Formation Of Carcinogenic Compounds Research Articles

Antimicrobial stability of Cosmos caudatus extract at varies pH and temperature, and compounds identification for application as food sanitiser

The occurrence of foodborne diseases and food poisoning due to the consumption of contaminated foods is increasing nowadays, thus become a major threat to food industries in particular. In order to overcome this problem, prevention must be taken at the early stages of food preparation like sanitization. Typically, chemically based antimicrobial sanitisers were used in food industries to remove dirt and microbial population on food surfaces or food equipment. However, the emergence of microbial resistance and consumer awareness on the formation of carcinogenic compounds and safety issues in long term effects has led researchers to find an alternative. Therefore, a study was conducted to find a natural food sanitiser that was able to minimize the number of harmful bacteria without a change in the food quality and safety. In this study, the stability of Cosmos caudatus extract at different pH (pH 3, pH 7, pH 8 and pH 11) and temperatures (25°C, 30°C, 50°C, 80°C and 121°C) were determined for suitability as food sanitiser. The identification and quantification of this plant extract also were performed using HPLC and LC-MS/MS analysis to detect the major compounds which contributed to the biological activity of C. caudatus extract. Generally, results showed that the antimicrobial activity of C. caudatus extract was stable after exposure to various pH and temperatures, in fact, the extract increased its antimicrobial activity at lower acidity (pH 3) and higher temperature (50°C) against most pathogens. Furthermore, quercetin 3-O-rhamnoside was identified as a major compound in C. caudatus extract with the relative amounts of 29.66 mg/g. It can be concluded that C. caudatus extract is stable when exposed to various pH and temperatures. These useful findings have proved the antimicrobial stability of C. caudatus extract after exposure to several pH and temperatures thus can be further developed as a food sanitiser in food industries.

The incorporation of polysaccharides in grilled beef patties: influence on the levels of polycyclic aromatic hydrocarbons and heterocyclic aromatic amines

The effects of wheat fiber (1 and 2%) and the mixture of xanthan and guar gums (0.5%; 4:1) incorporations in beef patties on the levels of formed polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HCAs) were evaluated. In this regard, the samples were stored at − 18 °C during different storage times (days 0, 45, and 90) and then were grilled at 175 °C for 5 min. At day 0, a significant (P < 0.05) difference in the formation of PAHs and HCAs among treated beef patties and control samples was noted. The formation of carcinogenic compounds at day 0 was reduced while fiber and gums together were added. The highest reduction in PAHs and HCAs levels among treatments was related to benzo [b] fluorantene (36–42%) and 2-amino-3-methyl-imidazo [4, 5-f] quinoline (60–74%), respectively. Also, the frozen storage of samples for 45 and 90 days significantly (P < 0.05) caused an increase and decrease in the PAHs and in HCAs levels, respectively. Therefore, the incorporation the combination of wheat fiber (2%), xanthan and guar gums (0.5%) can be suggested as a promising strategy to reduce the levels of PAHs and HCAs in beef patties.

Interactions of preservatives in meat processing: Formation of carcinogenic compounds, analytical methods, and inhibitory agents.

Meat products are important for balanced diets because of their nutritional richness. However, noxious compounds may be formed by interactions among reactants and specific conditions in processed meats. N-nitroso compounds, heterocyclic aromatic amines, polycyclic aromatic hydrocarbons, 1,4-dinitro-2-methyl pyrrole (DNMP), and ethyl nitrolic acid (ENA) are among the main compounds of toxicological concern. This review corroborates the International Agency for Research on Cancer (IARC)'s decision to classify those foodstuffs as carcinogenic to humans. Furthermore, this paper also aimed at clarifying how noxious compounds are formed in meat products, as well as their health effects for consumers. The preservatives abuse and the use of forbidden additives may increase the formation of carcinogens. Risks are not only due to preservatives, since some compounds are formed during processing or digestion, without clear link to any additive. Regulation should set specific residue limits for other noxious compounds in meat products, such as DNMP and ENA. The scope of control programs should be extended instead of assessing the proper use of additives only. Thus, reliable analytical methods for the quantitation of carcinogens should be available. Fermentative and enzymatic processes for bioconversion are among the main strategies to solve these problems in foodstuffs. The use of antioxidants is the most common approach, because of its low cost and effectiveness. In the future, the IARC classification should rather consider different categories of processing, as well as the chemical and microbiological composition of meat products. Further studies are still required to clarify the increase on cancer risk due to the consumption of meat products and to elucidate the main mechanisms of carcinogenicity. Notwithstanding, such carcinogens cannot be neglected, but continuously investigated, including their health implications in relation to other foods.

