Carotenoids from persimmon juice processing.

The aim of this study was the use and revalorization of two persimmon by-products A and B generated in the juice production process. The by-product B resulting from a pectinase enzymatic treatment of peels and pulp to optimize juice extraction was especially suitable for recovery of valuable bioactive carotenoids. The extraction solvents and solvent combinations used were: ethanol, acetone, ethanol/acetone (50:50 v/v) and ethanol/acetone/hexane (25:25:50 v/v/v). HPLC-DAD analysis detected and identified a total of nine individual carotenoids namely violaxanthin, neoxanthin, antheraxanthin, lutein, zeaxanthin, ß-cryptoxanthin 5,6-epoxide, ß-cryptoxanthin, α-carotene, and ß-carotene. ß-cryptoxanthin and ß-carotene represented 49.2% and 13.2% of the total carotenoid content (TCC) in the acetone extract from by-product B. TCC contributed greatly to antioxidant activity of acetone extract derived from this by-product. Pectinase enzymatic treatment of persimmon peels and pulp followed by absolute acetone extraction of carotenoids could be an efficient method to obtain a rich extract in these compounds that could be used as nutraceutical ingredient.

Sediment toxicity and bioaccumulation assessment in abandoned copper and mercury mining areas of the Nalón River basin (Spain).

Sediment toxicity and metal bioaccumulation were assessed at sites affected by historical copper (Cu) and mercury (Hg) mining activities in the Nalón River basin, Asturias, Spain. Toxicity assessment of stream sediments was based on a 28-day oligochaete Tubifex tubifex sediment bioassay, which allowed the classification of sites into three levels of toxicity: 11 sites were classified as nontoxic (including Cu mine sites), three sites as potentially toxic, and seven sites as toxic (all located in Hg mine districts). The greatest levels of arsenic (As), chromium, Hg, lead (Pb), and zinc (Zn) in T. tubifex were measured at sites affected by Hg mining and the highest Cu levels in tissues at Cu mining sites. Chronic toxicity responses were best explained by As and Hg sediment concentrations and by As, Pb, and Zn tissue residues. Residue levels of As, Hg, Zn, and Pb were successfully used to predict sediment chronic toxicity and estimate effective tissue residues.

Roasting and packaging in nitrogen atmosphere protect almond var. Guara against lipid oxidation.

The effect of packaging in nitrogen (N2) atmosphere or in air on the quality of peeled and roasted almond var. Guara during storage for 20 weeks at 20 °C ± 1 °C and 65-70% relative humidity (RH) was studied. No changes in the sugar, fat, protein or fiber contents were observed during the storage period nor in color. Only the lipid fraction showed significant changes with the kind of packaging atmosphere. The composition of fatty acids remained unchanged during the 5 month storage in all the samples. Packaging in N2 atmosphere was seen to have a protective effect against the accumulation of conjugated dienes (CD) in peeled almonds, while in roasted almonds, the protective effect was lower and even nil by the end of storage. The contrary effect was observed for the ultraviolet (UV; K270) index which increased more slowly in the roasted samples packaged in N2, while in peeled samples it reached the same levels at the end of storage regardless of the packaging atmosphere. No effect of the packaging atmosphere was observed on the evolution of the peroxide value in the tested samples (peeled or roasted almonds). None of these changes in the lipid fraction was reflected in the final sensory quality of the samples and the taster panel found no changes in the sensory quality in any case.

Influence of irrigation and organic/inorganic fertilization on chemical quality of almond (Prunus amygdalus cv. Guara).

The chemical quality of almonds variety Guara cultivated in nonirrigated farming (NI) and drip-irrigated farming (DI) conditions with different fertilizing treatments, two organic treatments (T1 and T2) and a mineral treatment (C), all of them with a N-P-K proportion of 1-2-1, is studied. Almonds obtained in irrigated farming showed higher content in sugars and organic acids and a better quality of oil. Among the fertilizing treatments employed, the organic ones have shown the best results related to chemical quality, regardless of the quantity of fertilizer employed (9.5 kg per T1 tree vs 4.5 kg per T2 tree). The organic treatments produced almonds with a higher content of sugar, organic acids and fiber and a similar fat content. These results are interesting from a commercial point of view since the consumers, even under the same conditions of chemical quality, prefer those products cultivated under organic conditions due to their benefits for health and because these practices are environment-friendly.

Ecotoxicity assessment of river sediments and a critical evaluation of some of the procedures used in the aquatic oligochaete Tubifex tubifex chronic bioassay.

