RESUMO
Globally, agriculture is the primary water consumption sector. This study used water footprint (WF) as a bottom-up tool and satellite imagery as a top-down tool to estimate the internal water use (WU) in the agricultural sector in an innovative way to show the effects of water-intensive use in agriculture in an arid country. The WF of Iran has been quantified for 19 main crops and for related agricultural products exported from Iran to partner countries. Using a bottom-up approach, Iran's total yearly agriculture net water consumption is estimated to be 42.43 billion cubic meters (BCM) per year. Out of 42.43 BCM total net internal water use, only 1.61 BCM is virtual-water export related to these 19 products, and the remaining 40.82 BCM is for internal use. Our results using satellite imagery show that in case of using all possible lands for agriculture, it would require 77.4 BCM. However, not all these lands are within human reach, and the maximum available water is way lower than this amount. Using satellite imagery, the total evaporation from agricultural lands shows 55.27 BCM for 2020, which agrees with national reports during 2005-2014. This study shows that agricultural water consumption tends to use internal water resources at a maximum level for export and national use, significantly impacting renewable and non-renewable water resource availability, especially in groundwater.
RESUMO
Natural bio-based zein films were prepared by incorporating cinnamon essential oil (CEO) and chitosan nanoparticles (CNPs) at 2% and 4% (w/w) amounts, respectively, in order to provide mechanical and antimicrobial functionalities. The physical, mechanical, structural and antibacterial properties of the enriched zein films were also scrutinized. The results showed that the combination of CEO-CNPs significantly improves the tensile strength and decreases the elongation of zein film composite. According to X-ray diffraction (XRD) results, zein film experienced more crystallinity in the presence of CNPs and also combination of CNPs-CEO. Nano-scale size of CNPs and their uniform distribution within the zein film were monitored by scanning electron microscopy (SEM) and proved by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The antimicrobial properties were investigated against Escherichia coli and Staphylococcus aureus, observing that their growth was considerably inhibited by addition of CEO alone and in combination with CNPs in zein films, while CNPs-loaded zein film had no significant effect on the growth of microorganisms. Thus, it can be concluded that the reinforced zein based composites could be suggested as potential degradable film-forming materials for food packaging applications.
