The Spoilage Challenge in Fruit Harvesting

How often have you had to discard apples purchased just days earlier? Fruits are notoriously perishable, and mishandling often leads to waste. Alarmingly, between 20% and 40% of harvested fruits never reach consumers. Given this wastage, can the United Nations’ “Zero Hunger by 2030” initiative be achieved?

Even the fruits that do reach consumers can be discarded due to superficial flaws. If deemed unattractive, they may end up in the trash despite being perfectly edible—a troubling reality.

Current Methods for Harvesting Fruits

In most cases, fruits are picked manually, relying on the skill and judgment of fruit pickers to differentiate between ripe and unripe fruits. Two main approaches exist: destructive and non-destructive.

The penetrometer exemplifies a destructive method, measuring the firmness of the fruit by puncturing its surface. While this helps assess ripeness, it damages the fruit and often misses vital data.

In contrast, non-destructive techniques utilize wave emissions to evaluate maturity. Near-infrared spectroscopy (NIRS) sends radiation onto the fruit, measuring the reflected light to create a unique spectrum for each type. This allows for an assessment of ripeness based on various chemical properties.

Challenges with Existing Techniques

Both invasive and non-invasive methods have limitations, highlighting the need for a new approach to determine fruit maturity. Key challenges include:

• The unclear relationship between wavelength and quality attributes in non-destructive methods.
• Non-invasive techniques provide only a general overview without detailed analysis of the fruit’s layers.
• Limited sampling can lead to inaccurate representations of ripeness, as fruits on the same plant can vary.

In the U.S., 60% of agricultural land used for fruit production is wasted, and in regions with high food insecurity, such as sub-Saharan Africa, food loss can reach 50% according to the FAO. Reducing food loss at the initial supply chain stages is essential, and advancements in fruit quality assessment technology could enhance food production efficiency.

The Promise of New Technology for Assessing Fruit Ripeness

Introducing ultrasound technology. Often associated with medical diagnostics, ultrasound uses high-frequency sound waves to provide insights into objects, including fruits, without causing harm.

This innovative technology emerged from a group of Chilean researchers, who submitted a patent application in 2019, now approved for commercial use. Imagine an assembly line where fruits pass through a tunnel with a device equipped with two transducers—one emitting ultrasound waves and the other capturing the reflected signals. This setup can evaluate a fruit's ripeness at a rate of one fruit per second, achieving a remarkable 93% accuracy.

The software analyzes the different ultrasound signals from the fruit’s layers to assess maturity levels. Ripe fruits are packaged for delivery, while those still unripe are redirected for processing into juice or jam.

In Summary

At first glance, the connection between sound and fruit quality may not seem obvious. However, considering the massive food waste prevalent in our industry, it’s evident that traditional methods are insufficient. Sound technology may be part of the solution we need to enhance food supply management efficiency.

Each year, approximately one-third of global food supplies are lost or wasted. By optimizing food management, we could significantly alleviate world hunger and reduce greenhouse gas emissions by 10%.

Fresh fruits and vegetables are among the most commonly discarded items. Current assessment techniques—both destructive and non-destructive—fail to maximize efficiency throughout the supply chain. The ultrasound detection system offers a promising alternative, as it:

• Accurately gauges ripeness and assesses the maturity of each fruit layer.
• Is non-invasive, ensuring the fruit remains undamaged during evaluation.
• Processes up to 60 fruits per minute with an impressive 93% accuracy.
• Classifies fruits for supermarket delivery or for juice and jam production.

As we advance in agricultural technology, ultrasound may be the breakthrough we need to significantly reduce global food loss. Sound and food—who would have thought they could be interconnected? From using music to treat wastewater to employing sound to eliminate harmful bacteria in meat, the potential applications are vast.

Are you intrigued by the fascinating interplay between sound and the natural world? Discover how music influences plant growth, enhances taste perceptions, and more by subscribing to my newsletter for a journey into sound awareness.