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The objectives of this research were to carry out a chemical analysis of the base malts, to evaluate the effect of malting and roasting on both color and compounds associated with the antioxidant capacity (anthocyanins, phenolic compounds, melanoidins), and the capacity itself by ABTS and DPPH assays in base malt and caramel malt of blue corn. In order to provide styles of beers with different sensory characteristics as well as health benefits for the consumer, and since malt is the heart of beer, different cereals and pseudo-cereals have been malted. In addition to this, with the intention of taking advantage of the phenolic compounds present in the blue corn grain, and of developing color compounds as well as antioxidant activity through roasting, both blue corn base and caramel malts were developed. Results showed that the protein content was within the specified range for barley malt and, despite the malting not having a significant effect on the color parameters, a decrease in the anthocyanin content was observed. On the contrary, an increase in the content of phenolic acids as well as in the antioxidant capacity by DPPH assay in the base malt with respect to the grain was noticed. Additionally, the color of caramel malts increased in luminosity and chroma, and decreased in tone due to roasting. Likewise, the concentrations of anthocyanins and phenolic compounds depended on the roasting conditions. Moreover, the higher the roasting temperature was, the higher the concentrations of melanoidins were. Finally, malts that had a greater amount of phenolic compounds showed greater antioxidant capacity by ABTS assay, while malts that had a higher melanoidins content showed a greater antioxidant response by DPPH assay. In accordance with the results, it was concluded that the combined use of base and caramel malts to produce corn beer musts could provide significant amounts of compounds that will impact its color and antioxidant capacity, thereby favoring the chemical stability of the product. [ABSTRACT FROM AUTHOR]

The purpose of this study was to identify visible and microscopic symptoms as well as certain biochemical changes associated with chilling injury ( CI) in ' Atlixco' cactus stems. Cladodes were harvested, disinfected, minimally processed and stored at 4, 12 and 26 C for 14-21 days. Results indicated that cactus stems were sensitive to CI at 4 and 12 C and exhibited pitting and bronzing as visible symptoms of this disorder. Confocal microscopy showed that mitochondrial integrity was maintained at 4 C whereas a deterioration of these organelles occurred at 12 and 26 C. Electrolyte leakage, together with an increase in the levels of Adenosine triphosphate ( ATP), glutathione and the reduced form of ascorbic acid were associated with CI. In spite of the presence of CI at 4 C, cactus stems were still able to preserve their taste quality and no adverse effects were observed on either firmness or color for 21 days. Practical Applications Minimally processed products should be refrigerated at ≤4 C in order to maintain their quality and prevent the growth of harmful microorganisms. However, the refrigeration of cactus stems at suboptimal temperatures causes the appearance of chilling injury ( CI). Previous studies have mentioned the general symptoms of this physiological disorder in cactus stems, but no one has described the symptomatology in detail and there is yet to be reported histological and biochemical characterization that might serve to confirm or diagnose its presence. This study describes the symptoms of CI and provides histological and biochemical indicators for its early identification during storage. It also constitutes the preliminary stage to the future application of postharvest technologies that induce tolerance to CI, preventing browning and preserving the quality of minimally processed cactus stems in order to expand their domestic and international markets. [ABSTRACT FROM AUTHOR]