Carolina Fredes

Anthocyanin profiling of wild maqui berries (Aristotelia chilensis [Mol.] Stuntz) from different geographical regions in Chile

BACKGROUND Maqui (Aristotelia chilensis) is a Chilean species which produces small berries that are collected from the wild. Anthocyanins, because of their health benefits, are the major focus of interest in maqui fruit. For this study, we examined anthocyanin and phenolic content of maqui fruits from individuals that belonged to four geographical areas in Chile, and used DNA marker analysis to examine the genetic variability of maqui populations that had distinctly different fruit anthocyanin content. RESULTS Twelve primers generated a total of 145 polymorphic inter simple sequence repeat-polymerase chain reaction (ISSR-PCR) bands. ISSR-PCR showed different banding patterns for the individuals evaluated, confirming that maqui populations belonged to different genotypes. Maqui fruit from four different geographical regions during two consecutive growing seasons showed high total anthocyanin (6.6-15.0 g cy-3-glu kg⁻¹ fresh weight (FW)) and phenolic (10.7-20.5 g GAE kg⁻¹ FW) contents and different anthocyanin profiles. CONCLUSION Three maqui genotypes exhibited significantly higher anthocyanin content than the others, as measured by pH differential method and high-performance liquid chromatography-mass spectrometry. Significant genetic diversity was noted within each ecological population. ISSR-PCR analysis provided a fingerprinting approach applicable for differentiation of maqui genotypes.

Comparison of the total phenolic content, total anthocyanin content and antioxidant activity of polyphenol-rich fruits grown in Chile

In the last 10 years, interest in research on polyphenol-rich fruit species has increased due to the potential health benefits of these species, mainly attributed to their high anthocyanin content and antioxidant activity. Six polyphenol-rich fruit species (blueberries, raspberries, blackberries, strawberries, pomegranates and maqui berries) were harvested at the same maturity stage during the same growing season and were compared according to their total phenolic (Folin-Ciocalteu method) and total anthocyanin (pH differential method) contents and antioxidant activity using ferric-reducing antioxidant power (FRAP assay) and 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging capacity methods. With the results of this study, the polyphenolic status of the main polyphenol-rich fruit species that are grown in Chile were compared, and maqui berry showed the highest total phenolic (14.6 g gallic acid equivalent kg -1 of fresh weight [g GAE kg -1 FW]), total anthocyanin (9.3 g cyanidin-3-glu kg -1 of fresh weight [g cy-3-glu kg -1 FW]) contents, and antioxidant activity (152.0 mmol Fe 2+ kg -1 of fresh weight [mmol Fe 2+ kg -1 FW] and 1.5 mg of fresh weight [FW]) with significant differences from the other fruit species that were analyzed. Nevertheless, bioavailability studies to test the benefits of the species’ dietary antioxidants should be performed in order to establish scientific evidence in this area. Durante los ultimos 10 anos, el interes en la investigacion de los frutos ricos en polifenoles ha incrementado debido a sus potenciales efectos beneficiosos para la salud atribuidos principalmente a contenidos altos de antocianinas y una alta actividad antioxidante. Seis especies de frutos ricos en polifenoles (arandanos, frambuesas, moras, frutillas, granadas y maquis) fueron cosechados en el mismo estado de madurez durante la misma temporada de produccion y comparadas de acuerdo a sus contenidos de fenoles totales (metodo Folin Ciocalteu), antocianinas totales (metodo pH diferencial) y actividad antioxidante determinada por los metodos de FRAP (poder antioxidante para reducir el hierro ferrico) y del radical DPPH (2,2-diphenylpicrylhydrazil). Los resultados de este estudio permiten comparar el estatus polifenolico de los principales frutos ricos en polifenoles que crecen en Chile, donde el maqui presenta el mayor contenido de fenoles totales (14,6 g EAG kg -1 pf), antocianinas totales (9,3 g ci-3-glu kg -1 pf), y actividad antioxidante (152,0 mmol E Fe +2 kg -1 and 1,5 mg pf) con diferencias significativas con las otras especies de frutos analizadas. Sin embargo, se deben realizar estudios de biodisponibilidad para probar los efectos beneficos sobre la salud humana de los antioxidantes de esta especie para poder establecer evidencia cientifica en esta area.

