Presentation on theme: "Lecture Material - Food Safety Inneke Hantoro"— Presentation transcript:
1Lecture Material - Food Safety Inneke Hantoro FOOD ALLERGY
2What is food allergy?Food allergy is an abnormal response to a food triggered by the body’s immune system.The symptoms of an allergic reaction are caused by biologically active chemicals produced by the immune system in its attempt to protect the body from a foreign invader.Allergic reactions to food can cause serious illness or even death.Food allergy is different with food intolerance although both can show similar symptoms.
3Types of food allergyIgE-mediated food allergy (immediate hypersensitivity)e.g. peanut allergy, cows’ milk allergyCell-mediated food allergy (delayed hypersensitivity)involving sensitized immune cells in the small intestine, usually lymphocytes, that are sensitized to the specific substance that triggers the reaction inflammation on certain sites, symptoms appearing 24 hours or more after ingestione.g. celiac diseaseImmediate hypersensitivity : terjadi langsung setelah mengonsumsi makanan mengandung allergenDelayed hypersensitivity: involving sensitized immune cells in the small intestine, usually lymphocytes, that aresensitized to the specific substance that triggers the reaction inflammation on certain sites 24 hours or more after ingestion
4How do allergic reactions work? An immediate allergic reaction involves two actions of our immune system:Our immune system produces immunoglobullin E (IgE) – a type of protein that works against a specific food – antibody.IgE attaches basophils (white blood cells) and to mast cells – cells found in all body tissues. The typical sites of allergic reactions include nose, throat, lungs, skin and GI tract.
5Once sensitized, exposure to the same food allergen on a subsequent occasion can result in an allergic reaction. When this happens, the allergenassociates with the mast cell- or basophil-bound IgE, and cross-links two ofthe IgE molecules. A series of biochemical events is initiated which causescell membrane disruption and the release of a variety of mediators containedwithin granules existing in the mast cells and basophils. The granules in mastcells and basophils contain most of the important mediators of the allergicreaction.While several dozen substances have been identified as chemicalmediators emanating from mast cell and basophils, histamine is responsiblefor most of the immediate effects of allergic reactions.
6How do allergic reactions work? Food allergens are proteins within the food that enter our bloodstream after the food is digested.Food allergen go to target organs such as skin, nose, etc and cause allergic reactions.An allergic reaction to food can take place within few minutes to an hour.
7How do allergic reactions work? The symptoms of cell-mediated allergic reactions do not begin to appear until 6–24 hrs after ingestion of the offending food. These reactions develop slowly, reaching a peak at approx. 48 hrs and subsiding after 72–96 hrs.The mechanisms of cell-mediated food allergies are not nearly as well understood.They involve an interaction between specific food allergens and sensitized T lymphocytes - a major component of the gut-associated lymphoid tissue. Lymphocyte stimulation initiates the release of cytokines and lymphokines which produces a localized inflammatory response.Antibodies are not involved in these reactions.T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity
8Celiac diseaseCeliac disease, or gluten-sensitive enteropathy, is a malabsorption syndrome occurring in sensitive individuals upon the consumption of wheat, rye, barley, triticale, spelt, and kamut.The consumption of wheat or other offending grains or products made from these grains elicits inflammatory damage to the absorptive epithelial cells in the small intestine.
9Celiac diseaseThe loss of absorptive function along with the ongoing inflammatory process results in a severe malabsorption syndrome characterized by diarrhea, bloating, weight loss, anemia, bone pain, chronic fatigue, weakness, muscle cramps, and, in children, failure to gain weight and growth retardation.The inflammatory mechanism involved in celiac disease is mediated by intestinal T lymphocytes.Bloating is any abnormal general swelling, or increase in diameter of the abdominal area.
10The allergic symptoms Itching in mouth as we start to eat the food. GI symptoms such as vomiting, diarrhea or abdominal pain after the food is digested in stomach.When the food allergens enter and travel through the bloodstream, they may cause the blood pressure to drop.As the allergens reach the skin, they can cause hives or eczema.When the allergen reach the lungs, they may cause asthma.
11Cross - ReactivityIf we have a life-threatening reaction to a certain food, our body will show how to avoid similar foods that might trigger this reaction.For example: if someone has a history of allergy to shrimp, he/she will also show allergic reactions to crab, lobster and crayfish.
12Cross contact allergen Cross contact allergens occur when a residue or other trace amount of an allergenic substance is unintentionally added into a food not intended to contain that allergenic substance and where such occurrences are sporadic.
13Common Food Allergies In adults: Shellfish, peanuts, tree nuts (walnuts), fish, eggs, wheat, soy.In children:Eggs, milk, peanuts, soy.Tree nuts and peanuts can cause deadly food allergy reactions called anaphylaxis!
