Mercedes Del Río-Celestino

Modulation of genotoxicity and cytotoxicity by radish grown in metal-contaminated soils

Members of the Brassicaceae family are known for their anticarcinogenic and genetic material protective effects. However, many of the species of this family accumulate high amounts of metals, which is an undesirable feature. Radish (Raphanus sativus L.) has shown to accumulate metals in roots to a higher extent than others members of Brassicaceae. The main objectives of this work are (i) to study the distribution of the accumulated As, Pb and Cd in radish plants and (ii) to establish the genotoxic, antigenotoxic and cytotoxic activities of the root and shoot of this vegetable. Results indicate that (i) the shoots of radish accumulate higher concentrations of metal(oid)s than roots; (ii) the shoots were genotoxic at the different concentrations studied, with the root showing such genotoxic effect only at the highest concentration assayed; (iii) the antigenotoxic potential of radish is reduced in plants with high metal content and (iv) the tumouricide activities of the radish plants were negatively correlated to their metal(oid) contents. An interaction between metal(oid)s and the isotyocianates (hydrolysis products of the glucosinolates) contained in the radish is suggested as the main modulator agents of the genotoxic activity of the plants grown in contaminated soils with metal(oid)s.

Use of visible and near-infrared spectroscopy for predicting antioxidant compounds in summer squash (Cucurbita pepo ssp pepo).

The food industry and plant breeding programmes require fast, clean and low-cost screening techniques for nutritional compounds determination in food matrices. This is the first report on the study of the potential of near-infrared spectroscopy (NIRS) for the prediction of antioxidant compounds in summer squash tissues collected since 2009-2012. Modified partial least-squares (MPLS) regression was used to correlate spectral information and the different antioxidant compounds in the samples. The coefficients of determination in the external validation (r(2)ev) obtained were for ascorbic acid (0.77 and 0.86), chlorophyll a (0.79 and 0.66), chlorophyll b (0.86 and 0.79) and total phenolic compounds (0.65 and 0.68) in exocarp and mesocarp tissues, respectively, supporting that NIRS is able to predict in a rapid way these components for screening purposes. Major wavelengths influencing the calibration equations showed that chromophores as well as fibre components of the fruits highly participated in developing the NIR equations.

An approach to the phytochemical profiling of rocket [Eruca sativa (Mill.) Thell].

BACKGROUND Eruca sativa (rocket) contains a wide range of compounds with nutraceutical and organoleptical properties. This research aimed to characterise the nutraceutical interest of four rocket accessions by analysis of glucosinolates, isothiocyanates, phenolics, carotenoids and carbohydrates. Different methods based on chromatographic separation with ultraviolet absorbance or mass spectrometry detection were used. RESULTS The total content of glucosinolates ranged from 14.02 to 28.24 µmol g(-1) of dry weight. Glucoraphanin represented up to 52% of the total glucosinolates in leaves of one accession. Accessions showed differences in the hydrolysis of glucoraphanin to the isothiocyanate sulforaphane. No correlation between these compounds was observed, which insisted differences in the myrosinase activity within accessions. Rocket leaves had variable phenolic profiles represented by quercetin-3-glucoside, rutin, myricetin, quercetin and ferulic and p-coumaric acids. A high variability was observed for the total carotenoids ranged from 16.2 to 275 µg g(-1) with lutein as the main carotenoid. Glucose was the predominant sugar, representing >70% of the total soluble carbohydrates. CONCLUSIONS Some accessions could be candidates for future breeding programmes because of their pattern of beneficial compounds for human health. However, further research is essential to evaluate the biological activity of these accessions before designing functional food.

Characterization and prediction by near-infrared reflectance of mineral composition of rocket (Eruca vesicaria subsp. sativa and Eruca vesicaria subsp. vesicaria).

