Microorganisms in Foods

1
Microorganisms in Foods

• Lecture 12
• March 4, 2013
• Dr. Ponnusamy

2
Food Microbiology

• The Beneficial Microorganisms..
• Probiotics
• Prebiotics
• The Not-So-Beneficial Microorganisms..
• Food borne Illness
• Food Spoilage
• Food borne pathogens

3
The Good and Bad of Microorganisms

• Harmful effects
• Food borne diseases
• Food infections
• Food poisoning
• Viral borne infections
• Food spoilage

• Beneficial effects
• Fermentation
• Cheese
• Yogurt
• Fermented sausages
• Wine
• Sauerkraut
• Probiotics

4
Lets start with the GOOD bacteria..
5

• PRO- PRE- BIOTICS
• FOR THE COLON
• The friendly bacteria for fermentation are called
  the probiotics (pro-life)
• Certain fibers in food, called prebiotics,
  specifically support these probiotic bacteria.

6
Foods for Colon Health

• Probiotics Live bacteria
• Improve intestinal microbial balance
• Yogurt live with active cultures

7
Probiotics

• Means for life
• Live microorganisms which when administered in
  adequate amounts confer a health benefit on the
  host

Bifidobacterium adolescentis
Saccharomyces boulardii
http//microbewiki.kenyon.edu
http//www.institut-rosell-lallemand.com
Lactobacillus rhamnosus
http//www.gutflora.org
Source FAO/WHO Report October 2001
8
Foods for Colon Health

• Prebiotics Fiber
• Stimulate growth of beneficial bacteria in colon
• Inulin, Polydextrose, Resistant starch
• Sources yogurts fortified with prebiotics,
  wheat, whole grain and dairy products, legumes,
  leafy greens, artichokes, bananas, berries,
  chicory, garlic, honey, leeks, onions to
  name a few

9
Why abnormal gut microflora?
Health Conditions
Factors
Smoking Western type diet Age Physical activity
level Public health practices Smaller
Families Premature delivery Cesarean
section Perinatal antibiotic use Lack of
breastfeeding

• Type 2 diabetes
• Cancer
• Coronary heart disease
• Cholesterol
• Obesity
• Digestive disorders (IBD)
• Allergies
• Common cold
• Infections
• Diarrhea
• Lactose intolerance
• Impaired immunity

Abnormal gut microbiota
10
The Good Microorganisms Probiotics

• Human probiotics where?
• Gastro-intestinal
• Skin
• Scalp
• Oral cavity
• Underarm and feet
• Urogenital
• including vaginal

• Expected Benefits with Consumption
• Increased tolerance to infections
• Control of diarrhea
• Reduction of blood pressure
• Cholesterol reduction
• Allergy control
• Immunomodulation
• Cancer reduction

http//www.cook.rutgers.edu/dbm/foodMicrobiologyn
p.pdf
11
ACTION OF PROBIOTICS
12
Global Probiotic Market

• The market is currently valued at 22.6 billion
  and projected to reach 28.8 billion in 2015
• Target consumers are mainly located in Japan,
  Europe and USA
• Growth factors include
• Consumer understanding of the effect of nutrition
  on health
• Rising healthcare costs

Source Global Probiotic Market to Grow
Analyst. FLEXNEWS. 27 Sept 2010. Web. 27 Sept
2010.
13
Probiotic Products

• Dairy foods
• Beverages, yogurt, kefir, ice cream, cheese
• Non-dairy foods
• Beverages, bars, chocolate, cereal, pizza,
  condiments
• Dietary supplements
• Infant formula, drops, tablets, capsules, powders
• Clinical therapeutics

14
Rapid Emergence of Probiotics

• The reported health benefits of probiotic
  bacteria found in cultured and dairy products
  include
• improving digestive absorption
• cleaning the intestinal tract
• production of enzymes
• increasing the availability of vitamins and
  nutrients- especially vitamin B, vitamin K,
  lactase, fatty acids and calcium

15
Probiotics
16
Probiotic Market Overview

• The total international probiotic market in
  yogurts, kefirs and fermented dairy beverages
  translates to 10 billion with growing annual
  sales
• US Sales of probiotics was estimated to be
  approximately 764 million and was expected to
  rise to 1.1 billion in 2010 an average annual
  growth rate (AAGR) of 7.1
• The appeal of such benefits served to bolster
  yogurt sales significantly in a number of markets
  and made probiotic yogurt the second fastest
  growing dairy products category, with CAGR growth
  of more than 16, between 1998 and 2005