14Anaphylactic reaction is a severe reaction of rapid onset that involves most organ systems (multiple organ failure) and that results in circulatory collapse and a drop in blood pressure.The 1st symptoms usually are burning, itching, irritation of the lips, the inside of the mouth and the throat.Followed by nausea, vomiting, abdominal pain, and diarrhea.
15Food Allergen The allergenic moiety of the food is usually a protein. Allergenic proteins are usually not denatured under food processing conditions and relatively resistant to digestion.Other foods can produce allergen as well, but not as often, e.g. strawberries.The foods to which adults or children usually react are those foods they eat often, e.g.:Soy and rice allergy in JapanCodfish allergy in ScandinaviaPeanuts allergy in US
16Types of Food Allergens Milk proteins: caseins, whey proteins (beta-lactoglobulin), serum proteins (albumin).Egg proteins: ovalbumin, conalbumin (ovotransferrin) and ovomucoid (heat stable).Grain proteins: gliadins, glutenins, albumins and globulins.Peanuts the most frequently cited causes of life threatening anaphylactic reactions!Soy beanSeafoodetc
18The pathogenesis-related (PR) proteins represent a heterogeneous collection of 14 plant protein families that are all involved inplant resistance to pathogens or adverse environmental conditions.2 Manyplant food allergens are homologous to such PR proteins (Table 2.2).3,4Storage proteins are the cause of well-known allergic reactions to peanutsand cereals.3 PR proteins are responsible for pollen–fruit or latex–fruit crossreactivesyndromes.3,4
21Food Allergy Tests Skin tests Identifying the type of IgE that is fixed to the skin mast cell. For example: scratch test.Blood tests analyze blood or blood serumRAST (radioallergosorbent test) or ELIZA ( enzyme-linked immunosorbent assay).These tests measure the presence offood-specific IgE in blood andthe total IgE level in blood.Skin test usually also use negative control: the fluid used for diluting the allergenextract (diluent)And positive control: histamine phosphate (2.7 mg/mL, equivalentto 1 mg/mL of histamine base).
22Food IntoleranceFood intolerance is more common than food allergy, but it doesn’t relate to the immune system.Food intolerance is caused by the lack of our body’s ability to digest certain substances.Some people may have a food intolerance that has a psychological trigger.
23Types of Food Intolerance Food poisoning: foods contaminated with microbes, such as bacteria and bacterial products (e.g. toxins).Histamine toxicityA reaction like an allergic reaction when people consume histamine containing foods, such as in cheese, some wines, tuna and mackerel.
24Types of Food Intolerance Lactose intoleranceIt caused by lactase deficiency.Lactase is an enzyme that is in the lining of the gut.Lactase breaks down lactose, a sugar found in milk and most milk products.Lactose is used by bacteria to form gas which causes bloating, abdominal pain and diarrhea.At least one out of ten people suffer lactose intolerance.
25Types of Food Intolerance Food additives, such as:MSG, when it is taken in large amounts can cause some of the following signs: flushing, sensation of warmth, headache, chest discomfort and feeling of detachment.Sulfites, in high concentrations can pose problem for people with severe asthma.
26How to treat food allergy? Avoiding to eat foods which can trigger allergic reaction.Exercised- induced food allergyThe allergic symptoms may appear as exercise increases and body temperature rises. Therefore, it is required to avoid eating for a couple of hours before exercising.Taking medicine such as antihistamines to relieve GI symptoms, hives, sneezing and runny nose or taking bronchodilators to relieve asthma symptoms.
27Consumer Protections & Labeling Food manufacturers are generally responsible about posting alerts concerning allergen contamination and recalling their products.Labeling of foods containing allergens have to be clear and consistent.The application of GMP in food manufacturing to avoid cross-contamination of food products by foreign allergens.The awareness of the consumers in checking the labels.
28Labeling The general labeling recommendations are: all allergen information should be grouped together to be easily identified and not hidden amongst other labeling informationproduct description and representation should provide an accurate expectation of the product and should not be misleading
29LabelingThe print size should be big enough to be easily read, preferably at a minimum 1.5mm with sans serif font, and the font colour should contrast distinctly from the background. The use of lower or upper case will depend on the overall presentation of labeling information.(FSZAN)
30LabelingA consistent approach in the presentation of allergen information will help allergic consumers more quickly and easily identify foods of concern, helping to minimize accidental consumption of unsuitable foods.The recommended format consists of:an ingredient list declaring in bold allergenic substances and their derivatives; andan allergen summary statement; anda precautionary statement.
32ReferencesFood Allergy: An Overview U.S. Department of Health and Human Services. Retrieved fromJoneja, J. V Dietary Management of Food Allergens and Intolerances: A Comprehensive Guide 2nd Edition.J. A. Hall Publications LTD. Vancouver.