Ever notice how some fruits, like oranges, have a sharp, tangy taste, while others, like potatoes, seem plain? The answer lies in the fascinating world of acids present in fruits and vegetables!
These acids contribute to the explosion of flavours we enjoy and play a crucial role in the plant’s biological processes. Understanding these acids is a key concept in General Science, frequently tested in competitive exams like SSC, UPSC, Railways, and various state PSCs.
But fear not, fellow aspirants! This blog post is your one-stop guide to conquering this topic. We’ll delve into an updated list of acids present in fruits and vegetables, explore their impact on taste and plant health, and even touch upon the concept of pH value, a favourite amongst competitive exams.
So, sharpen your pencils and prepare to ace your next exam with this comprehensive breakdown of acids in fruits and vegetables!
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Acids Present in Fruits and Vegetables
List of Acid Present in Food Items
SL. No | Acid | Food Source |
---|---|---|
1. | Citric Acid | Citrus fruits- lemon, Orange, Grapefruit |
2. | Tartaric Acid | Tamarind, Grapes, Pineapples, Potatoes, Carrots |
3. | Acetic Acid | Vinegar |
4. | Oxalic Acid | Pepper, Spinach, Tomato |
5. | Tannic Acid | Tea |
6. | Caffeotannic Acid | Coffee |
7. | Benzoic acid | Cranberries, prunes and plums |
8. | Malic Acid | Apple, Ripe Bananas, Bananas, pomegranates, grapes, berries, tomatoes, and broccoli |
9. | Lactic acid | Milk, Curd, Cheese |
10. | Butyric acid and Caproic acid | Butter |
11. | Glutamic acid | Onion |
12. | Palmitic acid and oleic acid | Ghee |
13. | Carbonic acid and | Soda Water (Carbonated Beverages) |
14. | Phosphoric acid | Soft drinks (Fruit) |
15. | Caprylic acid and Palmitic acid | Coconut oil and Palm oil |
16. | Arachidic acid | Ground nut oil |
17. | Oleic acid | Olive oil |
18. | Erucic acid | Mustard oil |
19. | Lauric acid | Coconut milk |
20. | Linoleic acid (55%) | Soybean oil |
21. | Myristic acid | Coconut oil |
22. | Pantothenic acid | Chicken, Eggs, Mushrooms, Avocado |
23. | Folic Acid | Asparagus, Brussels sprouts, Spinach, Lettuce. |
24. | Ascorbic Acid | Amla, Gooseberry, Guava |
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Natural Acids Present in Fruits
Sl. No | Type | Predominant Acid(s) |
---|---|---|
1. | Bananas | Malic |
2. | Kiwifruit | Citric |
3. | Limes | Citric, malic, tartaric and oxalic acids |
4. | Lemons | Citric, malic, tartaric and oxalic acids |
5. | Apples | Malic, Succinic acids |
6. | Apricots | Malic and Citric acids |
7. | Avocados | Tartaric Acid |
8. | Grapefruit | Citric, tartaric, malic and oxalic acids |
9. | Grapes | Malic and tartaric, citric and oxalic acids. |
10. | Kumquat | Citric |
11. | Loganberry | Malic, citric acids |
12. | Nectarine | Malic |
13. | Orange Peel | Malic, citric and oxalic acids |
14. | Orange | Citric, malic and oxalic acids |
15. | Passionfruit | malic |
16. | Peaches | Malic and citric acids |
17. | Pears | Malic, citric, tartaric and oxalic acids |
18. | Pineapples | Citric and malic acids |
19. | Plums | Malic, tartaric and oxalic acids |
20. | Raspberry | Citric |
21. | Rosehip | Malic |
22. | Quinces | Malic acid |
23. | Salad | Citric and malic |
24. | Strawberries | Citric, malic, shikimic, succinic acids |
25. | Tangerine | Citric |
26. | Youngberries | Citric, malic and Isocitric acids |
27. | Bilberry | Citric acid |
28. | Blackberries | Malic and Quinic acids |
29. | Blueberries | Citric, Malic, Citramalic, quinic, glutamic and aspartic acids |
30. | Boysenberries | Citric, malic, and Isocitric acids. |
31. | Cherries | Malic, Citric, Tartaric, Succinic |
32. | Crabapple | Malic |
33. | Cranberries | Citric, malic and benzoic acids. |
34. | Currants | Citric, tartaric, malic and succinic acids |
35. | Elderberries | Citric, malic, shikimic and quinic acids |
36. | Figs | Citric, malic and acetic acids |
37. | Gooseberries | Citric, malic, shikimic and quinic acids |
Natural Acids Present in Vegetables
Sl. No | Type | Predominant Acid(s) |
---|---|---|
1. | Beans | Citric, Malic acids |
2. | Broccoli | Malic, Citric, Oxalic and Succinic acids |
3. | Carrots | Malic, Citric, Fumaric acids |
4. | Mushrooms | Lactarimic, Cetostearic, Fumaric acids |
5. | Peas | Malic acid |
6. | Potatoes | Malic, Citric, Oxalic acids |
7. | Rhubarb | Malic, Citric and Oxalic acids |
8. | Tomatoes | Citric, malic and Oxalic acids |
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Acidic Fruits list with pH value
According to the United States Environmental Protection Agency (EPA), foods with a pH above 7 are considered alkaline, whereas those below 7 are acidic.
