Cadmium, Copper, Lead, and Zinc Contents of Fish Marketed in NW Mexico

To assess if they were within the safety limits for human consumption, the Cd, Cu, Pb, and Zn contents of fish muscles, bought from separate stalls of the fish markets of nine cities of NW Mexico, were determined by atomic absorption spectrophotometry. Considering all fish and markets, the mean contents were Zn: 23.23±5.83, Cu: 1.72±0.63, Cd: 0.27 ± 0.07, and Pb: 0.09 ± 0.04 µg/g (dry weight). Cu, Zn, and Pb did not reach levels of concern for human consumption, but the high Cd values determined in Mazatlán (Mugil cephalus: 0.48±0.15; Diapterus spp.: 0.57±0.33; Lutjanus spp.: 0.72±0.12; small shark: 0.87±0.19 µg/g dry weight) indicate that this was the only metal of concern for human health because the daily individual consumption of fish muscle to reach the PTDI would be within 0.27 and 0.41 kg

Agronomic Behavior of Mexican Roselle Cultivars Produced under Protected Agricultural Conditions

Growth dynamics and morphological traits are used to define the characteristics of roselle cultivars Hibiscus sabdariffa. The morpho–agronomic variability of plants was evaluated, as well as the concentration of macro and micronutrients in leaves of Mexican roselle cultivars in hydroponic and greenhouse conditions. The following roselle cultivars were studied: ‘Cruza Negra’, ‘UAN16-2′, ‘Criolla Huajicori’, ‘UAN 6 Puga’, ‘UAN 25-1′ and ‘4Q4′. The relative growth rate of the crops was fitted to a positive cubic, negative quadratic and positive linear model, whereas stem diameter, fitted to a linear model, had a negative quadratic response. The foliar surface of the cultivars ‘4Q4’, ‘Cruza Negra’, ‘UAN16-2’ and ‘Criolla Huajicori’ was directly related to the size of the flower, the calyx and the corolla. Nitrogen and potassium are the elements that showed the highest concentration in the cultivars Criolla Huajicori and Cruza Negra, while in the other four cultivars the highest concentrations of minerals in the leaf were nitrogen and calcium. The leaves of cultivar 4Q4 provided the greatest amount of minerals, with 83,565 mg kg−1 dry basis. Criolla Huajicori was the cultivar that exhibited the tallest height, the most productive branches and the greatest calyx number per plant; however, Cruza Negra exhibited the highest yield by having the longest calyx