Lead (Pb) is the most common heavy metal contaminant in the environment. Pb is not an essential element for plants, but they absorb it when it is present in their environment, especially in rural areas when the soil is polluted by automotive exhaust and in fields contaminated with fertilizers containing heavy metal impurities. To investigate lead effects on nutrient uptake and metabolism, two plant species, spinach (Spinacia oleracea) and wheat (Triticum aestivum), were grown under hydroponic conditions and stressed with lead nitrate, Pb(NO3)2, at three concentrations (1.5, 3, and 15 mM). Lead is accumulated in a dose-dependent manner in both plant species, which results in reduced growth and lower uptake of all mineral ions tested. Total amounts and concentrations of most mineral ions (Na, K, Ca, P, Mg, Fe, Cu and Zn) are reduced, although Mn concentrations are increased, as its uptake is reduced less relative to the whole plant's growth. The deficiency of mineral nutrients correlates in a strong decrease in the contents of chlorophylls a and b and proline in both species, but these effects are less pronounced in spinach than in wheat. By contrast, the effects of lead on soluble proteins differ between species; they are reduced in wheat at all lead concentrations, whereas they are increased in spinach, where their value peaks at 3 mM Pb. The relative lead uptake by spinach and wheat, and the different susceptibility of these two species to lead treatment are discussed.

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Plastic packaging has been widely criticized due to the environmental pollution it entails. Biopolymer‐based films could provide an interesting eco‐friendly alternative. This study aimed to investigate the effect of plasticizer type on the physicochemical and mechanical properties of gelatin, pectin, starch, gelatin/pectin, gelatin/starch, and starch/pectin‐based films. Films were prepared using the casting method. Among the six types of films studied, gelatin/pectin‐based film plasticized with sorbitol displayed the best functional properties. Tensile strength and elongation at break were 52.46 MPa and 19.80%; moisture content, water vapor permeability, and water resistance were 19.96%, 3.24 × 107 g s–1 m–1 Pa–1, and 19.96%, respectively. Mentha pulegium and Lavandula angustifolia essential oils were incorporated into the selected film and their effects on the film's characteristics were evaluated. The incorporation of essential oils resulted in films with enhanced antibacterial properties, lower water vapor permeability, and reduced mechanical properties. Practical applications Biopolymer‐based films have attracted widespread attention as an alternative to plastic packaging. In this study, we have demonstrated that gelatin/pectin‐based film plasticized with sorbitol at 30% displayed good mechanical and physicochemical properties. The incorporation of Mentha pulegium and Lavandula angustifolia essential oils into this matrix resulted in films with important antimicrobial activity and adequate mechanical and physicochemical characteristics. The selected combination could be used as bioactive packaging to preserve and prolong the shelf life of food.

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The effect of adding four Lactococcus lactis subsp. Lactis, Lactococcus lactis subsp. lactis Bv. diacetylactis and Lactobacillus paracasei autochthonous strains as single starters (A and B) on the microbiological, physicochemical and sensory characteristics of Moroccan goat’s milk cheese was investigated. Batches with a commercial starter (C) and with raw goat’s milk without starter (D) were also made as controls. The results indicated that the different starter cultures used significantly affected the compositional characteristics of Moroccan goat’s cheese. At the first day of ripening, the pH values of cheeses manufactured with any type of starter were significantly higher than those made without starter. No significant differences (P >0.05) in values of total solids (T.S.), proteins, ash, FAT and lactose content were found between any of the batches after 7 days of ripening. The autochthonous starters in Moroccan cheesemaking were successful at reducing the levels of coliforms earlier in ripening than in cheeses made without starter and even in those made with the commercial starter. These results suggest that the combined activity of L. Lactis subsp. lactis, L. Lactis. subsp. Lactis bv. diacetylactis and L. paracasei, produces cheese with good sensory characteristics.