POLYPHENOL CONTENT AND ANTIOXIDANT ACTIVITY OF MAQUI ( Aristoteliachilensis [MOLINA] STUNTZ) DURING FRUIT DEVELOPMENT AND MATURATION INCENTRAL CHILE

Maqui ( Aristotelia chilensis [Molina] Stuntz, Elaeocarpaceae) is a Chilean native species which produces small berries that are mainly collected from the wild. The health benefits of maqui fruit are attributed to their high polyphenol content as well as their wide variety of anthocyanins and flavonols. One of the main factors that affect the polyphenol content in fruit is the maturity stage at harvest. The objective of this study was to determine total phenol and total anthocyanin content and antioxidant activity (by ferric reducing ability of plasma [FRAP] assay) of maqui fruits harvested at different fruit maturity stages from two wild populations located in Central Chile. Each maturity stage was determined by days from fruit set, berry size, and soluble solids. Total phenol content declined while total anthocyanin content increased from the green to light red stage. Nevertheless, both total phenol and anthocyanin content increased from the light red to dark purple stage. The highest anthocyanin content and antioxidant activity was found in the late maturity stage (dark purple). The results show that ripening in maqui fruit can be expected with 1100 growing degree-days (91 d after fruit set) in Central Chile. At this moment of harvest, fruits with 18-19° Brix have the highest anthocyanin content and antioxidant activity (FRAP). This study constitutes the first advances in the understanding of maqui fruit ripening and corresponding antioxidant activity.

The Encapsulation of Anthocyanins from Berry-Type Fruits. Trends in Foods

During the last decade, many berry-type fruits have been recognised as good sources of anthocyanins. Nevertheless, the use of anthocyanins in the development of food colourants and healthy and/or functional ingredients has been limited because of their low stability under given environmental conditions and interaction with other compounds in the food matrix. This review compiles information about the encapsulation of anthocyanins from twelve different berry-type fruit species as a technology for improving the stability and/or bioavailability of anthocyanins. Encapsulation by spray drying has been the primary method used to encapsulate anthocyanins, and some studies attempt to keep anthocyanin microparticles stable during storage. Nevertheless, more studies are needed to determine the stability of anthocyanin microparticles in food matrices over the product shelf life in the development of food colourants. Studies about encapsulated anthocyanins in simulated gastrointestinal models have primarily been conducted on the release of anthocyanins from microparticles to evaluate their bioavailability. However, adding anthocyanin microparticles to a food vehicle must guarantee the health properties attributed to the specific anthocyanins present in berry-type fruits.

The powerful colour of the maqui ( Aristotelia chilensis [Mol.] Stuntz) fruit

Over the past 10 years, the research interest on maqui has increased due to the potential health benefits of the fruit, which are largely attributed to the high anthocyanin content and high antioxidant capacity. Furthermore, maqui fruit has earned the name of ‘superfruit’, and several products based on the dehydrated fruit and maqui juice are available on the international market. Although the maqui fruit is not frequently consumed by the Chilean population from urban areas, its use is deeply rooted in rural and native cultures (Mapuche and Huilliche). This review summarises the validation of the traditional uses of maqui and new evidence highlighting the principal role of anthocyanins in the antioxidant, anti-inflammatory and anti-diabetic activity of maqui fruit. The identification of a particular anthocyanin (delphinidin-3-glucoside-5-sambubioside) in maqui fruit and its anti-diabetic effect in in vivo models, in addition to its presence at higher concentrations in some maqui genotypes, encourages investigation into maqui genotypes that may have higher contents of particular anthocyanins. However, information concerning maqui domestication is still deficient.

Phenolic profiles of nectar and honey of Quillaja saponaria Mol. (Quillajaceae) as potential chemical markers

Quillaja saponaria Mol. (Quillajaceae) is one of the most important melliferous species in Chile, mainly as a source of monofloral honey. Honey made by A. mellifera presents biological activity against pathogens and antioxidant capacity associated with the presence of phenolic compounds deriving from the nectar, as a result of bee honey foraging. The aim of this study was to identify and quantify the phenolic compounds from the floral nectar of Q. saponaria and the honey made in apiaries in the central zone, and compare the composition of the chromatographic profiles of nectar and honey to known phenolic compounds. The results obtained by HPLC-DAD (high-performance liquid chromatography with diode-array detection) showed a similar profile of phenolic compounds, in which gallic acid, myricetin, rutin, quercetin and naringenin were identified. The phenolic compounds detected could be used as a reference for future studies for determining potential chemical markers of this honey, complementing the present identification of honeys by determining their botanical origin. The identification of bioindicators of the floral origins for honey of this species could provide added value to honey commercialization by certifying the botanical origin of their chemical features and biological attributes.

