Huitlacoche – A 21 st Century Culinary Delight Originated in the Aztec Times. In: Tunick MH, González de Mejía E, editors. Hispanic Foods: Chemistry and Bioactive Compounds. Washington: American Chemical Society; 2012. pp. 83-100. [DOI: 10.1021/bk-2012-1109.ch007]

Green Synthesis of Ag NPs Using Ustilago maydis as Reducing and Stabilizing Agent

Ustilago maydis (UM) is a fungus that grows naturally on Zea mays; it reduces the corn yields, and thus, it represents huge economic loss; however, it can be used as an exotic food, and in the present work, it is successfully used as a reducing and stabilizing agent for the preparation of silver nanoparticles (Ag NPs) due to its content of amino acids and biosurfactants. The effects of the concentration of UM aqueous extract, pH, and sunlight on the particle size, surface plasmon resonance, stability, and morphology of Ag NPs obtained by green synthesis were evaluated. A green reduction was observed only in presence of UM, and colloidal Ag NPs were obtained with or without the presence of sunlight; nevertheless, continuous sunlight exposure greatly increased the reaction rate. Ag NPs tend to increase in size from 153 nm to 1400 nm at a higher pH and a greater amount of UM, and also, UM tends to stabilize the Ag NPs preventing their agglomeration according to measurement of zeta potential (−10.75 ± 0.84 mV) and SEM observation; furthermore, surface plasmon resonances were more intense between 400 and 480 nm of wavelength adding greater amount of UM. This study concludes that UM not only reduces AgNO3 but also acts as stabilizer of Ag NPs.

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

•

The extraction method affected the recovery of phenolic compounds.

•

Digestible carbohydrates were the main component in proximate analysis.

•

The polarity of the solvent used favoured the recovery of bioactive compounds.

•

Digestion conditions exerted a significant effect on phenolics release.

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.

Fungi as a Source of Food

In this article, we review some of the best-studied fungi used as food sources, in particular, the cheese fungi, the truffles, and the fungi used for drink fermentation such as beer, wine, and sake. We discuss their history of consumption by humans and the genomic mechanisms of adaptation during artificial selection.

Phenolic Compounds, Antioxidant Activity and Lipid Profile of Huitlacoche Mushroom (Ustilago maydis) Produced in Several Maize Genotypes at Different Stages of Development

Huitlacoche mushroom (composed by the fruiting bodies growing on the maize ears from the basidiomycete Ustilago maydis) is a culinary delicacy with a great economic and nutraceutical value. In this work, phenolic content, antioxidant activity, ergosterol and fatty acids profile from huitlacoche produced in 15 creole and in one hybrid maize genotypes, and harvested at different stages of development were determined. The hybrid crop was studied in raw and cooked samples. Total phenolic content ranged from 415.6 to 921.8.0 mg gallic acid equivalents per 100 g of flour. Samples exhibited attractive antioxidant activities: 75 % of antiradical activity on average by DPPH methodology, and ORAC values up to 7661.3 μmol Trolox equivalents /100  g. Important quantities of ferulic acid, quercetin, ergosterol, linoleic and oleic acids were observed. Stage of development and cooking process had an effect on evaluated compounds, sometimes negative and sometimes positive. Results suggest that huitlacoche is an attractive food source of phenolics with excellent antioxidant potential and interesting lipidic compounds.