Aflatoxin and Food Safety: Recent South American Perspectives

South America (SA) is predominantly a tropical and subtropical continent and provides environmental conditions favorable for fungus growth on food crops, especially the species Aspergillus flavus and A. parasiticus. Depending on the grain and weather conditions in certain regions of SA, high levels of aflatoxins (AFLs) can be produced during harvesting or storage. That is a real problem in most of the continent. South American economies rely upon government policies to address issues of food safety. As expected, the exporting countries must comply with the standards and regulations that are implemented by the importing country. Thus, the highest quality and safest commodity food products are sold internationally. Conversely, food for internal consumption does not meet the same high quality standards compared with exports. Some SA governments have established food safety guidelines and regulations for AFL control in national food supplies. Research is currently being conducted to determine the levels of naturally occurring AFLs in a range of locally processed foods. These countries include: Brazil, Argentina, Colombia, Venezuela, and Uruguay, the main grain exporting countries in SA. Most contaminated food commodities in SA include peanut and peanut products, followed by corn. The regions most affected by AFL contamination in SA include mainly the peanut‐producing countries of northern SA as well as Brazil, Argentina, Uruguay, and Paraguay. Aflatoxin contamination of feeds and foodstuffs seems greater in Colombia and Ecuador. On the other hand, AFLs in corn is high in Venezuela. This review summarizes work published on AFLs throughout the previous decade. While most of the research has been performed in Brazil, Argentina, and Uruguay, other SA countries including Colombia and Venezuela also have played an important role in AFL research. Conversely, few studies on AFLs have been performed in Bolivia, Chile, Ecuador, and Peru, and no studies have been done in French Guyana, Guyana, Paraguay, and Suriname. There is a lack of data on the SA population exposure to AFLs, either using biomarkers or by evaluating the incidence of hepatocellular carcinoma (HCC) and its relation to AFLs in SA diets.     

田菁及其与硫酸铵混合施用时水稻对肥料氮和土壤...

应用标记15_M的田菁和硫铵进行一季水稻盆栽试验的结果表明,1.田菁和硫铵单独施用,田菁氨素的17.6％和41.8％分别为稻秆和谷粒利用,硫铵氨素的分别为15.1％和29.0％。这两种肥料氮在谷粒中分布的比例较大,稻杆和谷粒对田菁氨的利用率都高于硫铵氮.2.施用硫铵有促进水稻吸收土壤氨素的作用,比不施氨对照增加71.8％;相反,施用田菁减弱了水稻对土壤氨的吸收,比对照减少37.1％。3.田菁和硫铵混合施用,除了可使水稻对田菁氨的吸收增加(5.2％)。对硫铵氨的吸收减少(5.3％)外,亦有促进水稻增加吸收土壤氨素的作用,4.与硫铵单独施用的结果相比,这两种肥料混合施用,可以在消耗较少量土壤氨素的基础上,更好地维持水稻生长所需的氨营养供应。     

Evaluation of arsenic levels in grain crops samples, irrigated by tube well and canal water

The aim of this study was to evaluate the uptake of arsenic (As) by grain crops (wheat, maize and sorghum) grown on agricultural soil irrigated with tube well water (SIT) as test samples and for comparative purposes, same grain crop samples grown on agricultural soil irrigated with fresh canal water (SIC) were marked as control samples, collected simultaneously from three sub-districts of Khairpur, Pakistan. Moreover, this paper demonstrated the total and EDTA (0.05 M) extractable As in both understudied soils that correlate with the respective total As in the edible parts of the studied grain crops. A significantly high accumulation of As was found in grains grown on SIT as compared to those grown on SIC. This study highlights the increased danger of growing food crops in the agricultural land continuously irrigated by As contaminated ground water.     

Influence of processing on trichothecene levels

Trichothecene mycotoxins frequently occur in cereal grains that are intended for food production. The process of converting grains into food and drinks for consumers has significant effects on the levels of toxins in the final food. Surveillance of retail food and drinks of cereal origin demonstrates that trichothecenes do survive the production processes employed. Trichothecenes are relatively heat stable chemicals, with high water solubility, properties that affect their processing fate. It is known that the extent of transmission into final food products is dependent on the pattern of Fusarium infection in the grains. For dry-milled products, the most highly contaminated fractions are those that contain the whole or the outer portions of the grain. For wet milling, the trichothecenes primarily transfer to the aqueous fractions, the most contaminated streams enter the animal food chain, although there is no evidence of significant trichothecenes transmission into animal products. However, anomalies remain in the understanding of the processing effects of several major cereal processes used in European food production (e.g. baking and brewing).     

