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New Hand Held Scientific Instrument to Help Cherry Growers Determine Optimum Times

As the consumers are very much health conscious and they would like to have the fresh fruits. The nutritious value is also high of the fresh fruits. How to check the freshness was always the requirements of the consumers, suppliers and the traders involve in the export of the fruits and vegetables. This export may be overseas or to the other cities. It is taking time to reach these fruits with short shelf life to other cities, destination. The instruments available in labs were very much in help but the requirement of the hand held instruments in Canada had solved the problem. Fortunately, advances in science are making it possible to measure cherries’ quality while they are still hanging on the tree, without damaging any in the process. A team of researchers at Agriculture and Agri-Food Canada (AAFC) in Summerland is working with mobile hand-held optical spectrometers to develop models to precisely gauge the quality of cherries, and predict their firmness and flavour after storage or shipping.

Fruit " quality " is a concept encompassing sensory and mechanical properties, nutritive values, safety and defects. Fruit quality has declined, determining consumer dissatisfaction, largely due to the wrong harvest date; in addition, quality is badly defined since the parameters mainly considered are fruit size and skin color. Other attributes such as flesh firmness, sugar content, acidity and aroma, are perceived by the consumer as fruit global quality, are seldom considered by the farmer and by other individuals along the chain. Up to now, several studies have been carried out on fruit quality assessment by using traditional methods, which are affordable and fast, but do not consider other quality traits, as antioxidant power, aroma volatile emission, soluble sugars and organic acids content.

An optical spectrometer is a scientific instrument that emits light and measures how much of that light reflects back to the instrument. You hold the device against a cherry, it shines light on the surface of the intact fruit, and it measures the amount of light of each wavelength reflected back. The reflected light depends on the chemical composition of the fruit. Spectrometers were once cumbersome pieces of equipment, suited only for laboratory use, but now they are designed specifically for use in orchards.

Dry matter is what’s left in the fruit after all the water is removed. In cherries, dry matter is equivalent to sugar content, and is a good indicator of ripeness, quality after storage and flavour.

A grower who knows the dry matter content of their cherries can determine how well that fruit will do in storage, and decide which fruit to sell immediately and which to store or ship internationally. In short, using dry matter to make decisions on storage, shipping and market selection could lead to a consistent supply of crisp and delicious cherries from Canadian growers.

The ‘old fashioned way’ of measuring dry matter isn’t practical for an orchard operation. You cut fruit into thin slices, weigh it and bake it at 60oC in an oven for two to three days until all the water is removed, then weigh it again. Your sample size is limited by oven space, samples are tedious to process, and valuable time is lost waiting for results. That could mean missing the best time for harvesting and shipping your cherries.

After the team completes validation of the scientific models for commercial spectrometers, growers will have a tool that can produce instant dry matter readings on as much fruit as needed without damaging any of it.

Spectrometers have traditionally been quite expensive, costing several thousands of dollars. They have also generally been too large to use outside of a laboratory setting and require a laptop to operate.

To shrink the instrument, the research team incorporated a spectrometer chip made with micro-electro - mechanical system or MEMS, technology that has drastically reduced the size of spectrometers. This allowed the team to build the first research-grade spectrometer that is about the size of a typical garage door opener.

To test its effectiveness, the science team decided to see how well it was able to detect the ripeness of a piece of fruit.

It turns out there is a relationship between the ultraviolet fluorescence of chlorophyll in the skins of fruits like apples, oranges and bananas and the softness of the fruit inside. Using a spectrometer to measure the fluorescence of chlorophyll allows scientists to tell whether the fruit is ready to eat, or if it could use a few more days to reach prime sweetness.

Although spectroscopy has not yet been used to determine fruit ripeness in the field, it has frequently been used in the lab.

"Ripeness testing using spectrometers is non-destructive and very fast," said Anshuman Das a postdoctoral researcher at the MIT Media Lab and coauthor of the new study. "It does not involve much sample preparation, so it's an attractive approach."

Growers and packers are making it a top priority to ensure cherries make the journey in top form, impressing both international buyers and consumers. Shipping cherries overseas is a high stakes game – every container carries approximately $100,000 of fruit. International consumers are becoming increasingly picky and buyers will only accept high quality cherries at port.

Fortunately, advances in science are making it possible to measure cherries’ quality while they are still hanging on the tree, without damaging any in the process. A team of researchers at Agriculture and Agri-Food Canada (AAFC) in Summerland is working with mobile hand-held optical spectrometers to develop models to precisely gauge the quality of cherries, and predict their firmness and flavour after storage or shipping.

Dr. Peter Toivonen leads the Postharvest Physiology program at AAFC’s Summerland Research and Development Centre, which includes research technician Brenda Lannard and biologist Changwen Lu. Together, they are fine-tuning models using specific commercial spectrometers to make this technology useful for Canadian cherry producers.

The team is determining the best values for fruit quality and storability for cherry varieties, including Lapins, Staccato, Sweetheart and many others that are grown commercially. The work includes finetuning and expanding the use of the technology by developing specific protocols for working under a variety of conditions while ensuring consistent and meaningful readings. The team is also working to identify any limitations to the technology before transferring it to end-users. As with other technologies, users – most likely skilled quality assurance or field service staff – will need training before putting these devices to work in the field. Working with industry to properly implement the technology will be the key to success.

Using hand-held spectrometers, in combination with knowledge generated from Dr. Toivonen’s research, will give cherry growers precise data on their crop’s ‘best before’ date. “Being able to reliably measure the maturity and quality of cherries, without sacrificing any of that crop to sampling, will save hundreds of thousands of dollars a year on container shipment claims for the industry,” estimates Dr. Toivonen.

Consumers’ expectations are high and if Canadian growers can improve their reputation for consistent high quality and flavour, the industry will benefit. Growers could see a 10-20 percent  increase on returns thanks to improved consistency in quality.

“People are doing this work in other countries. If we are not part of it, we are behind,” advises Dr. Toivonen. Luckily, his team is working to keep the industry on the leading edge and consumers happy. 

 

Chander Mohan
Krishi Jagran



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