The aim of this study was to evaluate the influence of Inca muña phenolic antioxidants in the reduction of acrylamide (AA) in potato chips. The potatoes were cut into 2 mm thick slices, the addition of antioxidants was evaluated by immersion at atmospheric pressure and by vacuum impregnation (VI) at 80 kPa for 10 min. In both cases, two antioxidant concentrations were used (1 and 2 mg Gallic acid equivalents (GAE) mL-1) and times of 15, 30, 60 and 120 s. The greatest reduction of AA was obtained by VI with 1 mg GAE mL-1 for 120 s (67.4%) and 2 mg GAE mL-1 for 15 s (59.3%); while immersion at atmospheric pressure with 2 mg GAE mL-1 for 30 s and 60 s resulted in reductions of 50.8 and 50.9%, respectively. Besides, the addition of phenolics from Inca muña had no influence on the colour of potato chips. VI treatment resulted in increased amounts of phenolic compounds and antioxidant capacity in the potato chips being the most abundant phenolic compounds hesperidin and luteolin glucoside; while in the control samples phenolic corresponded to chlorogenic acid isomers.

This research aimed to evaluate the HPLC-DAD profile of phenolic compounds, their content and antioxidant capacity in hypocotyls extracts of yellow, red and black maca during pre -harvest, harvest and natural post-harvest drying. A significant increase in total phenolic compounds and antioxidant capacity was observed from pre-harvest to natural post-harvest drying in all three ecotypes. During harvest, red maca had the highest concentration of phenolic compounds. HPLC-DAD analysis revealed the prevalence of 11 phenolic compounds, but with different concentrations in each ecotype and in each stage of study, such as six flavanol derivatives (flavan -3-ol), four derivatives of benzoic acid and an o-coumaric acid derivative. Post-harvest drying, under natural conditions, caused a significant loss (yellow maca 89.90%, red maca 82.49% and black maca 66.31%) of phenolic compounds, mainly derived from benzoic and o-coumaric acid, until non-detectable limits, only two flavanol derivatives (flavan-3-ol) tolerated these conditions. The results of the study sugg est improving cultivation techniques and post-harvest management to preserve the content of phenolic compounds.

Este trabajo tuvo como objetivo evaluar el perfil HPLC-PDA de los compuestos fenólicos, su contenido y capacidad antioxidante en los extractos de los hipocótilos de maca amarilla, roja y negra durante las etapas de pre-cosecha, cosecha y secado natural post-cosecha. De la pre-cosecha al secado natural post-cosecha, en los tres ecotipos, se observó un incremento significativo de los compuestos fenólicos totales y su capacidad antioxidante. En la cosecha, la maca roja presentó la mayor concentración de compuestos fenólicos. Los análisis HPLC-PDA revelaron la prevalencia de 11 compuestos fenólicos, pero con diferentes concentraciones en cada ecotipo y en cada etapa de estudio, seis derivados del flavanol (flavan-3-ol), cuatro derivados del ácido benzoico y un derivado del ácido o-cumárico. El secado post-cosecha en condiciones naturales, generó una pérdida significat iva (maca amarilla 89,90%, maca roja 82,49% y maca negra 66,31%) de compuestos fenólicos, principalmente derivados del ácido benzoico y o-cumárico, llegando a límites no detectables, toleraron estas condiciones dos derivados del flavanol (flavan-3-ol). Los resultados del estudio sugieren mejorar el manejo post cosecha para preservar el contenido de compuestos fenólicos.

Abstract The loquat cultivar Golden Nugget (leaves, flowers and fruits), which has potential commercial importance in Chile, was analyzed for targeted bioactive composition (total phenolic contents: TPC, phenolic profiles and triterpenic acids) and in vitro bioactivity such as antioxidant capacity (AC) and inhibitory activity against enzymes relevant for hyperglycemia (α-amylase and α-glucosidase) and hypertension (angiotensin I-converting enzyme, ACE-I) management. Leaves and flowers had higher TPC and AC than fruits and hydroxycinnamic acid derivatives were found in all structures by HPLC. Chlorogenic acid and quercetin derivatives were detected only in leaves and flowers, which also inhibited the α-amylase and α-glucosidase enzymes, but flowers showed the highest anti-hyperglycemia activity. No inhibition of ACE-I and hyperglycemia-relevant enzymes were found in loquat fruits; additionally, TPC and AC were high at the green stage. Loquat leaves and flowers are sources of phenolic bioactives with potential for diet-based hyperglycemia management. No triterpenic acids were found in any of the loquat parts.

Resumen El cultivar de níspero Golden Nugget (hojas, flores y frutos), el cual presenta un potencial comercial importante para Chile, fue analizado en su composición en compuestos bioactivos (contenido de fenólicos totales: TPC, perfil de fenólicos y ácidos triterpénicos) y bioactividad in vitro como capacidad antioxidante (AC) y actividad inhibitoria de las enzimas relevantes para el control de la hiperglicemia (α-amilasa and α-glucosidasa) y la hipertensión (enzima convertidora de la angiotensina-I, ACE-I). Las hojas y flores tuvieron mayores contenidos de TPC y AC que las frutas y se encontraron principalmente derivados de ácidos hidroxicinámicos en todas las estructuras por HPLC. Solo se detectó ácido clorogénico y derivados de quercetina en las hojas y flores, las cuales inhibieron las enzimas α-amilasa and α-glucosidasa, aunque las flores mostraron la mayor actividad antihiperglicémica. Las frutas no mostraron inhibición de la ACE-I ni actividad antihiperglicémica, sin embargo los TPC y la AC fueron mayores en el estado verde de madurez. Las hojas y flores del cultivar de níspero evaluado constituyen fuentes de fenólicos bioactivos con potencial para el manejo de la hiperglicemia. No se encontraron ácidos triterpénicos en todas las estructuras evaluadas.