Acidity levels of common fruits
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Acidity Levels in Common Fruits: pH and Organic Acid Content
Citrus Fruits: High Acidity and Ascorbic Acid Content
Citrus fruits such as oranges, lemons, and grapefruits are well-known for their high acidity. The pH values for citrus fruits typically range from 2.24 to 3.87, indicating strong acidity. These fruits also have high ascorbic acid (vitamin C) content, with oranges containing up to 59 mg/100g, lemons around 50 mg/100g, and grapefruits about 44 mg/100g. The acidity and ascorbic acid levels can vary depending on factors like ripeness, temperature, and environmental conditions, but citrus fruits consistently rank among the most acidic common fruits13.
Apples: Malic Acid as the Main Contributor to Acidity
In apples, malic acid is the primary organic acid responsible for their tartness. The acidity level in apples is largely determined by the concentration of malic acid, with some wild apple species also containing notable amounts of citric acid. However, cultivated apples generally have much lower citric acid levels. The total acidity in apples can vary widely due to genetic factors, with certain genes (such as Ma, Ma3, and Ma10) playing significant roles in controlling malic acid accumulation and, consequently, the fruit's pH and taste267810.
Other Fruits: Organic Acid Profiles
- Peach: The main acids in peaches are malic and citric acids, with their levels changing during fruit development. High-acid peach cultivars retain more malic and citric acid, while low-acid types show more rapid acid breakdown as the fruit ripens.
- Grape: Tartaric acid is the dominant acid in grapes, making up 58–90% of the total acid content in grape juice. This gives grapes a distinct tartness compared to other fruits.
- Strawberry and Blueberry: Citric acid is the predominant acid in both strawberries and blueberries, accounting for over 60% of the total acid content in their juices.
- Sweet Cherry and Apple: Malic acid is the main acid in both sweet cherry and apple juices, making up the majority of their total acid content.
Factors Affecting Fruit Acidity
The acidity of fruits is influenced by several factors:
- Genetics: Specific genes regulate the accumulation and storage of organic acids in fruit cells, directly affecting acidity levels26710.
- Ripeness: Unripe fruits generally have higher acid content, which decreases as the fruit matures35.
- Environmental Conditions: Temperature, sunlight, and soil composition can all impact the acid and ascorbic acid content in fruits.
Conclusion
Common fruits display a wide range of acidity levels, primarily determined by their organic acid composition and genetic background. Citrus fruits are among the most acidic, with low pH and high ascorbic acid content. Apples and cherries are dominated by malic acid, while grapes are rich in tartaric acid, and berries like strawberries and blueberries are high in citric acid. These acidity levels not only influence fruit flavor but also their nutritional value and potential health effects12345678+1 MORE.
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