Mechanism and synergistic effect of sulfadiazine (SDZ) and cadmium toxicity in spinach (Spinacia oleracea L.) and its alleviation through zinc fortification.

Cadmium (Cd) and antibiotic's tendency to accumulate in edible plant parts and fertile land is a worldwide issue. The combined effect of antibiotics and heavy metals on crops was analyzed, but not mitigation of their toxicity. This study investigated the potential of zinc oxide nanoparticles (ZnO NPs) to alleviate the SDZ and Cd toxicity (alone/combined) to promote spinach growth. Results revealed that the ZnO 200 mg L-1 spray decreased the malondialdehyde (MDA) 14%, hydrogen peroxide (H2O2) 13%, and electrolyte leakage (EL) 7%, and increased the superoxide dismutase (SOD) 8%, peroxidase (POD) 25%, catalase (CAT) 39% and ascorbate peroxidase (APX) 12% in spinach leaves under combined SDZ+Cd (25 mg Kg-1 +50 mg Kg-1) stress compared to ZnO 100 mg L-1 spray. Likewise, ZnO NPs 200 mg L-1 spray enhanced the zinc (Zn) 97%, iron (Fe) 86%, magnesium (Mg) 35%, manganese (Mn) 8%, and potassium (K) 23% in shoots under combined SDZ+Cd (25 mg Kg-1 +50 mg Kg-1) stress compared to ZnO 100 mg L-1 spray. Further, ZnO 200 mg L-1 spray reduced Cd uptake in roots by 9% and shoots 15% under combined SDZ+Cd (25 mg Kg-1 +50 mg Kg-1) stress compared to ZnO 100 mg L-1. Overall, ZnO NPs alleviated the SDZ and Cd toxicity and enhanced spinach growth in all treatments.

The influence mechanism of brown rice starch structure on its functionality and digestibility under the combination of germination and zinc fortification.

This study explored the influence of germination and fortification on the functionality and digestibility of brown rice from the perspective of starch structure changes. The surface of germinated brown rice starch appeared some pits and holes under the action of endogenous hydrolase, and the amylose content, relative crystallinity and short-range order of the starch decreased significantly after germination. However, the fortification treatment seemed to intensify the enzymatic hydrolysis of germinated brown rice starch, showing deeper pits, lower short-range order and less double helix structure. These changes in structural characteristics led to a significant decrease in peak viscosity, enthalpy change (ΔH) and starch hydrolysis rate after germination and fortification treatment. As the germination time increased, the trend became more obvious. And the peak viscosity and enthalpy change (ΔH) of fortified brown rice reached the minimum values of 290.89 cP and 13.73 J/g after 34 h of germination, respectively, while the starch hydrolysis rate reached the maximum value of 85.42 %. Overall, the combination of germination and fortification could be an effective method to adjust the functional and digestive characteristics of starch by changing its structural characteristics.

Foliar application of biosynthesised zinc nanoparticles as a strategy for ferti-fortification by improving yield, zinc content and zinc use efficiency in amaranth.

Deficiency in zinc is widely prevalent in developing countries. Ferti-fortification is one of the easiest and quickest options for improving the zinc content in food. Consumption of such food can provide zinc in adequate amounts to the individual. Nanotechnology is now envisioned as the future of agriculture owing to the immense advantages of nanoparticles over bulk materials. In this work, the effect of zinc nanoparticles (Nps) synthesized via biological route using moringa leaves extract was studied on seed germination, its growth parameters, zinc content and nutrient use efficiency in amaranth crop. Moringa leaves are rich in plant metabolites such as amino acids, alkaloids, flavonoids, sugars and fatty acids as confirmed by the UPLC-MS system analysis. The XRD studies show that the biosynthesized Nps were hexagonal crystals with an average size of 23.69 nm. The particle size as indicated by scanning electron microscopy was between 15 to 30 nm, and by DLS was 22.8 nm. Foliar application of 10 ppm biosynthesized zinc Nps, resulted in the highest plant height and fresh weight. Although, an increase in concentration of zinc applied through foliar route led to higher zinc content in the plant biomass, the nutrient use efficiency indices indicated that zinc Nps at 10 ppm concentration resulted in better nutrient recovery, improved yield and productivity with respect to the nutrient input. This reflects the advantage of biologically synthesized Nps over the bulk counterparts. These results show that the biologically synthesized Nps can be an attractive alternative to conventional fertilizers for nutrient biofortification and better crop yields.

Reconsidering the Tolerable Upper Levels of Zinc Intake among Infants and Young Children: A Systematic Review of the Available Evidence.

