Author: Buliyaminu Adegbemiro Alimi
Site of publication: ScienceDirect
Type of publication: Review
Date of publication: May 9, 2019
Introduction
Street foods are enjoying increasing patronage due to industrialization which is forcing many city dwellers to eat their major daily meals out of home. Street food vending is a common feature of most cities and towns in developing countries. Aside provision of ready-made instant meals at relatively in expensive prices, teeming urban dwellers are attached to street foods because of its gustatory attributes. These attributes are linked to the culinary prowess of the vendors.
Street food vending activities in most developing countries are mostly outside the regulation and protection of the governments. The economic importance of the activities is not well appreciated due to the informal nature of the enterprise and lack of official data on volume of trade involved. Street food vending makes up the significant proportion of informal sector of the economy of most developing countries. About 28.5% labor force in Mexico were reportedly employed in the informal sector, 30.8% of the activities in this sector were in the street food which employed over 120,000 vendors in Mexico City alone in 1998. Street food vending in Malaysia is a multi-million US dollar trade providing direct employment for over 100,000 vendors with gross annual sales volume of about 2 billion US dollars.
However, the sector is fraught with unwholesome activities which have been reported to pose serious concerns over the safety of the practitioners, especially the health of the consumers. These unwholesome activities traversed the whole chain of street food business from agricultural raw materials to the final retail street foods and have been fingered in the outbreak of diseases and illnesses. The prevention, maintenance and treatment of diseases from street food borne illnesses were reported to result in heavy drain on the purse of individuals and governments in the developing countries due to huge spending involved.
Risk Factors
Agricultural practices
Growing world population is putting tremendous pressure on food production. The attendant effect is the increasing need to maximize available resources for improved farm yield to feed the growing population. Farmers use inorganic agrochemicals and organic manure to improve the yield of farm produce, prevent competition with weeds and maintain the quality by preventing infestation by insects and spoilage by microorganisms on the field and during storage.
The use of these chemicals is well regulated in developed countries through the enactment and enforcement of acts and laws which control and limit their usage for agricultural practices. These laws are to prevent the residual effect of these chemicals on consumers. However, opposite is the case in developing countries where farmers use excessive chemicals to achieve bumper yields. Farmers in developing countries often patronize easily synthesized, cheap and patent expired chemicals.
Street food vending activities in most developing countries are mostly outside the regulation and protection of the governments. The economic importance of the activities is not well appreciated due to the informal nature of the enterprise and lack of official data on volume of trade involved
Residues from excessive chemical applications to boost farming operations have been reported in high concentrations in soils, livestock and aquatic animals. Significant relationship has been established between residual chemical accumulation in the soil and uptake by crops during growth. These chemicals are stored in the edible parts of crops, livestock and aquatic animals. Scientific research has proven that the presence of the residual agro-chemicals in foods is detrimental to human health. The accumulation of foreign chemicals such as lead (Pb), arsenic (As), cadmium (Cd), copper (Cu) and mercury (Hg) in human system has been linked to immune-suppression, hypersensitivity to chemical agents, breast cancer, reduced sperm count and infertility.
Sources and quality of raw foods and ingredients
Quest for profit maximization by the vendors or the need to make street foods affordable for the consumers make some vendors patronize cheap and unsafe ingredients that may be detrimental to the health of the consumers.
Results of survey conducted by Omemu and Aderoju showed that vendors of street foods in Nigeria considered the volume (94%) and the price (93%) than the freshness and cleanliness when buying raw foods to be cooked or vended. In the study conducted in India, Choudhury et al. observed that procurement habits of food items by street vendors differ according to the size of the establishments and was significantly (p < 0.05) influenced by the type of vendors, ownership and average monthly income.
The study reported that all the mobile vendors and owners of small restaurant procure unlabeled and unpacked food grains and semi-processed ingredients from grocery shops. While majority (87%) of owners of small restaurants procures labeled and packed condiments, dry fruits and spices from grocery, most (44%) of the mobile food vendors purchase condiments and spices, nuts and dry fruits from traditional weekly or daily markets with 37% of them prepared, dried and powdered their own ingredients at home. Close to 56% of mobile vendors used unlabeled and unpacked condiments and spices.
