All the food particles contain loads of nutrients that make them attractive sources for microbial growth and these include various microorganisms, such as bacteria, fungi, and yeasts (Ravichandran, 2018). Most of such incidents are common at food places where there is poor hygienic condition. Major contribution of food-borne diseases in India is made by the food sendee industries in 60-80 per cent of the cases (Lin, 2011). Most people love Chinese recipes and these are quite popular in urban areas of India. Moreover, some liquids, such as milk, sugarcane juice, and other juices have been found to contain higher microbial loads of various species, such as Vibrio spp, Shigella spp, and Bacillus spp is 6.5 cfu/100 mL (Suggannaya et al., 2007; Mahale et al., 2008). There may be common incidences of contamination of food particles with Clostridium botulinum especially where open defecation is prevalent, such as in developing countries like India (Jaiswal, 2011). Rotten eggs, meat, and chicken get infected with Salmonella, Shigella or Listeria spp (Majumdar, 2010), whereas packaged food can be adulterated with various microbial contaminants during the different processing steps. A few such cases have been reported in canned meat/fish adulterated with Clostridium perferigens and enterotoxins from Staphylococcus aureus in baked food and dairy products, whereas frozen products have been found contaminated with Bacillus cereus (Jaiswal, 2011). Listeria monocytogenes and Clostridium botulinum have been reported to be the other major contaminants (FAO, 2011). Fungal contamination is another cause that comes from open fields. Poisoning in case of rice is caused by Penicillium, Fusarium, Rhizopus and Aspergillus spp (Jaiswal, 2011). Cereal crops infected and damaged by insects are vulnerable to contamination by Aspergillusflavus and Aspergillus parasiticus (Srilakshmi, 2011). In residential complexes, there are cases of infection by some protozoans, such as Cryptosporidium parvum, Toxoplasma gondii, Clonorchis sinensis and viruses, such as Norwalk virus and hepatitis A virus (FAO, 2011). Since milk is an effective medium for microbial growth, some of the common outbreaks are due to pathogens, like Listeria monocytogenes, E. coli 0157:H7, Salmonella Campylobacter, and Staphylococcus aureus (Well et al., 1991; Bean et al., 1996; Coia et al., 2001; Chyea et al., 2004).
Fungi or moulds are the microorganisms that are responsible for causing food spoilage. One mode for food spoilage is fungal toxins, known as mycotoxins (Table 3). Mycotoxins are secondary metabolites secreted by fungal organisms and can harm all humans and animals by causing mycotoxicoses; this is a major health concern. Some of the toxic effects of myctoxins have been discussed and reviewed (Adeyeye, 2016). Moulds are omnipresent wherever they find moisture (Richard, 2007; Adejumo and Adejoro, 2014). All types of foodstuffs are rich in moisture and thus act as perfect sources/substrates for growth of moulds (Adeyeye, 2016). The mould growth in foodstuff leads to some significant financial losses (Bayman and Baker, 2006; Richard, 2007; Adejumo and Adejoro, 2014). Some geographical and external factors play important roles in stimulating the contamination (Jonathan and Esho, 2010). The common fungi known to contaminate Indian foods are Aspergillus, Penicillium, Fusarium, aflatoxins, ochratoxins, patulin, zearalenone (Kumar et al., 2008). Human health has been adversely affected by mycotoxins, mainly aflatoxins and ochratoxin A (Moss, 1994; Ashiq, 2015). Aflatoxin is a potent carcinogen and upon combination with Hepatitis A virus it is found responsible for many thousands of human death per annum, mostly in tropical countries (Shephard and Leggott, 2008). Mycotoxins, such as aflatoxins, produced by Aspergillus flavus and Aspergillus parasiticus, cause diseases known as aflatoxicosis in livestock, domestic animals and humans throughout the world (Wood, 1992; Rustom, 1997; Ashiq, 2015). Ochratoxin A is another type of mycotoxin which infects cereals and is a causative agent for urinary tract, cancer and kidney damage (Richard, 2007; Ashiq, 2015). Fumonisins produced as a toxin by Fusarium spp. Is known to adulterate maize crop and can cause serious health concerns in humans and animals by leading to equine encephalomalacia