- Lemon (2-2.6)
- Lime (2 -2.8)
- Orange (3.7 – 4.3)
- Grapes (2.9 – 3.8)
- Tangerine (3.9)
- Pineapple (3-4)
- Kiwi (3.1 – 3.9)
- Apple (3.3 – 4)
- Pomegranate (2.9-3.2)
- Blue Plums (2.8 – 3.4)
- Tomato (4.3 – 4.9)
- Cranberry (2.3 to 2.5)
- Passionfruit (2.7-3.1)
- Mango (3.4 -6)
- Blueberries (3.1 – 3.3)
- Pineapples (3.2 – 4)
- Peaches (3.3 – 4)
- Sour cherry (3.06–3.35)
- Apricots (3.3 – 4.8)
Acids Present in Foods [Infographic]
The acids in the list below are the most known food items asked in all competitive exams under the General Science section.
Citric Acid vegetables List
Citric acid acts as a natural preservative and is commonly added to foods and soft drinks to provide a tart, acidic flavor. It’s commonly found in citrus fruits, but it can also be present in various vegetables, often as part of their metabolic processes. Here’s a list of vegetables that naturally contain citric acid, although typically in smaller amounts compared to fruits:
- Tomatoes – Tomatoes have a noticeable amount of citric acid, which contributes to their tangy taste.
- Potatoes – Potatoes contain small amounts of citric acid.
- Broccoli – Contains citric acid in minor quantities.
- Carrots – Carrots have low levels of citric acid.
- Peppers – Both sweet and hot peppers can contain citric acid.
- Spinach – This leafy green contains small amounts of citric acid.
- Lettuce – Lettuce includes citric acid in its composition.
- Celery – Celery has trace amounts of citric acid.
- Cucumbers – contain small quantities of citric acid.
- Artichokes – Artichokes also have some citric acid content.
These vegetables may contain citric acid naturally, but the concentration is significantly lower compared to citrus fruits like lemons, limes, and oranges. The presence of citric acid in these vegetables contributes to their overall nutritional profile and taste.
Sample Questions
Q1: Which fruit is present with acetic acid?
Answer: Natural sources of acetic acid include grapes, apples, strawberries, pineapples, and oranges.
Q2: Name the acid present in lemon juice.
Answer: Citric Acid
• Citric acid is a colourless, weak organic acid that occurs naturally in citrus fruits. Citrate is a citric acid derivative widely used as an acidifier, flavouring, and chelating agent.
Q3. Which acid is present in potatoes?
Answer: Potatoes contain various acids, such as citric, malic, tartaric, oxalic, fumaric, and succinic. Among these, chlorogenic acid is the most abundant, which typically ranges from 62.95 mg·100 g−1 FM to 126.77 mg·100 g−1 FM in potatoes. [Source: National Library of Medicine]
Q4. Which acid is present in Apple?
Answer: The main acid present in apples is malic acid. The name “malic” comes from the Latin word “malum” which means apple! Malic acid contributes to the tart flavour of many fruits, including apples, grapes, and cherries.
Q5. Which acid is in Curd?
Answer: Curd primarily contains lactic acid. (Also, lactic acid is present in Milk)
Q6. What acid is in spinach?
Answer: Spinach contains oxalic acid. This acid is a naturally occurring compound found in many plants, including leafy greens like spinach and vegetables like rhubarb, beet greens, and even some fruits. While oxalic acid offers some benefits, it can also bind to certain minerals like calcium, potentially hindering their absorption.
