Effect of phytase treatment of sorghum flour, an alternative for gluten free foods and bioaccessibility of essential minerals.

This study evaluated the effect of phytase treatment on the bioavailability of iron (Fe), calcium (Ca), zinc (Zn), and myo-inositol phosphate fractions in sorghum flour; and characterized its macronutrients and minerals. The proximate composition and mineral content indicated that, sorghum flour has a nutritional potential superior to wheat and maize. The results obtained in the solubility and dialysis assays indicated that, naturally occurring minerals (without phytase treatment) in sorghum flour, presented considerable bioaccessibility; reaching 32, 47 and 67% of dialyzable Fe, Zn, and Ca respectively. The use of phytase had a positive influence on the reduction of myo-inositol phosphates, mainly the IP6 fraction, present in sorghum flour samples, and an increase in the soluble percentage (Fe 52% for one sample, for Zn higher than 266%) and dialyzed minerals (Fe 7.8-150%; Zn 19.7 for one sample; and Ca 5-205%) for most samples. Therefore, the essential minerals naturally occurring in sorghum have an absorption potential; and the use of phytase reduced the IP6 fraction and improved the availability of the minerals evaluated.

Influence of Maturation Stages in Different Varieties of Wine Grapes ( Vitis vinifera) on the Production of Ochratoxin A and Its Modified Forms by Aspergillus carbonarius and Aspergillus niger.

Ochratoxin A is the main contaminant mycotoxin of grapes produced mainly by Aspergillus niger and Aspergillus carbonarius. Besides, it is possible that the formation of modified mycotoxin occurs through the plant defense mechanism or also by fungus actions itself. The objective of this study was to evaluate the influence of grape variety and maturation stage on the formation of OTA and modified mycotoxin. The determination of OTA was performed by high-performance liquid chromatography, and a high-resolution mass spectrometry was used for the detection of modified ochratoxin. A positive correlation was observed between the following grapes physicochemical parameters: pH, total soluble solids, total glycosides in glucose, total anthocyanin, and OTA levels produced by A. niger and A. carbonarius. Therefore, the higher the concentrations of these parameters, the greater the production of mycotoxin in grapes. Among the elected targets, we identified the 14-decarboxy-ochratoxin A in Muscat Italia variety at veraison and 15 days after the beginning of veraison stages; and ethylamide-ochratoxin A as a biomarker in the Syrah variety at the ripeness stage.