The objective of this study was to examine the physicochemical composition, thermal properties, quality, and sensorial characteristics of bread with substitution of wheat flour with ayocote bean (Phaseolus coccineus) or black bean (Phaseolus vulgaris) flours at 10, 20, and 30%. Ayocote and black bean contain 21.06 and 23.94% of protein, 3.06 and 5.21% of crude fiber, and 3.1 and 5.21% of ash, respectively, directly influencing bread composition. Bread with ayocote and black bean presented higher values in those components in contrast with control bread. The protein content increased in a range of 14–34%; ash increased by 10% to double, and crude fiber also increased. In vitro protein digestibility was similar for bread with 10% of substitution and control, and it decreased in samples with 30% of wheat substitution. Thermal analysis by DSC denoted that the addition of those legumes reduces retrogradation, as seen in 45.33–65.65 °C endotherm, producing higher endotherms of amylose-lipid complexes and protein denaturalization. Finally, the addition of black bean and ayocote bean decreased specific volume when the replacement percentage was 30% black bean and 20 and 30% for ayocote. An increase in nutrient content without sensorial properties affectation could be observed in substitution around 10 and 20%.

Globally, there is growing concern over the presence of lead (Pb) in foods because it is a heavy metal with several toxic effects on human health. However, monitoring studies have not been conducted in Mexico. In this study, we estimated the concentrations of Pb in the most consumed foods and identified those that exceeded the maximum limits (MLs) for Pb in foods established by the International Standards. Based on the Mexican National Health and Nutrition Survey, 103 foods and beverages were selected and purchased in Mexico City retail stores and markets. Samples were analyzed twice using atomic absorption spectrophotometry. Values above the limit of quantification (0.0025 mg/kg) were considered to be detected. The percentage of detected values was 18%. The highest concentration was found in infant rice cereal (1.005 mg/kg), whole wheat bread (0.447 mg/kg), pre-cooked rice (0.276 mg/kg), black pepper (0.239 mg/kg), and turmeric (0.176 mg/kg). Among the foods with detected Pb, the levels in infant rice cereal, whole wheat bread, pre-cooked rice, and soy infant formula exceeded the MLs. The food groups with the highest percentages of exceeded MLs were baby foods (18%) and cereals (11%). Monitoring the concentration of contaminants in foods is essential for implementing food safety policies and protecting consumer health.

Cadmium (Cd) is a toxic heavy metal widely distributed in foodstuffs. In Mexico, few studies have evaluated Cd content in foods. This study aimed to determine Cd concentrations in foodstuffs that are highly consumed and bought in Mexico City to identify foods exceeding the Maximum Level (ML) and to assess the health risks of theoretical Cd intake from a diet following the Mexican Dietary Guidelines. A total of 143 foodstuffs were analyzed by atomic absorption spectrophotometry. Theoretical Cd intake was estimated in portions per week and compared with the Cd Tolerable Weekly Intake (TWI = 2.5 μg/kg per body weight). A total of 68.5% of the foodstuffs had detectable Cd concentrations. Higher concentrations were found in oyster mushrooms (0.575 mg/kg), romaine lettuce (0.335 mg/kg), and cocoa powder (0.289 mg/kg). Food groups with higher mean concentrations were vegetables (0.084 mg/kg) and snacks, sweets, and desserts (0.049 mg/kg). Ancho chili and romaine lettuce exceed the ML. The theoretical Cd intake estimation was 1.80, 2.05, and 3.82 μg/kg per body weight for adults, adolescents, and school-age children, respectively. This theoretical Cd intake represents a health risk only for school children exceeding the TWI by 53.2%. Our study confirms the presence and risk of Cd in Mexican foodstuffs and highlights the importance of monitoring programs.