Dairy Field, 2006 Business Communications
Company (BCC) Research, 2005 Euromonitor
Source Nexis - Dairy Field, March 2007,
Euromonitor Industry Profile Global Dairy
Products Market, October 2006
17
The Not-So-Beneficial Microorganisms
18
The Not-So-Beneficial Microorganisms

• The ones that cause
• Food borne Illnesses
• Food intoxications
• Food infections
• Food Poisoning
• Food Spoilage

19
Foodborne Illness

• Illness occurring as a result of ingesting food
  or water contaminated with
• Infectious agents
• Bacteria, molds, yeasts
• Viruses, prions
• Parasites
• A toxin or chemical
• Bacterial toxin
• Pesticides, Heavy metals
• Other chemical contaminants

20
Harmful Food Infection vs. Food Poisoning

• Food infection
• Live cells delivered by contaminated food
  organism multiply once food is ingested
• Salmonella E. coli
• Food poisoning (intoxication)
• Caused by preformed toxin in the food organism
  may or may not be alive and growing
• Clostridium botulinum Staphylococcus aureus

21
FINDINGS CDC Estimates of Food borne Illness
in the United States- 2011

• CDC estimates that each year roughly 1 in 6
  Americans (or 48 million people) gets sick,
  128,000 are hospitalized, and 3,000 die of food
  borne diseases.

22

• CDC has estimates for two major groups of
  foodborne illnesses
• Known foodborne pathogens 31 pathogens known to
  cause foodborne illness.
• Many of these pathogens are tracked by public
  health systems that track diseases and outbreaks.

23

• Unspecified agents
• Agents with insufficient data to estimate
  agent-specific burden known agents not yet
  identified as causing foodborne illness
• microbes, chemicals, or other substances known to
  be in food whose ability to cause illness is
  unproven and agents not yet identified.
• Because you cant track what isnt yet
  identified, estimates for this group of agents
  started with the health effects or symptoms that
  they are most likely to cause
• acute gastroenteritis.

24
CDC Estimated Data on Foodborne Disease in the
United States- 2011
Top 5 Pathogens Estimated number of hospitalizations
Salmonella, nontyphoidal 19,336
Norovirus 14,663
Campylobacter spp. 8,463
Toxoplasma gondii 4,428
E.coli (STEC) O157 2,138
From W_Fanaselle FDA, CFSAN
25
CDC Estimated Data on Foodborne Disease in the
United States- 2011
Top 5 Pathogens Estimated number of deaths
Salmonella, nontyphoidal 378
Toxoplasma gondii 327
Listeria monocytogenes 255
Norovirus 149
Campylobacter spp. 76
From W_Fanaselle FDA, CFSAN
26
Specific Product Concerns

• Produce
• Imported foods
• Juice
• Eggs
• Raw milk

27
2006 Nationwide Outbreak of E. coli

• Source Spinach
• Illness in 26 states
• 204 cases of illness reported to the CDC
• 31 cases involving a type of kidney failure
• 104 hospitalizations and 3 deaths
• Four implicated fields on Four ranches
• Cause Cattle and pig feces

28
2008-9 Peanut Salmonella RecallMore than 31
million pounds 125 items affected in salmonella
probe

• Case count is 677 in 45 states with latest
  confirmed, most recent reported illness beginning
  on February 8, 2009
• The outbreak is continuing, though the numbers of
  new cases have declined modestly since December.
• FDA and CDC are concerned that illness will
  continue to occur if people eat recalled
  peanut-containing products that are still on
  their shelves at home.
• Consumers should check at home for recalled
  peanut butter containing products and discard
  them.
• Major national brands of jarred peanut butter
  found in grocery stores are NOT on the Peanut
  Corporation of America (PCA) recall list.

http//www.cdc.gov/salmonella/typhimurium/update.h
tml
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Listeria outbreak

• In 2011, a Listeria outbreak in cantaloupe caused
  30 deaths and 146 illnesses across 28 states.
• Listeria is particularly dangerous because it
  lives in soil, infecting the inside of cantaloupe
  as well as the outside.
• Additionally, it thrives in cold temperatures
  (such as refrigerator).

