Linking the platelet antiaggregation effect of different strawberries species with antioxidants: metabolomic and transcript profiling of polyphenols / Asociando el efecto de antiagregación plaquetaria de distintas especies de frutillas con antioxidantes: perfil metabolómico y transcriptómico de polifenoles

A comparative study of antioxidant properties, platelet antiaggregation activity and transcriptional analysis of flavonoid biosynthesis genes were performed in Fragaria x ananassa, F. vesca and F. chiloensis subsp chiloensis f. chiloensis and f. patagonica. Furthermore, differences in flavonoid content were found by UHPLC-MS. The highest free radical scavenging activity by DPPH assay was observed in F. chiloensis f. chiloensis, meanwhile, F. vesca presented the highest antioxidant capacity by FRAP. Biosynthetic flavonoids- related transcripts were higher abundant in F. x ananassa and lower in F. vesca. Additionally, all strawberry extracts showed antiaggregant effect (1 mg mL-1), but F. vesca and F. chiloensis subsp. chiloensis f. patagonica were still active at lower concentration. This study suggests that platelet antiaggregation effect of different strawberries could be due to isoflavones and flavonoids precursors in addition to anthocyanins. Results could usefully to take decisions in future breeding programs to improve the content of healthy compounds in strawberry fruits.

Se realizó un estudio comparativo de propiedades antioxidantes, actividad de antiagregacion plaquetaria, análisis transcripcional de genes de biosíntesis de flavonoides y contenido de estos en Fragaria x ananassa, F. vesca and F. chiloensis subsp chiloensis f. chiloensis and f. patagonica. La mayor actividad removedora de radicales libres por DPPH se observó en F. chiloensis f. chiloensis, mientras F. vesca presentó la mayor capacidad antioxidante mediante FRAP. Transcritos relacionados con biosíntesis de flavonoides fueron mas abundantes en F. x ananassa y menores en F. vesca. Adicionalmente, todos los extractos de frutillas mostraron efectos antiagregante (1 mg mL-1), pero F. vesca and F. chiloensis subsp. chiloensis f. patagonica fueron activos a concentraciones menores. Este estudio sugiere que efectos de antiagregación plaquetaria en distintas frutillas podría deberse a isoflavonas y precursores de flavonoides además de antocianinas. Los resultados podrían ser útiles en programas de mejoramiento genético para mejorar el contenido de compuestos saludables en frutilla.

Effect of edible quinoa protein-chitosan based films on refrigerated strawberry (Fragaria × ananassa) quality

Background Strawberries are non-climacteric fruits with a low respiration rate, but are subject to serious fungal deterioration during postharvest handling. The edible coatings based on chitosan (CH), quinoa protein-chitosan (Q/CH) and quinoa protein-chitosan-sunflower oil (Q/CH/SO) may provide a solution to this problem. Thus, in this work CH, Q/CH and Q/CH/SO were elaborated and applied to fresh strawberries, and its effect on the strawberries shelf life during storage for 15 d was evaluated by mold and yeast count, fungal decay, carbon dioxide rate, physicochemical properties, and sensory evaluation. Results On all analysis days, the strawberries coated with the film-forming CH, Q/CH and Q/CH/SO solutions presented a significant lower amount of mold and yeast growth than the uncoated strawberries. Coated strawberries with Q/CH/SO decreased the CO2 emission rate by 60% compared to the uncoated strawberries. The color of the strawberries was not influenced by the films. There was no significant difference between the different coating groups and the uncoated group in the physicochemical parameters. Sensory analysis showed that the coating application retained the total sensorial quality. Conclusions Fresh strawberries coated with CH, Q/CH/SO and Q/CH edible films had longer shelf lives than uncoated fruits.

