How Chemistry Gives Spices Their Kick

Capsaicin¹

Capsaicin is the molecule responsible for the heat in chili peppers. It binds to receptors in our mouths that normally detect temperature, tricking Receptors in our mouth into sensing an increase in temperature. It’s also used in topical creams for joint and muscle pain relief due to its ability to desensitize nerve endings temporarily.

Cinnamaldehyde²

Cinnamon owes its signature scent and flavor to cinnamaldehyde, a compound found in the bark of cinnamon trees. In the kitchen, cinnamaldehyde is what gives cinnamon its signature kick in everything from apple pie and oatmeal to curries and chai. Its bold scent also makes it a go-to in cosmetics and home fragrances. Cinnamaldehyde has antimicrobial properties. Its aromatic structure makes it a favorite in both culinary and cosmetic applications.

Eugenol³

Cloves contain eugenol, a compound with a warm, spicy aroma and mild numbing effect. Eugenol also plays a flavorful role in the kitchen. It’s what gives mulled wine, baked goods, and savory spice blends their distinctive depth. Beyond cooking, eugenol is also a key ingredient in perfumes and essential oils.

Piperine⁴

Black pepper gets its sharp, spicy bite from piperine—a compound that does more than just wake up your taste buds. In the kitchen, piperine is what makes black pepper a versatile seasoning, adding depth to everything from scrambled eggs to steak rubs. It’s also used in fragrances.

Curcumin⁵

Curcumin is the bright yellow compound in turmeric, known for its antioxidant and anti-inflammatory properties. It adds earthy flavor and rich color to curries, soups, rice dishes, and more. Curcumin is also a staple in nutritional supplements and skincare products.

Why It Matters

Spices are more than flavor enhancers—they’re natural compounds that can affect everything from our mood to our memory. National Chemistry Week is the perfect time to appreciate how these tiny compounds bring science and flavor together.