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.

Chemometrics optimization of carbohydrate separations in six food matrices by micellar electrokinetic chromatography with anionic surfactant.

Multivariate statistical design modeling and the Derringer-Suich desirability function analysis were applied to micellar electrokinetic chromatography (MEKC) results with anionic surfactant to separate carbohydrates (CHOs) in different food matrices. This strategy has been studied with success to analyze compounds of difficult separation, but has not been explored for carbohydrates. Six procedures for the analysis of different sets of CHOs present in six food matrices were developed. The effects of pH, electrolyte and surfactant concentrations on the separation of the compounds were investigated using a central composite design requiring 17 experiments. The simultaneous optimization of the responses for separation of six sets of CHOs was performed employing empirical models for prediction of optimal resolution conditions in six matrices, condensed milk, orange juices, rice bran, red wine, roasted and ground coffee and breakfast cereal samples. The results indicate good separation for the samples, with appropriate detectability and selectivity, short analysis time, low reagent cost and little waste generation, demonstrating that the proposed technique is a viable alternative for carbohydrate analysis in foods.