ABSTRACT
The stability of anthocyanin (ACN) freeze-dried powders from Andes berry (Rubus glaucus Benth) as affected by storage, addition of maltodextrin as a carrier agent, and illumination was evaluated in isotonic model beverages. The ethanolic ACN extract was freeze dried with and without maltodextrin DE 20. Isotonic model beverages were colored with freeze-dried ACN powder (FDA), freeze-dried ACN powder with maltodextrin (MFDA), and red nr 40. Beverages were stored in the dark and under the effect of illumination. Half life of the ACNs, changes in color, total phenolics content (TPC), and antioxidant activity were analyzed for 71 d. Addition of maltodextrin and absence of light stabilized the color of beverages and improved ACN and TPC stability during storage. The antioxidant activity of the beverages was higher when they were colored with MFDA and highly correlated with ACN content. There was no correlation between antioxidant activity and TPC. It is concluded that addition of maltodextrin DE 20 as a carrier agent during freeze-drying improves the color and stability of nutraceutical antioxidants present in Andes berry extract. This suggests a protective enclosing of ACNs within a maltodextrin matrix with a resulting powder that could serve as a supplement or additive to naturally color and to enhance the antioxidant capacity of isotonic beverages.
Subject(s)
Anthocyanins/analysis , Antioxidants/analysis , Beverages/analysis , Food Coloring Agents/chemistry , Fruit/chemistry , Phenols/analysis , Rosaceae/chemistry , Anthocyanins/chemistry , Antioxidants/chemistry , Chromatography, High Pressure Liquid , Dietary Supplements/analysis , Food Handling , Food Preservatives/chemistry , Freeze Drying , Half-Life , Kinetics , Osmolar Concentration , Phenols/chemistry , Pigmentation , Polysaccharides/chemistry , Quality ControlABSTRACT
The stability of sprayed-dried microencapsulated anthocyanins from Andes berry (Rubus glaucus) and Tamarillo (Solanum betaceum), as affected by storage time, water activity (Aw) and temperature was compared. The fruits were osmotically dehydrated with ethanol and the anthocyanin extract was microencapsulated with maltodextrin DE 20 by spray drying. Half life of the anthocyanins; changes in color, total phenolics, and antioxidant activity of the powders, were analyzed during storage at two different temperatures ( 25 °C and 40 °C) and two Aw levels (0.20 and 0.35). A decrease in monomeric anthocyanin was observed in both samples. The half life of the Andes berry pigments ranged between 11 and 32 days while the half life of the tamarillo pigments ranged between 9 and 21 days. A darkening effect occurred in both samples as a result of storage time. The antioxidant activity decreased while the phenolic content increased with time. Antioxidant activity of Andes berry samples was highly correlated with anthocyanin content and total phenolic content while the antioxidant activity of tamarillo samples was highly correlated with total phenolic content. These results would be useful in developing applications for spray-dried anthocyanins as powdered food-grade colorants.
Se comparó el efecto del tiempo de almacenamiento, la temperatura y la actividad de agua (Aw) sobre la estabilidad de antocianinas microencapsuladas de Mora de Castilla (Rubus glaucus) y tamarillo (Solanum betaceum). Las frutas se sometieron a deshidratación osmótica con etanol y el extracto antociánico se microencapsuló con maltodextrina ED 20 por atomización. La vida media de las antocianinas; los cambios en color, fenoles totales y actividad antioxidante se analizaron durante el almacenamiento a dos temperaturas ( 25 °C y 40 °C) y dos niveles de Aw (0,20 y 0,35). Se observó una disminución de la antocianina monomérica en las dos muestras. La vida media de los pigmentos de mora de Castilla varió entre 11 y 32 días, mientras que la vida media de los pigmentos del tamarillo varió entre 9 y 21 días. Hubo oscurecimiento de las muestras como resultado del tiempo de almacenamiento. La actividad antioxidante de las dos muestras dismi-nuyó, mientras que el contenido fenólico aumentó con el tiempo. La actividad antioxi-dante de las muestras de mora de Castilla presentó una alta correlación con los con-tenidos de antocianinas y fenoles totales mientras que la actividad antioxidante de las muestras de tamarillo se correlacionó con el contenido de fenoles totales. Estos resultados son útiles en el desarrollo de aplicaciones de antocianinas microencapsu-ladas como colorantes alimenticios.
ABSTRACT
Anthocyanins, total phenolic content, ascorbic acid content, and the antioxidant activity were determined in extracts of Andes berry fruit (Rubus glaucus Benth). Anthocyanis (ACNs) were isolated and characterized by means of high-performance liquid chromatography (HPLC) with photodiode array detection and electro spray ionization/mass spectrometry (PDA-ESI/MS/MS) analysis. The anthocyanin (ACN) content was 45 mg/100 g FW. The isolated anthocyanins were characterized as cyanidin 3-sambubioside, cyanidin 3-glucoside, cyanidin 3-xylorutinoside, cyanidin 3-rutinoside, pelargonidin 3-glucoside, and pelargonidin 3-rutinoside. The ascorbic acid content was 10.1 mg/100 g FW. The total phenolic content as determined by the Folin-Ciocalteau method was 294 mg GAE/100 g FW while the antioxidant activity as measured by ABTS(.) (+) radical scavenging capacity and ferric reducing antioxidant power (FRAP) was 2.01 and 4.50 mmol TE/100 g FW or 8.22 mmoles ferric iron reduced/100 g FW, respectively. The high phenolic content and antioxidant capacity of Andes berry suggest that this fruit could be a rich source of natural pigments, nutraceuticals, and natural antioxidants.