Aflatoxin M1: Prevalence and decontamination ...

http://informahealthcare.com/mby ISSN: 1040-841X (print), 1549-7828 (electronic) Crit Rev Microbiol, Early Online: 1–10 ! 2015 Informa Healthcare USA, Inc. DOI: 10.3109/1040841X.2014.958051

REVIEW ARTICLE

Aflatoxin M1: Prevalence and decontamination strategies in milk and milk products Critical Reviews in Microbiology Downloaded from informahealthcare.com by University Of Massachusetts on 05/12/15 For personal use only.

Amir Ismail1, Saeed Akhtar1, Robert E. Levin2, Tariq Ismail1, Muhammad Riaz1, and Mamoona Amir1 1

Department of Food Science and Technology, Bahauddin Zakariya University, Food Science and Technology, Multan, Pakistan and Department of Food Science, University of Massachusetts Amherst, MA, USA

2

Abstract

Keywords

Aflatoxin M1 (AFM1) in milk is among the most carcinogenic compounds, relatively high levels being consumed, especially by the most vulnerable age groups, i.e. infants and the elderly. Reports on its prevalence are constantly being received from various parts of the world compelling nations to establish their own standard limits for AFM1. Global review of the literature indicates the existence of methods of partial decontamination of AFM1, however; evidence based studies do not suggest that any single strategy as a coherent and complete solution to the issue. Microbial decontamination of AFM1 has emerged as the most suitable method up to now but the stability of toxin-microbial cell complexes still remains questionable. This review discusses the chemical nature, established maximum permissible limits and prevalence of AFM1 in various countries from 2009 to 2014. Moreover, the possible mechanisms for AFM1 reduction mainly the microbial decontamination and the stability and bioaccessibility of microbial-AFM1 complexes are also discussed.

Bioaccessibility, carcinogenic, mechanism, standard limits, vulnerable

Introduction Aflatoxins are the secondary metabolites of molds including Aspergillus flavus, Aspergillus parasiticus, Aspergillus nomius, Aspergillus fumigatus and Aspergillus tamari. Deaths of thousands of turkeys on account of feeding on groundnut meal heavily attacked by molds in 1960s, lead to the discovery of aflatoxins (Eaton & Groopman, 1994). Aflatoxins are found in a number of food commodities such as cereals, dried fruits, milk, peanuts and cottonseeds and are frequently reported in the developing countries due to their suitable environmental and social conditions (Issazadeh et al., 2012; Pitt, 2000). Aflatoxins identified from feed and food have been classified and listed on the basis of their toxicity, some major aflatoxins on toxicity grounds are B14G14B24G2. Milk animals through their feed are intoxicated with aflatoxin B1 (AFB1) and B2 (AFB2) which are transformed into aflatoxin M1 (AFM1) and M2 (AFM2), respectively, in the liver of animals from where these become part of their milk (Abbas et al., 2004). The International Agency for Research on Cancer (IARC) of WHO (2002a,b) referred AFM1 as 10-fold less toxic than AFB1 but still categorized it as a group 1 human carcinogen on the basis of its toxicity and prevalence levels in milk. AFM1

Address for correspondence: Dr Muhammad Riaz, Department of Food Science and Technology, Bahauddin Zakariya University, Boson Road, Multan 60800, Pakistan. E-mail: [email protected]

History Received 24 June 2014 Revised 20 August 2014 Accepted 21 August 2014 Published online 8 April 2015

(MW 328.27 Da) and AFM2 (MW 330.29 Da) are C4 hydroxylated metabolites of AFB1 and AFB2, respectively, in the liver of animals through cytochrome P450 enzymes (Paniel et al., 2010). A number of factors govern the conversion of aflatoxin B1 into aflatoxin M1 such as breed, diet, health, digestion rate and lactation stage of animal (Duarte et al., 2013). The extent of AFB1conversion into AFM1 varies greatly and ranges from 0.3% to 6.2% (Var & Kabak, 2009). AFM1 possess a high affinity for milk’s protein fractions particularly casein and therefore its concentration in cheese is higher than that of the milk from which it is derived (Kamkar et al., 2008; Prandini et al., 2009). Milk is defined as the lacteal secretion of animals that is suckled by their offspring’s and is the only food for them during the first few months of their lives (Galvano et al., 1996). The presence of a wide array of easily accessible and biologically available macro- and micro-nutrients makes milk a primary source of nutrition for humans and other young mammals. The per capita consumption of milk estimated by FAO in the year 2009 is 50.70 kg (FAO, 2014). Exceptionally higher quality and safety standards are required for this highly demanded delicate food commodity for peoples of all ages particularly for the vulnerable age groups. The level of aflatoxins in milk varies greatly with season, animal breed, infection history and history of feed and milking time (Anfossi et al., 2011). These toxins are normally detected after 12–24 h of AFB1 and AFB2 contaminated feeding (Battacone et al., 2003; Prandini et al., 2009) while if the contaminated feed is terminated the toxin reaches an

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undetectable level after 72 h (Rahimi & Karim, 2008). The concentration of AFM1 has been reported higher in winter as compared to summer season, while morning milk is found to have a higher percentage of toxin than evening milk. The possible reasons behind the higher AFM1 level in winter include favorable temperature and moisture for toxin production in harvested and stored feed in contrast to open grazing of animals in the summer season, while lack of activity could be the reason for the higher toxin percentage in morning milk (Asi et al., 2012; Bilandzic et al., 2014; Hussain & Anwar, 2008). Worldwide prevalence of cancer has increased up to 32.6 million with 8.2 million recorded deaths in 2012 (Ferlay et al., 2013). Aflatoxins are strongly being linked with hepatocellular carcinoma (Wild & Gong, 2010) which is reported as the third leading cause of cancer related mortality (WHO, 2008) and for this very reason milk and milk products are strictly being monitored for the presence of AFM1. Higher per capita milk consumption rates and possible toxicity threats from AFM1 has directed the attention of recent researchers to identify possible strategies for decontamination of milk. Although various methods have been adopted so far including the treatment of milk with heat, nanoparticles and microbial cells, not a single method has been observed to completely eliminate the contaminant from food systems. The most suitable way to protect food from aflatoxin contamination is the improvement of agricultural practices and better storage conditions, which on a practical basis appears very difficult, particularly for developing countries. Therefore, scientists and researchers are endeavoring to find safe, cost effective, environmental friendly and efficient methods for aflatoxin decontamination. Negligible or minor effects of heat degradation of AFM1 residues in milk has been suggested by some research groups, however some more effective strategies like microbial decontamination for reducing residual levels of AFM1 has also been recently proposed (Bakirci, 2001; Choudhary et al., 1998; Corassin et al., 2013; Deveci, 2007; Govaris et al., 2001; Kabak & Ozbey, 2012; Serrano-Nino et al., 2013). This review is a response to the worldwide development in AFM1 prevalence, surveillance and decontamination strategies. Exploration of advanced research data on AFM1 prevalence, toxicity and counter strategies to decontaminate the toxin consolidates the need for a critical appraisal that has not yet been undertaken according to the best of our knowledge. This review comprehensively discusses the nature and toxicity of AFM1, latest work on prevalence levels of AFM1 in milk, maximum permissible limits for AFM1 in various countries, degradation of AFM1 particularly through microbial means and the stability of microbial–AFM1 complexes.

