The objective of this work was the recovery of chitosan by ultrasound-assisted extraction (UAE) from white shrimp (Litopenaeus vannamei) chitin, and the physicochemical and structural characterization of the obtained biopolymer, as well as its antimicrobial effect on Pythium ultimum growth. A 23 factorial design was used to evaluate chitosan extraction conditions. Instrumental analysis techniques for chitosan characterization and radial growth inhibition, as an antifungal activity test, were performed. The ultrasonically extracted chitosan (UC) reached a yield of 86.96% with 100% solubility, a degree of deacetylation (DDA) >78%, molecular weight (MW) of 3.928 × 105 g mol−1, and a crystallinity index (Icr) of 87%, calculated through nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR), size exclusion chromatography (SEC), and X-ray diffraction (XRD), respectively. The inhibitory activity of the chitosan was evaluated against the oomycete Pythium ultimum, observing a 93% radial inhibition over 24 h. UAE proved to be an excellent alternative to the conventional deacetylation, reducing reaction time and obtaining a UC with higher MW and (Icr) than the commercial one, which could potentiate its applications.
In the present work, the total phenolic content (TPC), total flavonoids content (TFC), antioxidant activity, and phenolic profile from pulp (PU) and peel (PE) extracts obtained from the ciricote (Cordia dodecandra A. DC.) fruit by ultrasound-assisted extraction (UAE) in immature (IM), semimature (SM), and mature (MM) stages were investigated. The effect of the diameter of the ultrasonic probe in the IM stage was also evaluated. The TPC and antioxidant activity in IM fruit extracts by UAE increased up to 11.01 and 23.82 times, respectively, compared to the maceration method. The main phenolic compounds in the PE of IM fruit identified by UPLC-DAD-ESI-MS/MS were quantified as caffeic acid, rutin, and rosmarinic acid, distributed as 45.82, 41.45, and 12.72%, respectively. The PE extracts of IM fruit obtained with the 3 mm diameter probe had 1.27, 2.44, and 1.37 times the TPC (19.93 ± 0.28 mg GAE (Gallic equivalents) g−1 dw), TFC (34.85 ± 4.99 mg RE (Rutin equivalents) g−1 dw), and antioxidant activity (122.09 ± 17.09 µTE (Trolox equivalents) g−1 (DPPH)), respectively, compared to those obtained with a 13 mm diameter probe. The results obtained suggest the use of the ciricote native fruit as a source of bioactive compounds, directly as fresh fruit or processed, thus helping to increase its production and consumption.
Peach is a fruit highly appreciated by consumers; however, it is highly perishable, so drying is an alternative to preserve its physical and chemical properties. In this study, the effect of drying in natural and forced convection at three different temperatures (40 °C, 45 °C and 50 °C) and solar drying with two air velocities (1 m/s and 3 m/s) on the color, texture, total phenol content and antioxidant capacity of peach (Prunus persica (L.) Batsch), were evaluated. The experimental data of the drying kinetics were adjusted to five different mathematical models (Page, Logarithmic, Two-term exponential, Wang and Singh, and Verma et al.). The model that best represented the experimental data in natural convection was the Wang and Singh model (r2 > 0.998; RMSE < 0.016; χ2 < 2.85 × 10−4); in forced convection (45 °C and 50 °C), it was the Verma et al. model (r2 > 0.997; RMSE < 0.025; χ2 < 8.12 × 10−4); and finally, for solar drying, it was the Logarithmic model at 3 m/s (r2 = 0.999; RMSE < 0.012; χ2 < 1.12 × 10−4) and Wang and Sing model (1 m/s) (r2 = 0.998; RMSE = 1.31 × 10−4; χ2 = 1.92 × 10−4). The highest color difference was in samples dried by the natural convection method. The highest values of hardness were obtained by the solar drying method. The value of chlorogenic acid increased with the temperature of natural convection, while the concentration of neochlorogenic acid increased with the temperature at forced convection. For solar drying, the values of chlorogenic acid were greater at 3 m/s; in contrast, the neochlorogenic acid was greater at 1 m/s.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.