Physicochemical and nutritional alterations induced by two-spotted spider mite infestation on strawberry plants

Background Strawberry is a pseudofruit mainly cultivated in temperate climate regions. Considering its high levels of ascorbic acid and phenolic compounds, the consumption of strawberry fruit can be beneficial to health. The Brazilian strawberry production revolves around 3000 tons per year, significantly influencing the food market and generating income to farmers. However, this production can be partially impaired by two-spotted spider mite (TSSM) Tetranychus urticae Koch infestations, due to decreases in the quality and quantity of fruit. Since there are no data in the literature about alterations caused by TSSM infestation in strawberry plants, our work aimed towards evaluating nutritional and physicochemical parameters of TSSM-infested strawberry plants, along with the related chemical treatment (CT) (acaricide) or biological treatment (predatory mite Phytoseiulus macropilis Banks). Results Strawberry fruit from TSSM-infested plants present the highest levels of acidity and exhibit low levels of anthocyanin and phenolic compounds, while fruit from TSSM-infested plants + biological control using predatory mite shows high levels of soluble solids, phenolic compounds and ascorbic acid, along with a high soluble solid content/titratable (SSC/TA) acidity ratio, which indicates high quality fruit. Conclusions Our results suggest that TSSM infestation decreases fruit quality and that the biological control of TSSM using a predatory mite is a suitable alternative to organic production, since the presence of predatory mite does not affect fruit quality and development.

Biosynthesis of flavonoids in achenes of Fragaria chiloensis ssp. chiloensis / Biosintesis de flavonoides en aquenios de Fragaria chiloensis ssp. chiloensis

Fragaria chiloensis ssp. chiloensis has two native botanical forms. Fruits from both botanical forms, Fragaria chiloensis ssp. chiloensis f. chiloensis (native white strawberry) and f. patagonica (native red strawberry), were collected from Bio-Bio Region, and a comparative study in the biosynthesis and pigment accumulation was performed from achens. The fruit was classified in four different developmental and ripening stages in order to establish the differences in the transcriptional profile of structural genes and the chemical compounds. A differential expression of those genes involved in the biosynthesis (phenylpropanoid and flavonoids) of anthocianins was found. The differential expression of genes was concomitant with the increase in the level of cyanidin 3-glucoside (C3G) along the fruit development for both botanical forms. On the contrary, undetectable level of cyanidin 3-glucoside (P3G) was observed in the f. chiloensis. Albeit, P3G increase rapidly from the development stage 2, reaching the maximum value at stage 4 in Fragaria chiloensis ssp. chiloensis f. patagonica.

Fragaria chiloensis ssp. chiloensis presenta dos formas botánicas nativas. Los frutos de ambas formas botánicas, Fragaria chiloensis ssp. chiloensis f. chiloensis (frutilla nativa blanca) y f. patagonica (frutilla nativa roja), fueron colectadas en la región del Bio-Bio, realizándose un estudio comparativo en la biosíntesis y acumulación de la pigmentación en aquenios. Para ello, el fruto fue clasificado en cuatro distintos estadios de desarrollo y maduración a fin de establecer las diferencias en los perfiles transcripcionales de genes estructurales y de compuestos químicos. Se determinó una expresión diferencial de los genes responsables de la formación de antocianinas, concomitante con un incremento en los niveles de cianidina 3-glucósido (C3G) en tanto avanza el desarrollo del fruto en ambas formas botánicas. Por el contrario, se observó niveles indetectables de pelargonidina 3-glucósido (P3G) en f. chiloensis, lo cual contrasta con lo observado en f. patagonica, donde P3G se incrementa rápidamente a partir del estadio 2, alcanzando un máximo valor en estadio 4.

Folate content and retention in selected raw and processed foods / Contenido de folatos y retención en determinados alimentos crudos y procesados

Adequate intake of folate reduced the risk of abnormalities in early embryonic brain development such as the risk of malformations of the embryonic brain/spinal cord, collectively referred to as neural tube defects (NTDs). Folate is extremely sensitive to destruction by heat, oxidation and UV light. The purpose of this study was to evaluate the use of different extraction procedures and enzymatic treatment to determine folate concentrations in variety of foods using a microbiological assay (MA) with Lactobacillus rhamnosus as the test organism. This study also aimed to evaluate the retention of folate in foods after using different cooking processes. Nine of the most commonly consumed foods in Argentina and that contain folate were analyzed: broccoli, spinach, potato, lentil, soy (raw and boiled); hen whole egg and yolks (raw, boiled and fried); beef liver (raw and cooked); strawberry (raw) and white bread. For this study, rat plasma (RP) and human plasma (HP) conjugases together with acetate and phosphate buffers were tested. In extraction step for all analyses, RP conjugase was selected since it was easily available in our laboratory and small quantities were required. The acetate buffer was chosen since better growth and more reproducible results were obtained in the different conditions assayed. The results allowed the foods to be grouped into a) rich sources of folate: hen eggs, yolks, spinach, soybean (raw) and strawberry (100 and 350mg/100g fresh weight (FW); b) good sources of folate: broccoli (raw), soybean (boiled), lentils (raw) and potato (56 to 83mg/100g FW) and c) moderate sources of folate: broccoli, lentils (boiled), white breads, onions and beef liver (15 to 30mg/100g FW). The folate retention was in the range 14-99% according to both type of food and method of processing. Contents and losses of folate vary widely according to type of food and cooking method.

