Commercial Mayonnaise

Commercial Mayonnaise

Mayonnaise (in Hebrew “מיונז”) is an emulsion — a stable mixture of oil in water, held together by the lecithin in egg yolk. In terms of composition, that is almost the whole story: about 75-80% of mayonnaise’s weight is vegetable oil. Everything else — egg, vinegar, salt and a pinch of mustard — is less than a quarter.

That is why it has 680 calories per 100 grams, and it is also why it turns any dish it goes into an entirely different dish calorie-wise.

By the way, mayonnaise has a reputation as the main culprit in picnic food poisoning — a reputation it doesn’t deserve, and we’ll explain why below.

Nutrition facts per 100 grams

In practical terms: a tablespoon of mayonnaise (14 grams) is about 95 calories and 10.3 grams of fat. Two tablespoons in a tuna salad add almost 200 calories — more than the tuna itself.

“Light” — what actually replaces the oil

When you remove 60% of the oil, you create a gap that has to be filled. In reduced-fat mayonnaise it is filled with water, modified starches, gums (guar, xanthan) and sugar — and sometimes more salt, to make up for the lost flavor.

The result is mixed:

• Calories — a real and significant improvement, sometimes threefold.
• Sugar — light mayonnaise usually contains more sugar and carbohydrates than regular mayonnaise (8-14 grams vs. 0.6).
• Sodium — often higher.
• The ingredient list — much longer.

The practical conclusion: if the goal is calories, “light” works. But it is usually better to simply use less regular mayonnaise than to switch to a more processed product with sugar and thickeners.

The fat — less dramatic than people think

The oil in commercial mayonnaise is usually soybean or canola oil, meaning it is rich in linoleic acid (omega-6). The argument that this fat is “inflammatory” is common online, but the research picture is more complex:

• Large systematic reviews found that replacing saturated fat with linoleic acid lowers LDL and improves cardiometabolic risk markers.
• The claim that linoleic acid raises inflammation markers in humans was not supported in controlled trials.
• What does deserve attention is the ratio of omega-6 to omega-3 in the Western diet — and the fix is to add omega-3 (salmon, sardines, flax seeds), not necessarily to cut omega-6.

The real downside of mayonnaise is not the type of fat but the amount: 680 calories per 100 grams, at a density that is very easy not to notice.

The myth: mayonnaise and food poisoning

“Don’t take a salad with mayonnaise to a picnic” is a rule of thumb almost everyone knows, and it is the opposite of reality.

Commercial mayonnaise is made from pasteurized eggs and is very acidic — a pH of around 3.6-4.0, thanks to the vinegar and lemon juice. Such an acidic environment inhibits bacterial growth, including Salmonella. In lab studies, adding commercial mayonnaise to a protein salad slowed bacterial growth rather than speeding it up.

So what does cause poisoning from such salads? The ingredients the mayonnaise is mixed with — cooked chicken, hard-boiled eggs, potatoes, tuna — and above all time and temperature. A salad that has sat in the sun for four hours is dangerous whether or not it contains mayonnaise.

The important exception: homemade mayonnaise is made from raw, unpasteurized egg yolk, and it does pose a Salmonella risk — especially for pregnant women, children, the elderly and the immunocompromised. They should use pasteurized eggs or commercial mayonnaise.

Benefits

• Texture and flavor. Mayonnaise plays a real technological role — it binds salads, adds moisture to dry dishes and improves mouthfeel.
• Vitamin E and vitamin K from the vegetable oil, in reasonable amounts.
• Fat that aids absorption. Carotenoids in a vegetable salad — lutein, lycopene, beta-carotene — are fat-soluble, and a tablespoon of mayonnaise increases their absorption significantly. This is true of any fat source, but it is true of mayonnaise too.
• A reasonable fat profile. Mostly unsaturated, with only 11.8 grams of saturated fat per 100 grams — less than butter or hard margarine.
• Microbial safety in the commercial version — as detailed above.

Downsides and considerations

• Extreme calorie density. 680 calories per 100 grams — among the highest of any food product. The problem is that it is spread, not measured.
• Sodium. 635 mg per 100 grams, and sometimes more in light versions.
• “Mayonnaise” that isn’t mayonnaise. In Israel and Europe there is a minimum oil and egg-yolk requirement for a product to be called “mayonnaise”. Cheap products are sold as “mayonnaise sauce” or “mayonnaise-flavored spread” and contain less oil and more starch, sugar and stabilizers.
• Added sugar. Present in some brands, and in almost all “light” versions.
• Homemade mayonnaise and Salmonella — as detailed above.
• Shelf life after opening. An opened jar keeps in the fridge for about two months; homemade mayonnaise — only 3-4 days.

Practical use

• Measure, don’t spread. A teaspoon (5 grams) is 34 calories; a tablespoon (14 grams) is 95. When you scoop from the jar by eye, the real number is usually double.
• Cut it by half. Half mayonnaise and half Greek yogurt in a tuna or egg salad — almost the same texture, about half the calories, and a protein bonus.
• Alternatives that work: diluted raw tahini (adds calcium and fiber), mashed avocado, 5% white cheese, or mustard — which is almost calorie-free.
• Read the name on the jar. “Mayonnaise”, not “mayonnaise-flavored sauce”.
• Check for sugar in the ingredient list — especially in reduced-fat versions.
• Picnic safety: the real rule is temperature and time, not mayonnaise. A salad containing protein should not stay out of the fridge for more than two hours (and only one hour on a hot day).
• Homemade mayonnaise: pasteurized eggs, immediate refrigeration, use within 3-4 days.
• Make use of the fat: a tablespoon of mayonnaise in a colorful vegetable salad is not just flavor — it improves carotenoid absorption.

Summary

Commercial mayonnaise is, for practical purposes, oil in a jar: 75% of its weight and 680 calories per 100 grams. The type of fat is not the problem — it is mostly unsaturated, and the fear of “inflammatory omega-6” is not well supported by controlled trials. The problem is the amount spread without measuring, and the simplest fix is a measured teaspoon or diluting it with yogurt. Finally, a myth worth letting go of: mayonnaise is not the culprit in picnic food poisoning — it is acidic and pasteurized, and the real culprits are the chicken, the egg and the potato that sat in the sun for four hours.