Compositional analyses of white,brown and germinated forms of popular Malaysian rice to offer insight into the growing diet-related diseases

Diet-related metabolic diseases, and especially obesity, are metabolic disorders with multifactorial aetiologies. Diet has been a cornerstone in both the aetiology and management of this metabolic disorders. Rice, a staple food for over half of the world's population, could be exploited as part of the solution to check this menace which has been skyrocketing in the last decade. The present study investigated nine forms of rice from three widely grown Malaysian rice cultivars for in vitro and in vivo (glycaemic index and load) properties that could translate clinically into a lower predisposition to diet-related diseases. The germinated brown forms of MRQ 74 and MR 84 rice cultivars had high amylose content percentages (25.7% and 25.0%), high relative percentage antioxidant scavenging abilities of 85.0% and 91.7%, relatively low glycaemic indices (67.6 and 64.3) and glycaemic load (32.3 and 30.1) values, and modest glucose uptake capabilities of 33.69% and 31.25%, respectively. The results show that all things being equal, rice cultivars that are germinated and high in amylose content when compared to their white and low amylose counterparts could translate into a lower predisposition to diet-related diseases from the dietary point of view in individuals who consume this cereal as a staple food.     

Estimated Dietary Exposure to Mycotoxins after Taking into Account the Cooking of Staple Foods in Japan

Mycotoxins are commonly present in cereal grains and are not completely destroyed during their cooking and processing. When mycotoxins contaminate staple foods, the risk for exposure becomes serious. In East Asia, including Japan, rice is consumed as a staple food, and with the increasingly Westernized lifestyle, the consumption of wheat has increased. The mycotoxins commonly associated with rice and wheat are total aflatoxin (AFL) and ochratoxin A (OTA), respectively. This study examined the retention of AFL and OTA during the cooking of rice and pasta. AFL was retained at 83%–89% the initial level after the cooking of steamed rice. In pasta noodles, more than 60% of the OTA was retained. These results show that AFL and OTA are relatively stable during the cooking process, suggesting that a major reduction in the exposure to these mycotoxins cannot be expected to occur by cooking rice and pasta. The estimated exposure assessment at the high consumer level (95th percentile) and the mycotoxin contamination level determined by taking into account these reductions in the present study should be useful for the establishment of practical regulations for mycotoxins in staple foods.     

A 90-day toxicology study of high-amylose transgenic rice grain in Sprague–Dawley rats

A transgenic rice line (TRS) with high amylose level has been developed by antisense RNA inhibition of starch branching enzymes. Compositional analysis of TRS demonstrated that the content of resistant starch (RS) was significantly higher compared to conventional non-transgenic rice. High level of RS is an important raw material in food industry and has various physiological effects for human health. In order to provide the reliable theory basis for field release of TRS rice, we evaluated the potential health effects of long-term consumption of the TRS. The 90-day toxicology feeding experiment was conducted in Sprague–Dawley rats fed with diets containing 70% of either TRS rice flour, its near-isogenic rice flour or the control diet. The clinical performance variables (body weight, body weight gain and food consumption) were measured and pathological responses (hematological parameters and serum chemistry at the midterm and the completion of the experiment, urinalysis profile and serum sex hormone response at the completion of the experiment) were performed. Besides, clinical signs, relative organ weights and microscopic observations were also compared between TRS group and its near-isogenic rice group. The combined data indicates that high-amylose TRS grain is as safe as the conventional non-transgenic rice for rat consumption.     

A two-generation reproduction study with transgenic Bt rice TT51 in Wistar rats

TT51 is a transgenic Bt rice created by fusion a synthetic CryAb/CryAc gene into rice MingHui63. A significant number of animal feeding studies with transgenic crops have been carried out with the rapid development of transgenic crops. However, the evidence is far from identifying whether certain novel transgenic crops possess potential danger for human or animal health after long-term consumption. Rice-based diets, containing 60% ordinary grocery rice, MingHui63 rice or TT51 rice by weight, were fed to two generations of male and female rats in order to determine the potential reproductive effects of TT51. In this study, both clinical performance variables and histopathological responses were examined and compared between groups. There were no significant differences between groups on body weights, food consumption, reproductive data and relative organ/body weights. There were some statistically significant differences in hematology and serum chemistry parameters, but no histological abnormalities were seen in the brain, heart, liver, spleen, kidneys, stomach, small intestine, thymus, ovaries, uterus, testes and epididymides. Based on the results, under the circumstance of this study TT51 show no significant differences on reproduction performance of rats compared with MingHui63 and the control.     

