Food additives: the sweet'n'low down.

Take a munch out of a juicy burger with gooey cheese and crunchy bacon strips--a medley of mouthwatering flavors. And those fat-free potato chips! Not only are they finger-licking oily, they taste as crispy as if they were fried yesterday--even though the bag sat on the store shelf for weeks. Then take a gulp of sugarless cola. It's so syrupy you'd swear it was chock-full of the real thing. If these treats aren't your healthiest bet, then why are they so irresistible?

For one thing, aaauwes, me 2,800 substances--some natural ingredients, others artificial chemicals--that U.S. food makers use to flavor, freshen, and sweeten their goods. "Additives are a fact of food life," says Jackie Newgent, a registered dietitian with The American Dietetic Association. Without your burger meat, cheese, and chips might turn green with mold even before reaching your local supermarket, and your packaged hamburger buns wouldn't have a single vitamin. "Still, most people are suspicious of additives--and confused by what they really are," says Newgent.

No doubt for many shoppers, additives have a negative spin. Consumer-protection groups voice concern over some chemical additives' potential health hazards. And a renewed interest in healthy foods has led many food makers to trumpet "No Additives or Preservatives" on their packages.

Now food researchers are serving up other options to replace additives, and extend food safety and shelf life. One is irradiation, approved by the U.S. Food and Drug Administration (FDA) in 1997. Irradiation is used to zap some hamburger beef and tomatoes with low-dose radiation (gamma and X-rays) to kill harmful bacteria like E: coli and salmonella.

Another new technology may revolutionize food production. Hydrostatic pressure applies 100,000 pounds (45,454 kg) of water per square inch to such products as vacuum-packed, all-natural guacamole. The process retards bacteria, and gives the guacamole a shelf life of six weeks in supermarkets--30 days longer than most fresh-chilled foods.

THE DISH ON ADDITIVES

Today, food and drink makers use additives to spur your appetite in a number of ways:

* Need to feed your sweet tooth? One additive, aspartame, delivers sweetness with a fraction of sugar's calories. Surprisingly, aspartame is made of mostly natural chemicals, such as amino acids (building blocks of protein) and methyl esters, alcohol compounds that eliminate water. Together these chemicals enhance sweet flavor.

* Does creamy texture make you salivate? Emulsifiers or food thickeners help make a scoop of chocolate ice cream feel like a smooth ride rather than a rocky road. Common emulsifiers: lecithin (often made from soybeans), alginates (chemical salts found in algae), and glycerides (syrupy chemicals found in alcohols).

Emulsifiers keep ingredients in, say, creamy salad dressings from separating. How do emulsifiers do their job? They're made of two-ended molecules, or atomic particles: one end bonds easily to fats, the other to water-based molecules. These molecules let emulsifiers easily combine different ingredients, like sugar and cream.

* Fresh-food fan? Food makers use additives as preservatives to give their products "farm fresh" taste. Preservatives serve two basic functions: Antimicrobials, chemicals such as nitrates and phosphates--found in breads, cheese, and potato chips--slow the growth of molds and bacteria. They either directly destroy bacteria, or provide an "environment" adverse to microbial growth.

Antioxidants like BHA and ascorbic acid (Vitamin C) keep fats and oils in baked goods from going rancid. Much of food spoilage is due to oxidation, the reaction between oxygen in the air and food. Antioxidants slow the breakdown of oxygen in foods.

With so many additives in your foods, it's only natural to wonder: Are the foods you eat safe? Are you safe?

THE BEEF WITH ADDITIVES

"Americans have the safest food supply in the world, in part because of additives," says dietitian Newgent. While some consumer groups cry foul when it comes to additive health hazards, few scientific studies confirm the concern, Newgent claims. For one thing, the Food Safety and Inspection Service (FSIS) and FDA monitor the safety and nutritional value of all substances added to food during production, processing, packaging, and storing. For another, most foods contain minuscule amounts of additives--hardly enough to cause negative reactions.

