Lec17 food ingredients I

Protein & food allergies

When a protein from a food is absorbed without being completely digested, a food allergy is triggered The first time the protein is consumed and absorbed intact, immune system is stimulated When consumed again, immune system causes an allergic reaction

Is HFCS WORSE THAN OTHER SWEETENERS?

When consumed in large amounts, HFCS has the potential to increase body fat In addition, the production of HFCS may have an impact on the environment But will eliminating HFCS from our food supply necessarily make our diets healthier or protect the environment?

Hidden allergens

Eggs - baked goods, noodles Milk - pies, cheese Soy - baked goods, candy, tv dinners Wheat - flours, soup mixes, snacks Peanut - candy, baked goods, ice cream Fish - seafood flavors New food labels should help

Food Intolerance食物耐受不良

More common than allergies Food poisoning Histamine组胺 toxicity (cheese, wine, fish) Lactose intolerance Food additives (MSG) Gluten intolerance (small intestine) Corn products True allergy - avoid food (immune system) Intolerance - small amount is ok (digestive system)

How are food allergies diagnosed?

Physician Medical history, physical exam Skin test Lab tests Oral food challenge Elimination diet Double-blind food challenge

Who gets a food allergy?

- About 3 to 8 percent of children have reaction - Only 1 to 2 percent have true food allergies - Children usually grow out of sensitivity by age 4 (not peanuts, tree nuts, shellfish) - About 1 to 2 percent of adults

What are high intensive sweeteners?

- Many times sweeter than table sugar (sucrose), - smaller amounts of high-intensity sweeteners are needed to achieve the same level of sweetness as sugar in food People choose to use- why? -do not contribute calories or only contribute a few calories to the diet -High-intensity sweeteners generally will not raise blood sugar levels

Are there other sugar substitutes that are not high-intensity sweeteners?

- Yes. Sugar alcohols糖醇, another class of sweeteners, can be used as sugar substitutes. - Sugar alcohols are slightly lower in calories than sugar; do not promote tooth decay龋齿; not cause a sudden increase in blood glucose. - They are used primarily to sweeten sugar-free candies, cookies,and chewing gums.

How does FDA regulate the use of high intensity sugar in food

A high intensity sweetener is regulated as a food additive, unless its use as a sweetener is generally recognized as safe (GRAS). -GRAS determination: based on scientific procedures is that experts qualified by scientific training and experience to evaluate its safety conclude, based on publically available information, that the substance is safe under the conditions of its intended use. A company can make an independent GRAS determination for a substance with or without notifying FDA. Regardless of whether a substance is approved for use as a food additive or its use is determined to be GRAS, scientists must determine that it meets the safety standard of reasonable certainty of no harm under the intended conditions of its use. This standard of safety is defined in FDA's regulations.

Artificial sweeteners

Also called Non nutritive sweeteners commonly used as sugar substitutes or sugar alternatives High-intensity sweeteners, like all other ingredients added to food in the United States, must be proven safe for consumption.

MILK ALLERGIES

Protein in milk- Casein 酪蛋白 Avoid milk- seek alternative sources of milk- soy milk, almond milk, rice milk

Cross Reactions (food and non-food)

Ragweed- Watermelon, cantaloupe, honeydew, bananas Birch pollen-carrots, apples, hazelnuts, potatoes Banana - latex * If allergic to one shellfish or legumes, likely allergic to all!

Symptoms of food allergies

Reaction within minutes to two hours How soon and how severe depend on sensitivity to food, how much was consumed, other foods consume, and preparation May have minor symptoms at first

Six high-intensity sweeteners are FDA-approved as food additives in the US:

SACCHARIN糖精 ASPARTAME ACESULFAME POTASSIUM SUCRALOSE三氯蔗糖 NEOTAME纽甜 ADVANTAME糖精

Symptoms

Severe reactions more common in peanuts, tree nuts, shellfish, fish, and eggs Also more common in those with asthma哮喘 Death usually seen in peanuts or tree nuts

Understanding fructose metabolism果糖代谢

good evidence that this sugar may promote weight gain Fructose not as effective as glucose at stimulating release of hormones that suppress appetite and promote weight loss; nor does fructose inhibit release of hormones that stimulate appetite When compared to glucose, fructose contributes more to fat synthesis and less to appetite suppression抑制 This leads to overweight and weight gain

Are high intensity sweeteners safe to eat?

Based on the available scientific evidence, the agency has concluded that the high-intensity sweeteners approved by FDA are safe for the general population under certain conditions of use. - ADI: Acceptable Daily Intakes- levels that should not be exceeded when using these products - ADI of Saccharin: 45 sweetener packets; - ADI of Sucralose: 23 packets

Most common food allergies

Children Milk, egg, peanuts, wheat, soy, tree nuts Most will outgrow eggs, milk, wheat, and soy Adults Peanuts, tree nuts (almonds, walnuts), fish, shellfish (shrimp, lobster, crab), mollusks (oysters, clams, scallops)

Eating out with allergies

Chinese, Indonesian, Mexican, etc dishes usually made with peanuts Cross-contamination of allergens Not as easy to read ingredient list

Tips to prevent allergies

Do not consume allergic foods Read the ingredient list If traveling, bring special foods When eating out, ask about foods

HIGH FRUCTOSE CORN SYRUP玉米糖浆

High fructose corn syrup, a spruced-up version of the familiar table product, has taken the spotlight as the leading alternative to high priced cane sugar and beet sugar. A mixture of glucose and fructose produced from corn. The most common form of high fructose corn syrup (HFCS) has 55 percent fructose and 45 percent glucose. Is an aqueous solution sweetener derived from corn after enzymatic hydrolysis of cornstarch, followed by enzymatic conversion of glucose (dextrose) to fructose implicated as a cause of obesity

In what food?

High-intensity sweeteners are widely used in foods and beverages marketed as "sugar-free" or "diet," including baked goods, soft drinks, powdered drink mixes, candy, puddings, canned foods, jams and jellies, dairy products, and scores of other foods and beverages

Trans fat反式脂肪

If saturated animal fats are unhealthy, trans fats are far worse." You're almost better off eating butter and bacon." "Harvard scientists estimate that trans fats may contribute to more than 30,000 premature deaths per year."

Gluten Intolerance

Intolerance, called celiac disease乳糜泻, attacks villi of small intestine Diarrhea, abdominal bloating, cramps, weight loss, anemia