Health impacts of AFM1 Initially AFM1 was categorized as group 2B human carcinogen (IARC, 1993) but later on, with the accumulation of scientific knowledge related to the toxicity of AFM1, it was reclassified as group 1 human carcinogen (IARC, 2002a,b). AFM1 is both an acute and chronic toxin whose absorption takes place in small intestine from where it further goes to the

Crit Rev Microbiol, Early Online: 1–10

liver (Prandini et al., 2009). Although, it is less toxic than its parent compound, i.e. AFB1, it is a serious health concern for the potential milk consumers of low immunity levels, more specifically for children under 6 years and the elderly people. Moreover, AFM1 does not require any sort of prior activation in contrast to its parent compound (Klich et al., 2000). The major target organ of AFM1 toxicity in human beings is the liver. Clinical studies on the metabolism of AFM1 in rat models and human cell line systems have revealed the inability of liver microsomal system to metabolize the toxin (Neal & Colley, 1978; Neal et al., 1998). The studies on AFM1 linkage with hepatitis had shown that the carriers of hepatitis were more prone towards hepatocellular carcinoma if they were fed foods contaminated with aflatoxins (Giolo et al., 2012; Sun et al., 1999). Worldwide 0.55–0.60 million cases are reported for hepatocellular carcinoma each year and out of these around 0.025–0.15 million cases are due to aflatoxins (Liu & Wu, 2010). AFM1 possesses a direct toxic behavior on cultured human cell line systems (Caloni et al., 2006). In a broader prospect, AFM1 has been documented to be a human carcinogen (IARC, 2002a,b), a cytotoxin (Neal et al., 1998), teratogenic (Sassahara et al., 2005) and a genotoxic agent (Lafont et al., 1989; Shibahara et al., 1995). Legislation Due to the serious health impacts of aflatoxins, they are highly being observed in food imports and exports. AFM1, since its declaration as human carcinogen by the IARC (2002a,b), is particularly monitored by regulatory bodies and the agencies have imposed stringent limiting standards in comparison with the 20 ppb specified limit of other mycotoxins in foods (Serrano-Nino et al., 2013). The maximum permissible limit for AFM1 varies greatly from country to country (Table 1) depending on the developmental and economic condition of a country. A number of factors are involved in setting legal limits for mycotoxins such as AFM1 including availability of survey data for the toxic compounds, data regarding the level of toxin contamination in various commodities and the methods of analysis. Other influential factors could be the economic condition and political situation such as business prospects and the adequacy of the food supply. More or less all the developed countries have set maximum permissible limits for AFM1 while most of the developing countries are relying on the legal limits set by international agencies like Codex Alimentarius Commission (2001) and European Union (EU, 2006). The legal limit for AFM1in milk ranges from 0.05 ppb as adopted by EU and Codex Alimentarius Commission and as high as 0.5 ppb adopted by Brazil and Serbia. The lenient standard limits for AFM1 adopted by many of the developing countries could be linked with the higher prevalence rate of liver cancer in developing countries of Asia and Africa and vice versa for the developed countries of Europe and America (Jemal et al., 2010). The maximum limit of AFM1 for mother’s milk established by EU is 25 ng/L (Adejumo et al., 2013). The data presented in Table 1 shows that the most stringent rules for AFM1 contamination in milk are adopted by the EU. Countries including France, Australia and Germany are

Aflatoxin M1

DOI: 10.3109/1040841X.2014.958051

Table 1. Maximum permissible limits of aflatoxin M1 for milk and milk-products followed in various countries.

Country European Union


USA Switzerland Australia Germany Belgium Sweden France Iran

China Turkey

Netherlands Brazil Japan India Morocco

Maximum permissible limit (ppb) 0.05 0.25 0.50 0.05 0.25 0.02 0.05 0.05 0.05 0.05 0.05 0.05 0.20 0.02 0.05 0.05 0.50 0.05 0.025 0.05 0.02 0.20 0.50 0.50 0.50 0.05 0.50

Type of product

References

Milk Cheese Milk Milk Cheese Butter Milk Milk Milk Milk Milk Milk Cheese Butter Yoghurt Ice cream Milk Milk Cheese

European Union (2006) Elkak et al. (2012) Ertas et al. (2011) Dashti et al. (2009) Dashti et al. (2009) Dashti et al. (2009) Fallah (2010) Fallah (2010) Fallah (2010) Fallah (2010) Dashti et al. (2009) Sani et al. (2010) Mohajeri et al. (2013) Fallah (2010) Fallah (2010) Fallah (2010) Xiong et al. (2013) Bakirci (2001) Sarimehmetoglu and Kuplulu (2004) Yoghurt Atasever et al. (2011) Butter Fallah (2010) Cheese Fallah (2010) Milk Dashti et al. (2009) Milk Han et al. (2014) Milk Siddappa et al. (2012) Milk Zinedine et al. (2007) Powdered Milk Zinedine et al. (2007)

following the standard limits of the toxin set by the EU. However, many of the developing countries have more flexible permissible limits for AFM1 than that of the EU possibly due to economic constraints and lack of scientific and consumer based knowledge. Prevalence of AFM1 AFM1 in milk and milk products is frequently being reported throughout the world particularly in developing countries. The prevalence of AFM1 around the globe from the year 2009 to 2014 in various milk products is summarized in Table 2. Prevalence in milk The maximum prevalence of AFM1 has been reported in the developing economies, specifically the African countries where the levels of the toxin in milk and milk products were found alarming (Table 2). Considering the EU limits for AFM1 as standards, nearly 100% of the samples of milk and milk products studied in Nigeria and Sudan were reported to contain exceptionally higher levels of AFM1 than the stated norms (Suliman & Abdalla, 2013; Susan et al., 2012). A health and food survey of 112 Nigerian children of whom 79 were experiencing protein energy malnutrition were reported with the risk of AFM1 toxicity through contaminated milk. Extremely dangerous levels of AFM1 were reported in the milk samples fed to protein energy malnourished and healthy children of Nigeria (Onyemelukwe et al., 2012). Earlier studies from Pakistan also reflect the same picture of food safety, indicating that 94% of the milk possessed AFM1

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levels higher than EU tolerable limits (Hussain & Anwar, 2008). Almost parallel trends of AFM1 prevalence in milk were suggested by Sefidgar et al. (2011) and Panahi et al. (2011) validating 100% of raw and pasteurized milk samples in Iran carrying the contaminant at higher than prescribed EU standards. A study conducted in India by Siddappa et al. (2012) measured the level of AFM1 in raw, pasteurized and UHT milk samples and found 48.8% raw, 42.8% pasteurized and 64.4% UHT milk samples exceeding the EU maximum permissible limits for AFM1. The major reasons behind the high incidence of AFM1 in developing countries could be farmer and consumer unawareness, economic and technological constraints and suitable environment for optimum growth of toxin producing fungus. Better control over AFM1 toxicity in developed nations may be associated with strong food and feed standards, strict vigilance systems, law enforcement, standards, technological advancements, farmer and consumer awareness and unfavorable environmental conditions for toxin production (Cano-Sancho et al., 2010; Ertas et al., 2011). Prevalence in cheese The presence of AFM1 in cheese might be associated with the use of aflatoxin contaminated raw or powdered milk for cheese manufacturing or due to the fungus that grows on cheese (Mohammadi, 2011). AFM1concentration in cheese has always been found to be high perhaps due to the fact that AFM1 has strong affinity for casein proteins in milk. The caseins being the major portion of cheese proteins establishes linkages with AFM1 consequently the complexes between AFM1 and caseins develop larger structures showing insolubility in water. This is one of the factors associated with the deposition of AFM1 in cheese hence compelled the countries to establish their maximum residue limits (MRL) for cheese much higher as compared to raw milk. The European Union has established 0.25 ppb MRL for cheese (Prandini et al., 2009). The effect of storage on various types of cheese is reported diverse, some cheese types show no effect of storage, some show increase in beginning and a later on decrease while some show decrease in content (Brackett & Marth, 1982; Govaris et al., 2001; Oruc et al., 2007). Fallah et al. (2009) determined the level of AFM1 in white cheese (n ¼ 72) in Iran and found 30.5% samples exceeding the EU limits. In another study conducted in Iran by Mohajeri et al. (2013), AFM1 level was measured in two cheese types, i.e. white (n ¼ 45) and Lighvan (n ¼ 37) cheese, and found 64.4 and 10% samples exceeding the EU limits, respectively. AFM1 level in cheese was also found below the standard limits in Greece (Kaniou-Grigoriadou et al., 2005). In Kuwait, 40 cheese samples were analyzed for AFM1 content out of which only one sample exceeded the EU limits (Dashti et al., 2009). In Lebanon, 12% of the total cheese samples collected from small local industries were found exceeding the EU limits while none of the imported or large local industry cheese sample was found exceeding the limits. Situation indicate a stringent quality monitoring system being observed by progressive milk processing industries as a major factor to maintain toxin levels below the critical limits (Elkak et al., 2012).