BACKGROUND Minerals are essential for human nutrition and must be obtained from our diet. Crucifer vegetables are a good source of these nutrients. Our objectives were to determine the genetic variability for mineral content and to evaluate the use of near-infrared reflectance spectroscopy (NIRS) for prediction of ashes and minerals among and within the rocket species Eruca vesicaria subsp. sativa and vesicaria. The minerals studied were iron (Fe), copper (Cu), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn) and zinc (Zn). RESULTS The maximum mean values obtained for all the accessions (mean ± SE) were 235.5 ± 1.5 mg ashes kg(-1), 273.3 ± 4.2 mg Fe kg(-1), 18.1 ± 0.4 mg Cu kg(-1), 2.8 ± 0.1 g Na kg(-1), 71.6 ± 1.0 g K kg(-1), 64.6 ± 1.2 g Ca kg(-1), 6.8 ± 0.1 g mg kg(-1), 101.6 ± 1.2 mg Mn kg(-1), and 67.1 ± 0.4 mg Zn kg(-1) of dry weight. CONCLUSION The statistical analysis showed significant differences for all the minerals, except Ca, for each accession studied individually and for accessions grouped within countries. The results indicate that NIRS can be used as a rapid screening method for determining total mineral, Fe, Na, K, and Zn in rocket.

Determining the mineral composition in Cucurbita pepo fruit using near infrared reflectance spectroscopy

BACKGROUND Efforts through conventional breeding to improve the mineral content in horticultural crops have not always been successful mainly due to the fact that standard analytical methods are both costly and time-consuming. We investigated the feasibility of applying near infrared reflectance spectroscopy (NIRS) to the estimation of essential mineral composition in the skin and flesh of summer squash fruits (Cucurbita pepo subsp. pepo) using a 200-sample set from diverse morphotypes. RESULTS The coefficients of determination in the external validation (R(2) VAL) obtained for the skin and flesh of the fruit were: total mineral content, 0.84 and 0.70; P, 0.74 and 0.62; K, 0.83 and 0.67; Ca, 0.57 and 0.60; Mg, 0.78 and 0.45; Fe, 0.78 and 0.65; Cu, 0.67 and 0.66; Mn, 0.67 and 0.64; Zn, 0.80 and 0.79 and Na, 0.33 and 0.33; respectively. CONCLUSIONS NIRS combined with different spectral transformations by modified partial least-squares (MPLS) regression has shown to be useful in determining the mineral composition of summer squash fruit, being a fast and low-cost analytical technique. Components such as chlorophyll, starch and lipids were used by MPLS for modelling the predicting equations. The promotion of micronutrient-rich summer squash varieties could have a significant long-term beneficial impact on the health of mineral deficient human populations.

Cytotoxic and genotoxic effects of metal(oid)s bioactivated in rocket leaves (Eruca vesicaria subsp. sativa Miller)

Rocket is an important source of essential elements. However, it may also accumulate toxic elements such as metal(oids). The objectives of the present work were (i) to study the uptake of arsenic, lead, cadmium and zinc in rocket grown in contaminated soils, (ii) to establish the genotoxic and cytotoxic activities of this vegetable material, and (iii) to study the modulator role of the glucosinolate and metal contents in the genotoxic/cytotoxic activities. Lead, cadmium and zinc leaf concentrations in our study were over the concentrations allowed by the statutory limit set for metal(oid) contents in vegetables. The accessions were non genotoxic at the different concentrations studied, although one of the accessions showed the highest mutation rates doubling those of negative control. The cytotoxicity assays with HL60 human leukaemia cells showed that the tumouricide activities of rocket leaves decreased with the increasing of metal(oid) concentrations and also with the decreasing of glucosinolate concentrations in their tissues. An interaction between metal(oid)s and glucosinolate degradation products contained in rocket leaves is suggested as the main modulator agents of the biological activity of the plants grown in metal-contaminated soils.

Application of visible/near‐infrared reflectance spectroscopy for predicting internal and external quality in pepper

BACKGROUND The characterization of internal (°Brix, pH, malic acid, total phenolic compounds, ascorbic acid and total carotenoid content) and external (color, firmness and pericarp wall thickness) pepper quality is necessary to better understand its possible applications and increase consumer awareness of its benefits. The main aim of this work was to examine the feasibility of using visible/near-infrared reflectance spectroscopy (VIS-NIRS) to predict quality parameters in different pepper types. Commercially available spectrophotometers were evaluated for this purpose: a Polychromix Phazir spectrometer for intact raw pepper, and a scanning monochromator for freeze-dried pepper. RESULTS The RPD values (ratio of the standard deviation of the reference data to the standard error of prediction) obtained from the external validation exceeded a value of 3 for chlorophyll a and total carotenoid content; values ranging between 2.5 < RPD < 3 for total phenolic compounds; between 1.5 < RPD <2.5 for °Brix, pH, color parameters a* and h* and chlorophyll b; and RPD values below 1.5 for fruit firmness, pericarp wall thickness, color parameters C*, b* and L*, vitamin C and malic acid content. CONCLUSION The present work has led to the development of multi-type calibrations for pepper quality parameters in intact and freeze-dried peppers. The majority of NIRS equations obtained were suitable for screening purposes in pepper breeding programs. Components such as pigments (xanthophyll, carotenes and chlorophyll), glucides, lipids, cellulose and water were used by modified partial least-squares regression for modeling the predicting equations.

