Laser Shows if Fruit's Beauty is Only Skin Deep

May 08, 2005
Laser Shows if Fruit's Beauty is Only Skin Deep

The produce industry is working with the Agricultural Research Service (ARS) to make sure that fruits and vegetables taste as good as they look. They're counting on "machine vision" tools that can predict the quality of fruit or vegetable flavor--right after picking and in the packing plant--without ever touching the product. Machine vision uses optical sensors to inspect objects.

Image: Using a multispectral imaging system to collect light scattering from the fruit, visiting assistant professor Yankun Peng (from Michigan State University) estimates apple firmness.

Today, batches of fruits and vegetables are judged by sample tastings, but there is no guarantee that all of the produce in the batch will taste the same. Samples are also tested for firmness by mechanically stabbing them with a thick, steel probe. With both methods, the tested produce has to be thrown away.

While there are machine vision tools that can check skin-deep traits like size, color and bruising, it is difficult to judge deep, internal qualities like taste and texture of apples and many other fruits. Now Renfu Lu, an agricultural engineer with the ARS Sugar Beet and Bean Research Unit in East Lansing, Mich., has developed machine vision prototypes that "taste" every single piece of produce from right after harvest to when it passes by on the packing line.

Lu and ARS colleagues on the campus of Michigan State University have tested their laser prototype on apples and peaches. It should work with any produce that is at least as large as an apple or peach. The detector focuses four laser beams, each a different light wavelength, into one sharp beam that shines into individual fruits.

Laser light photons momentarily scatter all the way to the fruit's core and back. The amount of light bounced back after interacting with tissue reflects firmness. Peaches and apples are separated by whether they are soft, firm or hard.

Since scattered light also indicates the amount of light absorbed by the fruit, and that absorption is affected by sugar levels in the fruit, this technology can be used to predict flavors, such as sweetness in apples.

Source: Agricultural Research Service

Explore further: Physicists create tool to foresee language destruction impact and thus prevent it

add to favorites email to friend print save as pdf

Related Stories

Designing exascale computers

Jul 23, 2014

"Imagine a heart surgeon operating to repair a blocked coronary artery. Someday soon, the surgeon might run a detailed computer simulation of blood flowing through the patient's arteries, showing how millions ...

A tree may have the answers to renewable energy

Jul 23, 2014

Through an energy conversion process that mimics that of a tree, a University of Wisconsin-Madison materials scientist is making strides in renewable energy technologies for producing hydrogen.

Recommended for you

Affirmative action elicits bias in pro-equality Caucasians

7 hours ago

New research from Simon Fraser University's Beedie School of Business indicates that bias towards the effects of affirmative action exists in not only people opposed to it, but also in those who strongly endorse equality.

Narcissistic CEOs and financial performance

Jul 24, 2014

Narcissism, considered by some as the "dark side of the executive personality," may actually be a good thing when it comes to certain financial measures, with companies led by narcissistic CEOs outperforming those helmed ...

Election surprises tend to erode trust in government

Jul 24, 2014

When asked who is going to win an election, people tend to predict their own candidate will come out on top. When that doesn't happen, according to a new study from the University of Georgia, these "surprised losers" often ...

User comments : 0