Ensuring that fruit and vegetables are at peak ripeness at the time of purchase is a delicate and challenging process.
Ripening chambers are required for many fruits to provide the ideal conditions for ripening. Specialised sensors must monitor climatic conditions to control the chamber’s efficiency.
This guide will explain which fruits require a ripening chamber and what types of sensors are suited to monitoring their climatic conditions.
What is the difference between climacteric and non-climacteric fruits?
All fruits produce ethylene during their lifetime, the level differs according to both the type of fruit and the stage of development. Fruits can be classified according to ethylene production capacity during ripening into climacteric and non-climacteric classes. Climacteric fruits are those that exhibit increased ethylene production during ripening and also respond to external ethylene production increasing the rate of ripening. There is no increase in ethylene production during ripening by non-climacteric fruits but they can still ripen if they are exposed to an external source of ethylene.
Fleshy fruits such as tomatoes, bananas, avocados, apples, and peaches are examples of climacteric fruits. Raspberries, pineapples, grapes, strawberries, and citrus fruits are examples of non-climacteric fruits.
Fruit ripening occurs after it is fully grown. Ripening is a process where the fruit undergoes a metabolic process resulting in physical differences in the texture, taste and colour of the fruit. Fruits will soften, taste sweeter due to the conversion of starch into fructose (sugars), and become more orange/red or purple/red/blue due to a build-up of carotenoids or anthocyanins and a breakdown of chlorophyll.
How Ripening Chambers Control The Ripening Process
Ripening chambers are designed to ensure that fruits reach peak ripeness when they are placed on supermarket shelves.
The conditions in a ripening chamber must be strictly controlled to ensure there is no wastage. Temperature and humidity can be adjusted to accelerate or slow down the ripening process.
Ethylene gas and CO2 are also essential for controlling the process.
Parameters will vary according to the type of fruit being stored. Air flow must be consistent to ensure that all fruit ripens evenly. For health and safety, CO2 levels must also be controlled.
Sensors for Controlling Conditions in a Ripening Chamber
Sensors are required to monitor:
- Humidity
- Temperature
- CO2 Levels
- Ethylene Concentration
and in some instances oxygen levels.
The accuracy and reliability of sensors will determine the ripening process and the quality of the final produce.
Challenges for Sensors in a Ripening Chamber
Sensors in a ripening chamber must contend with high humidity levels that can affect accuracy or cause corrosion. It can also shorten the life of a sensor.
Sensors need to:
- remain stable
- Have a high degree of accuracy
- Be resistant to condensation
- Be resistant to contamination
- Meet IP65 protection regulations
We recommend our E + E Elektronik sensors for climate control as they are reliable in humid conditions and provide accurate measurements for humidity, temperature and CO2 in ripening chambers.
EE872 Probe for CO2, Humidity, Temperature and Ambient Pressure
EE211 High Humidity Temperature Transmitter
and our SmartGAS NDIR flow sensor modules for gas sampling systems:
0-2000 ppm ethylene (C2H4) flow sensor module
You can explore our whole range of sensors at Omni Sensors at Transmitters or contact us for advice about buying the most suitable products for your needs.
