Photonics has long played an important role in the food industry, with light technologies used to grow and pick crops on the farm to keep our food fresh, safe and free from counterfeit ingredients throughout the production process. UV-Vis and near-infrared spectrometers, UV LEDs and solid-state optical sensors are some of the many light technologies used in today’s agricultural and food applications.
UV-LEDs enhance plant growth
EOS LightPulse, a company based in Madrid, Spain, makes horticultural LEDs. Its grow lights incorporate deep UV LEDs from Crystal IS in addition to visible LEDs, and they’re used for the growth of plants indoors and in greenhouses. Deep UV light triggers a key photoreceptor (UVR8) and increases the concentration of compounds such as resveratrol in grapes, vitamin D in mushrooms, terpenes, cannabinoids such as CBD and THC in cannabis and other oils and compounds in plants that are important to humans.
In addition, UV light also impacts the organoleptic properties (taste, smell & texture) of plants. Finally, UV light also kills fungus and protects plants from powdery mildew formation, thereby maximizing yield.
The grow light includes an array of multi-wavelength visible LEDs for the photosynthesis of plants and Crystal IS deep UV LEDs of two different wavelengths. The 275 nm UV LED is used to increase cannabinoid production and the 255 nm UV LED to prevent mildew formation and the UV light is pulsed at the optimum dosage to maximize the positive impact of UV without stunting plant growth. In addition, the 255 nm LED is also used in the curing and storage of cannabis, to prevent mildew formation. All the LEDs can be controlled with a smartphone application and allows growers to create customized lighting recipes.
Unlike UV lamps, the UV LEDs can be turned on and off as needed, to match the growth and flowering cycle of the plant and operated in a pulsed mode, to avoid damage to plants from excessive UV exposure. Repeated turning on and off of UV lamps, in contrast, drastically reduces their lifetime. The LED solution also reduces energy costs due to lower power consumption and decreased cooling costs due to lack of infrared heat from the LEDs. In addition, the use of cold light sources such as LEDs enables the light to be moved closer to the plant canopy which helps in vertical farming. Finally, the ability of UV LEDs to kill fungus helps reduce the use of fungicides in preventing mildew formation.
Spectral sensor detects counterfeit ingredients
Because olive oil brings premium prices, counterfeit products or products with counterfeit ingredients such as chlorophyll and beta-carotene are sometimes added olive oil. The Spark is a solid-state optical sensor from Ocean Optics that is used like a spectrometer to analyze extra virgin olive oil to compare it to other types in order to determine authenticity. Researchers looked at extra virgin olive oil, regular olive oil, rapeseed and sunflower oils. They found a variation in the characteristic spectrum of each oil sample, with true extra virgin oil having the strongest absorbance. Regular olive oil has a lower level of absorbance, but maintains the same general spectral shape of the extra virgin olive oil. The rapeseed and sunflower oils show completely different spectral shapes. Once the true extra virgin olive oil is identified, they look for diluted or adulterated oils. For instance, if chlorophyll has been added to give the olive oil a darker green color, the absorbance spectrum changes. This type of testing using the solid-state optical sensor can be incorporated into process lines or embedded into quality control systems.
Fourier transform infrared spectroscopy in milk production
The dairy industry is making use of Fourier transform infrared spectroscopy, which offers complex measurement capabilities including both transmittance and reflectance. For example, there are companies that manufacture analytical solutions for the dairy and other food industries, such as measuring sugar content in yogurt. They can use near infrared detectors including those from Laser Components in their spectrometers to test for milk adulteration, fat, protein, lactose, acidity and more. These analyzers are used in production environments by dairies for quality control as well as lab analysis of fat and total solids on finished products, and in the analysis of protein, lactose and total solids on raw material.
Near infrared in meat analysis
Meat producers are using near-infrared spectroscopy to measure reflected light in analyzing samples for certain parameters such as fat, moisture and protein content.
StellarNet has a new, portable spectroscopy tool called StellarCASE-NIR that uses an InGaAs photodiode and a patent-pending 3D optical collection design to measure large sample areas without having to move them. Each instrument comes with an integrated Windows tablet with ChemWiz software installed. To analyze parameters, you set the calibration reference, set a meat sample on the fixture and click “analyze.”
Food analysis made easy
Complex analysis of food and food parameters has never before been as sophisticated and simple at the same time. A trend that we’re seeing across many light technologies is ease of use, to the point where a degree in chemistry or physics isn’t needed to operate the equipment. With state-of-the-art technologies incorporated into today’s analytical tools being used in the food industry, this trend can only result in enhanced food safety and freshness.
Written by Anne Fischer, Managing Editor, Novus Light Technologies Today