Have you ever wondered how a hard, green fruit turns into a sweet, juicy delight? The secret is the complex science of fruit ripening. This process has intrigued scientists for years1. A plant hormone called ethylene is at the heart of this amazing change2. But, how does this gas start the ripening? And what about other factors that add to the taste and feel of the fruit?
- Ethylene is a crucial plant hormone that starts the ripening process in many fruits.
- Some fruits, like bananas and apples, can keep ripening after they’re picked. But others, like grapes and berries, do not.
- After being picked, fruits make more ethylene. This shortens their life and makes them more open to getting sick.
- By using certain technologies before and after picking fruits, we can control how much ethylene they make. This can change how they ripen.
- Knowing about the science of fruit ripening can help make fruit taste better, feel better, and last longer.
What is Fruit Ripening and the Role of Ethylene?
Fruit ripening changes fruits, making them enjoyable to eat. This process increases the fruit’s respiration, making more ethylene, and softens the flesh. It also raises the sugar levels and enhances the aroma and flavor3.
Fruit Ripening Process
The rise of ethylene signals fruit to ripen. Ethylene affects color, texture, smell, and taste, influencing the fruit’s time it stays fresh after picking3. It’s made through a complex chain of enzymes. Many genes are found in tomatoes that help in making this ethylene. Plus, certain regulators, like RIN, control the process3.
This signaling works through a series of steps. Key players are EIN3/EIL1 and ERFs, which manage ripening genes. The parts that sense ethylene, like EIN2 and EIN3, are vital here. They help in responding to the ethylene signal for ripening3.
Climacteric and Non-Climacteric Fruits
Fruits fall into two main types: climacteric and non-climacteric. Climacteric fruits, like peaches, bananas, and apples, keep ripening after picking4. A rise in ethylene gas and faster breathing makes this happen4. Non-climacteric fruits, however, like cherries and grapes, do not ripen more after picking. They need to be fully ripe when harvested4.
Climacteric Fruits and Ethylene Production
Climacteric fruits are unique. They create ethylene that speeds up their own ripening4. This burst in ethylene is key for fruits to turn sweet, colorful, and soft5. Keeping ethylene levels in check helps keep these fruits fresh after picking4.
Non-Climacteric Fruits and Ripening
Non-climacteric fruits like oranges and strawberries don’t have a big ethylene burst to ripen4. Hormones like auxin and gibberellin instead help them ripen6. They change color and taste to attract animals that spread their seeds6. Some, like dragon fruit, ripen like berries but vary a lot in how they maturing6.
Knowing how climacteric and non-climacteric fruits ripen is critical. It helps determine the best time to pick and how to store them well5. With this knowledge, everyone from growers to shoppers can enjoy the finest fruit3.
Characteristic | Climacteric Fruits | Non-Climacteric Fruits |
---|---|---|
Ethylene Production | Autocatalytic increase during ripening | No significant peak in ethylene production |
Respiration | Climacteric rise in respiration during ripening | No climacteric rise in respiration |
Ripening Process | Can continue to ripen after harvest | Must be harvested at full maturity |
Hormonal Regulation | Ethylene-dependent | Influenced by various hormones (auxin, gibberellin, jasmonic acid) |
Examples | Peaches, bananas, apples, avocados | Cherries, grapes, strawberries, blueberries |
“Understanding the ripening patterns of fruits is crucial for determining optimum harvest dates and post-harvest storage practices.”5
Recognizing the differences between climacteric and non-climacteric fruits helps everyone choose the best fruit. Growers, sellers, and buyers can have a great fruit experience6.
Measuring and Controlling Ethylene Levels
Ethylene plays a big role in making fruits ripe. To measure it, we often use gas chromatography. This tool can spot ethylene in tiny amounts7. By sealing fruits in a container, we can test the ethylene they give off. This tells us how ripe they are and how long they’ll last7.
Methods for Measuring Ethylene
Methods to check ethylene levels have gotten better for the fruit business. New sensors can find ethylene in amounts as small as 20-10 parts per billion8. These sensors are easy to move around and don’t cost much, less than €10,000. They help farmers and shippers watch ethylene as fruits move from the farm to the store8.
It’s important to measure ethylene carefully. Even a little bit, like less than 1 part per million, can start the ripening of certain fruits8. It’s key to keep measurements accurate, especially before the big ripening phase. This careful watch helps fruits stay fresh longer8.
Preharvest and Postharvest Ethylene Regulators
We can control how fruits ripen before or after picking them. Beforehand, we use things like Ethephon, ReTain®, and Harvista™. These help control ethylene and when fruits ripen7. After picking, 1-MCP (SmartFresh™) can stop fruits from ripening too fast. This keeps them good for a longer time9.
But, using 1-MCP might make fruits less tasty, lowering their flavor by 35% on average9. This shows it’s a trade-off. We need to find a balance between managing ethylene and keeping fruits and veggies tasty9.