Safe upper levels (UL) of zinc intake for children were established based on either (1) limited data from just one study among children or (2) extrapolations from studies in adults. Resulting ULs are less than amounts of zinc consumed by children in many studies that reported benefits of zinc interventions, and usual dietary zinc intakes often exceed the UL, with no apparent adverse effects. Therefore, existing ULs may be too low. We conducted a systematic bibliographic review of studies among preadolescent children, in which (1) additional zinc was provided vs. no additional zinc provided, and (2) the effect of zinc on serum or plasma copper, ceruloplasmin, ferritin, transferrin receptor, lipids, or hemoglobin or erythrocyte super-oxide dismutase were assessed. We extracted data from 44 relevant studies with 141 comparisons. Meta-analyses found no significant overall effect of providing additional zinc, except for a significant negative effect on ferritin (p = 0.001), albeit not consistent in relation to the zinc dose. Interpretation is complicated by the significant heterogeneity of results and uncertainties regarding the physiological and clinical significance of outcomes. Current zinc ULs should be reassessed and potentially revised using data now available for preadolescent children and considering challenges regarding interpretation of results.

Insight into the Prospects for Nanotechnology in Wheat Biofortification.

The deficiency of nutrients in food crops is a major issue affecting the health of human beings, mainly in underdeveloped areas. Despite the development in the methods of food fortification, several barriers such as lack of proper regulations and smaller public-private partnerships hinder its successful implementation in society. Consequently, genetic and agronomic biofortification has been suggested as the potential techniques for fortifying the nutrients in diets. However, the time-consuming nature and restricted available diversity in the targeted crop gene pool limit the benefits of genetic biofortification. In agronomic biofortification, organic fertilizers face the problem of prolonged duration of nutrients release and lesser content of minerals; while in inorganic fertilizers, the large-sized fertilizers (greater than 100 nm) suffer from volatilization and leaching losses. The application of nanotechnology in agriculture holds enormous potential to cope with these challenges. The utility of nanomaterials for wheat biofortification gains its importance by supplying the appropriate dose of fertilizer at the appropriate time diminishing the environmental concerns and smoothening the process of nutrient uptake and absorption. Wheat is a major crop whose nano-biofortification can largely handle the issue of malnutrition and nutrients deficiency in human beings. Though several research experiments have been conducted at small levels to see the effects of nano-biofortification on wheat plants, a review article providing an overview of such studies and summarizing the benefits and outcomes of wheat nano-biofortification is still lacking. Although a number of review articles are available on the role of nanotechnology in wheat crop, these are mostly focused on the role of nanoparticles in alleviating biotic and abiotic stress conditions in wheat. None of them focused on the prospects of nanotechnology for wheat biofortification. Hence, in this review for the first time, the current advancement in the employment of different nanotechnology-based approaches for wheat biofortification has been outlined. Different strategies including the supply of nano-based macro- and micronutrients that have shown promising results for wheat improvement have been discussed in detail. Understanding several aspects related to the safe usage of nanomaterials and their future perspectives may enhance their successful utilization in terms of economy and fulfillment of nutritional requirements following wheat nano-biofortification.

Studies on in vitro bioavailability and starch hydrolysis in zinc fortified ready-to-eat parboiled rice (komal chawal).

Zinc fortified parboiled rice (komal chawal) was produced from a low amylose variety of rice by applying 'brown rice parboiling' method. In addition to the effect of milling on fortification, the effectiveness of fortification upon the amount of bioaccessible (in vitro digest) and bioavailable (cellular uptake) form of Zn was tested. The effect on glycaemic index was also assessed by employing an in vitro starch hydrolysis assay. The bioaccessible form of Zn in the unmilled fortified rice were ranged in between 4.24 and 11.07 mg/100 g, which was significantly higher (p < 0.05) than the milled and unfortified parboiled rice. Similarly, the % absorption of bioavailable Zn was negligible in the unfortified parboiled rice as compared to the fortified rice (14.5-24.5%). The estimated GI of fortified parboiled rice samples was in the range of 50.97-59.79, which was lower than the unfortified parboiled rice (58.80-62.53) and raw rice (78.71-84.64). The results thus demonstrated that Zn fortified komal chawal can be a novel and rapidly produced micronutrient enhanced ready-to-eat rice.

Zinc biofortification of cereals-role of phosphorus and other impediments in alkaline calcareous soils.

Alkaline calcareous soils are deficient in plant nutrients; in particular, phosphorus (P) and zinc (Zn) are least available; their inorganic fertilizers are generally applied to meet the demand of crops. The applied nutrients react with soil constituents as well as with each other, resulting in lower plant uptake. Phosphorus availability is usually deterred due to lime content, while Zn availability is largely linked with alkalinity of the soil. The present manuscript critically discusses the factors associated with physicochemical properties of soil and other interactions in soil-plant system which contribute to the nutrients supply from soil, and affect productivity and quality attributes of cereals. Appropriate measures may possibly lessen the severity of nutritional disorder in cereal and optimize P and Zn concentrations in grain. Foliar Zn spray is found to escape most of the soil reactions; thus, Zn bioavailability is higher either through increase in grain Zn or through decrease in phytate content. The reactivity of nutrients prior to its uptake is deemed as major impediments in Zn biofortification of cereals. The article addresses physiological limitation of plants to accumulate grain Zn and the ways to achieve biofortification in cereals, while molecular mechanism explains how it affects nutritional quality of cereals. Moreover, it highlights the desirable measures for enhancing Zn bioavailability, e.g., manipulation of genetic makeup for efficient nutrient uptake/translocation, and also elucidates agronomic measures that help facilitate Zn supply in soil for plant accumulation.

