The sticky substance in a chikoo, also known as sapodilla, is natural latex. This fluid, technically called 'chicle', is a natural defense mechanism produced by the tree, Manilkara zapota, and is most prominent in unripe fruit. Historically, this latex was the primary ingredient for chewing gum. When the fruit ripens, the chicle is reabsorbed, and the accompanying tannins, which give unripe fruit a bitter taste, break down.
Why Unripe Chikoo is Sticky
Chicle: The Original Chewing Gum
The chikoo tree, like other members of the Sapotaceae family, is a natural source of latex. This sticky, milky substance is its way of protecting itself from pests and animals. When a chikoo fruit is young and unripe, it is packed with this chicle. Before synthetic alternatives, this same substance was collected by 'chicleros' in Mexico and Central America to produce natural chewing gum. The latex is tasteless and is composed of about 15% rubber and 38% resin, which gives it its gummy texture. While the chicle in an unripe chikoo is technically harmless, it is not pleasant to eat due to its astringent, mouth-drying effect.
Tannins and Astringency
Beyond the sticky latex, unripe chikoo fruit is also rich in tannins. Tannins are naturally occurring plant compounds that are responsible for the dry, puckering sensation you get from underripe fruit. As the fruit matures, these tannins and the latex are reabsorbed, allowing the fruit's natural sugars to become dominant. This is why a fully ripe chikoo is wonderfully sweet and lacks the sticky mouthfeel. Eating an unripe chikoo is not recommended, as the high tannin content can cause an itchy throat or even mouth ulcers, especially in children.
How to Choose a Perfectly Ripe Chikoo
Selecting a ripe chikoo is key to avoiding the sticky latex and astringent taste. The ripening process is a climacteric one, meaning the fruit continues to ripen after being picked.
Step-by-step guide to ripeness:
- Check for soft spots. A ripe sapodilla will be soft to the touch all over, much like a soft boiled potato. Gently press the fruit with your thumb; it should yield to a slight pressure.
- Scratch the skin. Gently scrape the skin with your fingernail. If the color underneath is a yellowish-brown or orange, the fruit is ripe. A green color indicates it needs more time.
- Inspect the stem. For fruit picked directly from the tree, a fully ripened chikoo will not release the white, milky latex (chicle) from its stem.
- Observe the skin. While an unripe chikoo has a smooth, firm skin, a ripe one will have slightly wrinkled or saggy skin.
- Look for color. A ripe fruit is typically a uniform brown or yellowish-brown color. A green hue suggests it is still unripe.
Comparing Unripe and Ripe Chikoo
| Feature | Unripe Chikoo | Ripe Chikoo |
|---|---|---|
| Sticky Substance | High concentration of natural latex (chicle). | Reabsorbed; no sticky substance. |
| Taste | Bitter and highly astringent due to tannins. | Very sweet, with a malty or caramel-like flavor. |
| Texture | Hard and firm flesh. | Soft, juicy, and slightly grainy flesh. |
| Skin Color | Firm, with green visible when scratched. | Soft and saggy, with a brown or orange color when scratched. |
| Eating Experience | Unpleasant, can cause an itchy throat. | Delicious, with a custard-like texture. |
How the Ripening Process Eliminates the Sticky Latex
The Climacteric Process
Chikoo is a climacteric fruit, which means it continues its ripening process after being harvested. During this phase, the fruit releases ethylene gas, which triggers the production of enzymes. These enzymes, such as pectinase and cellulase, break down the fruit's cell walls, leading to a softening of the flesh. Simultaneously, the enzymes cause the starch to convert into sugar, increasing the fruit's sweetness. Crucially, this same enzymatic process is responsible for the reabsorption of the bitter tannins and the sticky latex.
The Enzyme Action
As the chikoo ripens, specific enzymes target and break down the complex compounds that make up the chicle and tannins. This is a natural part of the fruit's maturation, designed to make the fruit palatable and attractive to animals that will disperse its seeds. The breakdown of these compounds is what transforms the hard, astringent, and sticky fruit into the soft, juicy, and sweet treat that chikoo lovers enjoy.
Conclusion: Ripe is Right
In conclusion, the sticky white substance in chikoo is a completely natural latex known as chicle, found primarily in unripe fruit. It is not harmful, but it is accompanied by astringent tannins that make the fruit unpleasant to eat. The solution to this sticky problem is simple: wait for the chikoo to ripen properly. By selecting fruit that is soft, has a saggy skin, and shows no milky sap when picked, you can ensure a delicious, sweet, and non-sticky experience. The natural ripening process will take care of the rest, leaving you with a perfectly edible tropical delight.
Key Takeaways
- Chikoo's Sticky Secret: The gummy, milky fluid in an unripe chikoo is a natural latex called chicle, historically used to make chewing gum.
- Ripeness is Key: As the fruit ripens, the chicle and bitter tannins are reabsorbed, so you should only eat the fruit when it is fully soft and ripe.
- Signs of a Ripe Chikoo: A ready-to-eat chikoo will feel soft to the touch, have slightly saggy skin, and show a brownish-orange color when scratched.
- Avoid Unripe Fruit: Eating unripe chikoo is not recommended due to its astringent, mouth-drying effect and potential to cause throat irritation.
- Natural Defense Mechanism: The sticky latex is the tree's natural way of protecting its fruit from pests before it is ready to be eaten.
- Enzymatic Breakdown: The ripening process involves enzymes that break down the sticky chicle and tannins, converting starches into sugars.
FAQs
Question: What is the scientific name for the sticky substance in chikoo? Answer: The sticky substance in chikoo is a natural latex commonly referred to as chicle. The chikoo tree itself is known scientifically as Manilkara zapota.
Question: Is the chicle in chikoo dangerous to eat? Answer: While not dangerous, the chicle from unripe chikoo is intensely astringent and can cause an unpleasant, dry, and mouth-puckering sensation. It's best to wait until the fruit is ripe.
Question: How can I tell if a chikoo is ripe enough to eat? Answer: A ripe chikoo will feel soft to the touch, and the skin may be slightly wrinkled. If you scratch the skin, the color underneath should be yellow-brown or orange, not green.
Question: Why do some chikoo fruits have a sticky substance and others don't? Answer: The presence of the sticky latex is an indicator of ripeness. Unripe chikoo fruits contain high levels of chicle, which is naturally reabsorbed into the fruit as it matures.
Question: How can I remove the sticky residue from my hands after handling unripe chikoo? Answer: You can use a bit of oil, such as cooking oil, to help dissolve the chicle from your hands. Rub the oil on the affected area, and then wash your hands with soap and water.
Question: Can I use the sticky chicle for anything? Answer: Historically, chicle was the main ingredient for chewing gum. While you can't use it directly from the fruit for this purpose, the commercial use highlights its properties.
Question: Does the sticky latex have any nutritional value? Answer: The latex itself is not meant for consumption and has no significant nutritional value. The nutritional benefits of chikoo are found in the flesh of the ripe fruit, which is rich in fiber, vitamins, and minerals.
Question: What happens to the tannins and chicle as the chikoo ripens? Answer: As the chikoo ripens, specific enzymes break down both the astringent tannins and the sticky chicle. This process sweetens the fruit and eliminates the unpleasant stickiness.
Question: How long does it take for an unripe chikoo to ripen? Answer: Underripe chikoo can take about 7 to 10 days to ripen at room temperature. The process is climacteric, so the fruit will continue to ripen after harvesting.
