Cu Nanoparticles in Hydrogels of Chitosan-PVA Affects the Characteristics of Post-Harvest and Bioactive Compounds of Jalapeño Pepper

Abstract

Peppers are consumed all over the world due to the flavor, aroma, and color that they add to food. Additionally, they play a role in human health, as they contain a high concentration of bioactive compounds and antioxidants. The treatments used were an absolute control, Cs-PVA, and four treatments with 0.02, 0.2, 2, and 10 mg (nCu) g−1 (Cs-PVA). The application of Cu nanoparticles in chitosan-PVA hydrogels increases the content of capsaicin by up to 51% compared to the control. This application also increases the content of antioxidants ABTS [2,2′-azino-bis (3-ethylbenzothiazolin-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl), total phenols and flavonoids (4%, 6.6%, 5.9%, and 12.7%, respectively) in jalapeño pepper fruits stored for 15 days at room temperature; under refrigeration, it increases DPPH antioxidants, total phenols, and flavonoids (23.9%, 1.54%, and 17.2%, respectively). The application of Cu nanoparticles in chitosan-PVA hydrogels, even when applied to the substrate, not only has an effect on the development of the jalapeño pepper crop, but also modifies the post-harvest characteristics of the jalapeño pepper fruits.

Postharvest Behavior of Bioactive Compounds in Tomato Fruits Treated with Cu Nanoparticles and NaCl Stress

“…This results in that there is not necessarily a correlation between flavonoids and total phenols. This is observed in the results of the present study (Tables 1 and 2) as well as in other studies in tomato [1,31,34] and jalapeño pepper [11]. Table 2.…”

“…These compounds give the antioxidant capacity in the fruits due to the reduction of oxidative changes in cells by reducing the levels of free radicals [3]. It is suggested that Cu NPs have a stimulatory effect on the induction of antioxidant compounds derived from stress within the cells [11]. This may result in the formation of phenols as observed in this work.…”

“…Therefore, under this condition, it is normal to observe a higher concentration of flavonoids. Pinedo-Guerrero et al [11] reported that the higher content of flavonoids in jalapeño chili fruits was observed under refrigeration conditions. The lack of a precise response in flavonoids over storage time is normal.…”

“…This fact is very important, since β-carotene is the second most important carotenoid in the tomato and is an important antioxidant compound in human health [1]. As already mentioned, Cu NPs are believed to function as inducers of antioxidant compounds [11]. In addition, it has been demonstrated that the application of Cu NPs to the substrate induces the formation of lycopene in tomato [2].…”

“…Bioactive compounds such as lycopene, total phenols, vitamin C, carotenoids, and total flavonoids are very important because of their biological and physico-chemical properties, especially as antioxidant compounds and for the benefits they represent in human health [3]. hydrogels in certain post-harvest characteristics of the jalapeño pepper was studied [11]. However, the analysis of the bioactive compounds was not considered when the fruits were stored.…”