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Table 2. Aflatoxin M1 prevalence in various countries from 2009 to 2014.

Year

Region

Commodity

2009

Saudi Arabia

2009 2009 2010 2010

Serbia Iran Sri Lanka Iran

2010 2010 2010 2010

Iran Iran Pakistan Spain

2010 2011

Thailand Turkey

2011 2011 2011 2011 2011

Turkey Iran Iran Iran Egypt

2011

Lebanon

2012 2012 2012

Turkey Palestine Iran

2012 2012

Iran Pakistan

2012 2012 2012 2012

Iran Saudi Arabia Lebanon India

2012

Nigeria

2013 2013 2013 2013 2013 2014

Iran Iran Greece Sudan China Sudan

2014

South Africa

Milk Cheese Milk Cheese Raw Milk Milk Yoghurt Cheese Milk Milk Milk UHT Milk Yoghurt Cheese Milk Milk Yoghurt Dairy desserts Cheese Yoghurt Milk Milk Raw Milk Raw Milk Pasteurized Milk Milk powder Yogurt Milk Yoghurt Milk Milk Yoghurt Cheese Ice cream Mother Milk Milk Sweets Yoghurt Milk Cheese Milk Pasteurized Milk UHT Milk Fresh Milk Skimmed Milk Partially Skimmed milk Cheese Milk Milk Milk Milk Milk Milk Powder Rural Milk Commercial Milk

2014 2014 2014

Serbia China Croatia

Cow Milk Milk Cow Milk Goat Milk

Total samples

Positive samples

Range (ppb)

%Samples exceeding EU limit

177 40 90 210 87 91 68 72 210 196 84 72 72 72 240 50 50 50 60 80 72 100 122 48 37 19 22 64 64 40 40 40 40 40 8 232 138 60 96 111 45 7 45 10 10 10

176 32 90 161 29 66 45 59 116 196 68 68 2 0 240 43 28 26 38 70 72 100 122 37 8 5 17 28 21 8 34 14 16 12 8 177 134 59 79 61 45 3 29 10 10 10

ND–0.069 0.024–0.452 0.001–0.067 ND–0.79 ND–0.085 ND–0.250 ND–0.119 ND–1.200 ND–0.25 0.02–0.13 ND–100.04 ND–0.013 ND–0.051 – 0.014–0.197 ND–0.03 ND–0.08 ND–0.08 ND–0.38 ND–0.48 0.18–0.25 0.068–0.13 0.004–0.11 ND–0.14 ND–0.07 ND–0.02 ND–0.09 – – ND–0.076 ND–0.08 ND–0.12 ND–0.51 ND–0.2 0.007–0.011 ND–1.9 ND–1.5 ND–0.087 ND–0.19 ND–0.32 0.001–3.8 ND–3.8 ND–2.1 0.407–0.952 0.248–2.510 0.139–1.238

5.60 30.00 8.00 24.00 9.00 36.20 20.60 30.50 33.00 80.60 81.00 0.00 1.00 0.00 64.50 0.00 14.00 10.00 5.00 20.00 100.00 100.00 15.00 – – – – 17.00 6.00 5.00 20.00 0.00 18.00 0.00 0.00 32.00 78.00 63.00 0.00 17.00 49.00 43.00 64.00 100.00 100.00 100.00

82 90 196 143 72 35 12 125

39 56 91 143 43 35 12 107

ND–0.31 ND–0.131 – 0.018–0.086 ND–0.42 0.1–2.52 0.01–0.85 ND–0.20

12.00 31.00 1.00 99.00 24.00 100.00 50.00 81

85 150 200 337 32

85 148 45 337 32

0.01–0.20 ND–1.20 ND–0.06 0.003–0.162 0.003–0.04

86 86.00 1.5 6.70 0.00

The study of the distribution pattern of AFM1 in whey, curd and cheese made from milk naturally contaminated with AFM1 showed that in comparison with milk the level of toxin increased in curd and cheese by 3- and 4.5-fold, respectively, while it decreased in whey by 40% (Manetta et al., 2009).

References Dashti et al. (2009) Polovinski-Horvatovic´ et al. (2009) Fallah et al. (2009) Pathirana et al. (2010) Fallah (2010) Heshmati & Milani (2010) Sani et al. (2010) Muhammad et al. (2010) Cano-Sancho et al. (2010) Ruangwises & Ruangwises (2010) Ertas et al. (2011)

Atasever et al. (2011) Sefidgar et al. (2011) Panahi et al. (2011) Kamkar et al. (2011) Ayoub et al. (2011)

Khoury et al. (2011) Kabak & Ozbey (2012) Zuheir & Omar (2012) Nilchian & Rahimi (2012) Ghiasain & Maghsood (2012) Sadia et al. (2012) Issazadeh et al. (2012) Abdallah et al. (2012) Elkak et al. (2012) Siddappa et al. (2012) Susan et al. (2012)

Mohajeri et al. (2013) Darsanaki et al. (2013) Tsakiris et al. (2013) Suliman & Abdalla (2013) Xiong et al. (2013) Ali et al. (2014) Mulunda & Mike (2014) Kos et al. (2014) Han et al. (2014) Bilandzic et al. (2014)

Prevalence in yoghurt Yoghurt is a lactic acid fermentation product of milk and is consumed all over the world (Tamime & Robinson, 2007). It has been reported that the level of AFM1 is usually lesser in yoghurt as compared to that found in the milk used for its

Aflatoxin M1

DOI: 10.3109/1040841X.2014.958051

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which is much higher than the permissible limits (Atanda et al., 2007). Prevalence in mothers milk


Figure 1. Chemical structure of aflatoxin M1 (Durakovic´ et al., 2011).

