1. Microorganisms in Foods
Lecture 12
March 2, 2015
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. Let’s 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. Probiotics: Live bacteria
Foods for Colon Health
Probiotics: Live bacteria
Improve intestinal microbial balance
Yogurt – ‘live with active cultures’
Probiotic Therapy: Consuming products with beneficial bacteria and supplements

7. Probiotics Means ‘for life’
Live microorganisms which when administered in adequate amounts confer a health benefit on the host
Bifidobacterium adolescentis is found in healthy human and animal intestine. Isolated from feces of breast-fed newborns and was later use to treat infant diarrhea and is used to manufacture probiotic dairy foods.
L. rhamnosus was isolated from intestines of a healthy human subject and used in yogurt-based products.
S. boulardii is a strain of yeast discovered in southeast Asia. It grows in high temperature (98.6F) and mostly sold in capsules.
Bifidobacterium
adolescentis
Saccharomyces boulardii
Lactobacillus rhamnosus
Source: FAO/WHO Report October 2001

8. Stimulate growth of beneficial bacteria in colon
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?
Factors
Health Conditions
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
Probiotic bacteria offer many health benefits ranging from disease prevention via strong immune response to treatment of diseases.
-Public health practices include sanitation, antibiotic use and vaccination.
In clinical research, selected probiotic strains were shown to prevent certain types of cancers in gastrointestinal tract.
L. plantarum PH04 and L. reuteri showed cholesterol-lowering activity which is linked to cardiovascular disease.
Infections include respiratory, diarrhea, urinary track infection and gastrointestinal infections.

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

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
Probiotic products fall under the category of functional foods.
Source: “Global Probiotic Market to Grow – Analyst.” FLEXNEWS. 27 Sept 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
Non-dairy segment is growing partly to the need for convenience and dietary restrictions such as lactose intolerance and concern over cholesterol.
Yakult – L casei Shirota
Activia - Bifidobacterium lactis DN
LiveActive cheese – Bifidobacterium lactus and Lactobacillus rhamnosus
ProLife ice cream Amul – na
Attune chocolate bar - Lactobacillus acidophilus NCFM, Lactobacillus casei Lc-11 and Bifidobacterium lactis HN019.
Zukay – salsa, relish, dressing - lacto-fermented vegetable based products
Good Start Protect Plus – B. lactis BB-12
Florastol capsules – Saccharomyces boulardii

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 infections
Food Poisoning/ Intoxications
Food Spoilage

19. A pathogen is a microorganism capable of producing a disease
Pathogens in Foods
Bacteria
Parasites
A pathogen is a microorganism capable of producing a disease
Viruses
Prions
Molds

20. 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
Foodborne Illness is a broad term.

21. Harmful: Food Infection vs. Food Poisoning
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 ( in canned foods); Staphylococcus aureus

22. 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.

23. 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.

24. 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 can’t “track” what isn’t yet identified, estimates for this group of agents started with the health effects or symptoms that they are most likely to cause—
acute gastroenteritis.

25. 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

26. 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

27. Specific Product Concerns
Produce
Imported foods
Juice
Eggs
Raw milk 21 4

28. 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

29. 2008-9 Peanut Salmonella Recall More 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.

30. 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).

31. 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

32. 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

33. 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.
  ;

34. 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

35. 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

36. Microbial foodborne illness
Symptoms:
Mild: abdominal pain, nausea, diarrhea, vomiting
Severe:
spontaneous abortion
hemolytic uremic syndrome
arthritis
kidney failure and death

37. Timeline of Foodborne Illness
Best case: 6 days
Worst case: 23 days

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

40. Viruses in Foods Do not grow on foods
When consumed in foods, they can multiply in the human body
Cause food-borne illness
Are smaller in size than bacteria

41. Norovirus: gastroenteritis or stomach flu
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. PRIONS IN 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 Microbes Knowledge and Action Food 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. 2. identify critical control points 3. establish critical limits
Principles of HACCP:
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. Not a standalone program Identifies critical control points
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

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

56. SAFE FOOD HANDLING: VIDEO

57. REMEMBER! Cooking:

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: FATTOM
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,Campylobacter) 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 100°C). 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.
FATTOM

67. Fermentation preserves & produces foods like
Cheese
Yogurt
Fermented
sausages
Wine
& many more………..