Risk assessment to humans of mycotoxins in animal-derived food products

This paper addresses approaches for assessing potential human health hazards from the presence of natural toxicants, such as mycotoxins, in animal food products. At high levels in feed these mycotoxins may cause loss or illness of farm animals, through development of animal toxicoses, such as aflatoxicosis. At lower levels in feed these mycotoxins may have no apparent effect on livestock production, but their residues and related substances may move up the food chain. This indirect intake of mycotoxins and related substances from the consumption of animal food products may pose a health hazard to humans. These health hazards are compared to the possible health hazards from the direct intake by humans of cereal and other food crops that may contain mycotoxins.     

Acute and Sublethal Effects of a Non-Ionic Surfactant, Genapol OXD-080, on Mosquitofish Gambusia holbrooki (Girard)

Application of the biodegradable non-ionic surfactant Genapol OXD-080, a fatty alcohol polyglycol ester, in rice paddies has been considered as a method to mitigate damage caused by the Louisiana red swamp crayfish, Procambarus clarkii, to rice crops. The damages are a consequence of crayfish digging activities. The acute and sublethal effects of Genapol on a non-target key species were examined to assess the potential risk of contaminating the irrigation channels following its application in the rice paddies. Mosquitofish, Gambusia holbrooki, due to its abundance in irrigation channels, and because it is a predator with an intermediate position in the food chain, was selected as the key non-target species. The LC50 value for Genapol to mosquitofish was 2.9 mg l^-1, a value 17.2 times lower than the Genapol concentration needed to decrease crayfish digging activity (50 mg l^-1). For sublethal tests, three biological parameters were considered in laboratory experiments with mosquitofish: respiratory metabolism, food (energetic) consumption, and clutch survival. A significant decrease in the resting metabolism of mosquitofish was observed, even when Genapol exposure concentrations were very low (e.g., 0.75 mg l^-1). Thus, oxygen consumption rates of mosquitofish are strongly affected by to the presence of this surfactant in water. In contrast, mosquitofish food consumption and clutch survival seemed not to be affected by sub-lethal concentrations of Genapol. Yet, sub-lethal effect concentrations for mosquitofish are so much lower than the concentration necessary to decrease significantly crayfish activity, we conclude that there is a reasonable potential risk of damaging local mosquitofish populations if contamination of the irrigation channels with Genapol occurs.     

Occurrence,Impact on Agriculture,Human Health,and Management Strategies of Zearalenone in Food and Feed: A Review

Mycotoxins represent an assorted range of secondary fungal metabolites that extensively occur in numerous food and feed ingredients at any stage during pre- and post-harvest conditions. Zearalenone (ZEN), a mycotoxin categorized as a xenoestrogen poses structural similarity with natural estrogens that enables its binding to the estrogen receptors leading to hormonal misbalance and numerous reproductive diseases. ZEN is mainly found in crops belonging to temperate regions, primarily in maize and other cereal crops that form an important part of various food and feed. Because of the significant adverse effects of ZEN on both human and animal, there is an alarming need for effective detection, mitigation, and management strategies to assure food and feed safety and security. The present review tends to provide an updated overview of the different sources, occurrence and biosynthetic mechanisms of ZEN in various food and feed. It also provides insight to its harmful effects on human health and agriculture along with its effective detection, management, and control strategies.     

Safety assessment of consumption of glabrous canary seed (Phalaris canariensis L.) in rats

Canary seed is a nutrient-rich cereal grain; however, it has not been used in human food in part due to concerns regarding safety of consumption. Glabrous or hairless canary seed has potential human food use as trichomes are absent. The objective of the oral feeding studies reported here was to assess the safety of yellow and brown glabrous canary seed cultivars as human cereal foods. The first study was a 90-day rat oral toxicity study, which compared the effects of diets containing 50% of either brown dehulled glabrous, brown hulled glabrous, or brown hulled pubescent (hairy) hulled canary seed to a diet containing 50% wheat. No significant adverse effects were observed. In a 28-day and a 90-day study rats were fed yellow or brown glabrous canary seed groats in the AIN-76 diet at concentrations levels of 2.5%, 5% and 10%. The NOAELs in 90-day study were 5.15 g/kg/d and 5.23 g/kg/d for yellow and brown canary seed groats. Consumption of canary seed was associated with reduced incidence and severity of liver lipidosis as compared to controls. The combined results of these studies clearly demonstrate the safety of consumption of glabrous canary seed, and support its use as a human cereal grain.     

