Plants are fundamental elements of the human diet, either as direct sources of nutrients or indirectly as feed for animals. During the past few years, the main goal of agriculture has been to increase yield in order to provide the food that is needed by a growing world population. As important as yield, but commonly forgotten in conventional agriculture, is to keep and, if it is possible, to increase the phytochemical content due to their health implications. Nowadays, it is necessary to go beyond this, reconciling yield and phytochemicals that, at first glance, might seem in conflict. This can be accomplished through reviewing food requirements, plant consumption with health implications, and farming methods. The aim of this work is to show how both yield and phytochemicals converge into a new vision of agricultural management in a framework of integrated agricultural practices.
Sweet bell peppers are greatly appreciated for their taste, color, pungency, and aroma. Additionally, they are good sources of bioactive compounds with antioxidant activity, which can be improved by the use of elicitors. Elicitors act as metabolite‐inducing factors (MIF) by mimic stress conditions. Since plants rarely experience a single stress condition one by one but are more likely to be exposed to simultaneous stresses, it is important to evaluate the effect of elicitors on plant secondary metabolism as mixtures. Jasmonic acid (JA), hydrogen peroxide (HP), and chitosan (CH) were applied to fruits and plants of bell pepper as mixtures. Bioactive compounds, antioxidant activity, and quality parameters were evaluated. The assessed elicitor cocktail leads to an increase in the variables evaluated ( P ≤ 0.05) when applied to mature fruits after harvest, whereas the lowest values were observed in the treatment applied to immature fruits. Therefore, the application of the elicitor cocktail to harvested mature fruits is recommended in order to improve bioactive compounds and the antioxidant activity of sweet bell peppers.
Hylocereus spp. present two varieties of commercial interest due to their color, organoleptic characteristics, and nutritional contribution, such as Hylocerous polyrhizus and Selenicerus undatus. The fruit recognized as dragon fruit or Pitahaya is an exotic fruit whose pulp is consumed, while the peel is discarded during the process. Studies indicate that the pulp has vitamin C and betalains, and seeds are rich in essential fatty acids, compounds that can contribute to the prevention of chronic non-communicable diseases (cancer, hypertension, and diabetes). In the present study, polyphenolic compounds, biological activity, and fatty acids present in the peel of the two varieties of pitahaya peel were evaluated, showing as a result that the variety S. undatus had higher antioxidant activity with 51% related to the presence of flavonoids 357 mgRE/g sample and fatty acids (hexadecanoic acid and linoleate) with 0.310 and 0.248 mg AG/g sample, respectively. On the other hand, H. polyrhizuun showed a significant difference in the inhibitory activity of amylase and glucosidase enzymes with 68% and 67%, respectively. We conclude that pitahaya peel has potential health effects and demonstrate that methylated fatty acids could be precursors to betalain formation, as well as showing effects against senescence and as a biological control against insects; in the same way, the peel can be reused as a by-product for the extraction of important enzymes in the pharmaceutical and food industry.
The aim of this study was to evaluate the effect of foliar applications of hydrogen peroxide on the antimicrobial activity of Capsicum chinense Jacq. methanolic extracts. The effects of hydrogen peroxide application on metabolites accumulation of C. chinense var. Jaguar and var. Chichen Itza were evaluated. Total flavonoid and phenolic contents, as well as HPLC quantification of capsaicin and dihidrocapsaicin were carried out. Methanolic extracts were microbiologically tested against Staphylococcus aureus, Escherichia coli, Streptococcus mutants, Salmonella thompson, Listeria monocytogenes, Streptococcus faecalis, and Candida albicans. Total phenolics, flavonoids, and capsaicinoids contents in both varieties treated with hydrogen peroxide were found significantly higher as compared to control. The antibacterial activity of chili extracts was observed against Gram-positive and Gram-negative bacteria as well as anti-yeast. The results of in vitro antibacterial activity showed that hydrogen peroxide application increases the inhibitory effect against the pathogenic micro-organisms. Methanolic extracts of var. Jaguar, were the most active against S. aureus, S. Thompson, and C. albicans, while var. Chichen Itza was most potent against E. faecalis and E. coli. Thus, this study confirmed that metabolite-induced factors (MIFs) as hydrogen peroxide, increased secondary metabolites accumulation in C. chinense methanolic extracts and augmented their antimicrobial activity.
The genus Fusarium is a group of fungi producing several types of toxins with toxicological effect in both humans and animals. Such fungi are commonly found in soils so it can contaminate various types of crops, preferably cereals, leading to significant economic losses. Relative humidity, storage temperature and various handling in cereales increase the possibility of contamination by Fusarium toxins. Cereals naturally have secondary metabolites that may help attenuate contamination by these toxins, but it is necessary to know strategies and mechanisms that generate inactivation mycotoxins. This chapter reviews relevant information about cereal mycotoxin contamination, as well as the production of cereal secondary metabolites as a strategy to reduce the possibility of mycotoxin contamination.