P24: Effects of iodide on nitrite reduction by ascorbate and implications on nitrosoamine formation

Background Under acidic conditions of the stomach with gastric juice pH ranging from 1.7 to 2.6, nitrite is reduced to nitric oxide. When a diet rich in nitrate is consumed, it is partially reduced to nitrite in the mouth by oral bacteria followed by ingestion and partial reduction of nitrite to nitric oxide (NO) in the stomach. When the dietary nitrate is consumed along with protein, secondary amines from protein react with nitrite via the formation of reactive nitrogen species to form nitrosamines, which are carcinogenic. Ascorbic acid, also obtained from diet, can react with nitrite to form NO in the acidic gastric juice, which does not react with amines. Ascorbate has a protective effect on the formation of carcinogenic compounds like nitrosamines by reducing nitrite faster and out competing nitrosamine formation by reactive oxygen species and amines. Iodide can also reduce nitrite to NO in acidic pH, which is the basis of a nitrite assay used in nitric oxide analyzers. Although it has been suggested that dietary iodide would lead to increased nitrosamine formation the enhanced formation of NO from nitrite due to iodide suggests iodide would be protective against nitrosamine formation. Thus, the combined effect of ascorbate and sodium iodide in the presence of nitrite and amines under acidic conditions on nitrosamine formation was studied. Methods In this study the effect of ascorbic acid and sodium nitrite on nitrite reduction and nitrosamine formation was determined in vitro. Nitrite reduction to NO was determined under anaerobic conditions by ozone chemiluminescence by the Nitric Oxide Analyzer (NOA 280i, Sievers, GE Analytical Instruments, Boulder, CO). Nitrosamine concentrations were measured using absorption spectroscopy according to a modification of method by Mirvish et al., Science 175 (1972) 65–68. Results Both Iodide and ascorbic acid are effective in reducing nitrite to NO at the pH range that includes the pH of stomach. There is a synergistic effect of ascorbic acid and iodide on the rates of nitrite reduction to NO. Very low levels of nitrite are reduced to NO by either ascorbic acid or iodide alone. Nitrosomorpholine formation is reduced by iodide and ascorbate combined compared to ascorbic acid alone at pH 2. Conclusions The results indicate that, due to the increased rate of nitrite reduction byascorbic acid in the presence of iodide, nitrosation of morpholine to nitrosomorpholine can be reduced. Given that both nitrate and iodide are taken up by salivary glands and concentrated in the oral cavity, their combined effects on nitrosamine formation could have substantial impact. Disclosure This work was supported by NIH Grant HL058091.

Citrus Co‐Products as Technological Strategy to Reduce Residual Nitrite Content in Meat Products

Sodium or potassium nitrite is widely used as a curing agent in cured meat products because it inhibits outgrowth and neurotoxin formation by Clostridium botulinum, delays the development of oxidative rancidity, develops the characteristic flavor of cured meats, and reacts with myoglobin and stabilizes the red meat color. As soon as nitrite is added in the meat formulation, it starts to disappear and the nitrite that has not reacted with myoglobin and it is available corresponds to residual nitrite level. Health concerns relating to the use of nitrates and nitrites in cured meats (cooked and dry cured) trend toward decreased usage to alleviate the potential risk to the consumers from formation of carcinogenic compounds. Recently, some new ingredients principally agro-industrial co-products in general and those from the citrus industry in particular (albedo [with different treatments], dietetic fiber obtained from the whole co-product, and washing water used in the process to obtain the dietetic fiber) are seen as good sources of bio-compounds that may help to reduce the residual nitrite level in meat products. From these co-products, citrus fiber shows the highest potential to reduce the residual nitrite level, followed by the albedo and finally the washing water. The aim of this article is to describe the latest advances concerning the use of citrus co-products in meat products as a potential ingredient to reduce the nitrite level.

Impact of plant essential oils on microbiological, organoleptic and quality markers of minimally processed vegetables

