Is there acid in prunes? Understanding the fruit's acidity

January 1, 2026 •

3 min read

The pH of prunes typically falls between 3.7 and 4.2, indicating they are naturally acidic. So, is there acid in prunes? The simple answer is yes, but understanding the types and concentrations of these acids is key to appreciating their role in both flavor and health benefits.

Quick Summary

Prunes contain beneficial organic acids such as quinic, malic, and chlorogenic acids, contributing to their distinctive flavor profile and nutritional value. The fruit's low pH is a natural characteristic that, along with fiber and sorbitol, supports digestive health and provides antioxidant properties.

Key Points

Acids Present: Prunes contain natural organic acids, primarily malic and quinic acid, which give them their tangy flavor.
Antioxidant Acids: Phenolic compounds like chlorogenic and neochlorogenic acids are also present, providing powerful antioxidant effects.
pH Level: Prunes are moderately acidic, with a pH typically between 3.7 and 4.2, which is less acidic than many citrus fruits.
Digestive Benefits: The combination of acids, fiber, and sorbitol in prunes supports healthy digestion and regular bowel function.
Heartburn: While acidic, prunes are often tolerated better than citrus fruits by individuals with acid reflux, and their fiber content can help alleviate some digestive issues.
Nutritional Value: The natural acids are part of a complete nutritional profile that includes fiber, vitamins, and minerals, all contributing positively to health.

The Chemical Composition of Prunes

Yes, prunes contain several types of naturally occurring organic acids. The primary organic acids found in prunes are malic acid and quinic acid. These acids are crucial for the fruit's tangy flavor profile, which becomes more concentrated as plums are dried into prunes. Beyond these, prunes are also rich in phenolic compounds, notably chlorogenic and neochlorogenic acids. These are not just flavor contributors but powerful antioxidants linked to various health benefits.

The concentration of these acids is influenced by factors like the fruit's maturity, cultivar, and growing conditions. While present, the overall impact on the body is often positive, working synergistically with other components like fiber and sorbitol to aid digestion and overall health. Unlike highly concentrated synthetic acids, the acids in prunes are part of a complex nutritional matrix that supports the body.

Prune Acidity vs. Other Fruits

To put the acidity of prunes into perspective, it's helpful to compare their pH level to other common fruits. While prunes are acidic with a pH ranging from 3.7 to 4.2, they are less acidic than many citrus fruits. This means that for individuals sensitive to highly acidic foods, prunes may be a more tolerable option. The overall effect of a food on the body's acid-base balance is more complex than just its initial pH, but comparing the raw data provides useful context.

Comparing Prune Acidity with Other Fruits


Feature	Prunes	Oranges	Lemons	Apples	Tomatoes
pH Range	3.7–4.2	3.1–4.1	2.2–2.4	3.3–4.0	4.0–4.6
Primary Organic Acids	Quinic, malic	Citric, ascorbic	Citric, ascorbic	Malic, citric	Citric, malic
Notable Phytochemicals	Chlorogenic, neochlorogenic acids	Flavonoids	Flavonoids	Quercetin	Lycopene
Associated Health Benefits	Digestion, bone health, antioxidants	Vitamin C, antioxidants	High Vitamin C, antioxidants	Fiber, antioxidants	Antioxidants, Vitamin C

The Role of Prune Acids in Health

The acids in prunes play a significant role in their health benefits, extending far beyond simple flavor. For example, the phenolic acids, such as chlorogenic acid, function as powerful antioxidants. Antioxidants help protect the body's cells from oxidative damage caused by free radicals, which is a process linked to aging and chronic diseases like heart disease and cancer.

Moreover, the organic acids and other compounds in prunes have been studied for their effect on digestion. Quinic and malic acids, along with sorbitol and dietary fiber, work together to produce a gentle laxative effect, promoting regular bowel movements and improving overall gut health. The combination of soluble and insoluble fiber found in prunes also acts as a prebiotic, feeding the beneficial bacteria in your gut microbiome. This intricate interplay of components, including the acids, highlights why prunes are so effective as a digestive aid.

Addressing Common Acidity Concerns

Some people may worry that the acidity in prunes could cause or worsen heartburn or acid reflux. However, the connection is not always straightforward. While some individuals are sensitive to all acidic foods, prunes are often cited as a better option for those with acid reflux compared to more notoriously acidic fruits like oranges or grapefruit. The high fiber content of prunes is a known benefit for digestion and can help prevent constipation, a condition that can sometimes contribute to acid reflux symptoms.

For those with sensitive stomachs, introducing prunes gradually is advisable. Starting with a smaller portion allows the digestive system to adjust to the increased fiber and sorbitol content. The key is moderation. Excessive consumption of any dried fruit can cause digestive discomfort, but a standard serving of four to six prunes is generally well-tolerated and beneficial. The idea that prunes automatically trigger digestive issues is a myth, especially when consumed in appropriate quantities.

The Bottom Line on Prune Acidity

In conclusion, there is indeed acid in prunes, but this is a completely natural and beneficial aspect of the fruit. The presence of organic acids like malic and quinic acid, alongside antioxidant-rich phenolic acids, contributes to prunes' unique taste and significant health advantages. Their mild acidity, lower than many citrus fruits, means they are often well-tolerated and can even be a soothing element for digestive health due to their high fiber and sorbitol content. Rather than viewing the acidity negatively, it should be seen as an integral part of what makes prunes a nutritional powerhouse and a valuable addition to a healthy diet. For more detailed information on the health benefits of prunes, consider reviewing the comprehensive article by Healthline.

Frequently Asked Questions

No, the natural acidity in prunes is not bad for you. It comes from beneficial organic acids that contribute to flavor and overall health, aiding in digestion and providing antioxidant benefits.

Not typically. Although acidic, prunes are often well-tolerated by those with acid reflux. Their high fiber content can actually aid digestion, which sometimes helps alleviate heartburn symptoms.

The pH of prunes generally falls within the range of 3.7 to 4.2. This indicates they are moderately acidic, but less so than many common fruits like lemons or grapefruit.

Prunes contain several organic acids, with malic and quinic acid being the most prevalent. They also contain phenolic acids, such as chlorogenic and neochlorogenic acid, which act as antioxidants.

Prunes are less acidic than many citrus fruits, including lemons and oranges. Their pH is similar to or slightly lower than some apples and pears.

As with any acidic fruit, excessive consumption could potentially affect tooth enamel over time. However, the natural acids in prunes, especially in moderation, are not a significant risk. Maintaining good dental hygiene is key.

Prune juice can be slightly more or less acidic than whole prunes, depending on the processing and whether additives like citric acid are used. Always check the label for added ingredients.