Interesting Facts to Know
How does the type of acid in a fruit or vegetable affect its nutritional value?
The type of acid in a fruit or vegetable can affect its nutritional value in a few interesting ways:
Vitamin Content
- Some acids, like ascorbic acid (vitamin C), are essential nutrients. Citrus fruits, berries, and kiwifruit are rich sources of vitamin C, which plays a crucial role in immune function, collagen production, and antioxidant activity. A deficiency of Vitamin C causes scurvy.
Mineral Absorption
- Certain acids, like oxalic acid found in spinach and rhubarb, can bind to minerals like calcium, potentially hindering their absorption. However, these vegetables still offer other valuable nutrients, and cooking methods like boiling can help reduce oxalate content.
Digestion and Gut Health
- Some organic acids, like citric acid in citrus fruits and malic acid in apples, may stimulate the production of digestive enzymes and gastric juices, aiding digestion. Additionally, these acids can promote the growth of beneficial gut bacteria, contributing to overall gut health.
Availability of Other Nutrients
- Acids can sometimes enhance the bioavailability of other nutrients present in fruits and vegetables. For example, citric acid in tomatoes can improve lycopene absorption, a powerful antioxidant.
Flavour and Consumption
- The type of acid can significantly impact the flavour profile of a fruit or vegetable. Tartaric acid in grapes contributes to their tangy taste, while malic acid in apples gives them a crisp bite. These flavours can influence how much we consume – a tart fruit rich in vitamin C might appeal more than a bland one lacking this nutrient.
Overall, the type of acid in a fruit or vegetable is just one piece of the puzzle regarding nutritional value. However, it significantly influences vitamin content, mineral absorption, digestion, and even our enjoyment of these healthy foods.
Identifying Acids in Fruits and Vegetables: A Sensory Guide for Exam Success!
While a definitive identification requires lab analysis, some practical tips can help aspirants guess the acid in a fruit or vegetable based on taste and other properties. Remember, these are general guidelines, and exceptions exist.
Taste Buds Can Help You
- Tart and Tangy: This is a classic sign of citric acid, commonly found in citrus fruits (lemons, oranges, grapefruits) and some berries (cranberries, raspberries).
- Sharp and Sour: Apples, pears, and unripe grapes often contain high levels of malic acid, contributing to their sharp, acidic taste.
- Bitterness with a Zing: This could indicate the presence of tannic acid, found in cranberries, unripe grapes, and some plums. Tannins create a drying sensation in the mouth.
- Astringent Puckering (sensation of dryness, tightness, or puckering): This is a hallmark of oxalic acid, which is present in spinach, rhubarb, and some leafy greens. It creates a puckering sensation on the tongue.
Beyond the Taste
- Visual Clues: Some fruits, like cranberries and rhubarb, have a vibrant red colour due to anthocyanin pigments, which often co-occur with oxalic acid.
- Ripeness Matters: Unripe fruits tend to be higher in malic acid, giving them a sharper taste. As they ripen, the malic acid converts to sugars, resulting in a sweeter flavour.
By honing your sensory skills and knowledge of commonly occurring acids, you’ll be well on your way to impressing examiners with your ability to identify acids in fruits and vegetables during competitive exams!
Common misconceptions about acids in fruits and vegetables
Here are some common misconceptions about acids in fruits and vegetables that aspirants preparing for competitive exams should be aware of:
Myth #1: All acidic fruits are bad for your teeth.
Fact: While some acids can erode tooth enamel, fruits rich in vitamin C and other antioxidants can actually promote oral health. Moderation and proper dental hygiene are key!
Myth #2: Acidic fruits and vegetables cause heartburn in everyone.
Fact: Individual sensitivity plays a role. High in citric acid, Citrus fruits might trigger heartburn in some, while others might tolerate them well.
Myth #3: Cooking destroys all the acids in fruits and vegetables.
Fact: Some acids may degrade slightly with heat, but many remain intact after cooking. For example, tomatoes retain much citric acid even when cooked.
Myth #4: A bland taste equals a lack of acid.
Fact: Sugars can mask the presence of acids. A seemingly sweet fruit like a mango might still contain citric and malic acid.
Myth #5: Acids in fruits and vegetables have no purpose besides taste.
Fact: These acids are crucial in plant functions like ripening, providing structure, and deterring pests.
Is there a relationship between the colour of a fruit or vegetable and the type of acid it contains?
