A review of indigenous Mexican plants with edible stems and leaves and their nutritional and nutraceutical potential was conducted, complemented by the authors’ experiences. In Mexico, more than 250 species with edible stems, leaves, vines and flowers, known as “quelites,” are collected or are cultivated and consumed. The assessment of the quelite composition depends on the chemical characteristics of the compounds being evaluated; the protein quality is a direct function of the amino acid content, which is evaluated by high-performance liquid chromatography (HPLC), and the contribution of minerals is evaluated by atomic absorption spectrometry, inductively coupled plasma-optical emission spectrometry (ICP-OES) or ICP mass spectrometry. The total contents of phenols, flavonoids, carotenoids, saponins and other general compounds have been analyzed using UV-vis spectrophotometry and by HPLC. For the determination of specific compounds such as phenolic compounds, flavonoids, organic acids and other profiles, it is recommended to use HPLC-DAD, UHPLC-DAD, UFLC-PDA or gas chromatography-mass spectrometry. The current biochemical analysis and biological evaluations were performed to understand the mechanisms of action that lead to decreased glucose levels and lipid peroxidation, increased hypoglycemic and antitumor activity, immune system improvement, increased antibacterial and antifungal activity and, in some cases, anti-Helicobacter pylori activity.

The green bean is an important crop worldwide, because it is rich in protein, dietary fiber, vitamins, and minerals, as well as bioactive compounds that provide it with important functional properties; however, the composition of many landraces is still unknown. The purpose of this project was to characterize Phaselus vulgaris and coccineus L. landrace green beans on pH, titratable acidity, total soluble solids, total sugars, color parameters, total phenols, monomeric anthocyanins, and in vitro antioxidant activity (DPPH and FRAP). Regarding the content of total sugars, differences were registered between both species, as opposed to results observed in total soluble solids. Color parameters showed higher reddish tones for P. vulgaris landraces, though P. coccineus had a higher total phenolic content, especially the reddish landraces, which correlated directly to a higher antioxidant activity by DPPH and FRAP. In the protein content, the species P. vulgaris registered the highest content. These results could contribute to a greater use and even promote the genetic improvement of the outstanding pods that serve as one of the main food products in rural regions for higher benefits.

ISHS VIII International Postharvest Symposium: Enhancing Supply Chain and Consumer Benefits - Ethical and Technological Issues Effect of postharvest calcium treatments on firmness of guava fruit

Introducción: México es el principal productor de tuna en el mundo, con aproximadamente 400,000 toneladas por año. Sin embargo, es un fruto muy perecedero (9 a 15 días a temperatura ambiente), además la presencia de espinas en su pericarpio reduce su consumo y limita su comercialización causando así pérdidas en su producción. Por lo tanto, es necesario proponer alternativas de consumo como producto mínimamente procesado (PMP) y el uso de atmósferas controladas (AC) para alargar su vida poscosecha.Método: En rodajas de tuna roja minímamente procesada se aplicaron diferentes tratamientos de AC (AC1: 5% O2 + 95% N2, AC2: Aire + 10% CO2, AC3: 10% CO2 + 5% O2 + 85% N2 y aire como control) durante 16 días de almacenamiento a temperatura de 5 ºC. Cada cuatro días se analizó la concentración de azúcares totales (AT), sólidos solubles totales (SST), pH, actividad de polifenol oxidasa (PFO), pérdida fisiológica de peso (PFP) y calidad visual (CV). Resultados: Los tratamientos en AC presentaron menor PFP. El tratamiento con 10% CO2 + 5% O2 + 85% N2 contribuyó a la retención de la CV (6.24), PFP (9%) y pH (5.34), y el tratamiento con 10% CO2 + Aire en el contenido de azúcares (176.21 mg Glucosa mL-1); mientras que los (SST) y la actividad de PFO no presentó diferencia entre los tratamientos. Por su parte, el análisis multivariado de componentes principales (CP) explicó el 85% de la varianza en dos componentes para seis variables fisicoquímicas de los frutos de tuna.Conclusión: El uso de AC prolongó la vida poscosecha de los frutos de tuna roja mínimamente procesados hasta por 16 días de almacenamiento.