Leonardo Martinez-Cardenas

Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05) and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05) to the concentration of total phenolic compounds (R2 = 0.90) and ascorbic acid (R2 = 0.86). All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•.

Fishes in the lower San Pedro Mezquital River, Nayarit, Mexico

The San Pedro Mezquital River is the seventh largest river in Mexico, and flows through the Sierra Madre Occidental into the Marismas Nacionales Biosphere Reserve, on the coast of the state of Nayarit. The present study is to conform a systematic checklist of fishes in the lower basin of the San Pedro Mezquital River. In total, 52 species were collected from 24 families. Four native species were collected (Atherinella crystallina, Poecilia butleri, Poeciliopsis latidens and Poeciliopsis prolifica) that are federally protected. Five of the collected species were new records for the state of Nayarit. This checklist constitutes a first approximation of the fish fauna present in the San Pedro Mezquital River. However, the construction of the Las Cruces dam upstream, will modify the basin hydrology, worsen the introduction of exotic species and create habitat loss, which can have immediate negative impacts on the fish communities in this region.

Descripción de semillas silvestres de Euphorbia strigosa Hook and Arn del estado de Nayarit, México

espanolEn Mexico, Euphorbia strigosa se ha identificado como una especie con potencial ornamental, por su coloracion y su porte pequeno (35 cm, se considera una version enana de Euphorbia pulcherrima). La dificultad en la conservacion de E. strigosa se encuentra en la gran variabilidad de sus semillas en funcion de las condiciones ambientales y genotipicas donde la especie crece. Por lo tanto, el objetivo del presente estudio fue describir las semillas de E. strigosa, de plantas silvestres del Estado de Nayarit, Mexico (2013-2014). Se midieron variables grupales de peso de 1000 y 100 semillas, asi como el numero de semillas en 1 g y en 10 mL. Ademas, una muestra de 130 semillas de cada ano se les evaluo individualmente variables fisicas. Las semillas se clasifican en funcion de tres grados de luminosidad del color cafe (claro, medio y oscuro) y cuatro rangos de peso (3,0-8,0; 8,1-13,0: 13.1-18.0 y > 18,1 mg). Basado en la clasificacion de los factores: ano de colecta, luminosidad del color cafe y el peso, se formaron 22 subgrupos. En cada subgrupo se evaluo el porcentaje de germinacion. Se presentaron diferencias significativas en todas las caracteristicas evaluadas, lo que indica la diversidad morfogenetica de las semillas colectadas. EnglishIn Mexico, Euphorbia strigosa has been identified as a species with ornamental potential, as a result of its color and small size (35 cm, is considered a dwarf version of Euphorbia pulcherrima). The difficulty in the conservation of E. strigosa is found in the great variability of its seeds depending on environmental and genotypic conditions where the species grows. Therefore, the objective of the present study was to describe the seeds of E. strigosa wild plants of the State of Nayarit, Mexico (2013-2014). Group variables of 1000 and 100 seeds were measured, as well as the number of seeds in 1 g and in 10 mL. In addition, a sample of 130 seeds from each year were individually assessed for physical variables. The seeds were classified according to three degrees of luminosity of the brown color (Clear medium and dark) and four weight ranges (3.0-8.0; 8.1-13.0; 13.1-18.0 y > 18.1 mg). Based on the classification of factors: Year of collection, lightness of coffee color and weight, 22 subgroups were formed. In each subgroup the percentage of germination was evaluated. There were significant differences in all characteristics evaluated, which indicates the morphogenetic diversity of the seeds collected.

Preliminary observations on the effect of temperature on growth, condition and survival in Cichlasoma beani in culture conditions

The Mexican Cichlid, Cichlasoma beani has potential to be a candidate for the aquarium trade and the food industry. However, there are no studies regarding the effect of environmental factors on the species in culture conditions. The aim of this study was to examine the effect of temperature on growth, condition and survival of C. beani cultured in 26, 28 and 30 °C, for six weeks in recirculation systems. Fish were fed 2.4 mm pellets (40 % protein, 15 % fat) at a ration rate of 5 % body weight per day (dry weight food: wet weight fish).The final weight and specific growth rate at 30 °C was significantly greater ( P