Petunidin

Petunidin is an anthocyanidin, a purple-red, water-soluble pigment in the flavonoid family. It colors many berries and grapes and some flower petals. Its name comes from the petunia, a word the French took from a Tupi-Guarani word for tobacco. Purple petunia petals do hold petunidin and malvidin pigments.

In food it occurs attached to sugars, as in petunidin-3-glucoside. Blueberries lead the USDA data with 31.5 mg per 100 g.

Chemically it sits between two better-known pigments. It is delphinidin with one extra methyl group on the B ring. In a lab experiment, an enzyme added a second methyl to petunidin-3-glucoside to make malvidin-3-glucoside.

Some foods lean on it more than others. In a study of four red- and purple-fleshed potato cultivars, petunidin was the main anthocyanidin in the purple ones. A 2026 review calls petunidin-derived pigments the most distinctive feature of black goji berries.

Most readers do not know how little of it turns up in the body after a berry or a glass of wine. In a grape juice study, the blood peak of petunidin-3-glucoside was only 1.0 nmol/L, a tiny amount. In another study, only 0.18% to 0.23% of the anthocyanins in red wine or red grape juice reached the urine.

We found no trial that gave pure petunidin to people. Every human result below comes from a berry, a juice, a drink or a food survey, so none can be credited to petunidin alone.

Health benefits of petunidin

• ★Little petunidin absorbed, and it peaks lateAfter Concord grape juice, blood petunidin-3-glucoside peaked at only 1.0 nmol/L. After wild blueberry powder, petunidin glucuronide (a breakdown product) peaked in blood at about 8.8 hours.
• ★Blueberry powder changed blood petunidinIn 38 healthy adults aged 60 to 75, 24 g a day of freeze-dried blueberry for 90 days changed 11 blood compounds, including petunidin-3-glucoside. Changes in test errors tracked other compounds, not petunidin.
• Population studyLinked to lower odds of heart-kidney-metabolic diseaseIn US survey data, people with more petunidin intake had 0.749 times the odds of combined cardiovascular-kidney-metabolic disease. Other differences between people may explain this link.
• Population studyLinked to lower tooth decay odds in childrenIn 1,818 US children and teens, high intake of anthocyanidins, including petunidin, went with 0.69 times the odds of tooth decay. No separate number is given for petunidin.
• Population studyLinked to lower odds of nearsightedness in teensIn 839 US teens, more petunidin intake went with 0.64 times the odds of myopia (nearsightedness). The pigments come in the same foods, so petunidin cannot be separated from the rest.

Foods high in petunidin

Blueberries lead the USDA data for petunidin with 31.5 mg per 100 g, or 46.7 mg in a cup (148 g). Red wine has 1.98 mg per 100 g (2.91 mg in a 5 fl oz glass of 147 g), about 6% of the blueberry figure. Raspberries (0.31 mg) and strawberries (0.11 mg) follow, and the USDA data list only these four foods for petunidin.

Other foods appear in published analyses, mostly as a main pigment or a share of the pigment, not as milligrams of petunidin. In four red- and purple-fleshed potato cultivars, petunidin was the main anthocyanidin of the purple ones. Fully matured tubers held 10 to 39 mg of total anthocyanidins per 100 g fresh weight.

In native Andean potatoes, the main pigment was a petunidin glycoside (petanin). The darkest cultivar held 16.33 mg of total anthocyanins per gram of dry weight.

In black bean seed coats, delphinidin dominated, with lesser petunidin and malvidin. In 16 Korean kidney beans, petunidin 3-glucoside ranged from 0 to 0.17 mg per gram of dried seed coat.

Red table grapes carry petunidin 3-glucoside among 69 to 151 mg of skin anthocyanins per kg. Fresh blueberries had more petunidin-3-galactoside than bilberries, whose main pigments were delphinidin and cyanidin glycosides.

How much do people eat? In US food data from 2001 to 2002, cyanidin, delphinidin and malvidin supplied 45%, 21% and 15% of anthocyanin intake. So petunidin sits in the remaining 19% that it shares with two other pigments.

In a European study of 36,037 adults, cyanidins and malvidins were the main anthocyanidins. The ranking below is from USDA data.

How petunidin works

Most of what we know about how petunidin works comes from test tubes, cells and animals, plus a few absorption studies in people. Three ideas come up: its small chemical change from delphinidin, its poor and late absorption, and its effect on oxidative stress enzymes in cells. Here is each one, and what has been seen in people.

It is delphinidin with one extra methyl group

Petunidin is the B-ring 5’-O-methylated form of delphinidin, according to a 2019 bone study. In the lab, an enzyme called catechol-O-methyltransferase methylated the B ring of petunidin-3-glucoside to make malvidin-3-glucoside. So petunidin sits one step before malvidin. See our delphinidin and malvidin pages for the neighbors.

The extra methyl changes how it behaves, but not in one direction. In a comparison with delphinidin, petunidin scored higher in a cell-based antioxidant test and lower in two test-tube radical tests.

Purified standards were also heated, microwaved or treated with ultrasound. Delphinidin was more stable, microwaving broke both down fastest, and the breakdown products were weaker antioxidants. Petunidin broke into phloroglucinaldehyde, petunidin chalcone and 3-methoxy-4,5-dihydroxybenzoic acid.

In mice, blueberries and Concord grapes, rich in methylated pigments such as malvidin and petunidin, protected better against high-fat-diet damage than berries with fewer. Those berries hold many other compounds, so the result is not proof for petunidin.

Little is absorbed, and the pieces appear late

In 9 volunteers, only 0.18% to 0.23% of the anthocyanins in red wine or red grape juice reached the urine within 7 hours. The authors called any large health contribution questionable. After Concord grape juice, petunidin-3-glucoside peaked at 1.0 nmol/L in blood, the lowest value reported.