Scientific research has proven that the presence of the residual agro-chemicals in foods is detrimental to human health. The accumulation of foreign chemicals such as lead (Pb), arsenic (As), cadmium (Cd), copper (Cu) and mercury (Hg) in human system has been linked to immune-suppression, hypersensitivity to chemical agents, breast cancer, reduced sperm count and infertility
Studies have shown that home-made cereal flour and condiments used in street foods preparations are contaminated with Bacillus cereus.
Food preparation, handling and vending
The temperatures employed in the cooking and frying operations during street food preparations are high enough to kill the vegetative cells, but the resistant spores of micro-organisms may survive. However, the ways and manners street foods are being prepared, handled and vended predispose them to recontamination, cross contamination and transmission of pathogens and food borne illnesses. Most of the foods for street vending are usually prepared in bulk at different times ahead of retailing.
The long holding period of more than 6 h, sometimes at ambient temperature, were reported to be a common factor contributing to food borne illness through multiplication of microorganisms favored by holding temperature in the range of 5 and 60 ◦C (described as danger zone). Mosupye and von Holy suggested that holding conditions which favored the survival and germination of Bacillus spores may be responsible for the high load of Bacillusspp. isolated in ready to eat street foods.
Method of transportation plays a significant role in the contamination of street foods. It has been reported that transportation and display of meats play significant role in the acceleration of their spoilage and transmission of zoonotic diseases. The manner of moving slaughtered animal carcasses from slaughter points to retailing points in crude structures such as wooden push carts, open plastic or aluminum trays on heads or “off-road” vehicles increased the chances of cross contamination.
Meats are retailed in the markets and streets of Africa in open wooden trays that are usually difficult to wash thoroughly thereby harboring niches for microorganisms’ contamination of meats and deposition of airborne pollutants.
Non-regulation of time and holding temperature had been recognized as major risk factors in street foods that contribute to diseases outbreak. Majority of the vendors in Abeokuta, Nigeria (90%) and Ozamiz city, Philippines (55%), prepared their products on the morning of sale, while most of the vendors in Kampala, Uganda cooked foods on the premises (75%) and well in advance of consumption (77%).
Other risk factors identified in the preparation and handling of street foods include: the common use of stove charcoal for keeping and warming of food over a long period of time which may not provide adequate temperature enough to prevent proliferation of pathogenic microorganisms; as reheating of food at temperature below 40 ◦C could increase salmonella contamination, overheating at higher temperature could lead to loss of essential nutrients and flavors in the food; holding of foods at ground level and incessant uncovering of foods for dispensing exposed street foods to dust contamination and flies which has been linked to food borne diseases such as cholera and diarrheal.
Vending environments
Studies have raised serious concerns on the dangerous abuse street foods are exposed to in the vending environments. Street food vendors usually target high human traffic areas for the display of their products to enhance sales. Street food vending is a common site in such areas as major street corners, industrial/construction sites, bus/train terminals, public places and school compounds. The vending units are either mobile or stationary using open or protected crude structures such as push carts, display wooden tables, aluminum trays or bowls or chop bars.
The environments under which street foods are being prepared, vended and consumed predisposed them to recontamination and cross contamination from environmental pollutants such as airborne chemicals in dusts, exhaust discharges from moving vehicles and industrial engines, burning fumes and offensive smell from accumulated waste and effluent from industrial discharge, insects and rodents.
Airborne diseases and microbes which may be pathogenic if allowed to settle on the prepared food surfaces abound in dust.
Since nearness to customers is the primary target of street food vendors, vending sites usually lack basic facilities such as toilets, hand washing facilities, potable water, good drainage and waste disposal system. Where some of these facilities are provided, large concentration of vendors in human congested areas usually placed serious strain on them resulting in interference with city plans and adverse effects on daily life. All these conditions enhance the incidence of food borne illnesses and transmission of diseases among vast consumers of street foods.
Hygiene practices
Several studies on hygienic practices of street food vending confirmed WHO report that most street food vendors have knowledge of hygienic practices but concluded that majority of them do not put the knowledge into practice.