manufacturing. The possible reasons for decrease of AFM1 in yoghurt are the lactic acid bacteria (Fallah, 2010; Khoury et al., 2011), the low pH of the yoghurt and the formation of organic acids (Nilchian & Rahimi, 2012). The lactic acid bacteria bind AFM1 with their surface and detoxify it. However, the phenomenon of effect of low pH and organic acids to reduce the AFM1 content is not clear yet. Atasever et al. (2011) determined the level of AFM1 in 80 yoghurt samples in Turkey using ELISA technique and found 87.5% samples positive for AFM1 while 20% samples exceeded the Turkish limits for yoghurt (0.05 ppb). In Portugal, the level of AFM1 was measured through HPLC in 96 yoghurt samples, 18.8% of the total samples were found AFM1 positive while 6.25% samples exceeded the limits (Martins & Martins, 2004). In Iran AFM1 was measured through ELISA in pasteurized (n ¼ 40) and local yoghurt (n ¼ 10) and found 100% samples contaminated with AFM1, however only two samples were found exceeding the Iranian limit for AFM1 (0.05 ppb; Barjesteh et al., 2010). Sylos et al. (1996) determined the level of AFM1 in 30 yoghurt samples and reported the absence of toxin in all of the tested samples. The explanation provided for the absence of this toxin was the open grazing of cows in Brazil. Prevalence in butter The concentration of AFM1 in butter is based on the constituting milk’s level of toxin. In a study conducted in Turkey by Tekinsen & Ucar (2008) the level of AFM1 was determined in 92 butter samples. Alarmingly, 100% samples were found positive for AFM1 while 28% samples exceeded the maximum limit of 0.05 ppb established by Codex Alimentarius Commission. In another study conducted in Iran, 31 samples of butter were tested for AFM1 out of which 26% samples were found positive for AFM1, while 9.6% samples exceeded the Iranian standard limit of 0.02 ppb for AFM1 in butter (Fallah, 2010). Prevalence in ice cream A little data is published regarding the prevalence of AFM1 in ice cream. In a study conducted in Iran by Darsanaki et al. (2013) AFM1 content was measured in ice cream samples (n ¼ 90). They found 69% samples positive for AFM1 while 12% samples had toxin level beyond the permissible limits (0.05 ppb). The situation is worse in Nigeria where the mean AFM1 level recorded for ice cream samples was 2.23 ppb

Translocation of AFM1 in mother’s milk has been reported, referring to the systemic nature of the toxin eventually becoming a serious health threat for the infants and children on breast feeding. In Jordan, the average concentration of AFM1 recorded in mother’s milk was 0.067 mg/kg (Omar, 2012), much higher than the permissible limit (25 ng/L). In another study conducted in Nigeria, 82% mother milk samples were found contaminated with AFM1 of which 16% exceeded the EU limits (Adejumo et al., 2013). In an exceptional study from Iran, researchers have also reported minimal levels of AFM1 prevalence in a population of 136 samples of mother milk (Afshar et al., 2013). The presence of AFM1 in mother’s milk indicate that the mothers are consuming the aflatoxin containing diet mainly the dairy products and cereal foods (Omar, 2012). Estimated daily intake of AFM1 The safe limit for daily intake of AFM1 as reported by Cano-Sancho et al. (2010) is 1 ng/kg body weight. The review of various reports (Table 2) indicates that the estimated daily intake of this toxin is under the safe limit except in some countries especially Brazil. However, due to the severity of consequences, serious attempts are still required to maintain the toxin below the threshold level. The estimated daily intake (EDI) for AFM1 in Spain was reported to be 0.358– 0.434 ng/kg body weight for infants while for adults it was reported to be 0.08–0.1 ng/kg of body weight (Cano-Sancho et al., 2010). On the basis of milk consumption levels, the EDI value for AFM1 in Brazil reported by Shundo et al. (2009) for children and adults was 1.04 and 0.19 ng/kg body weight, respectively. The EDI of AFM1 in France reported by Leblanc et al. (2005) for children and adults was 0.09 ng/kg body weight and 0.22 ng/kg body weight, respectively. The EDI forAFM1 in Latin America reported by JECFA (2001) was 0.058 ng/kg body weight. The EDI for AFM1 in Lebanan by consuming various dairy products was estimated 0.14 ng/kg body weight (Hassan & Kassaify, 2014). Detection methods Different analytical techniques in use for detection of AFM1 in milk and milk products include enzyme-linked immunosorbent assay (ELISA), high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). The application of these techniques to achieve higher levels of accuracy in analytical results appears to require various degrees of enhanced sensitivity and safety besides rapidity and cost effectiveness. Higher analytical costs of AFM1 are one of the reported reasons for unavailability of surveillance data in the majority of developing countries (Trucksess, 2001). The most frequently adopted method worldwide for the detection of AFM1 is the ELISA. Due to its high sensitivity towards detection as well as quantification of AFM1, easy handling and low cost, ELISA could be suggested as an appropriate analytical tool (Cano-Sancho et al., 2010; Darsanaki et al., 2013; Khoury et al., 2011).

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The shortcomings of ELISA method are time consuming incubation, washing and mixing steps. HPLC is used as a confirmatory tool for AFM1 detection after initial detection with ELISA or sometimes also with TLC. In addition to these well-reviewed and documented, some less commonly engaged methods for the detection and quantification of AFM1 in milk and milk products are mass spectrophotometric (Sorensen & Elbaek, 2005), immunosensor based (Bachera et al., 2012) and spore based enzyme assays (Singh et al., 2013).


Decontamination of AFM1 Being a toxic compound the AFM1 is highly monitored and continuous research is being done to sort out a commercially implementable and widely accepted decontamination method for AFM1. Microwave heating of milk artificially contaminated with AFM1 was also found ineffective (Smajlovic et al., 2012) after the failure of series of experiments for AFM1 decontamination by employing heat (Awasthi et al., 2012; Bakirci, 2001; Govaris et al., 2001; Hassan & Kassaify, 2014; Sadeghi et al., 2013). Decontamination of AFM1 with clay particles without affecting the nutritional properties of milk has been investigated more recently. Saponite-rich bentonite was found as an effective clay material for the removal of AFM1 below the standard limits. It was further revealed that the clay retained the nutritional composition of milk while its residues in milk were in so much low quantity (0.4%) that they had no significant effect on the human health (Carraro et al., 2014). Bio-decontamination of AFM1 was frequently studied in the recent past to identify the food protection role of microorganisms. Microbial binding of AFM1 prevents absorption of this toxin in small intestine and the toxin goes untreated to large intestine and excreted. Numerous studies conducted around the globe validated microbial decontamination of AFM1 as the most promising strategy due to their effectiveness, specificity and environmental friendly behavior to reduce or eliminate possible contamination by aflatoxins in food and feed. Furthermore, application of membrane filters could also be evaluated as a safe strategy to remove the AFM1 bounded dead microbial cells from decontaminated milk. Numerous microbes have been studied to determine their aflatoxin binding potentials, but scientists are unable to execute a fully reliable and commercially implementable method for AFM1 decontamination in milk so far. Microbial decontamination of AFM1 The binding of AFM1 with microbial cells has been reported as a rapid decontamination process where the moieties come into instantaneous contact with each other with a minimum of 108 CFU/ml (Kabak & Var, 2008; Serrano-Nino et al., 2013). The exact mechanism of binding between AFM1 and microbial cells is not fully established. However; the most widely accepted hypothesis regarding the mechanism involved in the microbial removal of AFM1 and other mycotoxins is the adhesion of toxin molecules with cell components such as proteins and polysaccharides present in the cell wall or peptidoglycan. Metabolism and covalent bounding is not involved in microbial binding with such toxins since dead microbial cells also possess this binding ability (Kabak & Var,