30
Outbreaks Involving Raw Milk

• Outbreaks from dairy products was studied from
  1993 to 2006 in all 50 states
• CDC Reports The rate of outbreaks caused by
  unpasteurized milk (often called raw milk) and
  products made from it was 150 times greater than
  outbreaks linked to pasteurized milk
• http//www.cdc.gov/media/releases/2012/p0221_raw_m
  ilk_outbreak.html

31
Safety Concerns over Raw Milk

•  Raw milk product outbreaks led to much more
  severe illnesses, and disproportionately affected
  people under age 20.
• 60 percent of patients were younger than age 20
  children are more likely than
• adults to get seriously ill
• from the bacteria in raw milk.
• Consuming raw milk is not
• worth the risk

32
Safety Concerns over Raw Milk

• 13 of patients in raw milk outbreaks were
  hospitalized compared to 1 percent in pasteurized
  milk outbreaks.
• Raw milk outbreaks were all caused by bacteria,
  such as E. coli O157, which tend to produce more
  severe illnesses, according to the study.
• Pasteurized milk and cheese outbreaks were often
  caused by relatively mild infections like
  norovirus and Staphylococcus aureus.
•  www.cdc.gov/eid http//www.cdc.gov/foodsafety/r
  awmilk/raw-milk-index.html.

33
Spoilage Microorganisms in Foods

• Food Spoilage Microorganisms bacteria, yeasts,
  molds (yeasts and
  molds are fungi)
• It is important to be able to distinguish food
  borne illness from food spoilage

Spoiled food may not normally cause food
poisoning because it is rejected by the consumer
before ingestion
Food borne illness occurs when food is eaten
which looks normal, smells normal and tastes
normal you eat enough to make you ill from the
ingested pathogens or toxins
34
Microbial Food Spoilage Changes in Food Quality

• Odor
• due to production of volatile end compounds
• Color
  
• pigment production or oxidation
• Texture
• softening due to the breakdown of pectin in
  vegetables or the tissues by proteinases
• Accumulation of gas
• carbon dioxide, sulfur compounds
• Slime formation
• production of dextrans and/or amount of
  microorganisms

35
Microbial foodborne illness

• Symptoms
• Mild abdominal pain, nausea, diarrhea, vomiting
• Severe
• spontaneous abortion
• hemolytic uremic syndrome
• arthritis
• kidney failure and death

36
Timeline of Foodborne Illness
Best case 6 days Worst case 23 days
http//ocw.jhsph.edu/courses/nutritionalhealthfood
productionandenvironment/PDFs/FoodEnv-sec7f_Schwab
_GrahamOCW.pdf
37
Pathogens in Foods
Bacteria
Parasites

• A pathogen is a microorganism capable of
  producing a disease

Viruses
Prions
Molds
38
Where from microorganisms come into foods?

• CONTAMINATION
• Soil, contaminated water
• Oral-fecal route
• WASH HANDS AFTER VISITING
• THE BATHROOM!!!!
• Improper food handling
• FOOD HANDLERS WHO ARE
• UNWELL
• Improper temperature of food storage
• Improper cooking temperatures

39
Harmful Bacterial Pathogens of Public Health
Concern

• Escherichia coli
• Clostridium botulinum
• Salmonella species
• Campylobacter species
• Listeria species
• Staphylococcus aureus

• Aeromonas hydrophila
• Bacillus cereus
• Shigella species
• Vibrio spp.
• Yersinia enterocolitica

http//vm.cfsan.fda.gov/comm/ift-over.html
40
Viruses in Foods

• Do not grow on foods
• When consumed in foods, they can multiply in the
  human body
• Cause food-borne illness

41
Viruses in foods

• Norovirus gastroenteritis or stomach flu
• Destroyed by cooking
• Water, salads, raw shellfish potential carriers
• Hepatitis A
• Contagious viral disorder
• Inflammation of liver, jaundice, abdominal pain
• Contaminated water, shell fish
• Vaccine available

42
Molds in Foods

• Grow on breads, cheese,
• fruits
• Produce toxins,
• leading to food intoxication
• If a food appears suspiciously moldy, simply
  discard it!
• 
  Moldy bread

43
Parasites in foods

• Some are single-celled and tiny
• Example Toxoplasma
• Some are worms
• Tape-wormscitihealth.com
  Flat-wormsanimalcorner.co.uk

44
Prions in Foods sussex.ac.uk

• An infectious protein particle
• Folding of proteins
• is abnormal
• Not a microorganism

45
PRIONSIN FOODS

• Prions are the cause of mad cow disease
• BSE Bovine Spongiform Encephalopathy
• Caused by eating cow infected with this prion
• Mood swings leading to dementia and death

46
Prevention of Deleterious MicrobesKnowledge
and ActionFood Handling and Food Processing
47
Prevention of microbial illnesses of foods

• Prevent contamination
• Knowledge of how
• contamination occurs
• Handle, store, prepare
• foods safely

48
Preventive measures for Outbreaks

• At the field
• Irrigation water
• Proximity to cattle, pig, and other animal
  ranches
• Farm worker access to portable toilets and hand
  washing facilities
• At the processing plant
• Decontamination steps
• Distribution
• Maintaining appropriate temperatures
• Consumer education

49
HACCP (hah- sup) Hazard Analysis of Critical
Control Points

• A tool useful in the prevention of food safety
  hazards
• HACCP is not a stand alone program.
• HACCP program also includes
• good manufacturing practices
• sanitation standard operating procedures
• personal hygiene program.
• A flow diagram of the complete process is
  important in conducting the hazard analysis.