Even so, some people seem to be additive-sensitive, and for others, additives may be downright dangerous. One out of 20,000 babies is born with a rare disease called PKU, and can't digest one of the amino acids found in aspartame. The FDA also estimates one out of 100 people may suffer asthma attacks due to sulfites, chemical preservatives found in some dried fruit and seafood. Today the FDA requires foods containing sulfites to be labeled.

Nutritionists suggest you check all food labels for additives in case you think you may be sensitive. Want more sweet `n' low-down on additives? Turn the page.

RELATED ARTICLE: ADDITIVES - TASTER'S CHOICE

What is it?

A. SPARTAME

Aspartame, a white, odorless powder, is an "intense" sweetener. It's more commonly known by the brand names NutraSweet and Equal.

CAFFEINE

Caffeine is a stimulant (substance stimulating the heart and respiratory system) that looks like fine white powder.

MSG 

Monosodium glutamate, a flavor enhancer with little taste of its own, intensifies the flavor of other foods. The white powder or crystals resemble table salt or fine sugar.

NITRITES

Nitrites/nitrates are preservatives that protect food from fungi and bacteria. The table salt look-alikes extend foods shelf life and keep the color of preserved meats and fruits looking "farm fresh."

SULFITES

Sulfites preserve food shelf life, and reduce discoloration of fruit and veggies. Two sulfites: sulfur dioxide and sodium bisulfite. Sulfur dioxide is a gas and sodium bisulfite looks like salt.

What's in it?

Chemical Formula: [C.sub.14] [H.sub.18] [N.sub.2] [O.sub.5]

Made by combining amino acids (building blocks of protein) with methyl esters, alcohol compounds that eliminate water.

Chemical Formula: [C.sub.8] [H.sub.10] [N.sub.4] [O.sub.2]

Caffeine used in soda is mostly produced by removing caffeine during coffee production.

Chemical Formula: [C.sub.5] [H.sub.9] [NNaO.sub.4]

Made from sugar beets, starch, molasses, or artificially in labs

Chemical Formula: Sodium Nitrate - [NaNO.sub.2]

Potassium Nitrate [KNO.sub.2]

Manufactured in labs

Chemical Formula: Sulfur dioxide - [SO.sub.2] Sodium bisulfite - NaHSO

Manufactured in labs

What it in?

Carbonated drinks, candy, chewing gum, fruit-flavored drinks, chewable vitamins

Coffee, tea, chocolate, cola drinks (A 12-oz can may contain 30-60 mg, one-third to one-half the amount in a 7-oz cup of coffee.)

Meats, poultry, soups, snack foods, Chinese food

No one knows exactly how flavor enhancers work. One theory is they trigger an increase in salivation. That makes food break down faster and release more flavor.

Processed meats, ham, bacon pastrami, hot dogs

While nitrate itself is harmless, it readily converts to nitrite.

Raw potatoes prepared for French fries, relishes, some dried fruit, canned tuna, some cookies, pie and pizza crusts, fruit juices

What's the low-down?

Discovered in 1965 in an ulcer research laboratory, aspartame breaks down in the human body into byproducts that may include formaldehyde (embalming fluid) and formic acid (acid produced by ants).

Some consumers report dizziness and headaches.

Caffeine is mildly addictive and may result in withdrawal symptoms like headaches, irritability, and insomnia.

Excessive amounts can cause tremors, palpitations, and feelings of anxiety.

Some consumers report headaches, sleepiness, nausea, distorted perception, and vomiting.

Nitrites react with certain amines (parts of protein) in preserved food to produce nitrosamines, which if consumed in very large doses over a long period of time may cause cancer. Most foods contain minuscule amounts.

The FDA estimates that one out of every 100 people is sulfite sensitive.

Symptoms may include difficulty breathing and stomach aches.

Asthma sufferers should avoid sulfites altogether.