Safety assessment of foods from genetically modified crops in countries with developing economies

Population growth particularly in countries with developing economies will result in a need to increase food production by 70% by the year 2050. Biotechnology has been utilized to produce genetically modified (GM) crops for insect and weed control with benefits including increased crop yield and will also be used in emerging countries. A multicomponent safety assessment paradigm has been applied to individual GM crops to determine whether they as safe as foods from non-GM crops. This paper reviews methods to assess the safety of foods from GM crops for safe consumption from the first generation of GM crops. The methods can readily be applied to new products developed within country and this paper will emphasize the concept of data portability; that safety data produced in one geographic location is suitable for safety assessment regardless of where it is utilized.     

Characterization of Two O.-Methyltransferase-like Genes in Barley and Maize

Abstract

Tricin (3′,5′-dimethoxy-5,7,4′-trihydroxyflavone) is a characteristic flavone constituent of cereal grain plants that is credited for a variety of potential health benefits to humans. We have characterized the flavone-specific O.-methyltransferase genes of barley (Hordem vulgare. L., Gramineae), HvOMT1,. and maize (Zea mays. L., Gramineae), ZmOMT1., whose gene products use the flavone tricetin (5,7,3′,4′,5′-pentahydroxyflavone) as the preferred substrate and give rise to its 3′,5′-dimethyl derivative, tricin, as the major product. The fact that homologous enzymes catalyze the same reaction also in wheat and rice suggests the existence in cereal grain plants of a flavone-specific O.-methyltransferase multigene family. The natural occurrence of tricin in most monocot species implies the widespread occurrence of this gene family. The pharmacological significance of tricin as a naturally occurring constituent with a potential use as a nutraceutical, and the application of metabolic engineering methods to obtain tricin-enriched cereal grain products, are discussed.     

Concentrations of perfluoroalkyl substances in foods and the dietary exposure among Taiwan general population and pregnant women

This study quantified five perfluorocarboxylic acids (PFCAs) and two perfluorosulfonic acids in cereals, meats, seafood, eggs, pork liver, and milk in Taiwan using ultra-performance liquid chromatography-tandem mass spectrometry and evaluated the dietary exposure of the general population and pregnant women using per capita consumption and a questionnaire, respectively. Perfluorooctanoic acid (PFOA) and PFCAs of 10–12 carbons were found in almost all of the samples in considerable concentrations in rice and pork liver, reaching as high as 283 ng/g (PFOA in pork liver); the levels are two to three orders of magnitude higher than previous reports. Perfluorooctane sulfonate (PFOS), the most frequently mentioned perfluoroalkyl substance, was rarely detected in many food items (detection frequencies <20% in rice, flour, pork, chicken, salmon, squid, eggs, and milk) at <0.4 ng/g, except for beef, pork liver and some seafood (detection frequencies: 100%, GMs: 0.05–3.52 ng/g). Compared to populations in Western countries, people in Taiwan are exposed to much more perfluorohexanoic acid, PFOA, perfluorodecanoic acid, and perfluoroundecanoic acid (11.2, 85.1, 44.2, and 4.45 ng/kg b.w./day, respectively), mainly due to the higher contaminations in food. The exposure of 8.0 μg PFOA/person/day in the 95 percentile of pregnant women was due to their frequent consumption of pork liver.     

Long-term toxicity study on transgenic rice with Cry1Ac and sck genes

In the present work, we evaluated the chronic effects of the transgenic insect-resistant rice carrying Cry1Ac and sck genes on Sprague–Dawley (SD) rats through a 78-week feeding study. Based on the gender and weight, 180 SD rats were randomly and evenly assigned into three groups. GM rice and non-GM rice were separately formulated into diets at high levels. AIN-93 diet was used as a nutritional control. Body weight, food consumption, hematology and serum chemistry were monitored regularly. Rats were sacrificed for organ weight measurement and pathological examination at 52 weeks and 78 weeks. Body weight, food consumption, mortality rates, tumor incidences and pathological findings showed no significant difference among the three groups. Although certain differences in some hematology, serum chemistry parameters and relative organ weights were observed between GM rice group and control groups, they were not considered as treatment-related. Taken together, long-term intake of transgenic rice carrying Cry1Ac and sck genes at a high level exerts no unintended adverse effects on rats.     

