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Enzymes Fundamentals
Published in Sulaiman Al-Zuhair, Hanifa Taher, Supercritical Fluids Technology in Lipase Catalyzed Processes, 2016
Sulaiman Al-Zuhair, Hanifa Taher
The flour component that affects a dough’s rheological properties is the gluten protein. This plays a key role in providing the required quality of wheat by producing water absorption capacity, viscosity, elasticity, and cohesiveness. Generally, the quality of bread making is determined by the quality of the gluten. Gluten proteins consist of monomeric gliadins, connected by disulfide bonds (Wieser, 2007). During mixing and molding the dough, SS bonds are formed and broken between gluten proteins. When this take place, it leads to good dough development, and strong gluten networks are formed. Usually, chemical oxidants such as bromide are used to support bond formation and improve the flour. Nevertheless, it has been reported that adding bromate can have hazardous effects, thus it has been forbidden in many countries (Corrales et al., 1993). To find a substitute for bromate, ascorbic acid, commonly known as vitamin C, was considered and used as a flour improver in spite of it being less effective than bromate (Ranum, 1992). Due to concerns about using chemical oxidizing agents, the food industry searched for natural alternatives with a higher specificity. Enzymes that denaturate during baking have been proposed. Oxidoreductases have a beneficial effect on dough development and dough quality, where the latter influences other parameters such as volume, texture, and the crumb structure of baked products (Joye et al., 2009; Vemulapalli et al., 1998).
Nanocatalysts Based in Zeolites for Environmental Applications
Published in Vanesa Calvino-Casilda, Antonio José López-Peinado, Rosa María Martín-Aranda, Elena Pérez-Mayoral, Nanocatalysis, 2019
Isabel Correia Neves, António M. Fonseca, Pier Parpot
Bromate (BrO3−) is a stable, water-soluble inorganic contaminant with very low volatility and it has been classified as possibly carcinogenic to humans by the World Health Organization (WHO) and the United States Environmental Protection Agency (EPA). This ion is produced from the ozonation or chlorination of bromide-containing water (Freitas et al. 2015), while the nitrate (NO3−) ion, which is harmful to the mammalian organisms, is accumulated in water due to the excessive agricultural fertilizers and insufficient treatment of domestic and industrial effluents (Jung et al. 2014; Hamid et al. 2017; Vorlop and Prüsse 1999). Nitrate is transformed into ammonium (NH4+) and partially into nitrite ion (NO2-), which is responsible for the blue baby syndrome, and is also a precursor to the carcinogenic nitrous amine (Pintar 2003) by the action of living organisms. The agencies mentioned above established the maximum limits for nitrates in drinking water as 50 (WHO) and 25 mg/L (EPA) (Barrabés et al. 2006).
Chemical health risks
Published in Blanca Jiménez, Joan Rose, Urban Water Security: Managing Risks, 2009
Inés Navarro, Francisco J. Zagmutt
Many other factors influence water quality in urban cities. Different types of water treatment systems modify the composition of water in diverse manners. For example, ozone treatment, applied to remove pesticides, may lead to the formation of bromate from the bromide in the raw water (Bates, 2000). Water in the distribution system is subject to potential contamination from exposure to the elements and the nature of the materials through which the water is transported. Moreover, water use, consumption patterns and individual diet varies and affects a person’s potential exposure to contaminants.
Bromate Removal from Water Using Ion Exchange Resin: Batch and Fixed Bed Column Performance
Published in Ozone: Science & Engineering, 2023
Safal Mestri, Sedar Dogan, Chedly Tizaoui
Several health effects have been reported on ingestion of large amounts of bromate such as nausea, vomiting, abdominal pain, diarrhea, as well as effects on the kidney and nervous system (New York State Department of Health 2017). Some effects are reported as irreversible such as hearing loss and renal failure (WHO 2005). Bromate has also been proved to induce follicular cell tumors of thyroid and renal cell tumors which led to categorizing bromate as a potential carcinogen under certain dose conditions by the United States Environmental Protection Agency (US EPA). One significant research has also suggested that bromate induces oxidative stress from intracellular within kidney cells leading to DNA damage (WHO 2005) and chronic exposures to bromate cause testicular mesothelial and thyroid tumors in rats (Delker et al. 2006). Based on the assumptions about human cancer risks and toxic effects, EPA and World Health Organization (WHO) have promulgated a bromate concentration level of 10 μg/L in drinking water (WHO 2005; Yang, Dong, Jiang, Wang, Liu 2019a). The same bromate concentration limit was proposed by the European Commission and China (Delker et al. 2006; JRC 2016).
Bromate formation control by enhanced ozonation: A critical review
Published in Critical Reviews in Environmental Science and Technology, 2022
Ruchi Joshi, Thunyalux Ratpukdi, Kristofer Knutson, Amit Bhatnagar, Eakalak Khan
Although EOPs are efficient for the degradation of organic contaminants, undesired by-products are produced, particularly bromate (BrO3−) from the oxidation processes, thus limiting their applications (von Gunten, 2018). Bromate is a well-known by-product of ozone and ozone-based EOPs. Bromate concentrations ranging from 0.4 to 60 µg L−1 were reported in ozonated bromide-containing water (Butler et al., 2005). Since bromate is categorized as a suspected human carcinogenic compound, the maximum contaminant level (MCL) for bromate in drinking water is 10 µg L−1 in several countries (Jin et al., 2006; European Economic Commission, 1998; Health Canada, 2016; US EPA, 2006). Therefore, bromate formation is an important aspect to be considered when applying EOPs.
Bromate removal from water by acid activated and surfactant enriched Red Mud – the case of cooling water
Published in Environmental Technology, 2020
Fivos A. Megalopoulos, Maria T. Ochsenkuehn-Petropoulou
Bromate, a potential human carcinogen [1], has been detected in treated drinking and industrial waters with background bromide presence. Both the US EPA and the European Union have established a maximum contaminant level of 10 μg/L for bromate in drinking water [2,3]. Bromate can be formed during ozonation [4–6] or chlorination [7] of bromide containing source water. In cooling water treatment practice, bromate can be introduced to the circuit during chlorination [8] or be formed after application of bromine-based disinfection schemes. Bromine (in the form of hypobromous/hypobromite) is often employed when alkaline waters are treated and conventional hypochlorite is less effective. It is usually produced in situ after mixing solutions of hypochlorite and sodium bromide [9]. In the cooling circuit, bromate formation is attributed to hypobromous/hypobromite decomposition in the presence or absence of residual chlorine in the form of hypochlorous/hypochlorite [10]: