Jorge Ruiz-Ruiz

Antioxidant activity of Vigna unguiculata L. walp and hard-to-cook Phaseolus vulgaris L. protein hydrolysates

Recent research, using model systems, has shown that enzymatic hydrolysis of food proteins can make them act as direct scavengers of diverse free radicals. This study aimed at the characterization of protein hydrolysates with antioxidant properties from Vigna unguiculata L. walp and hard-to-cook Phaseolus vulgaris L. protein concentrates. The maximum values obtained for all the assays were 15.1 mM/mg of protein for Trolox-equivalent-antioxidative capacity, 98.2% for percentage of 2,2-diphenyl-1-picrylhydrazyl (DPPH) discoloration, 70.1% and 71.4% for iron and copper chelating activities, respectively. The reducing power of hydrolysates was higher than butylated hydroxytoluene (BHT) (control). The antioxidant activity of the hydrolysates may be a result of enzymatic hydrolysis generating peptides that exhibit this type of activity. The hydrolysates showed an increase of amino acids that have been associated with the biological activity of peptides with antioxidant activity, such as hydrophobic residues: Ala, Phe and Ile; hydrophilic: Lys and neutral: Ser and Gly.

Effect of extrusion conditions and lipoxygenase inactivation treatment on the physical and nutritional properties of corn/cowpea (Vigna unguiculata) blends

The influence of lipoxygenase inactivation and extrusion cooking on the physical and nutritional properties of corn/cowpea (Vigna unguiculata) blends was studied. Corn was blended in an 80:15 proportion with cowpea flour treated to inactivate lipoxygenase (CI) or non-inactivated cowpea flour (CNI). Extrusion variables were temperature (150°C, 165°C and 180°C) and moisture (15%, 17% and 19%). Based on their physical properties, the 165°C/15% corn:CNI, and 165°C/15% corn:CI, and 150°C/15% corn:CI blends were chosen for nutritional quality analysis. Extrudate chemical composition indicated high crude protein levels compared with standard corn-based products. With the exception of lysine, essential amino acids content in the three treatments met FAO requirements. Extrusion and lipoxygenase inactivation are promising options for developing corn/cowpea extruded snack products with good physical properties and nutritional quality.

A Survey of the Mosquito Species in Maxcanu, Yucatan, Mexico

A survey was carried out to identify the mosquitoes inhabiting human premises in the rural locality of Maxcanú, Yucatán, Mexico. Using the Centers for Disease Control and Prevention backpack aspirators, simple random sampling was carried out inside of 101 homes during the November 2013 rainy season. A total of 1,492 specimens were collected. Three subfamilies (Anophelinae, Culicinae, and Toxorhynchitinae) and 5 species were identified: Anopheles albimanus, Aedes aegypti, Culex interrogator, Limatus durhamii, and Toxorhynchites theobaldi. The most abundant species was Cx. interrogator (74%) followed by Ae. aegypti (25%). The Chao 1 and Bootstrap species richness estimator indicated that it was possible to collect 90% of the expected species. This is the 1st time that the presence of An. albimanus, Cx. interrogator, Li. durhamii, and Tx. theobaldi has been recorded in Maxcanú.

Correction to: In vitro antioxidant and anti-inflammatory activities of Melipona beecheii honey protein fractions

The original version of this article unfortunately contained error in affiliation of Dr. Jorge Carlos Ruiz–Ruiz and Acknowledgements section.

Antioxidant Capacity of Capsicum chinense Genotypes

The fruits of seven Capsicum chinense Jacq. genotypes grown in Yucatan, Mexico, were studied to determine their phenolic compounds, carotenoids, and ascorbic acid contents, as well as their free radical scavenging (ABTS assay) and antioxidant activities (s-carotene/linoleic acid assay). Phenolics, carotenoids, and ascorbic acid contents varied between genotypes. ABTS radical scavenging activity was highest in a yellow genotype, and antioxidant activity was most stable in a red genotype. Fruits from all seven studied genotypes are good antioxidant sources. Many of these benefits originate in peppers’ wide array of phytochemicals and high contents of vitamin C and carotenoids, which are vital nutritional antioxidants in the human diet.

Capsicum chinense : Composition and Functional Properties

Habanero pepper (Capsicum chinense Jacq.) was introduced to the Yucatan Peninsula, Mexico, via the Antilles. That place is currently the largest habanero pepper-producing region worldwide, with 732 ha under cultivation and 3700 t harvested annually. Its moisture content is within ranges reported for other commercial pepper varieties and is processed for its oleoresins and capsaicin for inclusion in many products. Most of total fruit capsaicin is found in the placenta (62 %). The antimicrobial properties of peppers can also be attributed to peptides in their seeds, and its high carotenoid content in mature stages makes colored pepper varieties good antioxidant sources.