Bioactive ingredients of huitlacoche (Ustilago maydis), a potential food raw material.

Huitlacoche (Ustilago maydis) is a staple food traditionally consumed in Mexico. On one hand, it is considered a pathogen and a devastating disease for maize (Zea mays), and, conversely, some reports highlight it as a culinary delight and a food alternative for its nutritional and functional characteristics. The present work aimed to compare two different methods: maceration and ultrasound-assisted extraction (UAE), in order to achieve the highest amount of total phenolic compounds (TPC), followed by the antioxidant capacity (AC) measurement, as well as the effect of the in vitro digestion. UAE produced the highest TPC content (13.44 mg GAE/mg ds) for a 1:5 huitlacoche:solvent ratio using ethanol at 75%. The maximum values for AC were 22.5 mg TE/mL (for DPPH assay) and 45.26 mg TE/mL (for ABTS assay). The in vitro digestion showed that AC is maintained and increased through the digestion process. Thus, huitlacoche can be revalorised as a potential food raw material for human nutrition and health.

Manufacture of magnesium-fortified Chihuahua cheese.

The aim of this study was to manufacture magnesium-fortified Chihuahua cheese and to evaluate the effect of magnesium fortification on quality parameters. Addition of magnesium chloride to milk during pasteurization (5.44, 10.80, 16.40, 22.00, and 25.20 g of MgCl2·6H2O/L of milk) resulted in cheese with increased magnesium content, proportional to the amount of magnesium added (up to 2,957.13 mg of Mg/kg of cheese). As magnesium content increased, coagulation time and moisture content also increased, whereas calcium content decreased. Higher levels of magnesium fortification (16.40 g of MgCl2·6H2O/L of milk or more) induced the development of bitter-acid flavors and softer texture. Addition of 10.80 g of MgCl2·6H2O/L to milk resulted in Chihuahua cheese that meets regulatory standards and possesses physicochemical and sensory characteristics similar to those of nonfortified Chihuahua cheese. Under this milk fortification level, the manufactured cheese is able to provide 148.4 mg of magnesium per day (35% of the recommended daily intake of magnesium for adult males and 46% for adult females) assuming 3 portions (28 g each) are consumed.

A Specific Thin Layer Chromatography Method for the Identification and Separation of Medium Chain Acylglycerols.

Medium chain fatty acids (MCFAs), have gained nutritional relevance in the past few years. They are continuously used in obtaining structured lipids like medium chain acylglycerols (MCAs) for various purposes. However, because of their chemical structure pertaining carbon chain length and the presence of saturated and unsaturated fatty acids, sensitive detection techniques are required for their correct identification and separation. In the present work, a specific thin layer chromatography (TLC) method for MCAs was developed. The proposed method consisted of the use of a mixture of hexane: acetone (70:30 v/v) as mobile phase, since it proved effectiveness for the separation of compounds of interest (MCAs) as well as having the necessary sensitivity to separate different species of monoacylglycerols (MAGs), diacylglycerols (DAGs) and triacylglycerols (TAGs) of MCFAs. For observation of the compounds, a single oxidizing agent was not sufficient, thus a combination of visualization reagents was used (first a 10 % solution of sulphuric acid in methanol followed by a 10 % solution of phosphomolybdic acid in methanol) achieving the correct visualization of the desired compounds.

Structured Mono- and Diacylglycerols with a High Content of Medium Chain Fatty Acids.

In the present work, direct enzyme-catalysed esterification of medium chain fatty acids (MCFA) from three different sources (Medium chain triacylglycerols, MCT; saponified MCT and a mixture of free MCFA) was evaluated to obtain structured mono- and diacylglycerols. The esterifications were carried out mixing the different sources of MCFA with glycerol at two weight ratios (1:1 and 4:1, w/w), using three immobilized lipases: Novozym 435, Lipozyme RM IM and Lipozyme TL IM; different reaction times (t = 0, 15, 30, 60, 120 min); enzyme loadings (5, 10 or 15% with respect to the total weight of substrates). The extent of esterification was determined by gas chromatography (GC) analysis of the acylglycerols produced. The highest incorporation of free MCFA into glycerol was obtained for a 1:1 (w/w) glycerol to free MCFA ratio, 5% of Novozym 435, at 50°C, 300 rpm, 10% of molecular sieves and a commercial MCFA mixture as starting material. Under these conditions, incorporation of at least 90% of MCFA into glycerol was achieved after 30 min of reaction.