Quantitative Modeling of Climate Change Impacts on Mycotoxins in Cereals: A Review

Our climate is projected to change gradually over time. Mycotoxin occurrence in cereal grains is both directly and indirectly related to local weather and to climate changes. Direct routes are via the effects of precipitation, relative humidity, and temperatures on both fungal infection of the grain and mycotoxin formation. Indirect routes are via the effects of the wind dispersal of spores, insect attacks, and shifts in cereal grain phenology. This review aimed to investigate available modeling studies for climate change impacts on mycotoxins in cereal grains, and to identify how they can be used to safeguard food safety with future climate change. Using a systematic review approach, in total, 53 relevant papers from the period of 2005–2020 were retrieved. Only six of them focused on quantitative modeling of climate change impacts on mycotoxins, all in pre-harvest cereal grains. Although regional differences exist, the model results generally show an increase in mycotoxins in a changing climate. The models do not give an indication on how to adapt to climate change impacts. If available models were linked with land use and crop models, scenario analyses could be used for analyzing adaptation strategies to avoid high mycotoxin presence in cereal grains and to safeguard the safety of our feed and food.     

Impact of sedimentary arsenic through irrigated groundwater on soil, plant, crops and human continuum from Bengal delta: Special reference to raw and cooked rice

Existence of arsenic-rich (exceeds 2,000 mg/kg) iron pyrite in Bengal delta sediments is responsible for arsenic release in aquifer. Ingestion of contaminated drinking water is not the only elevated source of arsenic to the diet. Irrigation of agricultural fields with arsenic-contaminated groundwater has led to arsenic build-up in soil, with subsequent elevation of arsenic in crops grown on these soils. About 50.7 and 11.2 kg of arsenic are withdrawn per year from 23 and 18 shallow tubewells, used for agricultural irrigation in the studied two districts Murshidabad and Nadia, respectively and deposited on lands throughout the year. Considerable higher amounts of arsenic are accumulated in paddy plants. Mean arsenic concentration in food categories is 107 microg/kg. Arsenic concentrations are high in cooked food and skin of the vegetables. Arsenic concentration in cooked rice increases with water arsenic concentration. About 70.2% of arsenic is recovered by using the analytical speciation extraction method. Inorganic arsenic and DMA contribute 89.5% and 10.5% of the total content of arsenic in food, respectively. About 0.081% and 1.57% of arsenic are accumulated in rice grain from arsenic-deposited lands and contaminated soils. The daily dietary intake of inorganic arsenic (mug/kg body wt./day) by an adult from rice grain itself (2.32) is higher than the WHO recommended PTDI value of inorganic arsenic (2.1) and inorganic arsenic contributes 96.8% of the total dietary intakes of arsenic. Population exposed to arsenic toxicity has been identified.     

Mycotoxins Exposure in Cabinda,Angola—A Pilot Biomonitoring Survey of Breastmilk

Breast milk is considered the ideal form of nutrition for newborns and infants. However, it can carry over contaminants, namely mycotoxins, with biological effects to which this population is particularly vulnerable. Human biomonitoring and surveillance programs are particularly scarce in low-income countries, where food security is a more urgent priority in comparison with food safety. This pilot survey aims to assess exposure of breastfed infants to aflatoxin M1 (AFM1), zearalenone (ZEN), and ochratoxin A (OTA) in Angola, and to evaluate the main socio-demographical and food consumption determinants of lactating mothers. All 37 breast milk samples analyzed are found to be contaminated with ZEN and OTA, although none are found contaminated with AFM1. Contamination levels are lower than previously reported for ZEN but higher in the case of OTA. A significant association between ZEN levels in breast milk and the consumption of cookies by the lactating mothers is found. As for OTA, higher levels are observed in the milk from mothers with younger infants, for which high estimated daily intake (EDI) is determined. As far as the authors are aware, this is the first survey of the occurrence of mycotoxins in breast milk in Angola, so further human biomonitoring works should follow, given that mycotoxins are a global health issue that directly impact the health of populations.