2008; Peltonen et al., 2001; Santin et al., 2003). The variable binding percentages of AFM1 by microbial cells are thought to be due to differences in the structure of cell walls and membranes, incubation time and temperature, AFM1 levels and pH (Khoury et al., 2011; Bovo et al., 2012). Lactic acid bacteria are the most frequently employed AFM1 binding agents in milk, due to their generally recognized as safe (GRAS) status, higher binding abilities and wide distribution in nature. Commercial strains of Lactobacillus and Streptococcus have been found to reduce AFM1 level in phosphate buffered saline (PBS), milk and yoghurt with variant binding capacities. Lactobacillus bulgaricus CH-2 and Streptococcus thermophilusST-36 were reported to bind 29% AFM1 in milk samples whereas; quite higher levels of AFM1 microbial decontamination (59%) were reported in yoghurt after an incubation period of 6 h (Ayoub et al., 2011; Khoury et al., 2011; Sarimehmetoglu & Kuplulu, 2004). Serrano-Nino et al. (2013) used five probiotic strains to investigate the role of their binding abilities with AFM1 in PBS. They found cell–toxin complexes in the range of 19.95–25.43% but interestingly the binding abilities of some strains were observed maximum after 4 h and a reduction after 12 h. More recently Elsanhoty et al. (2014) also reported that some strains of lactic acid bacteria had the potential to bind AFM1 and can lower the toxin level up to the safe limits. They also reported that the AFM1 content decreases by decreasing the pH of spiked broth. Being a potential determinant of milk quality, bacterial viability results in milk spoilage by fermentation. Utilization of viable bacterial cells for AFM1 decontamination could render product spoilage. Hence dead cells are exploited for binding AFM1 in milk and milk products. Surprisingly higher binding efficiency of heat killed cells, i.e. 46% was reported in PBS and skimmed milk medium as compared to viable cells where the AFM1 binding rate was 26.65–33.54%. The effect of contact times between microbes and toxin in the binding efficiencies of microbes was found to be nonsignificant (Bovo et al., 2012; Kabak & Var, 2008). The maximum microbial and AFM1 binding percentage has been reported by Corassin et al. (2013). The study reported a pool of three heat killed lactic acid bacteria (LAB), Saccharomyces cerevisiae and a combination of these two, possessed binding percentages of AFM1 in skim milk as 11.7, 92.7 and 100%, respectively. The combination of Saccharomyces cerevisiae and LAB pool was found to be most effective for binding capability; however the stability of the binding and percentages of bioaccessibility for AFM1 were not calculated which calls for further investigations by employing the same strains. Stability of microbial cell–AFM1 complex The stability of the complex between toxin and microbial cell is of paramount importance as far as the bioavailability of AFM1 is concerned. The effectiveness of toxin decontamination can be assumed to reflect the stability of the toxin– microbial cell complexes. A stable complex ensures the excretion of toxins from the human gut without resulting in any health loss to the body. The binding complex between AFM1 and microbial cells can be reversed during milk

Aflatoxin M1


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7

processing or its digestion in the human body. Hence, stability testing of the complex is of prime importance. The mechanism involved in the release of AFM1 after washing is still under investigation, however, it is suggested that a weak noncovalent complex is formed between AFM1 and microbial cell components, such that toxins are released easily by washing with PBS (Serrano-Nino et al., 2013). The differences in the amounts of bounded toxin released after washing could be due to strain differences in the binding sites of microbes or due to the cross linked interactions between the aflatoxin molecules present in the cell walls of two different bacteria (Hernandez-Mendoza et al., 2009). The data reported regarding the amount of AFM1 released after washing ranges from as low as 1.4–8.5% (Kabak & Var, 2008; Serrano-Nino et al., 2013) to as high as 40–87% (Bovo et al., 2012). However, it is important to note that despite variations, all the tested strains showed some sort of toxin release after washing steps indicating the weakness of binding between microbial cells and AFM1. The Bifidobacterium bifidum NRRL B-41410 strain has been found to result in the most stable AFM1 microbial complex up to now with merely a 1.4% reduction of AFM1 after washing with PBS (Serrano-Nino et al., 2013).

launched for milk producers and processors regarding the prevalence of AFM1, its sources, consequences and ways to block its entry in milk. The decontamination of AFM1 is still an unresolved issue and supplemental studies are required for understanding the mechanism of AFM1 binding with microbial cells, the genetic characteristics of microbes involved in binding and stability of the complex formed. The use of the human digestive model to calculate the bioaccessibility of AFM1 bound with microbial cells can be a very useful tool for understanding the real fate of this toxin in the human body. The inclusion of microbial cells for AFM1 binding could further be preceded by the removal of AFM1–microbial cell complexes through specially designed membrane filters to avoid the release of toxin in the human body. Studies are also needed to fully understand the roles of various variables such as incubation temperature and concentrations of bacterial cells in the toxin binding abilities of microbial cells. The use of experimental animals for efficacy studies can also prove valuable in identifying a remedy for AFM1. Further in vivo experiments should be performed for the evaluation of binding abilities of microbial cells before their commercial application in the dairy industry.

Bioaccessibility of AFM1

Acknowledgements

Bioaccessibility of a toxin is the amount of toxin available from contaminated food for intestinal absorption (Versantvoort et al., 2005). Bioaccessibility of aflatoxins depends on a number of factors, such as mode of entry, extent of contamination and type of food being contaminated (Kabak et al., 2009). Bio-accessibility of AFM1 is reduced with the formation of complexes of microbial cells and toxins. The percent bioaccessibility of a toxin depends on a number of factors including the nature of the binding agent and the complex generation conditions, e.g. pH and temperature (Bovo et al., 2012; Khoury et al., 2011). The bioaccessibility of AFM1 was first determined by Kabak & Ozbey (2012) who used six viable strains of probiotic bacteria to explore the reduction patterns of AFM1 using an in vitro digestion model having imitated gastrointestinal conditions. They observed 15.5–31.6% reduction in bioavailability of AFM1 in comparison with the control. The bioaccessibility of AFM1 in naturally contaminated and spiked milk samples ranged from 81.7% to 86.3% and 80.5% to 83.8%, respectively. Probiotic bacteria such as Lactobacillus rhamnosus, Lactobacillus acidophilus, Lactobacillus bulgaricus and bifidobacteria are focused on by researchers due to their claimed health benefits. The formation of AFM1 and live probiotic microbial cell complexes in human digestive models reduced bioaccessibility of AFM1 by 45.17% (Serrano-Nino et al., 2013). The study further validated survival of tested probiotic strains in the digestion process.

This review is a part of the PhD studies of Mr. Amir Ismail being carried out under the supervision of Dr Muhammad Riaz, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan, Pakistan. Higher Education Commission, Islamabad-Pakistan is highly acknowledged for providing a mammoth funding under the project number 1932 for the study.

Future research needs and conclusion AFM1 is widely spread in milk and milk products particularly in the developing countries. The lenient legislations for AFM1 adopted by developing countries are presumably resulting in higher rates of liver cancer; therefore, strict regulations should be adopted by all countries regarding the control of this highly toxic compound. Awareness programs should be

Declaration of interest The authors declare no conflicts of interest. The authors alone are responsible for the content and writing of this paper.

