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Abstract: The antioxidant and tyrosinase inhibitory properties of extracts of mango seed kernel (Mangifera indica L.), which is normally discarded when the fruit is processed, were studied. Extracts contained phenolic components by a high antioxidant activity, which was assessed in homogeneous solution by the 2,2-diphenyl-1-picrylhydrazyl radical and 2,2′-azinobis (3-ethylbenzothialozinesulfonic acid) radical cation-scavenging assays and in an emulsion with the ferric thiocyanate test. The extracts also possessed tyrosinase inhibitory activity. Drying conditions and extraction solvent were varied, and optimum conditions for preparation of mango seed kernel extract were found to be sun-drying with ethanol extraction at room temperature. Refluxing in acidified ethanol gave an increase in yield and the obtained extract had the highest content of total phenolics, and also was the most effective antioxidant with the highest radical-scavenging, metal-chelating and tyrosinase inhibitory activity. The extracts did not cause acute irritation of rabbit skins. Our study for the first time reveals the high total phenol content, radical-scavenging, metal-chelating and tyrosinase inhibitory activities of the extract from mango seed kernel. This extract may be suitable for use in food, cosmetic, nutraceutical and pharmaceutical applications. [Copyright &y& Elsevier]

The antioxidant effects of β-carotene, oil-soluble (bixin) and water-soluble (norbixin) annatto preparations and mixtures of these carotenoids with virgin olive oil polar extract were assessed in bulk olive oil and oil-in-water emulsions stored at 60 °C. Norbixin was the only carotenoid that inhibited the oxidative deterioration of lipids in both systems. Though bixin and β-carotene did not retard autoxidation, their mixtures with the polar extract from virgin olive oil enhanced the antioxidant effect of the olive oil extract. Norbixin (2 mM) was of similar activity to δ-tocopherol (0.1 mM) in stored oil. The combination of norbixin with ascorbic acid or ascorbyl palmitate in oil showed a reduction in formation of volatile oxidation products but not in peroxide value, compared with the analogous sample lacking norbixin. In olive oil-in-water emulsions, norbixin (2 mM) reduced hydroperoxide formation to a similar extent as δ-tocopherol (0.1 mM), which in turn was a better antioxidant than α-tocopherol. A synergistic effect between norbixin and ascorbic acid or ascorbyl palmitate was observed in the emulsion systems. [Copyright &y& Elsevier]

Highlights: [•] The phytate concentration in beans and cereal brans increase the soluble oxalate concentration by binding of calcium. [•] Soluble oxalate is present at higher concentration in bran samples than in beans. [•] Oat bran has a high soluble:insoluble oxalate ratio due to a low concentration of minerals. [ABSTRACT FROM AUTHOR]

The effect of wheat heat damage was estimated using hard red winter (HRW) wheat varieties grown in Oklahoma, and analyses were performed on wheat kernels, flour, and isolated starch. Wheat kernels were analyzed by photoacoustic spectroscopy (PAS), flour was analyzed by DSC, capillary zone electrophoresis (CZE) and rheometry, while starch was analyzed by DSC. DSC data showed little difference in the temperatures of starch gelatinization. The ΔH values increased at 50 °C storage temperature. PAS data revealed differences in sensitivities to heat between the three cultivars. The pericap of cultivar Jagger was about five times more heat resistant than the pericarp of the other two cultivars. CZE maps showed that gluten proteins from cultivar 2137 was more affected by the 60 days and 50 °C treatment than the other two cultivars. Non-linear steady shearing showed that all heat-treated flours had lower viscosity, which suggests a deleterious effect on the potential performance of yeasted baked products. Viscoelastic properties of the Jagger untreated suspension sample showed strong gluten. The linear and non-linear viscoelastic behaviours of Jagger cultivar were less altered by heat treatment than were the other cultivars. [Copyright &y& Elsevier]