Addition-omission of zinc, copper, and boron nano and bulk oxide particles demonstrate element and size -specific response of soybean to micronutrients exposure.

Plant response to microelements exposure can be modulated based on particle size. However, studies are lacking on the roles of particle size and specific microelements in mixed exposure systems designed for plant nutrition, rather than toxicology. Here, an addition-omission strategy was used to address particle-size and element-specific effects in soybean exposed to a mixture of nano and bulk scale oxide particles of Zn (2 mg Zn/kg), Cu (1 mg Cu/kg) and B (1 mg B/kg) in soil. Compared to the control, mixtures of oxide particles of both sizes significantly (p < 0.05) promoted grain yield and overall (shoot and grain) Zn accumulation, but suppressed overall P accumulation. However, the mixed nano-oxides, but not the mixed bulk-oxides, specifically stimulated shoot growth (47%), flower formation (63%), shoot biomass (34%), and shoot N (53%) and K (42%) accumulation. Compared by particle size, omission of individual elements from the mixtures evoked significant responses that were nano or bulk-specific, including shoot growth promotion (29%) by bulk-B; inhibition (51%) of flower formation by nano-Cu; stimulation (57%) of flower formation by bulk-B; grain yield suppression (40%) by nano-Zn; B uptake enhancement (34%) by bulk-Cu; P uptake stimulation by nano-Zn (14%) or bulk-B (21%); residual soil N (80%) and Zn (42%) enhancement by nano-Cu; and residual soil Cu enhancement by nano-Zn (72%) and nano-B (62%). Zn was responsible for driving the agronomic (biomass and grain yield) responses in this soil, with concurrent ramifications for environmental management (N and P) and human health (Zn nutrition). Overall, compared to bulk microelements, nanoscale microelements played a greater role in evoking plant responses.

Fortification of zinc in a parboiled low-amylose rice: effects of milling and cooking.

BACKGROUND: Rice is a staple diet for many people, however, it is not a good source of micronutrients. The process of parboiling induces several desirable changes in rice: it improves the retention of available micronutrients, and in the case of low-amylose varieties it eases the cooking requirement. During parboiling of brown rice, when soaking is conducted in micronutrient-rich solutions, it affects fortification. This study is aimed at examining the suitability of the method of zinc fortification by a brown rice parboiling process in a low-amylose rice. RESULTS: Application of the method of zinc fortification by a brown rice parboiling process increased the zinc content in unmilled rice. Milling caused a reduction in zinc content per gram of grain, indicating a high concentration of zinc at the outer layer. Both milled and unmilled rice could retain more than 86% of zinc upon cooking. Changes in colour values in uncooked rice, due to zinc fortification, were non-significant at P ≤ 0.05. Rehydration of zinc-fortified rice at 60 °C for 25 min yielded hardness values similar to that of its cooked form. CONCLUSION: The method of zinc fortification by brown rice parboiling is a pragmatic way to produce zinc-fortified parboiled rice to combat zinc deficiency with a reduced cooking requirement from a low-amylose rice variety. © 2019 Society of Chemical Industry.

Sensitivity of fatty acid desaturation and elongation to plasma zinc concentration: a randomised controlled trial in Beninese children.

Zn status may affect fatty acid (FA) metabolism because it acts as a cofactor in FA desaturase and elongase enzymes. Zn supplementation affects the FA desaturases of Zn-deficient rats, but whether this occurs in humans is unclear. We evaluated the associations between baseline plasma Zn (PZn) concentration and plasma total phospholipid FA composition, as well as the effect of daily consumption of Zn-fortified water on FA status in Beninese children. A 20-week, double-blind randomised controlled trial was conducted in 186 school age children. The children were randomly assigned to receive a daily portion of Zn-fortified, filtered water delivering on average 2·8 mg Zn/d or non-fortified filtered water. Plasma total phospholipid FA composition was determined using capillary GLC and PZn concentrations by atomic absorption spectrometry. At baseline, PZn correlated positively with dihomo-γ-linolenic acid (DGLA, r 0·182; P=0·024) and the DGLA:linoleic acid (LA) ratio (r 0·293; P<0·000), and negatively with LA (r -0·211; P=0·009) and the arachidonic acid:DGLA ratio (r -0·170; P=0·036). With the intervention, Zn fortification increased nervonic acid (B: 0·109; 95 % CI 0·001, 0·218) in all children (n 186) and more so in children who were Zn-deficient (n 60) at baseline (B: 0·230; 95 % CI 0·023, 0·488). In conclusion, in this study, Zn-fortified filtered water prevented the reduction of nervonic acid composition in the plasma total phospholipids of children, and this effect was stronger in Zn-deficient children. Thus, Zn status may play an important role in FA desaturation and/or elongation.