References Abbas HK, Zablotowics RM, Locke MA. (2004). Spatial variability of Aspergillusflavus soil populations under different crops and corn grain colonization and aflatoxins. Can J Bot 82:1768–75. Abdallah MIM, Bazalou MS, Al-Julaifi MZ. (2012). Determination of aflatoxin M1 concentrations in full-fat cow’s UHT milk sold for consumption in Najran-Saudi regarding its public health significance. Egypt J Appl Sci 27:40–54. Adejumo O, Atanda O, Raiola A, et al. (2013). Correlation between aflatoxinM1 content of breast milk, dietary exposure to aflatoxin B1 and socioeconomic status of lactating mothers in Ogun State, Nigeria. Food Chem Toxicol 56:171–7. Afshar P, Shokrzadeh M, Kalhori S, et al. (2013). Occurrence of ochratoxin A and aflatoxin M1 in human breast milk in Sari, Iran. Food Control 31:525–9. Ali MAI, El-Zubeir IEM, Fadel-Elseed AMA. (2014). Aflatoxin M1 in raw and imported powdered milk sold in Khartoum State, Sudan. Food Addit Contam B 7:208–12. Anfossi L, Baggiani C, Giovannoli C, Giraudi G. (2011). Occurrence of aflatoxin M1 in Dairy Products. In: Torres-Pacheco I, ed. Aflatoxins – detection, measurement and control, 3–20. Rijeka, Croatia: InTech. Asi MR, Iqbal SZ, Arino A, Hussain A. (2012). Effect of seasonal variations and lactation times on aflatoxin M1 contamination in milk of different species from Punjab, Pakistan. Food Control 25:34–8. Atanda O, Oguntubo A, Adejumo O, et al. (2007). Aflatoxin M1 contamination of milk and ice cream in Abeokuta and Odeda local governments of Ogun State, Nigeria. Chemosphere 68:1455–8.


8

A. Ismail et al.

Atasever MA, Atasever M, Ozturan K. (2011). Aflatoxin M1 levels in retail yoghurt and ayran in Erzurum in Turkey. Turk J Vet Anim Sci 35:59–62. Awasthi V, Bahman S, Thakur LK, et al. (2012). Contaminants in milk and impact of heating: an assessment study. Indian J Public Health 56: 95–9. Ayoub MM, Sobeih AMK, Raslan AA. (2011). Evaluation of aflatoxin M1 in raw, processed milk and some milk products in Cairo with special reference to its recovery. Researcher 3:5–11. Bachera G, Pala S, Kanungoa L, Bhand S. (2012). A label-free silver wire based impedimetric immunosensor for detection of aflatoxin M1 in milk. Sensors Actuators B 168:223–30. Bakirci I. (2001). A study on the occurrence of aflatoxin M1 in milk and milk products produced in Van province of Turkey. Food Control 12: 45–51. Barjesteh MH, Azizi IG, Noshfar E. (2010). Occurance of AFM1 in pasteurized and local yoghurt in Mazandaran province (Northern Iran) using ELISA. Global Vet 4:459–62. Battacone G, Nudda A, Cannas A, et al. (2003). Excretion of aflatoxin M1 in milk of dairy ewes treated with different doses of aflatoxin B1. J Dairy Sci 86:2667–75. Bilandzic N, Bozic D, Ðokic M, et al. (2014). Assessment of aflatoxin M1 contamination in the milk of four dairy species in Croatia. Food Control 43:18–21. Bovo F, Corassin CH, Rosim RE, de-Oliveira CAF. (2012). Efficiency of Lactic Acid bacteria strains for decontamination of aflatoxin M1 in phosphate buffer saline solution and in skimmed milk. Food Bioprocess Technol 6:2230–4. Brackett RE, Marth EH. (1982). Fate of aflatoxin M1 in parmesan and mozzarella cheese. J Food Prot 45:597–600. Caloni F, Stammati A, Frigge G, De-Angelis I. (2006). Aflatoxin M1 absorption and cytotoxicity on human intestinal in vitro model. Toxicon 47:409–15. Cano-Sancho G, Marin S, Ramos AJ, et al. (2010). Occurrence of aflatoxin M1 and exposure assessment in Catalonia (Spain). Rev Iberoam Micol 27:130–5. Carraro A, Giacomo AD, Giannossi ML, et al. (2014). Clay minerals as adsorbents of aflatoxin M1 from contaminated milk and effects on milk quality. Appl Clay Sci 88:92–9. Choudhary PL, Sharma RS, Borkartria VN. (1998). Effect of chilling and heating on aflatoxin M1 content of contaminated Indian cow’s milk. Egypt J Dairy Sci 26:223–9. Codex Alimentarius Commissions. (2001). Comments submitted on the draft maximum level for aflatoxin M1 in milk. Codex committee on food additives and contaminants 33rd sessions, Hauge, The Netherlands: FAO, Rome Publishers. Corassin CH, Bovo F, Rosim RE, Oliveira CAF. (2013). Efficiency of Saccharomyces cerevisiae and lactic acid bacteria strains to bind aflatoxin M1 in UHT skim milk. Food Control 31:80–3. Darsanaki RK, Aliabadi MA, Chakoosari MMD. (2013). Aflatoxin M1 contamination in ice-cream. J Chem Health Risks 3:43–6. Dashti B, Al-Hamli S, Alomirah H, et al. (2009). Levels of aflatoxin M1 in milk, cheese consumed in Kuwait and occurrence of total aflatoxin in local and imported animal feed. Food Control 20: 686–90. Deveci O. (2007). Changes in the concentration of aflatoxin M1 during manufacture and storage of white pickled cheese. Food Control 18: 1103–7. Duarte SC, Almeida AM, Teixeira AS, et al. (2013). Aflatoxin M1 in marketed milk in Portugal: assessment of human and animal exposure. Food Control 30:411–17. Durakovic´ L, Skelin A, Sikora S, et al. (2011). Impact of new synthesized analogues of dehydroacetic acid on growth rate and vomitoxin accumulation by Fusariugraminearum under different temperatures in maize hybrid. African J Biotech 10:10798–810. Eaton DL, Groopman JD. (1994). The toxicology of aflatoxins: human health, Veterinary and Agricultural Significance. San Diego: Academic Press. Elkak A, Atat OE, Habib J, Abbas M. (2012). Occurrence of aflatoxin M1 in cheese processed and marketed in Lebanon. Food Control 25: 140–3. Elsanhoty RM, Salam SA, Ramadan MF, Badr FH. (2014). Detoxification of aflatoxin M1 in yoghurt using probiotics and lactic acid bacteria. Food Control. 43:129–34.


