Paz Robert

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.

Influence of the Genotype on the Anthocyanin Composition, Antioxidant Capacity and color of Chilean Pomegranate (Punica granatum L.) Juices

The bioactive compounds content in pomegranate (Punica granatum L.) juice is variable and depends on agronomic factors, genetic and fruit maturity. In Chile, the areas with this crop have increased more than 65% in the last 5 years. This paper aims to determine the phenolic composition, antioxidant capacity and chromatic parameters of juices from eight Chilean pomegranate genotypes (PG2 to PG9), containing red (PG2 to PG6) or pink arils (PG7 to PG9). Color, total polyphenol content (using Folin-Ciocalteu reagent), total anthocyanins (by differences in absorbance at different pHs of the juice) and antioxidant capacity (oxygen-radical absorbance capacity, ORAC) were determined. Anthocyanins were identified and quantify using HPLC-DAD and HPLC/ESI-MS, the results were expressed as cyanidin-3-glucoside. ANOVA was used for establish differences between total polyphenols (TP), antioxidant capacity, total anthocyanins (TA), total polyphenols/total anthocyanins relations (TP/TA) and colour parameters. Statgraphics plus 7.0 was used. Genotypes PG2-PG6 (red arils) showing higher values for total polyphenols (10551280 mg L -1 ) and anthocyanins (588-1328 mg L -1 ) and higher ORAC values (21.2-24.4 μmol Trolox mL -1 ) than the pink arils PG7-PG9 (12.7-16.8 μmol Trolox mL -1 ) values. The latter genotypes showed the highest values of pH (3.5-3.7). The anthocyanin compounds identified in the juices were the 3-glucoside and 3,5-diglucoside derivatives of delphinidin, cyanidin and pelargonidin. Differences in their relative amounts were found among the Chilean pomegranate genotypes studied. The relationships between TP/TA and Pg/Cy (pelargonidin 3-glucoside and pelargonidine 3,5-diglucoside/cyanidin 3-glucoside and cyanidin 3,5-diglucoside) could be useful in the analytical characterization of Chilean pomegranate genotypes, as well as in the differentiation with other juices containing anthocyanins.

Microencapsulation of pulp and ultrafiltered cactus pear (Opuntia ficus-indica) extracts and betanin stability during storage.

Pulp (CP) and ultrafiltered (UF) cactus pear extracts were encapsulated with Capsul (C) by applying a central composite design (CP-C and UF-C systems) by spray-drying. To evaluate the effect of the extract, microparticles obtained under optimal conditions were characterised and stored at 60 °C. Betacyanin and betaxanthin encapsulation efficiency reached values above 98% for both systems studied. This efficiency was attributed to strong interactions between betalains and the polymer. Betalain degradation in CP-C and UF-C microparticles followed pseudo-first order kinetics. The betacyanin degradation rate constant was significantly higher for CP-C than for UF-C. These results suggested that the mucilage or higher sugar content of CP increased the hygroscopicity of the CP-C microparticles, leading to the degradation of betalain. The hydrolysis pathway was the main mechanism of betanin degradation during microparticle storage. These results demonstrate the potential utility of both CP-C and UF-C microparticles as natural colourants for healthy foods.

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.

Microencapsulation of H. pluvialis oleoresins with different fatty acid composition: Kinetic stability of astaxanthin and alpha-tocopherol.

Haematococcus pluvialis is a natural source of astaxanthin (AX). However, AX loses its natural protection when extracted from this microalga. In this study, a supercritical fluid extract (SFE) of H. pluvialis was obtained and added to oils with different fatty acid compositions (sunflower oil (SO) or high oleic sunflower oil (HOSO)). The oleoresins of H. pluvialis ((SO+SFE) and (HOSO+SFE)) were encapsulated with Capsul by spray drying. The stability of the oleoresins and powders were studied at 40, 50 and 70° C. AX and alpha-tocopherol (AT) degradation followed a zero-order and first-order kinetic model, respectively, for all systems. The encapsulation of oleoresins improved the stability of AX and AT to a greater extent in oleoresins with a monounsaturated fatty acid profile, as shown by the significantly lowest degradation rate constants and longest half-lives. Therefore, the encapsulation of H. pluvialis oleoresins is an alternative to developing a functional ingredient for healthy food design.

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.

Thermal stability of oils added with avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) leaf extracts during the French potatoes frying

Effect of the addition of avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) hydroalcoholic leaf extracts (AHE and OHE, respectively) on thermal stability of canola oil (CO) and high oleic sunflower oil (HOSO) during French potatoes frying at 180°C was studied. The extracts were characterized by the total phenolic content, phenol chromatographic profiles and antioxidant activity. B-type trimer procyanidins were the major phenolic compounds identified in AHE. OHE showed higher phenol content, antioxidant activity regarding AHE. CO+OHE and HOSO+OHE decreased the formation of polar compounds and showed an anti-polymeric effect with respect to oils without extracts, whereas AHE extract showed a prooxidant effect on HOSO. Therefore, OHE showed an antioxidant effect on HOSO and CO under the studied conditions. In addition, all systems (CO+AHE, HOSO+AHE, CO+OHE and HOSO+OHE) increased the retention of tocopherols. These results demonstrate the potential utility of OHE as natural antioxidant for oils.

Release kinetics of flavonoids in methyl linoleate from microparticles designed with inulin and channelizing agent

Quercetin (Q), naringenin (N) and epicatechin (E) were encapsulated with inulin (In) as encapsulating agent and Capsul (C) as channelizing agent by spray drying and applying a Box-Behnken design. Q-In, N-In, E-In, Q-In-C, N-In-C and E-In-C were characterised by encapsulating efficiency (EE) and their release profile in methyl linoleate (ML). The flavonoid EE was significant higher (p<0.05) for Q and E (over 60%) than for N (≈40%) in microparticles either without or with channelizing agent. An increase of the number of flavonoid hydroxyl groups enhanced EE, showing the influence of the flavonoid structural features. The release profile was fitted to Peppas and Higuchi mathematical models. The highest and lowest flavonoid release rate constants were found for N and E, respectively, for microparticles both with and without channelizing agent. The EE as indicator of flavonoid-inulin interaction was inversely related with the release rate constant in ML. Flavonoid release rate constant was significantly higher for microparticles with channelizing agent than for those without it, suggesting that Capsul induces the formation of channels inside the microparticles thus favoring the diffusion of flavonoids to ML. The mechanism of flavonoid release was only determined by channelizing agents, independently of the flavonoid nature, that is, Fickian and non-Fickian diffusion mechanisms in microparticles with and without Capsul, respectively.

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.