Se evaluó el efecto del tratamiento térmico a 80°C durante 1 minuto (tratamiento H) y este mismo tipo de tratamiento combinado con adición de sacarosa (tratamiento SH) sobre la calidad química y sensorial de puré de arazá durante 4 meses de almacenamiento a -20°C. Además, se incluyó un control sin tratamiento térmico ni sacarosa (control C). Los parámetros químicos evaluados fueron: vitamina C, compuestos fenólicos totales (TPC) y actividad antioxidante (AoA) medida por los métodos de la capacidad de reducción férrica del plasma (FRAP), ácido 2,2'-azino-bis (3-etilbenzotiazolina-6-sulfónico) (ABTS) y 1,1-difenil-2-picrilhidrazil (DPPH). La calidad sensorial se evaluó con un pánel entrenado. Después de cuatro meses de almacenamiento congelado el tratamiento SH fue más efectivo que el H en el control de la calidad química. SH proporcionó valores de AoA-FRAP (89%) y contenido de vitamina C (87%) similares, como también mayores valores de TPC (145%), AoA-ABTS (272%) y AoA-DPPH (115%) al compararlos con el control C antes del almacenamiento congelado. La calidad sensorial del puré SH (15±1) y del puré H (16±1) después de 4 meses a -20°C fue comparable a la del puré C antes del almacenamiento congelado (18±2). El uso de sacarosa combinado con tratamiento térmico y almacenamiento congelado preserva la calidad sensorial y química de puré de arazá.

The effects of a 80°C, 1 minute thermal treatment (H treatment) and of the same treatment combined with sucrose (SH treatment) on the chemical and sensory qualities of arazá purée were evaluated during 4 months of storage at -20°C. For the control, an untreated sample (C) was included. The chemical qualities evaluated were vitamin C content, total phenolic compounds (TPC), and antioxidant activity (AoA), which were measured with the ferric reducing ability of plasma (FRAP), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH), while a trained panel was used for the sensory quality evaluation. After 4 months of frozen storage, SH was more effective than H at controlling the loss of chemical quality. SH provided a similar FRAP-AoA (89%) and vitamin C content (87%), as well as a higher TPC (145%), ABTS-AoA (272%), and DPPH-AoA (115%), when compared to C before frozen storage. The total sensory qualities in both the SH purée (15±1) and the H purée (16±1) after 4 months at -20°C were comparable to those of the C purée before the frozen storage (18±2). Therefore, using sucrose combined with a thermal treatment and subsequent frozen storage preserves the chemical and sensory qualities of arazá purée.

The effects of the extraction system (50% methanol or 50% methanol pH 2.0), volume/material ratio, temperature, time and extractions with 70% acetone were evaluated in the total phenolic compounds (TPC) extraction and in antioxidant activities (AA) using FRAP and ABTS assays in guava fruit. The best yield was obtained when 0.5 g of guava were extracted first with 20 mL 50% methanol and then four times with 20 mL 70% acetone during 30 min at 50 °C. Among the different trials guava fruit exhibited high levels of AA as well as TPC.