Ertas N, Gonulalan Z, Yildirim Y, Karadal F. (2011). A survey of concentration of aflatoxin M1 in dairy products marketed in Turkey. Food Control 22:1956–9. European Commission (EU). Commission Regulation (EC) No. 1881/ 2006 of 19 December 2006. Official Journal of European Union, L364/5-24. Fallah AA. (2010). Aflatoxin M1 contamination in dairy products marketed in Iran during winter and summer. Food Control 21: 1478–81. Fallah AA, Jafari T, Fallah A, Rahnama M. (2009). Determination of aflatoxin M1 levels in Iranian white and cream cheese. Food Chem Toxicol 47:1872–5. FAO. (2014). Food and Agriculture organization, worldwide milk consumption per person per year, Rome. Available at http:// faostat.fao.org/site/610/DesktopDefault.aspx?PageID¼610#ancor [last accessed 14 Feb 2014]. Ferlay J, Steliarova-Foucher E, Lortet-Tieulent J, et al. (2013). Cancer incidence and mortality patterns in Europe: estimates for 40 countries in 2012. Eur J Caner 49:1374–403. Galvano F, Galofaro V, Galvano G. (1996). Occurrence and stability of aflatoxinM1 in milk and milk products: a worldwide review. J Food Prot 59:1079–90. Ghiasain SA, Maghsood AH. (2012). Infants’ exposure to aflatoxin M1 from mother’s breast milk in Iran. Iranian J Public Health 41: 119–26. Giolo MP, Minervino de Oliveira C, Bertolini DA, et al. (2012). Aflatoxin M1 in the urine of non-carriers and chronic carriers of hepatitis B virus in Maringa, Brazil. Braz J Pharm Sci 48: 447–52. Govaris A, Roussi V, Koidis A, Botsoglou NA. (2001). Distribution and stability of aflatoxin M1 during processing, ripening and storage of Telemes cheese. Food Addit Contam 18:437–43. Han RW, Zheng N, Wang JQ, et al. (2014). Survey of aflatoxin in dairy cow feed and raw milk in China. Food Control 34:35–9. Hassan HF, Kassaify Z. (2014). The risks associated with aflatoxins M1 occurrence in Lebanese dairy products. Food Control 37:68–72. Hernandez-Mendoza A, Guzman-de-Pen˜a D, Garcia HS. (2009). Key role of teichoic acids on aflatoxin B1 binding by probiotic bacteria. J Appl Microbiol 107:395–403. Heshmati A, Milani JM. (2010). Contamination of UHT milk by aflatoxin M1 in Iran. Food Control 21:19–22. Hussain I, Anwar J. (2008). A study on contamination of aflatoxin M1 in raw milk in the Punjab province of Pakistan. Food Control 19: 393–5. International Agency for Research on Cancer. (2002a). IARC monograph on the evaluation of carcinogenic risk to humans. Lyon: IARC, World Health Organization. IARC, International Agency for Research on Cancer. (1993). Some naturally occurring substances: Food items and constituents, heterocyclic aromatic amines and mycotoxins. In IARC monograph on the evaluation of carcinogenic risks to humans (Vol. 56, pp. 19e23). Lyon, France: World Health Organization, IARC. IARC, International Agency for Research on Cancer. (2002b). Some traditional herbal medicines, some mycotoxins, naphthalene and styrene, IARC MonogrEvalCarcinog Risk Hum, Lyon, France: IARC Press. pp. 1–556. Issazadeh K, Darsanaki RK, Pahlaviani MRMK. (2012). Occurrence of aflatoxin M1 levels in local yogurt samples in Gilan Province, Iran. Ann Biol Res 3:3853–5. JECFA (Joint FAO/WHO Expert Committee on Food Additives). (2001).Fifty-sixth meeting of the Joint FAO/WHO expert committee on food additives. Safety evaluation of certain mycotoxins in food; WHO food additives series 47; FAO food and nutrition paper 74, Geneva: WHO. Jemal A, Center MM, DeSantis C, Ward EM. (2010). Global patterns of cancer incidence and mortality rates and trends. Cancer Epidemiol Biomarkers Prev 19:1893–907. Kabak B, Var I. (2008). Factors affecting the removal of aflatoxin M1 from food model by Lactobacillus and Bifidobacterium strains. J Environ Sci Health B 43:617–24. Kabak B, Brandon EFA, Var I, et al. (2009). Effects of probiotic bacteria on the bioaccessibility of aflatoxin B1 and ochratoxin A using an in vitro digestion model under fed conditions. J Environ Sci Health B 44:472–80.


DOI: 10.3109/1040841X.2014.958051

Kabak B, Ozbey F. (2012). Aflatoxin M1 in UHT milk consumed in Turkey and first assessment of its bioaccessibility using an in vitro digestion model. Food Control 28:338–44. Kamkar A, Karim G, Aliabadi FS, Khaksar R. (2008). Fate of aflatoxin M1 in Iranian white cheese processing. Food Chem Toxicol 46: 2236–8. Kamkar A, Khaniki GRJ, Alavi SA. (2011). Occurrence of aflatoxin M1 in raw milk produced in ardebil of Iran. Iranian J Environ Health Sci Eng 8:123–8. Kaniou-Grigoriadou I, Eleftheriadou A, Mouratidou T, Katikou P. (2005). Determination of aflatoxin M1 in ewe’s milk samples and the produced curd and Feta cheese. Food Control 16:257–61. Khoury AE, Atoui A, Yaghi J. (2011). Analysis of aflatoxin M1 in milk and yogurt and AFM1 reduction by lactic acid bacteria used in Lebanese industry. Food Control 22:1695–9. Klich MA, Mullaney EJ, Daly CB, Cary JW. (2000). Molecular and physiological aspects of aflatoxin and sterigmatocystin biosynthesis by A. tamarii and A. ochraceoroseus. Appl Microbiol Biotechnol 53: 605–9. Kos J, Levi J, uragi O, et al. (2014). Occurrence and estimation of aflatoxin M1 exposure in milk in Serbia. Food Control 38:41–6. Lafont P, Siriwardana M, Lafont J. (1989). Gene toxicity of Hydroxylaflatoxins M1 and M4. Micr Alim Nut 7:1–8. Leblanc JC, Tard A, Volatier JL, Verger P. (2005). Estimated dietary exposure to principal food mycotoxins from the first French total diet study. Food Addit Contam 22:652–72. Liu Y, Wu F. (2010). Global burden of aflatoxin-induced hepatocellular carcinoma: a risk assessment. Environ Health Perspect 118:818–24. Manetta AC, Giammarco M, Giuseppe LD, et al. (2009). Distribution of aflatoxin M1 during Grana Padano cheese production from naturally contaminated milk. Food Chem 113:595–9. Martins ML, Martins HM. (2004). Aflatoxin M1 in yoghurts in Portugal. Int J Food Micro 91:315–17. Mohajeri FA, Ghalebi SR, Rezaeian M, et al. (2013). Aflatoxin M1 contamination in white and Lighvan cheese marketed in Rafsanjan, Iran. Food Control 33:525–7. Mohammadi H. (2011). A review of aflatoxin M1, milk and milk products. In: Guevara-Gonzalez RG, ed. Aflatoxins – biochemistry and molecular biology, 397–414. Rijeka, Croatia: InTech. Muhammad K, Tipu MY, Abbas M, et al. (2010). Monitoring of aflatoxin M1 in market raw milk in Lahore city, Pakistan. Pak J Zool 42:697–700. Mulunda M, Mike D. (2014). Occurrence of aflatoxin M1 from rural subsistence and commercial farms from selected areas of South Africa. Food Control 39:92–6. Neal GE, Colley PJ. (1978). Some high-performance liquid-chromatographic studies of the metabolism of aflatoxins by rat liver microsomal preparations. Biochem J 174:839–51. Neal GE, Eaton DL, Judah DJ, Verna A. (1998). Metabolism and toxicity of aflatoxins M1 and B1 in human-derived in vitro systems. Toxicol Appl Pharm 151:152–8. Nilchian Z, Rahimi E. (2012). Aflatoxin M1 in yoghurts, cheese and icecream in Shahrekord-Iran. World Appl Sci J 19:621–4. Omar SS. (2012). Incidence of aflatoxin M1 in human and animal milk in Jordan. J Toxicol Environ Health A Curr Issues 75:1404–9. Onyemelukwe GC, Ogoina D, Ibiam GE, Ogbadu GH. (2012). Aflatoxins in body fluids and food of Nigerian children with protein – energy malnutrition. African J Food Agri Nut Dev 12:6553–66. Oruc HH, Cibik R, Guns E. (2007). Fate of aflatoxin M1 in Kashar cheese. J Food Safety 27:82–90. Panahi P, Kasaee S, Mokhtari A, et al. (2011). Assessment of aflatoxin M1 contamination in raw milk by ELISA in Urmia, Iran. AmericanEurasian J Toxicol Sci 3:231–3. Paniel N, Radoi A, Marty J. (2010). Development of an electrochemical biosensor for the detection of aflatoxin M1 in milk. Sensors 10: 9439–48. Pathirana UPD, Wimalasiri KMS, Silva KFST, Gunarathne SP. (2010). Investigation of farm gate cow milk for aflatoxin M1. Trop Agri Res 21:119–25. Peltonen K, El-Nezami H, Haskard C, et al. (2001). Aflatoxin B1 binding by dairy strains of lactic acid bacteria and bifidobacteria. J Dairy Sci 84:2152–6. Pitt JI. (2000). Toxigenic fungi: which are important. Med Mycol 38: 17–22.

