Banana Ripening Process
Ethylene is a scientifically proven, effective and safe method for a banana ripening chamber. Being a natural plant hormone, it doesn’t cause any health hazards and even a very small amount is sufficient to stimulate the natural ripening process until the fruit itself starts producing ethylene in large quantities. Plus, a detraining agent, ethylene turns the banana peel from green to perfect yellow and maintains the flavour and aroma of the fruit, thus adding more value for the farmers and traders.
When this process happens inside a temperature and humidity-controlled environment, the ripening results are excellent!
Ideal Conditions for Banana Ripening Process
Optimum temperature & relative humidity
- 13 °C to 14°C & 90—95% humidity for storage and transport
- 15°C to 20°C & 90—95% humidity for ripening
Response to ethylene
Most commercial cultivars of bananas require exposure to 100—150 ppm ethylene for 24 to 48 hours at 15—20°C and 90—95% relative humidity to induce uniform ripening. Carbon dioxide concentration should be kept below 1% to avoid its effect on delaying ethylene action. The use of a forced-air system in a banana ripening chamber assures more uniform cooling or warming of bananas as needed and improved ethylene concentration throughout the ripening process.
Undoubtedly, safe storage and rapid delivery of perishable fruits are critical in the food industry. The use of a ripening chamber for banana can offer many advantages.
- Faster than traditional ripening: Traditional ripening methods for bananas and mangoes can be around four to six days but the use of a ripening chamber can reduce this period to 24—48 hours.
- Ripening in non-harvesting season: The use of a banana ripening chamber means that farmers or traders can ripen the fruits even in the non-harvesting season when used in conjunction with appropriate cold storage.
- Improved profits: Rapid ripening and useability in non-harvesting seasons mean more business and increased profits for both the farmers and the traders.
- Safety: As opposed to the use of toxic calcium carbide, a ripening chamber uses ethylene gas, which is a safe, efficient, and globally accepted ripening method.
- High quality: A banana ripening chamber ensures higher quality by reducing the risk of fruit spillage, breakage, dust, over, or under-ripening etc. Plus, for consumers, a spotless ripened fruit with the required yellow colour means high quality.
- Enhanced flavour and colour: Controlled temperature and relative humidity in a banana ripening chamber ensure perfect ambient conditions to enhance the flavour and yellowing of the fruit.
Significant Components of a Banana Ripening Chamber
The design of a banana ripening chamber depends on the working cycle. For instance, a banana ripening chamber is operated between four and six days for one cycle which consists of a number of steps.
The significant components of a banana ripening chamber include the following:
- Ripening Room: A banana ripening chamber is a special room with the following features.
- Air-tight to prevent ethylene leakage.
- Properly insulated to maintain the required temperature within limits. Generally, ripening temperatures for all fruits fall between 15°C and 26°C.
- Equipped with heating equipment to maintain appropriate room temperature in cold weather
- Designed for air stacking of boxes to allow proper air circulation among all the banana boxes. If the room is designed for solid stack palletized ripening, there is no need to air stack.
- Humidifiers: Adiabatic (mist) humidifiers are preferred. Steam type is optional. Usually, relative humidity should be in the range of 90 to 95%. If the humidity level in ripening chambers is not enough, the produce will be affected by water loss. So, maintaining high humidity helps to control the weight loss in the banana ripening chamber.
- Ventilation and gas extraction systems: Due to the respiration process of the fruits, the oxygen levels usually drop and CO2 levels increase. That is why suitable ventilation and foul gas extraction system should be installed to reduce CO2 levels for better ripening and quality fruits. CO2 level indication & automatic control system are optional features.
- Refrigeration system: Centralized multi-compressor, high-efficiency refrigeration system is needed for efficient operations. CFC-free refrigerant with heat exchangers removes heat (from respiration) using a suitable capacity refrigeration system. The cooling coil has high-velocity fans to ensure efficient air circulation through every produce in storage.
- Ethylene generator/injection: Ethylene generators (Liquid/Catalyst) are portable and are provided in the banana ripening chamber. Digital analyzer-cum indicator controllers for an automatic operation may also be offered. Apart from ethylene generators, ethylene cartridges and ethylene and ethylene/nitrogen cylinders are also available.Ethylene obtained from cylinders is often at a higher level, up to 1000 ppm (0.1%). Since it is a one-shot injection, more ethylene is introduced to compensate for the room leakage. If ethylene generators are used, the maximum achievable concentration is in the order of 400 ppm (0.04%) in a free space of 100 cubic meters. However, if the introduction of ethylene is uncontrolled, there is a risk that the ethylene level may reach or exceed the lower explosive limit (LEL) of 3.1% and be ignited by unprotected electrical apparatus, gas heating systems or other incendive sources, resulting in a fire or explosion.
Features of a Standard Banana Ripening Chamber
In summary, a standard banana ripening chamber will have the following features:
- Airtight, insulated ripening chamber
- Refrigeration rack system (with optional standby compressor)
- Air-cooled or water-cooled condensers
- Powder-coated evaporator casing and galvanized steel with exterior quality powder coating finishes
- Electrical control panel
- Safety protection system for running pieces of equipment like high or low-pressure switches, differential pressure switches, overload protection, etc.
- Ethylene generators or gas-discharge systems for ripening processes
- CO2 and ethylene analyzers to monitor levels of gas in the room
Expert Tips When Using a Banana Ripening Chamber
Here are som expert tips when using a banana ripening chamber for maximum value.
- Bananas are very sensitive to temperatures. Chilling may occur if the fruit is subjected to temperatures below 14°C for several hours. This causes the peel to have a smoky, dull grey appearance. However, it may not show up for 18 to 24 hours after chilling occurs. Cooked bananas on the other hand result from excessively high temperatures. In such cases, the banana peel will have a brown to orange appearance. The fruit may become excessively soft and have a short shelf life. It is equally important to maintain appropriate humidity levels around 85 to 95% in the banana ripening chamber.
- When bananas are ripening, ensure the release of carbon dioxide which will build up in the banana ripening chamber. The CO2 production begins as the fruit ripens and enters the “climacteric” phase or the period when bananas release ethylene and have an elevated rate of respiration and physiological changes. Carbon dioxide concentrations above 1% (10,000 ppm) will retard ripening, delay the effects of ethylene and cause quality problems. Therefore, it is recommended to vent rooms by opening the doors for 20 minutes every 12 hours, after the first 24 hours of ripening. Other venting methods are an automatic fan (either timed or sensor-based) or flow-though (constant) ventilation.
Bananas bruise easily, whether green or ripe. Therefore, careful handling at all stages will reduce bruising and enable you to sell the bananas for high value!
The cost of banana ripening chamber varies according to the capacity, features, and level of manual work involved. When choosing ripening chambers, make sure you have identified your requirements and the type of fruit or produce you want to ripen.
Rinac is a global leader in cold storage and processes and has helped traders and farmers reap the maximum benefit with eco-friendly, cost-effective, state-of-the-art fruit ripening chambers. To know more about our ripening chambers, click here!