of antioxidant activity [14; 15]. Phenolic compounds are known as effective antioxidants and have applications in health since phenolic compounds have an antioxidant function as free radical scavengers and metal chelating agents that are efficient in catalyzing lipid peroxidation [16]. Bromelain is an enzyme present in pineapples and has health benefits that include antitumor properties, digestive assistance, immunity modulation, improved wound healing, and cardiovascular and circulatory improvement [17; 18]. The health benefits of these compounds are associated with their ingestion, but very dependent on their bioaccessibility and bioavailability in the body.