Aflatoxin M1

9

Polovinski-Horvatovic´ M, Juric´ V, Glamocˇic´ D. (2009). Two year study of incidence of aflatoxin M1 in milk in the region of Serbia. Biotech Anim Husbandry 25:713–18. Prandini A, Tansini G, Sigolo S, et al. (2009). On the occurrence of aflatoxin M1 in milk and dairy products. Food Chem Toxicol 47: 984–91. Rahimi E, Karim G. (2008). Determination of aflatoxin M1 in raw milk producing in dairy farmsinChahar-Mahal-Bakhtiari province using ELISA. J Food Sci Technol 5:51–9. Ruangwises N, Ruangwises S. (2010). Aflatoxin M1 contamination in raw milk within the central region of Thailand. Bull Environ Contam Toxicol 85:195–8. Sadeghi E, Almasi A, Bohloli-Oskoii S, Mohamadi M. (2013). The evaluation of aflatoxin M1 factories of Kermanshah level in collected raw milk for pasteurized dairy. Zahedan J Res Med Sci 15: 26–9. Sadia A, Jabbar MA, Den Y, et al. (2012). A survey of aflatoxin M1 in milk and sweets of Punjab, Pakistan. Food Control 26:235–40. Sani AM, Nikpooyan H, Moshiri R. (2010). Aflatoxin M1 contamination and antibiotic residue in milk in Khorasan province, Iran. Food Chem Toxicol 48:2130–2. Santin E, Paulilo AC, Maiorka A, et al. (2003). Evaluation of the efficiency of Saccharomyces cerevisiae cell wall to ameliorate the toxic effects of aflatoxin in broilers. Int J Poultry Sci 2: 341–4. Sarimehmetoglu B, Kuplulu O. (2004). Binding ability of aflatoxin M1 ¨ niv Vet Fak Derg 51:195–8. to yoghurt bacteria. Ankara U Sassahara M, Pontes ND, Yanak EK. (2005). Aflatoxin occurrence in foodstuff supplied to dairy cattle and aflatoxin M1 in raw milk in the North of Parana state. Food Chem Toxicol 43:981–4. Sefidgar SAA, Mirzae M, Assmar M, Naddaf SR. (2011). Aflatoxin M1 in pasteurized milk in Babol city, Mazandaran Province, Iran. Iranian J Public Health 40:115–18. Serrano-Nino JC, Cavazos-Gardun˜o A, Hernandez-Mendoza A, et al. (2013). Assessment of probiotic strains ability to reduce the bioaccessibility of aflatoxin M1 in artificially contaminated milk using an in vitro digestive model. Food Control 31:202–7. Shibahara T, Ogawa HI, Ryo H, Fujikawa K. (1995). DNA-damaging potency and genotoxicity of aflatoxin M1 in somatic cells in vivo of Drosophila melanogaster. Mutagenesis 10:161–4. Shundo L, Navas SA, Lamardo LCA, et al. (2009). Estimate of aflatoxin M1 exposure in milk and occurrence in Brazil. Food Control 20: 655–7. Siddappa V, Nanjegowda DK, Viswanath P. (2012). Occurrence of aflatoxin M1 in some samples of UHT, raw & pasteurized milk from Indian states of Karnataka and Tamilnadu. Food Chem Toxicol 50: 4158–62. Singh NA, Kumara N, Raghua HV, et al. (2013). Spore inhibition-based enzyme substrate assay for monitoring of aflatoxin M1 in milk. Toxicol Environ Chem 95:765–77. Smajlovic A, Muminovic M, Mujezinovic I, Cupic V. (2012). Investigation of aflatoxin M1 degradation in milk. Veterinarski Glasnik 66:387–94. Sorensen LK, Elbaek TH. (2005). Determination of mycotoxins in bovine milk by liquid chromatography tandem mass spectrometry. J Chromatogr B 820:183–96. Suliman SE, Abdalla MA. (2013). Presence of aflatoxin M1 in dairy cattle milk in Khartoum State-Sudan. Int J Sci Tech Res 2:10–12. Sun Z, Lu P, Gail MH, et al. (1999). Increased risk of hepatocellular carcinoma in male hepatitis B surface antigen carriers with chronic hepatitis who have detectable urinary aflatoxin metabolite M1. Hepatology 30:370–83. Susan OK, Obansa AI, Anthony MH, Chidawa MS. (2012). A preliminary survey of aflatoxin M1 in dairy cattle products in Bida, Niger State, Nigeria. African J Food Sci Tech 3:273–6. Sylos CM, Rodriguez-Amaya DB, Carvalho PRN. (1996). Occurrence of aflatoxin M1 in milk and dairy products commercialized in Campinas, Brazil. Food Addit Contam 13:169–72. Tamime AY, Robinson RK. (2007). Tamime and Robinson’s yoghurt: science and technology. Cambridge: Woodhead Publishing Ltd. Tekinsen KK, Ucar G. (2008). Aflatoxin M1 levels in butter and cream cheese consumed in Turkey. Food Control 19:27–30. Trucksess MW. (2001). Rapid analysis (thin layer chromotographic and immunochemical methods) for mycotoxins in foods and feeds. In:

10

A. Ismail et al.


de Koe WJ, Samson RA, van Egmond HP, et al., eds. Mycotoxins and Phycotoxins in perspective at the turn of the millennium. Wageningen: Ponsen & Looyen, 29–40. Tsakiris IN, Tzatzarakis MN, Alegakis AK, et al. (2013). Risk assessment scenarios of children’s exposure to aflatoxin M1 residues in different milk types from the Greek market. Food Chem Toxicol 56: 261–5. Var I, Kabak B. (2009). Detection of aflatoxin M1 in milk and dairy products consumed in Adana, Turkey. Int J Dairy Tech 62:15–18. Versantvoort CM, Oomen AG, Van-de-Kamp E, et al. (2005). Applicability of an in vitro digestion model in assessing the bioaccessibility of mycotoxins from food. Food Chem Toxicol 43: 31–40.


WHO. (2008). The Global Burden of Disease: 2004 Update. Geneva: World Health Organization. Available at http://www.who.int/ healthinfo/global_burden_disease/2004_report_update/en/index.html [last accessed 27 Apr 2010]. Wild CP, Gong YY. (2010). Mycotoxins and human disease: a largely ignored global health issue. Carcinogenesis 31:71–82. Xiong JL, Wang YM, Mac MR, Liu JX. (2013). Seasonal variation of aflatoxin M1 in raw milk from the Yangtze River Delta region of China. Food Control 34:703–6. Zinedine A, Gonza´lez-Osnaya L, Soriano JM, et al. (2007). Presence of aflatoxin M1 in pasteurized milk from Morocco. Int J Food Microbiol 114:25–9. Zuheir IMA, Omar JA. (2012). Presence of aflatoxin M1 in raw milk for human consumption in Palestine. Walailak J Sci Tech 9:201–5.