50
Principles of HACCP VIDEO

• 1. Hazard analysis
• 2. identify critical control points
• 3. establish critical limits
• 4. monitor critical control points
• 5. establish corrective action
• 6. Record- keeping
• 7. Verification

51
HACCP Summing up

• Not a standalone program
• Identifies critical control points
• Specific to a particular food service operation
  and establishment
• Continuous and systematic approach to assure food
  safety.
• Both FDA and USDA are proposing umbrella
  regulations which will require HACCP plans of
  industry.

52
Safe Food Storage and Preparation
53
5 Major Risk Factors of Food Safety

• Poor personal hygiene
• Improper holding temperatures
• Inadequate cooking
• i.e. undercooking raw shell eggs
• Contaminated equipment
• Food from unsafe sources

54
Fight Bac Educating Consumers
www.fightbac.org
55
Proper food storage starts at the store

• Shop for shelf-stable items such as canned and
  dry goods first
• Buy refrigerated and frozen foods and hot deli
  items last
• Don't choose meat, fish, poultry or dairy
  products that feel warm to the touch or have a
  damaged or torn package
• Place leaking packages in plastic bags
• Choose only pasteurized dairy products
• Choose only refrigerated eggs
• Check "sell-by" and use by dates on packages
• Buy intact cans that are not bulging, leaking or
  dented on the seam or rim

http//www.fmi.org/consumer/foodkeeper/general.htm
56
SAFE FOOD HANDLING VIDEO
57
REMEMBER!Cooking
www.foodsafety.gov
58
REMEMBER!

• Thawing Frozen foods should be thawed in the
  refrigerator or microwave to ensure safety
• Spoilage
• Both low and high temperatures are used to
  prevent food spoilage

59
Take care Guidelines for Leftovers
60
REMEMBER THE PRINCIPLE FAT TOM

• Food medium for microorganism to grow
• Acidity lower pH of food prevents bacterial
  growth in foods
• Time cook and store for recommended time
• Temperature high temperature kills bacteria low
  temperatures stop their growth
• Oxygen packaging eliminates oxygen, so few or no
  bacteria
• Moisture dry the food and prevent bacterial
  growth

61
How to preserve foods
awakeandliving.com
62
Methods of food preservation

• Heating to kill, slow and stop bacteria in foods
  
• 1. Pasteurization kills pathogenic bacteria,
  reduces number of microbes, but some bacteria
  survive refrigeration storage needed
•  heating the milk briefly to  161 F for about 20
  seconds, to kill disease-causing microbes
  (e.g., Salmonella, Escherichia coli O157,Campyloba
  cter) that can be found in raw milk. 

63
Pasteurization

• Pasteurization does not significantly change the
  nutritional value of milk pasteurized milk is
  rich in proteins, carbohydrates, and other
  nutrients.
• Heat slightly affects a few of the vitamins found
  in milk-- thiamine, vitamin B12, and vitamin C.
• Foods that can be pasteurized eggs, milk,
  juices, spices, ice creams

64
Methods of Food Preservation

• Heating to kill, slow and stop bacteria in foods
  (examples juices, milk, eggs)
• 2. Aseptic processing sterilize food in a
  sterilized package using sterile process longer
  shelf life than pasteurized foods room
  temperature storage
• 3. Canning Foods sealed into cans and then
  heated to a high temperature (above 100C).
  Microbes in the food killed sealed can prevents
  fresh contamination Spores may survive

65
Methods of food preservation

• 4. Irradiation cold pasteurization
• Food exposed to x-rays, high-energy electrons to
  kill microorganisms, insects, inactivate enzymes
• Germination and ripening delayed
• Poultry, red meats, flour, spices, potatoes,
  fruits, vegetables, grains can be irradiated
• Increases safety and shelf-life of foods
• Does not produce radioactive foods no potential
  risks

66
Reducing the growth of microbes

• Many methods of food preservation are used.
• Processes such as fermentation, drying, pickling,
  all attempt to remove one or more of the factors
  necessary for the growth of food-spoiling
  microbes.
• FAT TOM

67

• Fermentation preserves produces foods like
• Cheese
• Yogurt
• Fermented
• sausages
• Wine
• many more..