SECTION 6 6.0 FOOD AND CONSUMER HEALTH

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FST 201 INTRODUCTION TO FOOD TECHNOLOGY SECTIO
N 6FOOD AND CONSUMER HEALTH DR MRS. J. M.
BABABJIDE
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• Introduction
• Consumer health can be defined in terms of what
  people consume in order to be healthy.
• Food is what we consume to give us nutrients for
  growth, sustenance and replacement of worn out
  tissues.

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• Food with little or no nutrients, incomplete
  nutrients when consumed on a regular basis will
  result into bad health such as growth
  retardation, sicknesses, loss of body immunity
  against diseases etc
• Food with contaminants are deleterious to human
  health
• Over processed food will lead to loss of protein
  and vitamin
• Regular consumption of food with only
  carbohydrate leads to a condition called
  kwashiorkor
• Lack of enough supply of energy results in a
  protruded belle, thin arms and legs or swollen
  body in a condition called marasmus.

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• Toxicants of Foods
• A toxicant is any chemical substance that can
  elicit a detrimental effect in a biological
  system. Food toxicant can be divided into three
  categories, namely endogenous, naturally
  occurring and synthetic.
• 1. Endogenous Toxicants
• substances produced by tissue cells in plants and
  other biological raw materials.
• chemical substances often serve the purpose of
  protecting plant tissues from pests, as well as
  from pathogenic organisms

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• Transmission to man can be direct consumption of
  toxic plants or from animals who have consumed
  the plant that are then used for human foods
• Examples include flavonoids, goitrogens,
  coumarins, cyanogenic compounds, herbal extracts,
  and mushroom toxins.

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2. Synthetic toxicants

• They are those that are synthetically produced,
  which found their way into our food supply
  through contamination of the food processing
  environment. e.g pesticides, additives,
  preservatives
• Pesticides include insecticides, herbicides,
  rodenticides, fungicides, fumigants etc.
• Amide herbicides (propanil) which is used
  extensively to control harmful weeds in rice
  crops could cause liver damage, central nervous
  system depression and death.

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• A new method of pest management (Integrated Pest
  Management-IPM) which is based on the minimal use
  of chemical pesticides to control insects was
  introduced in the 1980s. IPM seeks to integrate
  several techniques to control insects and other
  pests, instead of relying solely on chemicals.
• The concentration of residues that can be found
  in foods produced from treated crops is being
  regulated (maximum residue levels-MRL) in such a
  manner that strict compliance is demanded.

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• 3. Naturally occurring Toxicants
• They are those produced by organisms that
  contaminate the food products.
• Microorganism such as dinoflagellates, fungi, and
  bacteria can produce toxicants that upon
  consumption can cause diseases.
• Some toxin-producing organisms produce toxins in
  the food matrix (which can cause intoxication if
  consumed), while others produce toxins inside the
  victim (intoxification).
• some able to withstand heating temperature used
  in cooking, while others are able to tolerate
  extremes of pH without losing activity.

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• Some of these Micro organisms cause very serious
  diseases such as typhoid, dysentery,
  salmonellosis, cholera and food intoxications.
• They are generally specific depending upon the
  type of food and particular conditions of
  storage.
• e.g moulds (Aspergillus) are commonly associated
  with cereal product spoilage, Lactic acid
  bacteria (Lactobacillus) spoils raw milk and
  yeasts (Saccharomyces) spoil fruit juice when
  stored under unfavourable conditions.

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• The undesirable changes caused by microorganisms
  can be divided into those that cause food
  spoilage not usually associated with human
  disease and those that cause food poisoning which
  could be
• food infection,
• food intoxication or
• food intoxification.

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• Food infections are caused by disease organisms
  which are carried to the host through foods they
  multiply in the intestinal tract, vaginal trud
  etc and cause diseases through infection of their
  tissues.
• Examples of these diseases are cholera,
  salmonellosis, shigellosis, ameobiosis.

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• Cholera is caused by Vibrio comma, transmitted
  through drinking water and contaminated food.
• The symptoms are diarrhoea, watery stools and
  vomiting.
• Salmonellosis is caused by salmonella bacteria
  transmitted through foods such as meat, egg and
  fish. They are easily killed by normal good
  cooking, and must be eaten alive in sufficient
  number to cause infection.
• Symptoms are abdominal pain, diarrhea, frequent
  vomiting and occasional death may occur when
  untreated.

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• ii Food intoxication is caused by organisms
  which grow in food and produce chemical
  substances in the food which is toxic. Examples
  are
• Staphylococcal poisoning, caused by
  Staphylococcus aureus.
• Symptoms are salivation, nausea, vomiting,
  diarrhea and abdominal cramps. Sources of
  contamination are mouth, throat, nose through
  coughs and sneezes.
• Botulism which could be very fatal is caused by
  Clostridium botulinum transmitted through home
  canned foods which are not properly processed.
• Symptoms are vomiting, constipation, difficult of
  eye movement, difficulty in speaking. Death
  could result due to the paralysis of the muscles
  responsible for respiration.

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• iii Food Intoxification is caused by ingestion
  of bacteria that once inside the small intestine,
  begin to produce toxin.
• The organism E. coli O157H7 is a good example of
  this type of pathogen, able to produce toxin
  after damaging the lining of the intestine. These
  toxins are absorbed by the body, reaching the
  kidneys where they cause substantial damage to
  the convoluted tubules.
• In addition to serotype O157H7, other
  enterohemorrhagic E. coli serotypes are O145H-,
  O26H11, O104H21, and O111NM.

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• The following steps could be taken to avoid
  consumption of contaminated foods
• 1. Avoid overdose use of pesticides or
  preservatives such as sodium benzoate.
• 2. Samples of food crops or food product should
  be tested for residual pesticides or
  preservatives by appropriate agencies e.g. NAFDAC
  to ensure safety before they are distributed to
  the market for consumers.
• 3. In preparation of foods, simple unit
  operations such as peeling/dehulling, soaking,
  dewatering, boiling, roasting and drying could
  get rid of the natural food toxins and
  antinutritional constituents to insignificant
  levels when properly done.
• 4. Properly cooked food before consumption will
  prevent food poisoning by microorganisms.
• 5. Good hygiene, good handling of food to avoid
  recontamination after cooking and proper storage
  of food before consumption (Good Manufacturing
  Practices)

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• Risk Assessment for Biological Hazards
• Risk assessment refers to the determination of
  the risk posed by an entity or situation to a
  population. To carry out risk assessment of
  biological hazards, there is need to determine
  the probability of risk. In this method, the
  probability, or likelihood, of an adverse event
  occurring due to consumption of a biological
  hazard is determined. In addition, the magnitude,
  or severity, of the risk, even if unlikely to
  happen, is taken into consideration.

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• To carry out a risk assessment of biological
  hazards, the following steps is carried out
• 1. Identify and characterize the hazard (is it
  bacterial, viral, etc?)
• 2. Assess the dose required (number of
  microorganisms) necessary to produce illness.
• 3. Assess the exposure of the population to the
  particular biological hazard (prevalence of the
  organism in a particular food).

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• In conducting a risk assessment, several
  mathematical models of probability can be used.
  The most common is the Poisson distribution,
  expressed as
• P 1 - eRN
• where P probability (in percentage) of infection
  with a food borne pathogens, also known as the
  risk R is a constant specific to a particular
  pathogen, based on its growth characteristics,
  also known as the probability of getting sick if
  one cell of the pathogen is consumed and N is
  the number of cells of the pathogen present in a
  particular food.