and porcine pulmonary oedema in horse and pig, respectively. It mainly affects the animals that consume corn-based feeds (Ashiq, 2015). Mycotoxins are commonly produced by Aspergillus and Penicillium (Barbosa et al., 2013). Aflatoxic hepatitis and enteric ergotism are common in India and Kenya (Adeyeye, 2016). This type of adulteration is responsible for major monetary losses annually in human health (Shane, 1994; Vasanthi and Bhat, 1998). Aflatoxin B1 is a potent carcinogen that can seriously affect humans as reported by the International Agency for Research on Cancer (IARC, 2002). AFM1 is found to be acutely hepatotoxic than AFB1 (Creppy, 2002; Asi et al., 2012). Moreover, mycotoxins are heat-resistant and are known to survive high temperatures of processing, autoclaving, and pasteurization (Tajkarimi et al., 2008). Prevalent mycotoxin, that is commonly attracting food technologists worldwide, is patulin that contaminates apple juices (Gashlan, 2008; Saxena et al., 2009). These toxins can seriously affect and raise major health concerns in humans (Jha et al.,
- 2015). The fungal toxins are collectively known as mycotoxins. Food in the market is found to be contaminated with various toxins (Sudershan et al., 2009; Singh and Sumbali, 2011). The concentrations of different mycotoxins are reported to be high, as in the case of coffee which has ochratoxins (5 pg/kg), apple (312-405 pg/kg) with more than the tolerance limit (20 ppb) (Sugannaya et al., 2007). The pearl millet and rye grains are infected with Claviceps fusiforms and Claviceps purpurea that release ergotoxins containing alkaloids, steroids, lysergic acid, etc. (Saratchandra and Muralimanohar,
- 2013). Sudershan and co-workers (2009) have reported the presence of aflatoxin in milk and red pepper in the range of 0.1-1.0 pg/mL.
Insecticide/Pesticide Residues on Fruits and Vegetables
Chemicals that can kill the insects/pests of vegetables and fruits are known as pesticides. More than 1,000 pesticides are used around the world to ensure less damage to crop by pests. Many of the older and inexpensive recalcitrant pesticides are dichlorodiphenyltrichloroethane (DDT) and lindane which remain in soil and water. These chemicals were banned in 2001 by the Stockhom Convention, an international treaty in order to minimize the use of chemicals which can act as persistent ones. These chemicals through exposure enter the human body. According to a report of the FAO, in developing countries only 20 per cent of the expected outcome of agriculture comes from farming land and which can be enhanced by the use of insecticides. The maximum residue limit (MRLs) for pesticides in food has been mentioned by Codex standards. Various regulations and conduct related to pesticides have been decided by WHO and FAO to help in management of pesticides. Pesticides can be genotoxic, causing mutations. Vegetables and fruits can be contaminated with pesticide residues (Mebdoua, 2018).
Various fresh vegetables and fruit samples (around 70 per cent), such as strawberries, spinach and kale in US were found to contain pesticide residues. It has been reported that more than 90 per cent of Americans have detectable excretions of pesticides in urine and blood (Emily Holden, 2019). There can be many ill effects associated with pesticides, ranging from mild, acute to chronic including skin, eye, cancer, endocrine system and nervous system disorders. A pesticide named Chlorpyrifos has been banned by the Environmental Protection Agency as it is reported to cause disabilities in children (Emily Holden, 2019). In a similar study carried out at the Kerala University, 11 per cent of organically produced vegetables were found to contain pesticide residues collected from seven districts (Down to Earth, 2018). Other than pesticide residues, fruits are ripened by calcium carbide that is illegal to use in many countries. Moreover, some growth hormones can be injected to increase the size of the vegetables, leading to ill effects on children and adults. In children, hindrance in absorption of nutrients and thus growth has been observed. Poor excretion is involved with high pesticide residues on vegetables and fruits. However, in adults, they can be neurotoxic that results in reduction of body balance, coordination, and reduces fertility (Shirukar, 2018).