Cactus pears (Opuntia ficus-indica) are draught resistant plants originated in Mexico. Their flattened stem segments, called cladodes, have moisture, protein and fibre contents of 92, 1-2 and 4-6% respectively, and a pectin content in the range of 0.8-3.3% depending on the species. They also contain certain concentration of carotenoids which are of special interest because of their antioxidant activity. This work is aimed to identify and quantify the main carotenoids present in the stems and to evaluate the effect of thermal treatments on the antioxidant activity and concentration of carotenoids and phenolic compounds. The carotenoids -cryptoxanthin, -carotene and lutein were identified in the cladodes, the latter having the highest concentration. Thermal treatments increased the extractability of these pigments and the antioxidant activity was related to the carotenoids concentration. Total phenolic content decreased after the thermal treatments; however this result had little effect on the antioxidant activity. Mucilage present in the stems decreased the extractability of the carotenoids.

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Nanoparticles of bovine α-lactalbumin (α-LA) prepared by desolvation and glutaraldehyde crosslinking are promising carriers for bioactive compounds in foods. The objective of this work was to study the effect of changes in hydrophobic interactions by using different desolvating agents (acetone, ethanol, or isopropanol) and the use of a heat or high-pressure treatment step before the desolvation process on the size, structure, and properties of α-LA nanoparticles. In all cases, a high average particle yield of 99.63% was obtained. Smaller sizes (152.3 nm) can be obtained with the use of acetone as the desolvating agent and without any pretreatment. This is the first time that α-LA nanoparticles in the size range of 100 to 200 nm have been obtained. These nanoparticles, with an isoelectric point of 3.61, are very stable at pH values >4.8, based on their ζ-potential, although their antioxidant activity is weak. The use of the desolvating agent with the smallest polarity index (isopropanol) produced the largest particles (293.4 to 324.9 nm) in all cases. These results support the idea that controlling hydrophobic interactions is a means to control the size of α-LA nanoparticles. No effect of pretreatment on nanoparticle size could be detected. All types of nanoparticles were easily degraded by the proteolytic enzymes assayed.

Vanilla is one of the most popular species in the world. Its main compound, vanillin, is responsible for its characteristic aroma and flavor and its antioxidant and biological properties. Vanillin is very unstable in the presence of oxygen, light, and humidity, which complicates its use and preservation. Therefore, to solve this problem, this study aimed to develop vanilla oleoresin microcapsules. Vanilla oleoresin was obtained with supercritical carbon dioxide and microencapsulated by complex coacervation and subsequent spray drying (100 °C/60 °C inlet/outlet temperature). The optimal conditions for the complex coacervation process were 0.34% chitosan, 1.7% gum Arabic, 5.29 pH, and an oleoresin:wall material ratio of 1:2.5. Fourier Transform Infrared Spectroscopy (FT-IR) analysis of the coacervates before and after spray drying revealed the presence of the functional group C=N (associated with carbonyl groups of vanillin and amino groups of chitosan), indicating that microencapsulation by complex coacervation-spray drying was successful. The retention and encapsulation efficiencies were 84.89 ± 1.94% and 69.20 ± 1.79%. The microcapsules obtained from vanilla oleoresin had high vanillin concentration and the presence of other volatile compounds and essential fatty acids. All this improves the aroma and flavor of the product, increasing its consumption and application in various food matrices.

Extensive research has proven that fruits and vegetables contribute significantly to the body supply of bioactive compounds due to their antioxidant activity to protect organisms against harmful effects of oxygen radicals. A special case is the legumes that are also rich source of proteins, dietary fiber, micronutrients, and bioactive phytochemicals. Many legume species are still an irreplaceable source of dietary proteins for humans, especially in the mainly vegetarian diets of developing countries. Incorporation of leguminous seeds into the human diet can offer protective effects against chronic diseases because they contain a number of bioactive substances including phenolics that can increase protein digestibility and mineral bioavailability. However, technological processing and seed germination can impact the levels of natural endogenous antioxidants (e.g., phenolics, tocopherols; vitamin C) in leguminous seeds. Therefore, this chapter is a review about reports of antioxidant properties and their relationship with their total phenolic content of the most commonly consumed legumes. Researches about changes in the content of natural antioxidants during technological processing are included as well as some clinical reports concerning to the health benefits offered by legumes of higher consumption.

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BACKGROUND The development of bioactive compound delivery systems using protein‐based nanoparticles as carriers is a rapidly growing field of study. α‐Lactalbumin (α‐La) nanoparticles are adequate for this task because they are nonantigenic, biodegradable, and easily modifiable via the surface physical adsorption of other molecules. Here, the effect of poly‐L‐lysine (PLL) coating of α‐La nanoparticles on the stability against enzymatic degradation in the gastrointestinal tract was investigated. RESULTS α‐La nanoparticles were prepared by desolvation with acetone. It was observed that the pH of the initial protein suspension did not have a significant effect on the size, polydispersity index (PDI), or ζ‐potential of the nanoparticles, so the subsequent experiments were performed at pH 9, where 151.2 nm nanoparticles with a PDI of 0.072 and a ζ‐potential of −29.7 mV were obtained. The nanoparticles coating was performed with two MW‐range PLL at three concentrations. Coating efficiency increased as the polymer concentration increased and this was independent of the PLL MW. The best coating efficiency (90–95%) was obtained in the case of the 1 mg mL−1 PLL coating. Most PLL‐coated nanoparticles showed a good stability to the conditions of in vitro simulated gastrointestinal digestion compared with the uncoated nanoparticles. CONCLUSION It can be concluded that the acetone desolvation method at pH 9 is adequate to obtain α‐La nanoparticles with good characteristics. The process of PLL coating of nanoparticles showed an increase in efficiency with the increase in concentration of the polymer. The resulting coated nanoparticles had enhanced resistance to simulated gastrointestinal conditions. © 2021 Society of Chemical Industry (SCI).