There are other ways to handle ethylene besides with chemicals. Storing fruits in special air or packaging, or using devices that soak up ethylene, can also work. These methods keep the fruit fresh and their quality high7.
Tools like Ripe All Ethylene Generators and Mini Ripe Ethylene Generators use ethylene to help fruits ripen well. They make the ripening process more efficient. This leads to better quality fruits for us to enjoy7.
“Monitoring of ethylene concentration is not as common as O2 and CO2 monitoring in controlled atmosphere fruit stores, but research and development focus on implementing gas sensing systems for fruit monitoring, particularly for measuring CO2 and ethylene concentrations in containers.”8
Ethylene is crucial for fruit ripening. As we learn more about measuring and controlling it, we can do better in the fruit business. New tech and methods let farmers and shippers boost fruit quality and make them last longer. This means we get better fruit at the store8.
The Science Behind Fruit Ripening
The firmness of a fruit comes from its cell walls, made up of tough sugars. These include cellulose, hemicellulose, and pectin10. The breakdown of these cell walls makes the fruit soft. Enzymes help in this process by dissolving the sugars. The pressure inside the cell also affects how firm the fruit feels (turgor pressure)11.
When fruits ripen, starch turns into simple sugars like sucrose, glucose, and fructose. This change adds sweetness to the fruit12. The fruit also becomes less sour and bitter. At the same time, it starts to smell good because of new complex compounds.
Fruit ripening is complex and controlled by genes and other factors12. Good changes happen during ripening, like a softer texture, more sugars, less tartness, better color, and a nice smell12. But if the fruit ripens too much, it can spoil, leading to wasted crops12.
- Research shows plants can make ethylene. They produce more when their fruit is injured or cut10.
- When a plant makes ethylene, it triggers enzymes that break down its cell walls and change its color10.
- Plants make ethylene to signal important times, like when seeds start to grow or leaves change color10.
- The way plants react to ethylene has evolved and is still a topic of research today10.
Some fruits, like bananas, really respond to ethylene by becoming sweeter11. Ethylene helps ripe as well as some unripe fruits, called climacteric fruits, to ripen. Such fruits include tomatoes, avocados, apples, peaches, kiwis, and bananas. Ethylene triggers changes in these fruits as they ripen11.
Scientists study special tomatoes that don’t ripen normally. By looking at these tomatoes, they learn about genes that control ripening12. Genes like SlMADS-RIN and SlMADS-MC are very important for fruit to ripen properly12. By studying these genes, we understand more about how fruits develop and ripen12.
“The proverbial saying ‘one bad apple can spoil the whole basket’ is based on the practical effect of ethylene from a rotting apple accelerating the ripening of nearby apples.”11
Mutations in genes like COLOURLESS NON-RIPENING (Cnr) stop fruits from ripening normally. This makes the fruit have less ethylene and changes how it ripens12. The Cnr gene controls how other genes work, including TDR4, because of how it’s affected by methylation12. Genes like SBP-box help regulate the ripening of different fruits, showing their role in the process12.
Scientists are also looking at how to control and prevent fruit ripening for better shipping. They want to keep freshly picked fruit from ripening on its way to market101112.
Conclusion
Fruit ripening is fascinating and complex. It includes many changes in the fruit’s look, taste, and feel. The process is driven largely by a plant hormone called ethylene, especially in some fruits13.
Knowing about fruit ripening lets us make better plans for after harvest. This includes how to handle ethylene, what makes fruits soft and sweet, and how their color changes. With this info, everyone from growers to sellers can offer top-quality, tasty fruit. They can also cut waste and increase their fruit’s value14.
The future looks bright for how we ripen fruit. New tech and better understanding mean we can expect more reliable, nutritious, and enjoyable fruits worldwide. This progress will enhance our fruit experience and keep well-loved fruits fresh and tasty for all to enjoy15.
Source Links
- https://www.npr.org/sections/thesalt/2018/09/24/650585212/science-reveals-how-fruit-keeps-a-lid-on-ripening-until-the-time-is-right
- https://www.extension.umd.edu/resource/ethylene-and-regulation-fruit-ripening
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4677914/
- https://extension.umd.edu/resource/ethylene-and-regulation-fruit-ripening
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550874/
- https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.923484/full
- https://hundredxag.com/fruit-ripening-with-ethylene/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4006173/
- https://itsfresh.com/ethylene-control/
- https://www.scientificamerican.com/article/origin-of-fruit-ripening/
- https://kids.frontiersin.org/articles/10.3389/frym.2018.00016
- https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/fruit-ripening
- https://www.linkedin.com/pulse/science-behind-ethylene-ripening-breakthrough-fruit-industry-ravi
- https://www.thoughtco.com/fruit-ripening-and-ethylene-experiment-604270
- https://www.intechopen.com/chapters/88803
0 Comments