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Mexican spices are used in the supplementation of the human diet and as medicinal herbs for the particularly high amounts of compounds capable of deactivating free radicals. In addition, these spices can have beneficial effects on chronic, no-transmissible diseases such as type II diabetes and hypertension arterial. The objective of this study is to determine the content of phenolic compounds on the antioxidant activity and inhibitory enzymes of &alpha, amylase, &alpha, glucosidase and angiotensin-converting enzyme in melissa, peppermint, thyme and mint, which are subjected to microwave drying, conventional and freeze-drying to be used as alternative treatments. Spices were evaluated to determine total phenols, flavonoids, tannins, 2,2-Diphenyl-1-picrylhydrazyl (DPPH), (2,2&prime, azino-bis- (3-ethyl benzothiazolin-6-ammonium sulphonate) (ABTS) and Ferric Reducing/Antioxidant Power (FRAP), enzymatic activity. The investigation showed that conventional drying caused a decrease in antioxidant properties and inhibitory activity, in some species, while remained preserved in microwave drying and freeze-drying. The activity of polyphenol oxides and peroxidase decreases with high temperatures and these increase with the use of cold temperatures. This study aims to determine the extent of optimal drying required to preserve phenolic compounds, and the positive effect on antioxidant activity and enzymatic activity in in vitro models, which will produce benefits for the infusion processing industry and the pharmaceutical industry.

Commonly carotenoid determinations in tomato are performed in full ripening tomatoes. In this work six tomato ripening stages were established. The relationship among color parameters (L*, a*, b*, and hue), maturity stages, and leaf area with the lycopene and β-carotene concentration was analyzed with different regression models. The R2 values were low, showing that lycopene and β-carotene content was not well correlated with color during the ripening stages. The objective of this work was to provide an ANN model including leaf area index (LAI) and color readings as inputs to solve this lack of fit of the regression models for carotenoid estimations in tomatoes. Two multilayer perceptrons (MLPs) were trained and validated, with six input variables and one output variable, to estimate the concentration of both carotenoids in tomato samples at different ripening stages. Comparing the results of the MLPs with those obtained by regression models it was concluded that when the MLPs are used within the range studied, they are able to estimate lycopene and β-carotene concentrations of tomato with accuracy and reliability, solving the lack of fit by regression models.

The study of secondary metabolism in plants is an important source for the discovery of bioactive compounds with a wide range of applications. Today these bioactive compounds derived from plants are important drugs such as antibiotics, and agrochemicals substitutes, they also have been economically important as fl avors and fragrances, dyes and pigments, and food preservatives. Many of the drugs sold today are synthetic modifi cations of naturally obtained substances. There is no rigid scheme for classifying secondary metabolites, but they can be divided into different groups based on their chemical components, function and biosynthesis: terpenoids and steroids, fatty acid-derived substances and polyketides, alkaloids, phenolic compounds, non-ribosomal polypeptides and enzyme cofactors. The increasing commercial importance of these chemical compounds has resulted in a great interest in secondary metabolism, particularly the possibility of altering the production of bioactive plant metabolites by means of tissue culture technology and metabolomics. In today’s world the use of bioactive compounds derived from plants plays an important role in pharmaceutical applications. This review presents information about these metabolites and their applications as well as their importance in agronomy and bioactive effects on human health as nutraceuticals. This review includes also the new tendencies to produce these bioactive compounds under different stresses conditions such as biotic and abiotic stress that could be included in production systems.

Modifications in growing techniques can affect the yield and nutritional quality of various cultivated plant species. Owing to its high nutritional value, sweet pepper (Capsicum annuum L.) was used in this study as a model plant to investigate the effect of abiotic stress (Electrical conductivity [EC]) and elicitor (Salicylic acid [SA]) on yield and fruit quality parameters under conditions of greenhouse. Nonetheless, the application of elicitors, are stable molecules that induce the activation of transduction cascades and hormonal pathways, which trigger induced resistance to environmental stress. The combination in metabolomics of advanced analytical methods and bioinformatics tools provides wide chemical compositional data that contributes to corroborate (or not) the substantial equivalence. The aim was evaluated the endogenous H2O2 production caused by the effect of different concentrations of (SA) in Capsicum annuum L. in production after elicitation in seedling, and the production of secondary metabolites using GC-MS (flavonoids, tannins and phenolic content as well as the antioxidant properties) in plant and fruit of Capsicum annuum L. to relate their response in metabolic pathways. Results displayed that the use SA, induced an endogenous H2O2 and enzymatic activities related with plant defense as phenylalanine ammonia lyase and catalase. This production showed results that could be an indicator for determining application opportunity uses in agriculture for maintaining plant alert systems against a stress. These results were correlated with those obtained from cultivation of capsicum annum until obtaining the fruit at ripe stage had a high content of bioactive compounds that exhibited significant antioxidant properties. The correlation of the contents of flavonoids, tannins and total phenolics and the ability to remove free radicals of the sweet pepper was significant (r = 0.99, P

