• Ultrasound is a fast method for phenolic compounds recovery from C. chinense leaves. • Solvent polarity has a strong effect on the recovery of phenolic compounds. • Dielectric constant was propose to predict the most appropriate solvent for phenolic extraction. • Antioxidant activity correlates with total phenolic content of C. chinense leaves extracts. • Identification of phenolic compounds was performed by UPLC-PDA-ESI-MS/MS.

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.

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 (M_W) 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 M_W and (Icr) than the commercial one, which could potentiate its applications.

The effect of temperature (60, 70, 80, and 90 °C) and time (30, 45, 60, 75, and 90 min) on citric acid extraction of Haden mango (Mangifera indica L. cv. Haden) peel pectin was evaluated in the present study. In order to obtain a better understanding of both the extraction process and the characteristics of the pectin (obtained from an agro-industrial waste) for a future scaling process, the following characterizations were performed: (1) Kinetic, with the maximum extraction times and yields at all evaluated temperatures; (2) thermodynamic, obtaining activation energies, enthalpies, entropies, and Gibbs free energies for each stage of the process; (3) physicochemical (chemical analysis, monosaccharide composition, degree of esterification, galacturonic acid content, free acidity, Fourier-transform infrared spectroscopy, thermogravimetric and derivative thermogravimetric analyses); and (4) economical, of the pectin with the highest yield. The Haden mango peel pectin was found to be characterized by a high-esterified degree (81.81 ± 0.00%), regular galacturonic acid content (71.57 ± 1.26%), low protein (0.83 ± 0.05%) and high ash (3.53 ± 0.02%) content, low mean viscometric molecular weight (55.91 kDa), and high equivalent weight (3657.55 ± 8.41), which makes it potentially useful for food applications.

The physicochemical properties, proximate composition, minerals, total polyphenols, carotenoids, phenolic compounds, antioxidant, and antibacterial activities of ciricote (Cordia dodecandra A. DC.) tropical fruit were investigated. Minerals were quantified by using micro-Energy Dispersive X-Ray Fluorescence. Lutein and β-carotene were identified in ciricote fruit by using UPLC-PDA analysis. The highest values of the total polyphenols content and antioxidant activity were presented in ethanolic crude extracts obtaining by the ultrasonic-assisted method with freeze-dried fruit. The phenolic acids profile was identified and quantified by UPLC-PDA-ESI-MS. The main phenolic acids were caffeoyl hexoside, rufescenolide, quercetin 3-O-rutinoside, and rosmarinic acid. The ciricote extracts presented antibacterial activity against Staphylococus aureus (Gram+) and Salmonella typhymurium (Gram−). In conclusion, the ciricote (Cordia dodecandra A. DC.) tropical fruits could be very useful source of biological macromolecules, micro-elements, and phytochemical compounds for the food and pharmaceutical industry.

Avocado landraces have gained great interest due to their importance in maintaining biodiversity and the presence of bioactive compounds in their fruit, depending on fruit tissues or ripening stages. This study aimed to evaluate the morpho-physicochemical and nutritional components of the peel, pulp, and seed tissues from Lagunero (LA) and Criollo (CA) avocado landraces at different ripening stages. Additionally, phenolic profiles were analyzed by using UPLC-DAD/ESI-MS, and a principal component analysis (PCA) was constructed to determine variations among the determined contents from avocado landraces, fruit tissues, and ripening stages. The CA showed a 30% higher fruit weight and higher percentages of seed (0.52%) and peel (3.62%) weight yields as compared to the LA. Ripening significantly affected the physical characteristics of LA and CA, and a substantial decrease in hardness (83%) after 4 days of storage. In LA, ripening resulted in an increase in fat content in both the peel and pulp. In contrast, CA showed an increase in protein content in the peel and pulp but a decrease in seeds; fat content increased significantly in the pulp of CA and carbohydrates remained the predominant component in all tissues, though they decreased slightly in CA peels during ripening. The ripe LA peel presented approximately 50% more total phenolic compounds than other tissues. The unripe CA peel showed a higher antioxidant capacity according to DPPH (3831.97 µMol Eq Trolox/g dw) and ABTS+ (3674.70 µMol Eq Trolox/g dw) assays. The main phenolic compounds identified in the avocado peel were chlorogenic acid, catechin, quercetin-3-O-hexoside, quercetin-3-O-pentoside, coumaric acid, caffeic acid, neochlorogenic acid, ferulic acid, kaempferol-3-O rhamnoside, and quercetin-3-O-rhamnoside. The PCA analysis revealed a strong correlation between chlorogenic acid and caffeic acid with TPC, while catechin was more closely related to antioxidant activity. These findings suggest that peel and seed tissues of avocado landraces, often considered byproducts, are valuable sources of bioactive compounds with high antioxidant potential.