Auxin signalling regulation during induced and parthenocarpic fruit set in zucchini

Fruit set and fruit development can be limited due to ineffective pollination in off-season crops of Cucurbita pepo. To avoid this problem, parthenocarpy, the natural or artificial fruit development without fertilization, is required. The application of synthetic growth regulators is a common practice for inducing stimulative parthenocarpy in zucchini cultivars, but this method increases production costs and may cause other fruit defects. The disadvantages associated with this can be overcome through the use of vegetative parthenocarpic cultivars, which allow fruit set without any external stimuli. Three zucchini cultivars have been studied and differences have been found in parthenocarpic fruit development. Ethylene release of unpollinated fruit has corroborated the parthenocarpic fruit development. Vegetative parthenocarpy was observed in the Whitaker cultivar. Furthermore, the involvement of the auxin signalling pathway in controlling fruit set and parthenocarpy have been studied. Transcriptome analysis of auxin signalling genes, CpARF8, CpIAA9 and CpTIR1, have shown tissue-specific expression and have revealed a decrease in the expression levels of these genes in pollinated fruits after the fertilization signal, indicating their role in the transition from ovary to fruit. Nevertheless, it has also been shown that expression of these genes can be different between parthenocarpic cultivars.

Rapid and Cost-Effective Quantification of Glucosinolates and Total Phenolic Content in Rocket Leaves by Visible/Near-Infrared Spectroscopy

The potential of visible-near infrared spectroscopy to predict glucosinolates and total phenolic content in rocket (Eruca vesicaria) leaves has been evaluated. Accessions of the E. vesicaria species were scanned by NIRS as ground leaf, and their reference values regressed against different spectral transformations by modified partial least squares (MPLS) regression. The coefficients of determination in the external validation (R2VAL) for the different quality components analyzed in rocket ranged from 0.59 to 0.84, which characterize those equations as having from good to excellent quantitative information. These results show that the total glucosinolates, glucosativin and glucoerucin equations obtained, can be used to identify those samples with low and high contents. The glucoraphanin equation obtained can be used for rough predictions of samples and in case of total phenolic content, the equation showed good correlation. The standard deviation (SD) to standard error of prediction ratio (RPD) and SD to range (RER) were variable for the different quality compounds and showed values that were characteristic of equations suitable for screening purposes or to perform accurate analyses. From the study of the MPLS loadings of the first three terms of the different equations, it can be concluded that some major cell components such as protein and cellulose, highly participated in modelling the equations for glucosinolates.

Characterisation and prediction of carbohydrate content in zucchini fruit using near infrared spectroscopy

BACKGROUND Zucchini fruit plays an important part in healthy nutrition due to its high content of carbohydrates. Recent studies have demonstrated the feasibility of visible-NIRS to predict quality profile. However, this procedure has not been applied to determine carbohydrates. RESULTS Visible-NIR and wet chemical methods were used to determine individual sugars and starch in zucchini fruits. By applying a principal component analysis (PCA) with NIR spectral data a differentiation between the less sweet versus the sweetest zucchini accessions could be found. For the determination of carbohydrate content effective prediction models for individual sugars such as glucose, fructose, sucrose and starch by using partial least squares (PLS) regression have been developed. CONCLUSION The coefficients of determination in the external validation (R2 VAL) ranged from 0.66 to 0.85. The standard deviation (SD) to standard error of prediction ratio (RPD) and SD to range (RER) were variable for different quality compounds and showed values that were characteristic of equations suitable for screening purposes. From the study of the MPLS loadings of the first three terms of the different equations for sugars and starch, it can be concluded that some major cell components such as pigments, cellulose, organic acids highly participated in modelling the equations for carbohydrates.