Leaf area (LA) is a crucial biophysical variable that is indispensable for many physiological and agronomic models. A reliable and accurate model based on artificial neural networks (ANNs) is proposed to estimate LA of tomato growth under greenhouse conditions. The multi-layer perceptron (MLP) ANN topology was selected for the present study with 5 (ANN5) and three (ANN3) input variables, the architectures were 5-10-1 and 3-9-1, respectively. These MLPs were trained and tested to simulate the response of leaf area with linear measurements leaf length and width. In order to prove the selected topology the ANN was tested with data (leaf length and width) from different experimental growth conditions. Both models had good precision with root mean square errors (RMSEs) of 14.86 and 22.56 cm2, and mean absolute errors (MAEs) of 10.29% and 16.74%, and coefficients of determination (R2) of 0.94 and 0.89, respectively, indicating that the ANN5 model can accurately describe the complex relationship between climate factors (CO2, temperature, and radiation) in different treatments. LA development varied with the different treatments. For high levels of CO2 and temperature, the LA tends to increase highly with respect to the observed area. Variable impact analysis was performed on the input variables; width and length were the variables which impacted the most on LA estimation. Temperature and salicylic acid (SA) concentration were the variables which affect the tomato LA development during the simulations. Overall, ANN models are a useful tool in investigating and understanding the relationships between LA development and climate factors under greenhouse conditions.

Descriptive sensory analysis combined with a chemical analysis, provided insight regarding sensory significance for a better understanding of berrycactus' flavor. This study was based on the volatile components derived from the gas chromatography-olfactometry (GC-O) analysis. Four different ripening stages were used for the experiments: unripe, red, transition, and over-ripe. Besides red and transition stages were stored in sealed plastic bags for 7 d at 5 °C as an additional treatment in order to establish comparisons with fresh samples. GC-O analysis was performed following OSME (time-intensity) method. Moreover, chemical characterization was achieved through GC–MS analysis, each compound was tentatively identified by comparing its mass spectra with the spectra from the library NIST02, by its aroma notes and Kovats Index. The aroma descriptors found were: caramel, fruity, acetic acid, fresh, citrus, floral, and phenolics. Nine volatile compounds are among the most important in flavor of berrycactus: furfural, 5-methyl-2-furancarboxaldehyde, 2(5H)-furanone, 5-acetoxymethyl-2-furaldehyde, 2-cyclohexen-1-ol, octanoic acid ethyl ester, decanoic acid ethyl ester, octanoic acid, and phenylethyl alcohol. To better reflect the real responses of these compounds, the regression analysis of concentrations to ripening stages were performed. The 2,3-dihydro-3,5-dihydroxy-6-methyl-(4H)-pyran-4-one was found in berrycactus, it has been reported in chemical profile of other berries as a product of heat-induced reactions, however, this compound has no aroma activity. The data suggest that both furanones and esters contribute to the aroma of berrycactus. On the other hand, solid phase microextraction was found to be more useful in detecting esters and acids whereas solvent extraction was more effective in detecting furanones and ketones. Practical Application: This information could contribute to setting up favorable processing conditions; in order to retain the best sensory characteristics of berrycactus along with functional properties that would enhance commercialization and exploitation of this fruit and to promote berrycactus cultivation programs.

Fungi play a very important, but yet mostly unexplored role. Their widespread occurrence on land and in marine life makes them a challenge and a risk for humans (Brase et al., 2009). Fungi are ingenious producers of complex natural products which show a broad range of biological activities (Bohnert et al., 2010). However, a specific characteristic is the production of toxins. Mycotoxins (from “myco” fungus and toxin), are nonvolatile, relatively low-molecular weight, fungal secondary metabolic products (Brase et al., 2009). The most agriculturally important micotoxins are aflatoxins (AF) which are a group of highly toxic metabolites, studied primarly because of their negative effects on human health. Aflatoxins belong to a group of difuranocumarinic derivatives structurally related, and are produced meanly by fungi of genus Aspergillus spp. Its production depends on many factors such as substrate, temperature, pH, relative humidity and the presence of other fungi. It has been identified 18 types of aflatoxins; the most frequent in foods are B1, B2, G1, G2, M1, and M2 (Bhatnagar et al., 2002). These secondary metabolites contaminate a number of oilseed crops during growth of the fungus and this can result in severe negative economic and health impacts (Cary et al., 2009). The higher levels of aflatoxins have been found in cotton and maize seeds, peanuts, and nuts. In grains like wheat, rice, rye or barley the presence of aflatoxins is less frequent. Mycotoxins may also occur in conjugated form, either soluble (masked mycotoxins) or incorporated into/ associated with/attached to macromolecules (bound mycotoxins). These conjugated mycotoxins can emerge after metabolization by living plants, fungi and mammals or after food processing. Awareness of such altered forms of mycotoxins is increasing, but reliable analytical methods, measurement standards, occurrence, and toxicity data are still lacking (Berthiller et al., 2009). A variety of studies has been conducted in order to understand the process of crop contamination by aflatoxins. Mycotoxins are dangerous metabolites that are often carcinogenic, and they represent a serious threat to both animal and human health (Reverberi et al., 2010). Mycotoxins are considered secondary metabolites because