Arugula

Leafy vegetable · Rocket · Peppery salad green

The leaf that gives a salad some bite.

Arugula gives a salad peppery contrast and a tender leafy texture. Its flavor is also a lesson in plant chemistry: some compounds in the leaf are starting materials, and enzymes help turn them into the molecules we taste.

BOTANICAL SKETCH · NOT A SPECIMEN IDENTIFICATION KEY

Identity first

Arugula, rocket and rucola.

Eruca sativa is cultivated rocket, accepted as a species by Kew. [1] Diplotaxis tenuifolia, often called wild rocket, is another salad crop. [2] The shared kitchen name does not make the species identical.

“Baby” describes young harvested leaves, not a separate nutrient or a guarantee of a particular chemical composition. The plant name and growing conditions still matter.

Why it tastes peppery

The bite is part of the plant's chemistry.

Rocket leaves contain glucosinolates. Enzymes called myrosinases break these compounds down into isothiocyanates and other products associated with pungency. The starting compounds and their breakdown products are related, but they are not interchangeable names. [2]

Starting compounds

Glucosinolates

Enzyme step

Myrosinase helps break them down

Changed mixture

Isothiocyanates and other products

A 2011 study of 37 cultivated types compared chemical composition with sensory characteristics. Pungency was related to total glucosinolate content, while particular compounds were associated with bitterness. Aroma, crunchiness and juiciness also contributed to what tasters recognized as rocket flavor. Pepperiness is therefore only one part of the experience. [3]

Original food research

One bag may taste different from the next.

In a 2020 study, researchers examined rocket supplied to the UK market across a year. Higher glucosinolate levels were associated with hotter, more bitter and peppery perceptions, and lower consumer liking. Repeated harvests were also associated with higher glucosinolate concentrations. [2]

What can this seasonal comparison tell us?

The samples varied in cultivar, location and growing conditions. This was composition and sensory research, not evidence that sharper-tasting leaves produce greater health benefits.

Nutrients in context

A reference weight is not the same as a handful.

Hong Kong's Department of Health food profile lists these amounts per 100 g of arugula: [4]

Vitamin K

109 micrograms.

Beta-carotene

1,420 micrograms.

Folate

97 micrograms.

These values describe 100 g of leaves, not a whole salad or a loosely defined handful. Portion size is a separate question from nutrient concentration. A leaf’s strong flavor does not tell us that its portion supplies more of every nutrient.

In the kitchen

Keep the leaves lively.

Refrigeration helps keep the leaves usable; adding dressing near serving avoids a soggy salad. Leaves can also finish pasta or hot soup. [5]

Rinse loose, unwashed leaves with running water—not soap. Ready-to-eat packages need no further washing. [6]

Across the food–skincare boundary

A salad leaf and a cosmetic extract are different materials.

How is a cosmetic leaf extract different?

Eruca Sativa Leaf Extract is a cosmetic INCI for a solvent extract of the leaves, listed for skin conditioning. [7] The name identifies a plant part and preparation. It does not tell us that the extract contains the same nutrient amounts as fresh arugula, or turn food-composition findings into evidence for a finished cream.

At a glance

Reference box

Food: Arugula · Rocket · Rucola · Leafy salad vegetable.
Identity detail: Eruca and Diplotaxis rocket crops are related, not one interchangeable species.
Useful chemistry: Glucosinolates and their breakdown products help explain flavor.
Related topics: Vitamin K · Beta-carotene · Folate · Peach · Burrata.