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Microorganisms in Foods

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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……..
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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
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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.  www.cdc.gov/eid ;

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………..


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