La ingesta adecuada de folatos reduce el riesgo de las anormalidades en el desarrollo temprano del cerebro embrionario, tales como el riego de malformaciones en el cerebro/médula espinal, conocidas en conjunto como defectos del tubo neural (NTDs). Los folatos son extremadamente sensibles al tratamiento con calor, la oxidación y la luz UV. El objetivo de este trabajo fue evaluar el uso de diferentes procedimientos de extracción y de tratamientos enzimáticos para determinar el contenido de folato en distintos alimentos empleando un método microbiológico que utiliza el microorganismo Lactobacillus rhamnosus. En este trabajo se evaluó también la retención de folatos en alimentos sometidos a diferentes procesos de cocción. Se analizaron 9 de los alimentos que contienen folatos y más comúnmente consumidos en Argentina: brócoli, espinaca, papa, lente ja, soja (crudos y cocidos): huevo entero de gallina y yema (crudo, hervido y frito). Bife de hígado vacuno (crudo y cocido); frutillas (crudas) y pan: blanco. Se probó para este estudio conjugasas de plasma de rata (PR) y de plasma humano (PH) conjuntamente con buffers fosfato y acetato. En la extracción para todos los análisis se escogió la conjugasa de PR por ser accesible para nuestro laboratorio y por que se utiliza en pequeñas cantidades. El buffer acetato fue elegido debido a que se obtuvo resultados más reproducibles y un mejor crecimiento en las diferentes condiciones ensayadas. Los resultados permitieron agrupar los alimentos en: a) fuente rica de folatos: huevo y su yema, espinaca, soja (cruda) y frutilla (100 a 350mg/100g peso fresco); b) fuente buena de folatos: brócoli (crudo), soja (hervidas), lentejas (cruda) y papa (cruda y hervida) (56 a 83mg/100g peso fresco) y c) fuente moderada de folatos: brócoli y lentejas (hervidos), bife de hígado, pan blanco y cebollas (15 a 30mg/100g peso fresco). La retención de folato estuvo en el rango de 14-99% de acuerdo al tipo de alimento y el método de procesado. El contenido de folato y sus perdidas fueron muy variables dependiendo del alimento y del método de cocción empleados.

Avaliação de resíduos de agrotóxicos em polpas de morango industrializadas / Evaluation of pesticides residues in industrialized strawberry pulps

Amostras de polpas de morango industrializadas, comercializadas no estado de Minas Gerais, foram coletadas no período de 2006 a 2007 pelas Vigilâncias Sanitárias e encaminhadas à Fundação Ezequiel Dias para análise de resíduos de agrotóxicos. Realizou-se a extração pelo método de multiresíduos com acetona, diclorometano e hexano. Os extratos obtidos foram submetidos à análise por cromatografia a gás com detectores de captura de elétrons (CG-DCE), fotométrico de chama (CG-DFC) e nitrogênio fósforo (CG-DNF), espectometria de massa (CG-MS) e cromatografia a líquido de alta eficiência (CLAE) com detectores ultravioleta (UV) visível e fluorescência. Os resultados evidenciaram o uso inadequado de agrotóxicos, sendo detectados produtos não autorizados como acetato, captana, clorfenapir, clorpirifós, dimettoato, ometoato, endossulfam, fenarimol, folpete, metamidofós, procloraz e tetradifona e os autorizados azoxistrobina, difenoconazol, fenpropatrina, iprodiona e procimidona. Isso indica que as boas práticas agrícolas não estão sendo ocupadas poro alguns produtores e mostra a necessidade de fiscalização de alimentos processados, o que levaria à oferta de produtos de melhor qualidade.