The objectives of this study were to evaluate the efficacy of plant essential oils (EOs) for control of the natural spoilage microflora on ready-to-eat (RTE) lettuce and carrots whilst also considering their impact on organoleptic properties. Initial decontamination effects achieved using EOs were comparable to that observed with chlorine and solution containing oregano recorded a significantly lower initial TVC level than the water treatment on carrots (p < 0.05). No significant differences were found between the EO treatments and chlorine considering gas composition, color, texture and water activity of samples. The sensory panel found EO treatments acceptable for carrots throughout storage, while lettuce washed with the EO solutions were rejected for overall appreciation by Day 7. Correlating microbial and sensory changes with volatile emissions identified 12 volatile quality markers. Oregano might be a suitable decontamination alternative to chlorine for RTE carrots, while the identification of volatile quality markers is a useful complement to sensory and microbiological assessments in the monitoring of organoleptic property changes and shelf-life of fresh vegetables. Industrial relevance: There is industrial demand for natural alternatives to chlorine, which is commonly used for decontamination of fresh produce but which has limitations with respect to antimicrobial efficacy and possible formation of carcinogenic compounds in water. Plant essential oils have proven antimicrobial and other bioactive properties, however their usefulness in foods can be mitigated by their high sensory impact. This study examined the application of EOs for fresh produce decontamination addressing control of spoilage microflora and improving shelf-life characteristics whilst also considering the impact on organoleptic properties. The effectiveness of oregano as a decontamination treatment was comparable with that of chlorine. Carrot discs treated with the EO regimes were acceptable in terms of sensory quality and appreciation, therefore oregano could offer a natural alternative for the washing and preservation of fresh produce. Combining EOs with other natural preservatives might minimize doses and reduce the impact on organoleptic properties of fresh vegetables. © 2008 Elsevier Ltd. All rights reserved.

Role of commercial sanitizers and washing systems on epiphytic microorganisms and sensory quality of fresh-cut escarole and lettuce

Increasing concerns about the possible formation of carcinogenic compounds and the emergence of new, more tolerant pathogens, have raised questions on the use of chlorine in fresh-cut produce. There is a growing need to investigate the efficacy of new commercial sanitizing and other alternative technologies. In the present study, the effectiveness of chlorine and other commercial sanitizer agents (Sanova, Sanoxol 20, Tsunami 100, Purac FCC 80, Citrox 14W and Catallix) was evaluated on epiphytic microorganisms and their influence on the sensory quality of fresh-cut escarole and lettuce. Different sanitizer concentrations (manufacturer's recommended dose and half of this dose) and application systems (submersion and spray) were also compared. The antimicrobial efficacy of the treatments was evaluated, initially after washing, and after 8 days of storage simulating a commercial shelf-life (3 days at 4 °C + 5 days at 8 °C). All the tested washing solutions were more effective in reducing the microbial load than water washes, particularly in fresh-cut escarole. However, the microbial load of fresh-cut escarole and lettuce after 8 days of storage was very similar for most of the treatments despite the different application systems and concentrations of the sanitizers. Clearly epiphytic microorganisms of fresh-cut escarole and lettuce were able to grow rapidly during storage under low temperature, reaching similar or higher values than the unwashed fresh-cut produce at the day of production. The overall visual quality of fresh-cut salad leaves was scored as good or very good (≥6) after 8 days of storage, except for the product washed with Purac. Thus, despite the high number of mesophilic bacteria present in the product, between 6 and 8 log cfu g −1, it was not associated with a detrimental quality. Therefore, the determination of the initial epiphytic reductions of fresh-cut products after washing with different sanitizing agents provides little information about the microbial or sensory quality of the product at the time of consumption.

BIOLOGICAL DENITRIFICATION OF GROUNDWATER

Nitrate concentrations in groundwater have increased in many areas of the world. This causes serious concerns because of the link found between nitrate and the blue-baby syndrome, and of the possible formation of carcinogenic compounds in the digestive tract. Biological denitrification, bacteria-mediated reduction of nitrate to nitrogen gas, is a method used in the treatment of nitrate contaminated groundwater. The denitrifying microorganisms require carbon and energy substrates which may be organic or inorganic compounds. Treatment can take place in the aquifer (in situ treatment) or in above ground reactors. Numerous biological denitrification processes have been reported; this paper reviews some of this work and studies in progress in the author's laboratory. The choice of a biological denitrification system has to be considered on an individual basis. Although preventive measures are curbing the problem in some developed countries, nitrate pollution is still on the rise in many other countries. Innovative, low-cost biological denitrification processes are specially needed in developing countries.

A clean coal conversion technology

Technical feature:The Ralph M. Parsons Co. and the U.S. Dept. of Energy are developing preliminary designs and economic evaluations of commercial coal conversion facilities. The commercial designs already completed include a Fischer-Tropsch facility producing liquid hydrocarbons plus substitute natural gas by indirect coal liquefaction. More specifically, this facility will produce carbon dioxide-carbon monoxide-hydrogen syngas, which will then be purified and converted into hydrocarbon liquids. Part of the unreacted syngas will be upgraded to substitute natural gas by methanation. The Parsons design incorporates advanced technology and satisfies strict environmental requirements. Major pollution abatement efforts include: desulfurization of gases generated during coal conversion; removal of acid gases; and a combination of recycling and discharge of aqueous effluents. Of particular concern is the possible formation of carcinogenic compounds in coal tar. (2 diagrams, 1 drawing, 2 tables)