After a wild blueberry drink, the bioavailability of its anthocyanins was 1.1%. The petunidin glucuronide peaked about 8.8 hours later, after the parent pigments at about 2 hours. In 10 adults drinking a grape and blueberry beverage, petunidin appeared only in its native sugar form.

It may turn down oxidative stress enzymes in cells

In isolated rat hearts and rat heart cells deprived of oxygen, petunidin lowered NOX4, an enzyme that makes reactive oxygen species. The protection weakened when NOX4 was overexpressed. In mice with induced thyroiditis, petunidin also lowered NOX4 and PKM2, along with antibodies and inflammatory signals.

In diabetic mice, it reversed a rise in Keap1 and restored NQO1 in kidney mitochondria, which eased oxidative stress and ferroptosis. In mouse retinal immune cells it turned down OGT and NF-κB. All of these studies used cultured cells or animals, and the abstracts give little or no dose.

What has been seen in people

Human work tells us where petunidin goes, not what it does. The absorption studies show small amounts in blood and urine. The 90-day blueberry trial tied the cognitive changes to other compounds, not to petunidin.

The survey results are modest: odds ratios of 0.64 for myopia and 0.75 for combined disease and depression. They come from foods that carry many pigments and cannot show cause. The lab effects above come from cells and animals and have not been tested in people. All of these studies are among the cards above.

Is petunidin safe? Supplements, dose and interactions

Petunidin in food comes with the berries and other plants that carry it. We found no upper intake level for it or for anthocyanins as a group.

A 2015 review says dietary reference intakes do not exist for anthocyanins in the US, Canada or the EU. China has proposed 50 mg a day for total anthocyanins, it adds.

In 2014 the EFSA panel (EFSA is the EU’s food safety agency) presented its re-evaluation of anthocyanins as food additives. It said the toxicology data were too limited for a numerical acceptable daily intake. But it judged that exposure to aqueous (water-based) grape skin and black currant extracts at current uses is unlikely to be a safety concern.

• No petunidin supplement has been tested. We found no human trial of petunidin as a pill or extract, so there is no tested dose. In mice, the bone study gave 7.5 mg per kg a day by mouth, which cannot be turned into a human dose.
• Food-sized amounts in trials. The human studies here used 24 g of freeze-dried blueberry a day for 90 days, or 25 g in one drink. Others used 0.33 liters of juice, or 400 mL of wine or juice. The abstracts do not describe side effects, and none was designed to test safety.
• Pregnancy, breastfeeding, children and medicines. We found no safety data on petunidin in these groups or with drugs. Food amounts are the cautious choice, and a doctor or pharmacist can advise on berry extracts.

How to get more petunidin

• Best food. Blueberries give 31.5 mg per 100 g (46.7 mg a cup), far ahead of red wine (1.98 mg) and raspberries (0.31 mg). Purple potatoes and black goji berries also carry petunidin pigments, but we found no petunidin-only values for them.
• Expect low absorption. Only 0.18% to 0.23% of wine or juice anthocyanins reached the urine, and 1.1% of blueberry anthocyanins were bioavailable. We found no trial that tested eating petunidin with fat or other foods.
• Heat can break it down. In a lab test of purified petunidin, heat, ultrasound and microwaving all degraded it, and it was less stable than delphinidin. We found no cooking study in food, so treat this as a caution, not a rule.

Frequently asked questions about petunidin

What does petunidin do for the body?

Nobody knows yet, because no trial has tested petunidin alone. Human studies show that small amounts are absorbed after blueberries, grape juice or wine. US surveys link higher intake to lower odds of myopia (0.64 times the odds in 839 teens) and dental caries. In one analysis, it also went with lower odds of depression with cardiovascular-kidney-metabolic disease, but surveys cannot show cause.

Effects in cells and mice, such as bone gain and kidney protection, have not been tested in people.

Which foods are high in petunidin?

Blueberries lead the USDA data with 31.5 mg per 100 g (46.7 mg in a cup). Red wine has 1.98 mg, raspberries 0.31 mg and strawberries 0.11 mg. Published analyses also find petunidin pigments in purple potatoes, black bean seed coats, red grapes and black goji berries, but not as milligrams per serving.

What is the difference between petunidin, delphinidin and malvidin?

The number of methyl groups on the B ring: delphinidin has none, petunidin one and malvidin two. In lab comparisons petunidin scored higher than delphinidin in a cell-based antioxidant test and lower in two test-tube tests. Delphinidin was also more stable under heat. See our delphinidin and malvidin pages.

Is there a petunidin supplement, and how much should you take?

We found no human trial of petunidin as a supplement, so no dose is tested. Berry powders and juices contain it among many other pigments, and their results cannot be credited to it. The mouse bone study used 7.5 mg per kg a day, which is not a human dose.

Does petunidin have side effects?

We found no human safety data on petunidin alone. No upper intake level exists for anthocyanins. An EFSA panel judged that exposure to aqueous grape skin and black currant extracts at current food uses is unlikely to be a safety concern. We found no data for pregnancy, breastfeeding or medicine interactions, so ask a doctor before using extracts.

Is petunidin absorbed by the body?

Only a little. In 9 volunteers, 0.18% to 0.23% of the anthocyanins in red wine or grape juice reached the urine within 7 hours. After a wild blueberry drink, 1.1% of the anthocyanins were bioavailable, and the petunidin glucuronide peaked at about 8.8 hours in blood.

Does cooking destroy petunidin?

Heat can break it down in the lab. Purified petunidin degraded under heating, ultrasound and microwaving, microwaving fastest, and it was less stable than delphinidin. We found no study that measured petunidin in cooked food.