There isn’t a perfect one-to-one resemblance between a fruit’s or vegetable’s colour and the type of acid it contains. The colour of a fruit or vegetable depends on the pigments it contains.
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However, there are some potential links between pigments (responsible for colour) and the presence of certain acids that can be helpful for aspirants to be aware of:
Anthocyanins and Oxalic Acid
- Fruits and vegetables with vibrant red, purple, or blue hues often contain anthocyanin pigments.
- Interestingly, some research suggests that plants containing anthocyanins (like cranberries and rhubarb) might also be higher in oxalic acid.
- However, this isn’t a definitive rule, and exceptions exist.
Chlorophyll and Citric Acid
- The green colour in fruits and vegetables comes from chlorophyll pigments.
- While not a direct indicator of acid content, some green vegetables high in chlorophyll, like limes, might also contain citric acid.
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It’s important to remember that these are just potential connections, and the type of acid present depends on various factors beyond colour.
Fruits and vegetables can contain a blend of different acids, and some pigments don’t necessarily correlate with specific acids.
Here’s a key takeaway for aspirants
While colour can offer some clues, it’s not a foolproof way to identify the acid in a fruit or vegetable. For a more accurate guess, rely on a combination of taste, sensory observations, and knowledge of commonly occurring acids.
Some Health Benefits of Acids in Fruits and Vegetables
Acids in fruits and vegetables aren’t just taste bud tantalizers; they offer various health benefits. Let’s explore how some common acids contribute to your well-being:
Vitamin C (Ascorbic Acid): The champion we already discussed, boasts a robust immune system defence, promotes collagen production and acts as a powerful antioxidant.
Citric Acid: In citrus fruits, tomatoes, and berries, citric acid may prevent kidney stones by promoting citrate excretion, a natural inhibitor of stone formation. Additionally, it can enhance the absorption of iron from plant-based foods. [Remember this line; it’s most important for the exam.]
Malic Acid: Malic acid plays a fascinating role in our bodies. It’s a natural byproduct of the citric acid cycle, a crucial process responsible for generating cellular energy that fuels all living organisms, including humans. Studies suggest that malic acid itself may offer additional benefits, potentially promoting healthy energy levels and improved iron absorption, even contributing to clearer skin and better oral health. [Source: Dr. Axe]
Lactic Acid: While often associated with muscle burn during exercise, lactic acid from fermented foods like yoghurt and kimchi can promote gut health by supporting the growth of beneficial bacteria. These bacteria contribute to a healthy digestive system and may even boost your immune function.
Omega-3 Fatty Acids: Although not technically classified as a true acid, these essential fats in fatty fish offer many health benefits. They can improve heart health by lowering bad cholesterol (LDL) and raising good cholesterol (HDL), potentially reducing the risk of heart disease.
Optimizing Your Acid Intake
The key to reaping the benefits of these acids lies in consuming a balanced diet rich in fruits, vegetables, and some fermented foods. Here are some tips:
- Variety is Key: Include a diverse range of fruits and vegetables to ensure a good mix of acids and their benefits.
- Embrace Fermentation: Explore fermented foods like yoghurt, kimchi, and kombucha to introduce beneficial lactic acid bacteria into your gut microbiome.
- Fatty Fish Feast: Include oily fish like salmon, tuna, and sardines in your diet for a healthy dose of omega-3 fatty acids.
Several bacterial strains responsible for lactic acid production are categorized as probiotics. These beneficial bacteria play a crucial role in promoting gut health and supporting the immune system.
Healthline.com
Remember: Moderation is key. While most acids offer health benefits, excessive consumption of certain fruits high in citric acid, for example, might irritate sensitive stomachs.
Frequently Asked Questions (FAQ)
Answer: Tartaric acid and L-malic acids are present in grapes.
Answer: Apples, grapes, pineapples, strawberries, and oranges are natural sources of acetic acid. In addition to natural sources, vinegar (5-8% acetic acid) used in food also contains acetic acid.
Answer: Citric Acid
Answer: oxalic acid
Answer: Vegetables mainly contain citric, malic, and oxalic acids, and malic acid is the most abundant in most cases.
Answer: Malic acid, Citric acid, and Oxalic acid.
Answer: The pH range of vegetables varies from 4.2 to 6.2. This means the vegetables are weakly acidic. The majority of vegetables are alkaline.
However, their pH may change during processing and packaging to preserve them longer. Naturally, most vegetables are non-acidic.
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