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  • Author or Editor: A. Rodriguez x
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Blueberry (Vaccinium spp.) cultivation has experienced a notable increase both for its good organoleptic characteristics and the nutritional and functional properties of this berry. The aim of this study was the physicochemical characterization of blueberry juices obtained from 55 blueberry cultivars grown under the same environmental conditions for 2–4 years. The results provide a broad and robust database, both for the number of cultivars and the periods of monitoring thereof, in order to cover different aspects of blueberry processing, and more specifically, production of juices. Blueberries belonging to V. virgatum cultivars showed the higher values of total anthocyanin content, total phenolic content, antioxidant activity, soluble solids, and pH, and V. corymbosum cultivars the higher level of titratable acidity. Results also showed a high variability among cultivars. Observed variations can be used in plant breeding and classification of blueberry cultivars, at least, at the species level.

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Bisphenol A (BPA), bisphenol A dimethacrylate (BisDMA) and phthalic acid (PA) endocrine disruptors can migrate from the plastic lining of cans to foods producing serious health problems when they exceed allowable concentration limits for consumption. In this work, a method was assessed for the determination of BPA, BisDMA, and PA in vegetable food cans from Mexico using a food simulant. Those disruptors were determined by HPLC connected to an Evaporative Light Scattering Detector (ELSD), and simultaneous detection by UV-Vis detector was used for validation. The most frequently found disruptor in major concentration was PA over the range of 5.40 to 112.39 μg l−1. The samples analysed did not exceed the migration limit accepted by the US-FDA and US-EPA for bisphenols. Our results showed that HPLC-ELSD produces chromatograms with accurate signals and smaller detection limits than the UV-Vis detector for the substances analysed here.

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The use of melatonin as antioxidant has been extensively established. But what would the antioxidant function be if one were to go one step back in the anabolism of that amine, and orally administer its precursor — the amino acid tryptophan? Diurnal animals ( Streptopelia roseogrisea ) were administered orally capsules containing 125 or 300 mg L-tryptophan/kg b.w. for 7 days at the end of the light period (20 h ). A control group received capsules with methylcellulose. The antioxidant function was studied through the reduction of nitroblue tetrazolium (NBT) by superoxide anion, and through the levels of malonaldehyde (MDA) produced in the lipoperoxidation that occurs from the respiratory burst in response to the presence of a foreign particle in phagocytic cells (heterophils), which were extracted at 2 h — at the acrophase of melatonin in the blood stream. In the heterophils extracted from the group that received 125 mg kg −1 b.w. tryptophan, there was less oxidative stress as determined by the NBT reduction than in those from the 300 mg kg −1 b.w. group. In the study of the lipoperoxidation of the membranes as determined by the levels of MDA, however, no significant variations were observed between the different groups. The lower concentration (125 mg L-tryptophan/kg b.w.), administered orally, succeeded in diminishing the free radicals produced in the heterophils for the destruction of the ingested foreign agent, but not fully or maximally. The possible solution to this prooxidant/antioxidant imbalance would be to administer a lower concentration of tryptophan to attain the perfect balance for application in nutritional treatments.

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