The Microencapsulation of Maqui (Aristotelia chilensis (Mol.) Stuntz) Juice by Spray-Drying and Freeze-Drying Produces Powders with Similar Anthocyanin Stability and Bioaccessibility

The microencapsulation of maqui juice by spray-drying and freeze-drying was studied as a strategy to protect anthocyanins in new food formulations in order to improve the anthocyanin retention before consumption and the bioaccessibility. It is well known that the encapsulation method affects both the shape and size of powders, being assumed that undefined forms of freeze-drying powders might affect their stability due to the high permeability to oxygen. The objective of this study was to compare the microencapsulation of maqui juice by spray-drying and freeze-drying, evaluating the stability of specific anthocyanins in yogurt and after in vitro digestion. Results indicated that most relevant differences between spray-drying and freeze-drying powders were the morphology and particle size that affect their solubility (70.4–59.5%) when they were reconstituted in water. Nevertheless these differences did not affect the stability of anthocyanins as other research have proposed. Both encapsulation methods generated powders with a high stability of 3-O-monoglycosylated anthocyanins in yogurt (half-life values of 75–69 days for delphinidin-3-sambubioside). Furthermore, no significant differences in the bioaccessibility of anthocyanins between maqui juice powders (44.1–43.8%) were found. In conclusion, the microencapsulation of maqui juice by freeze-drying is as effective as spray-drying to produce new value-added food formulations with stable anthocyanins.

RELACION ENTRE EL ORIGEN FLORAL Y EL PERFIL DE ELEMENTOS MINERALES EN MIELES CHILENAS

In this report, 61 honey samples were collected in beehives located between IV and X Administrative Region of Chile. We focussed the analysis in risky chemical elements for human health and in the main chemical elements found previously in Chilean honeys. The analysis of Al, Sr, Cu, Fe, Mn and Zn were done by wet acid digestion method by ICP-OES. Lotus pedunculatus and Eucryphia cordifolia honeys showed the highest Al contents related to their geographical origin (Bio-Bio and Los Lagos Regions). The principal component analysis did not show groups of honeys with the some floral origin and a typical chemical element profile.

Comparison of methods for determining the color of Chilean honeys and the relationship of color with botanical origin in central Chile

M.J. Martin, C. Fredes, G. Nunez, R. Ginocchio, and G. Montenegro. 2014. Comparison of methods for determining the color of Chilean honeys and the relationship of color with botanical origin in central Chile. Cien. Inv. Agr. 41(3): 411-418. The color of honey has special relevance in the international market, as different markets demand specific colors of honey. Chile has very diverse native and exotic flora, which are used by bees (Apis mellifera) to produce a range of honey types, including honeys of different colors. In this context, determining the relationships between color and botanical origin among Chilean honeys is very relevant. The objectives of the present study were to compare three methodologies for determining color in Chilean honeys (Pantone®, optical density (OD), and Pfund) and to define the relationship between color and botanical origin of the characterized honeys. The most common honeys from the Libertador Bernardo O’Higgins Region (VI Region) of Chile were Galega officinalis, Quillaja saponaria, and Retanilla trinervia unifloral honeys, all of which have lighter colors than internationally described. Both the OD and Pfund methods could identify significant differences between dominant species; specifically, these methods were able to discriminate between G. officinalis and Q. saponaria honeys and between G. officinalis and R. trinervia honeys. The OD and Pfund methods revealed that honeys of G. officinalis (A530 nm: 0.93 and 95.53 mm Pfund) were darker than those of Q. saponaria (A530 nm: 0.42 and 80.66 mm Pfund) and R. trinervia (A530 nm: 0.35 and 73.41 mm Pfund). Although the three methods for determining the color of Chilean honeys had different efficacies, the OD method was able to discriminate among dominant species and honey types. Significant correlations among the dominant species were found for Chilean honeys from the Libertador Bernardo O’Higgins Region using both the OD and Pfund methods.