ABSTRACT
BACKGROUND: Vaccinium meridionale Swartz (mortiño) constitutes a source of bioactive phytochemicals, but reports related to its efficient and green production are scarce. In this study, pressurized liquid extraction (PLE) and ultrasound-assisted extraction of mortiño were compared. Total phenolic content (TPC) and antioxidant capacity (ABTSâ¢+ ) were determined. Beef burgers with 20 g kg-1 of mortiño (MM) or its PLE extract (ME) were manufactured. Lipid oxidation (TBARS) and instrumental color changes were measured after refrigerated storage. RESULTS: High TPC (up to 72 g gallic acid equivalent kg-1 extract) was determined in mortiño extracts, which was positively correlated with antioxidant activity. TBARS values of beef burgers containing either MM or ME did not change after refrigerated storage, whereas lipid oxidation of control burgers increased significantly. The color of burgers with added MM or ME was different (lower b* and a* values) from that of control burgers. However, the evolution of color after storage was similar between control and ME samples. CONCLUSION: Mortiño extracts with high TPC can be obtained by PLE. Both mortiño and its PLE extract are able to control lipid oxidation of beef burgers, but the extract is preferred from the color quality point of view. © 2017 Society of Chemical Industry.
Subject(s)
Antioxidants/analysis , Food Additives/analysis , Meat Products/analysis , Plant Extracts/analysis , Vaccinium/chemistry , Animals , Cattle , Color , Lipids/chemistry , Oxidation-ReductionABSTRACT
Vaccinium meridionale Swartz (Mortiño or Colombian blueberry) is one of the Vaccinium species abundantly found across the Colombian mountains, which are characterized by high contents of polyphenolic compounds (anthocyanins and flavonoids). The supercritical fluid extraction (SFE) of Vaccinium species has mainly focused on the study of V. myrtillus L. (blueberry). In this work, the SFE of Mortiño fruit from Colombia was studied in a small-scale extraction cell (273 cm³) and different extraction pressures (20 and 30 MPa) and temperatures (313 and 343 K) were investigated. Then, process scaling-up to a larger extraction cell (1350 cm³) was analyzed using well-known semi-empirical engineering approaches. The Broken and Intact Cell (BIC) model was adjusted to represent the kinetic behavior of the low-scale extraction and to simulate the large-scale conditions. Extraction yields obtained were in the range 0.1%-3.2%. Most of the Mortiño solutes are readily accessible and, thus, 92% of the extractable material was recovered in around 30 min. The constant CO2 residence time criterion produced excellent results regarding the small-scale kinetic curve according to the BIC model, and this conclusion was experimentally validated in large-scale kinetic experiments.
ABSTRACT
Antecedentes: Agraz es una baya globosa, de color púrpura intenso cuando está madura. Posee alta capacidad antioxidante comparada con bayas del mismo género, atribuido al contenido de compuestos polifenólicos. Objetivo: Evaluar la composición, actividad antioxidante y algunos parámetros microbiológicos de pulpa de agraz congelada (PAC) y pulpa de agraz liofilizada (PAL) y analizar su comportamiento durante 60 días de almacenamiento. Métodos: Se midieron pH, °Brix, acidez titulable, % humedad, cenizas, grasa, proteína, carbohidratos, calorías totales y actividad acuosa a intervalos de 15 días durante el almacenamiento. En las mismas condiciones se determinó el contenido de fenoles y antocianinas totales mediante Folin-Ciocalteau y método diferencial de pH, respectivamente. La actividad antioxidante mediante FRAP y ORAC. Resultados: no presentaron diferencias estadísticas significativas (p>0,05) durante el almacenamiento en pH, °Brix, aw (liofilizado), % humedad, grasa, cenizas, carbohidratos y calorías totales para PAC y PAL, indicando estabilidad de éstas variables a través del tiempo de almacenamiento. La acidez titulable expresada en mg de ácido cítrico/ml, varió significativamente (p < 0,05) a través del tiempo de almacenamiento para PAC y PAL entre 1,65-1,82 y 4,66-4,79 respectivamente. La proteína varió durante el almacenamiento para PAC y PAL entre 1,25-2,10 g y 4,70-5,20 g, y se observó para ambos un aumento significativo entre el día 15 y 60 de almacenamiento. PAC y PAL presentaron pérdidas significativas del contenido de antocianinas, fenoles totales y valor FRAP durante el almacenamiento; sin embargo la PAL conservó hasta el día 60 alto contenido de fenoles totales: 1046 mg eq de ácido gálico/100g), antocianinas totales: 82,64 (mg eq de cianidin-3-glicosido/100g), capacidad reductora (FRAP): 1032,17 mg de equivalentes de ácido ascórbico/100g y valor ORAC 33935 µmol de equivalentes de Trolox/100g. Conclusión: las variables fisicoquímicas analizadas en la PAL fueron estables y se conservó el contenido de compuestos polifenólicos por mayor tiempo comparado con la PAC. Considerando que el agraz tiene dos temporadas de cosecha al año en Colombia (mayo y diciembre), la liofilización es una estrategia que permitirá al productor abastecimiento constante de la fruta para el mercado.
Background: Andean berry is a globose berry, deep purple when it reaches its highest degree of maturity. It fruit has a high antioxidant capacity compared to other Vaccinum berries, attributed to the content of polyphenolic compounds. Objectives: To evaluate the composition, antioxidant activity and some microbiological parameters of frozen pulp of Andean berry (PAC) and freeze-dried pulp of Andean berry (PAL) and analyze their behavior during 60 days of storage. Methods: the variables pH, ° Brix, titratable acidity, % moisture, ash, fat, protein, carbohydrates, total calories and water activity (lyophilized) were measured at intervals of 15 days during storage. Under the same conditions the content of phenols and total anthocyanins by Folin-Ciocalteu and pH differential method respectively was determined. The antioxidant activity by FRAP and ORAC. Results: There were no significant differences (p>0,05) during storage in pH, ° Brix, Aw (lyophilized), % moisture, fat, ash, carbohydrates and total calories for PAC and PAL indicating stability of these variables over time storage. Titratable acidity expressed in mg citric acid/ ml, varied significantly p (<0.05) over time storage for PAC and PAL between 1.65 to 1.82 and 4.66 to 4.79 respectively. The protein varied during storage for PAC and PAL between 1.25 to 2.10 g and 4.70 to 5.20 g, and was observed for both a significant increase between day 15 and 60 of storage. PAC and PAL showed significant losses of anthocyanins, total phenols and FRAP value during storage; however the PAL retained until day 60 high content of total phenols: 1046 (mg gallic eq/100 g acid), anthocyanins: 82.64 (mg eq of cyanidin-3-glucoside/100g), reducing capacity (FRAP): 1032.17 mg ascorbic acid equivalents /100 g and ORAC value 33935 umol equivalents Trolox/100g. Conclusions: physicochemical variables analyzed in the PAL were stable and content of polyphenolic compounds retained for longer compared to PAC. Whereas Andean berry has two growing seasons a year in Colombia (May and December), freezedried is a strategy that will allow the producer constant supply of fruit on the market.
