ABSTRACT. The impacts of a potential climate change on rainfed maize crops in Mexico are analyzed. For that purpose, baseline scenanos based on current climate conditions and their relation with maize crop development were created. Climate change scenarios were further developed and the crop vulnerability under each scenario was assessed. Two methods were used to quantify vulnerability. In the first place, maps describing the suitability for crop production accorhng to climate conditions were produced. The differences between the baseline and the climate change scenarios allowed for estimating the area of the country likely to be positively or negatively affected. Secondly, the CERES-Maize model was applied to estimate rainfed maize crop yields at 7 sites in Mexico under the baseline and climate change scenarios. Adaptive measures were proposed and their feasibility was assessed on the basis of a simple cost-benefit analysis.

Abstract

Cagaita is a fruit from Brazilian cerrado, belongs to Myrtaceae family, and has important economic value. This work aimed to determine the total antioxidant capacity (extractable and nonextractable fractions) by different methods and to evaluate the use of paper spray mass spectrometry to obtain fingerprints of cagaita from different regions with the aid of principal components analysis. Cagaitas had higher antioxidant activity than those found in other fruits mentioned in literature, and the non-extractable fraction was 18.90 to 21.05% of the antioxidant capacity. The analysis of paper spray mass spectrometry in positive and negative ionization modes identified several substances, including organic acids, sugars, amino acids and several other classes of phenolic compounds. Analysis of the main components of cagaita samples permitted discrimination of the major constituents such as sugars and different kinds of phenolic compounds. Thus, this study demonstrated that paper spray mass spectrometry is a simple and ultrafast method with minimum sample preparation that allows the analysis of the chemical profile of cagaita.

No abstract

The objective of this study was to explore the extraction and identification of volatile organic compounds (VOCs) present in cagaita fruit (Eugenia dysenterica). Parameters such as type of extraction fiber, agitation, extraction time and extraction temperature were investigated. Initially, the VOCs were extracted using headspace solid-phase microextraction. Then, the compounds were identified using gas chromatography coupled to mass spectrometry. Results revealed the presence of at least 26 different compounds and the polyacrylate (PA) fiber promoted the extraction of a larger number of VOCs. Regarding the PA fiber, the most efficient extraction was achieved using a 50 rpm agitation at 45 °C for 30 min. The majority were monoterpenes (34.64%) and esters (36.28%). An increase in the extraction temperature promoted the isolation of more VOCs when using carboxen/polydimethylsiloxane (CAR/PDMS) and divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fibers. However, these fibers allowed the isolation of a smaller number of VOCs. The extraction time and agitation had no significant influence.