The environments under which street foods are being prepared, vended and consumed predisposed them to recontamination and cross contamination from environmental pollutants such as airborne chemicals in dusts, exhaust discharges from moving vehicles and industrial engines, burning fumes and offensive smell from accumulated waste and effluent from industrial discharge, insects and rodents
Although street vendors were reported to exhibit good personal cares, however, they were negligence to compliance with adequate hygiene practices at the preparation and vending sites. Inadequacy or near absence of basic facilities at the vending sites were mostly attributed for non-compliance with basic hygiene principles.
In the study on the hygienic practices by street food vendors in Trinidad, West Indies, Benny-Ollivierra and Badrie reported that most of the vending sites observed did not have pipe borne water, 97.5% did not have drain to channel waste water and toilet facilities. The report was not different for street food vending sites in Kingston, Jamaica, Lima, Peru, Philippines and Uganda. Lack of toilet and lavatory facilities at the vending sites forced most street food hawkers to seek secluded areas within the vicinity like bushes and uncompleted buildings for excretion. Idowu and Rowland reported that majority of the street food vendors studied in Abeokuta, Nigeria used dung hills and nearby bushes in place of toilets and clean up with sheets of paper.
Summary from different studies on the safety perception of street food vendors is that vendors are not completely ignorant of basic food safety practices. For examples, studies reported that most vendors knew that they must bath regularly and not attached bath to visible dirt or objectionable odor, washed their hands during food preparation, serving, after using the toilet, sneezing, coughing and handling contaminated materials like exchange of money, smoking is not good for their health and should not engage in it while serving foods.
However, the reality on the ground showed that all these were mere rhetoric and statements of the minds which were rarely put into actual practices by most vendors due to some factors. Connvenience and economic factors were the main reasons why most vendors were not implementing their knowledge of safety practices. Vendors in Malaysia regarded wearing of head covering, apron and glove as cumbersome and their regular removal as time wasting. They also preferred selling their products by the roadsides to designated places with adequate safety facilities because of better patronage which came with nearness to consumers.
Attitude of consumers to the hazards of street food
Consumers are the major risk bearers of the consequences of street food safety. The attitude of consumers to safety of street food varied and is dependent on some socio-economic factors. While some are cautious of where and how they purchase the street foods because of their knowledge of the hazards attached; others are beclouded with the urgency to satisfy their culinary drive and enjoy the gustatory attributes attached to the street foods.
Consumers’ attitude and perception of hazards in street foods is often driven by their level of education, income, knowledge of food safety, age and gender. Literature reported varied effect of these factors on the attitude of consumers to safety of street food and their perception of hazards inherent in its consumption.
It was recognized that policies and regulations for safe street food trade are very weak and poorly enforced in most developing countries and even non-existent in some countries. Therefore, strengthening of the policies and proper enforcement would undoubtedly ensure significant reduction in the hazards of street food consumption
Street food consumers in developing countries are generally more concerned about microbial hazards. Pathogens of significant public health importance such as Salmonella, S. aureus, Listeria monocytogenes, Campylobacter jejuni and E. coli have been isolated in some street foods in developing countries. Reports in literature show that consumers are aware that microorganisms especially bacteria are responsible for foodborne diseases but have very little knowledge about their pathogeneses.
Recommended approaches to ensure safe street food practice
Street food vending is an important component of socioeconomic activities in developing countries. Its significance is appreciated by the volume of trade involved, provision of readymade meals and employment for the teeming populace along the chain of the business. The benefits and contribution of street food trade to the economy of developing countries elicited recommendations from researchers on ways to mitigate the hazards in its consumption and safeguard the health of consumers.
It was recognized that policies and regulations for safe street food trade are very weak and poorly enforced in most developing countries and even non-existent in some countries. Therefore, strengthening of the policies and proper enforcement would undoubtedly ensure significant reduction in the hazards of street food consumption.
These would involve active participation of all stakeholders in street food trade such as governments, street food vendors, consumers’ associations, civil society groups and development partners. Raising the awareness on the treat of unwholesome practices in street food trading through dissemination of information in mass media and audience participatory programs was further recommended.
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