Pecan is a North American native tree that produces a stone fruit or kernel, commonly known as pecan nut,which is highly valuable worldwide due to its sensory quality, and health promoting properties derived from the presence of mono- and polyunsaturated fatty acids, tocopherols and monomeric and polymeric polyphenolic compounds. The increase in the demand for pecan nut leads to an increase in by-products such as leaves, cake and principally nutshell, which have high contents of bioactive components, making them interesting raw materials to produce nutraceuticals with health benefits. The phytochemical content of pecan oil and kernel, as well as that of the main pecan by-products is discussed in detail, paying special attention to the presence of individual polyphenols with monomeric and polymeric structures. Finally, studies regarding the biological activity and potential use of pecan oil, kernel and by-products are summarized and discussed.

One of the initial and critical procedures for the analysis of metabolomics data using liquid chromatography and mass spectrometry is feature detection. Feature detection is the process to detect boundaries of the mass surface from raw data. It consists of detected abundances arranged in a two-dimensional (2D) matrix of mass/charge and elution time. MZmine 2 is one of the leading software environments that provide a full analysis pipeline for these data. However, the feature detection algorithms provided in MZmine 2 are based mainly on the analysis of one-dimension at a time. We propose GridMass, an efficient algorithm for 2D feature detection. The algorithm is based on landing probes across the chromatographic space that are moved to find local maxima providing accurate boundary estimations. We tested GridMass on a controlled marker experiment, on plasma samples, on plant fruits, and in a proteome sample. Compared with other algorithms, GridMass is faster and may achieve comparable or better sensitivity and specificity. As a proof of concept, GridMass has been implemented in Java under the MZmine 2 environment and is available at http://www.bioinformatica.mty.itesm.mx/GridMass and MASSyPup. It has also been submitted to the MZmine 2 developing community.

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Although habanero peppers (Capsicum chinense, Jacq.) are highly appreciated as a result of their organoleptic and pungency properties, the crop faces edaphic stresses throughout Mexico. A study was conducted to determine how the photosynthetic parameters, vegetative growth, yield, and fruit quality of the plant change in response to suboptimal conditions in the substrate. Habanero plants were grown in an inert substrate (perlite) and exposed to increased salinity levels (4 and 7 dS·m−1) and reduced nitrogen and phosphorus conditions. Plants grown with a Hoagland-based solution were used as controls. High salinity conditions reduced the light-saturated photosynthetic rates (64% of the control) but did not compromise yield or fruit quality. This effect was possibly the result of the addition of Ca2+, which reduced salinity-induced calcium deficiency. Although comparable low nitrogen levels in previous studies were shown to cause a severe reduction in plant viability, in our study, low nitrogen reduced the light-saturated photosynthetic rates (47% of the control) and shoot:root ratio (67% of the control) but did not significantly affect yield or fruit quality. Low nitrogen and 7-dS·m−1 treatments increased fructose and glucose content (increases of 27% and 21%, respectively). Low phosphorus significantly affected plant growth and yield and reduced fructose content (73% of the control). Plants were not sensitive to low nitrogen and high salinity, possibly as a result of the use of nitrate-based fertilizers and the addition of calcium, respectively. These results provide guidelines for habanero pepper production under suboptimal edaphic conditions.

Habanero (Capsicum chinense) is appreciated for its aroma and pungency; however, little is known of the stress effects on Habanero fruits. This work, through untargeted metabolomics, measures changes in the Habanero fruit pericarp under increased salinity and nitrogen and phosphorus deficiency at three ripening stages. Responses to salinity and macronutrient deficiency are stress-and ripening stage-specific, with a few features (<1% in N and P deficit; ca. 1.5% in salinity) being consistently affected through maturation, with the most evident changes in ripe fruit. Results point to a threshold in salinity, between 4 and 7 dS•m −1 , above which a measurable response is seen. Nitrogen deficiency has a symmetric effect on feature abundance, pointing at a metabolite substitution in the pericarp; in contrast, phosphorus deficiency leads to an overall reduction in metabolite diversity, which could negatively affect the postharvest shelf-life. This work shows that untargeted approaches help to improve our understanding of Habanero fruit metabolism under stress conditions beyond traditional metrics.