Determination of Arsenic and It's Species in Dry Seafood by High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

Effects of Culinary Procedures on Concentrations and Bioaccessibility of Cu, Zn, and As in Different Food Ingredients

Although cooked diets are the primary sources for humans to absorb trace elements, there is limited data available on the concentrations and bioaccessibility of trace elements in cooked food ingredients. This work aims to evaluate the effects of culinary procedures on the concentrations and bioaccessibility of trace elements in common food ingredients. Twelve food species from the local market were treated with four culinary procedures (boiling, steaming, baking, and frying), then the bioaccessibility of copper (Cu), zinc (Zn), and arsenic (As) were evaluated using the in vitro digestion method. The subcellular distribution of these elements was also determined using the sequential fractionation method. The results show that culinary procedures decreased the retention rate of As during cooking (100% for raw and 65-89% for cooked ingredients) and the bioaccessibility of Cu and Zn during digestion (nearly 75% for raw and 49-65% for cooked ingredients), resulting in a reduction of the total bioaccessible fraction (TBF) of Cu, Zn, and As in food ingredients. The TBF of Cu, Zn, and As in all tested food ingredients followed the order: raw (76-80%) > steaming and baking (50-62%) > boiling and frying (41-50%). The effects of culinary procedures were associated with the subcellular distribution of trace elements. As was dominantly distributed in heat-stable proteins (51-71%), which were more likely to be lost during cooking. In comparison, Cu and Zn were mainly bound to the insoluble fraction and heat-denatured proteins (60-89% and 61-94% for Cu and Zn, respectively), which become less digestible in cooked ingredients. In conclusion, these results suggest that culinary procedures reduce the absorption of Cu, Zn, and As in various food ingredients, which should be considered in the coming studies related to nutrition and risk assessment of trace elements.

Recent Advancements in the Technologies Detecting Food Spoiling Agents

To match the current life-style, there is a huge demand and market for the processed food whose manufacturing requires multiple steps. The mounting demand increases the pressure on the producers and the regulatory bodies to provide sensitive, facile, and cost-effective methods to safeguard consumers' health. In the multistep process of food processing, there are several chances that the food-spoiling microbes or contaminants could enter the supply chain. In this contest, there is a dire necessity to comprehend, implement, and monitor the levels of contaminants by utilizing various available methods, such as single-cell droplet microfluidic system, DNA biosensor, nanobiosensor, smartphone-based biosensor, aptasensor, and DNA microarray-based methods. The current review focuses on the advancements in these methods for the detection of food-borne contaminants and pathogens.

Absorption and speciation of arsenic by microalgae under arsenic-copper Co-exposure

Combined pollutions of arsenic (As) and copper (Cu) are common in water bodies near mines, non-ferrous metal smelting and power plants. This study investigated the effect of Cu(II) on the absorption and speciation of As(V) by microalgae. We compared the absorption and speciation of arsenic by microalgae (mainly Cyanophyta and Chlorophyta) when exposed to single As(V) with that exposed to As-Cu co-exposure in laboratory. The results showed that in the case of single As(V) exposure, the inhibitory effect of As(V) on microalgae was primarily affected by the exposure time, instead of the concentration of As(V) in the water solution. Compared with single As(V) exposure, the presence of Cu(II) under As-Cu co-exposure promoted the absorption and accumulation of As(V) by algae. The combination effect of As and Cu on algae was antagonistic instead of synergistic within the tolerance range of algae to them. In the presence of Cu(II), more monomethylarsonous acid (MMA) and dimethylarsinous acid (DMA), which are volatile organic arsenic compounds, were produced in algae compared with the control. The finding that Cu(II) can mediate the absorption and speciation processes of arsenic in algae has significance in possible bioremediation of arsenic pollution in aquatic environment.

A novel aptasensor based on 3D-reduced graphene oxide modified gold nanoparticles for determination of arsenite

In this study, a sensitive aptasensor based on three-dimensional reduced graphene oxide-modified gold nanoparticles (3D-rGO/AuNPs) was fabricated for the determination of arsenite (As(III)). The 3D-rGO/AuNPs was fully characterized with various techniques. The 5'-thiolate aptamer was first self-assembled on a glassy carbon electrode (GCE) that it's modified with 3D-rGO/AuNPs via Au-S covalent bonding. In the presence of As(III), the G-quadruplex interaction was formed between a single-stranded DNA and the target, which produced a hindrance for electron transfer. Consequently, the electrochemical impedance spectroscopy signals of a GCE modified with 3D-rGO/AuNPs was increased. In order to improve the response of the designing aptasensor, the effect of the various parameters was optimized. Under the optimal conditions, the aptasensor has an extraordinarily low detection limit of 1.4 × 10^-7 ng mL^-1 toward As(III) with a dynamic range of 3.8 × 10^-7 3.0 × 10^-4 ng mL^-1. The 3D-rGO/AuNPs aptasensor displayed superior selectivity and reproducibility with an acceptable recovery for determination of As(III) in real water samples.