Sediment from 27 river sites in Northern Spain were tested with the aquatic oligochaete Tubifex tubifex (Annelida, Clitellata) 28-day chronic bioassay. Sampling sites were chosen from those established by regulatory water agencies for water-quality surveillance networks in rivers of the Basque Country and the Ebro basin. Inclusion of this test in an assessment programme with chemical and benthic community data currently collected by the water agencies will enable a more comprehensive ecotoxicological assessment. Cocoon and adult biomass were used as end points in addition to percent mortality, number of cocoons, young per adult, and percent of hatch end points as proposed in the American Society for Testing and Materials (ASTM) guidelines. Ecotoxicity assessment of the sediments was carried out by comparing mortality, growth, and reproduction in test sediments with their respective experimental control. Cluster analysis resulted in four groups of sediments that were compared using multidimensional scaling ordination (MDS), and the contribution of toxicity end points and the relationship of chemical variables to the MDS ordination space were assessed by principal component correlation (PCC). A gradient of sediments from nontoxic (4 controls and 6 sediments) to severely toxic (8 sediments) was observed, with all of the original biological end points contributing significantly to the ordination. The most toxic sediments could be separated into 2 groups based on the effects of pollutants on mortality (4 sediments) or on reproduction and growth (4 sediments). Remaining sites were grouped together as toxic sediments but showed a variable degree of sublethal effects. The acceptability criteria for validation of the bioassay, as recommended by the ASTM, measured in the control batch of each bioassay were achieved for survival and cocoon production (coefficient of variation [CV] and variability with regard to their average calculated through laboratory control charts). However, the ASTM criteria were found to be strict for the CV for total number of young, and a more realistic criterion is proposed. New criteria are also suggested to improve quality assurance of the bioassay, namely, a minimum number of cocoons per adult in the control group.

Physico-chemical and toxicological characterization of the historic estuarine sediments: a multidisciplinary approach.

The accumulation rates, the geochronology of metals and PAH contamination, and the Microtox toxicity are studied in five sediment cores (50 cm length) covering different areas of the Santander Bay, Northern Spain. Chronology given by (210)Pb and (137)Cs reveals significant differences in accumulation rates between sites (0.2-1.1 cm/year), as well as a variable degree of anthropogenic enrichment factors for Fe, Mn, Cu, Pb, Zn, Ni (from 1 to 15) and concentrations of summation Sigma 16PAHs (from 0.01 to 23.84 mg/kg dw) in sediments over the last 90 years. The results indicate the increasing contamination pressure from industrial and urban activities along the Bay. No toxic results from the Microtox test are obtained either with pore water or with normalised sediment aqueous extracts (European Norm EN 12457), suggesting low water solubility and low availability of contaminants in the studied sediments. However, the EC50 values from the Microtox Basic Solid Phase Test (BSPT) ranged from 0.03% to 2.35%, showing vertical toxicity profiles in accordance with metal and PAHs behaviour. The correlation degrees of Microtox BSPT toxicity to chemical concentration in sediment profiles are widely variable showing a high site-dependent toxicity. The oligochaete Limnodrilus hoffmeisteri has been used as a chronic bioassay over surface sediments of two of the studied sites, showing results coherent with the Microtox BSPT acute test results. Global results of the present work provide regional geochemical baselines for metals and PAHs and toxicological data now make it possible to obtain a preliminary quality assessment of the Santander Bay sediment profiles.

Oil quality and sensory evaluation of almond (Prunus amygdalus) stored after electron beam processing.

The changes in the lipid fraction and the deterioration of its quality were studied in almonds (Prunus amygdalus) of the variety Guara after treatment with accelerated electrons at doses of 3, 7, and 10 kGy, during a storage period of 5 months. In almond oil, the most significant difference from the nutritional point of view was seen in the fatty acid linolenic (18:3), which shows at 3 kGy a maintenance of the initial content during the whole storage period, whereas, at 7 and 10 kGy, the content in 18:3 disappears from the first moment. The quality indices of the oil (K(232), K(270)) decreased at all doses and remained stable during the time of storage. The peroxide value did not show changes at the doses of 3 and 7 kGy, in non-irradiated samples, but significantly increased when the maximum dose of 10 kGy was applied. These changes were reflected in the sensory analysis, in which the tasters did not find sensory differences between the controls and those irradiated at doses of 3 or 7 kGy, whereas almonds irradiated at 10 kGy exhibited a rancid flavor and a significant decrease in general quality.

Role of ethylene and abscisic acid in physicochemical modifications during melon ripening.

Hormonal metabolism associated with fruit ripening in two cantaloupe muskmelon cultivars, Talma and Manta, has been studied. The ethylene crisis began on day 33 after fruit set, reaching the maximum values of internal ethylene concentration and ethylene production rate on day 35 after fruit set. This was the optimum moment for consumption as shown by the higher content in soluble solids, ripening index, sensory analysis, and color parameter values. The b parameter and the b/a quotient values in peel were good indicators of the maturity stage, the optimum moment for harvesting being about day 33 after fruit set (when autocatalytic ethylene synthesis has begun), with values of 20 and 5 for the b parameter and b/a quotient, respectively. In both cultivars, free 1-aminocyclopropane-1-carboxylic acid (ACC) content increased until day 35 after fruit set and conjugated ACC increased in postclimacterium. The increase in both ACC-synthase and ACC-oxidase activities together could be responsible for the climacteric ethylene production. Significant differences in the abscisic acid evolution in Talma and Manta cultivars were reached, and also a possible stimulation of ethylene by this hormone could be established.