Forum: cooking.stackexchange.com
Tags: <refrigerator>
Title: What is the use of UV LEDs in my fridge?
Question: I have a new fridge in which there is, apparently, some LEDs emitting UVs. I read on the internet that it kills bacteria and helps the food last longer. Does this really work? And what about the claim that it somehow preserves vitamins?

Answers:
sents: text: Yes, the UV light will make your fruit and vegetables last longer.
text: Really it depends on the wavelength of UV.
text: 275nm is used for killing bacteria and will burn your retinas, 385nm is less harsh to the skin or eyes and will still kill bacteria to a degree.
text: I just read a study in which they used 285nm in a controlled refrigerator setting against a static test with no UV on strawberries and how long they would stay fresh.
text: The UV irradiated strawberries lasted 9 days without growing mold.
text: The non uv, started growing mold all over them by 9 days.
text: They tested the nutritional content of each and the UV treated had a higher content of nutrition then the non uv.
answer_details: author: cooking.stackexchange.com/users/35923/Ian
score: 5
sents: text: It's for sterilizations -- for years they've sold "UV pens" for hikers to sterilize water, and kits with UV lamps to keep fish tanks clean.
text: Of course, it won't help if items are in opaque containers, tightly packed, wrapped in foil, etc ...
text: so you'll likely need to start using clear containers for it to be beneficial ... and even then, it'll only help the outside of the food, and the shelves and walls of the fridge, not the inner portions of the food being stored.
text: UV light also causes clear plastics to degrade over time.
text: They'll become less transparent (typically taking on a yellow/brown hue), and become more brittle. ...
text: so it could also cause you to need to replace your storage containers much more often.
text: I have no knowledge of UV affects on vitamins.
answer_details: author: cooking.stackexchange.com/users/67/Joe
score: 2
sents: text: Whether UV might help a food last longer depends on what the food is.
text: Fats (like shortening or ghee), and most spices should be protected from light.
text: The UV in sunlight is part of what turns fats rancid, and helps dried herbs and spices loose their flavor.
text: You will never achieve a truly sterile environment at home.
text: Bacteria and molds are everywhere, in the air, on every surface.
text: In any case, any reduction in pathogens due to the UV is strictly a surface treatment, and the food will be quickly recolonized from the environment.
text: I recommend practicing good sanitation (such as not cutting vegetables on a board just used for raw chicken) in general, and not worrying about a gimmick such as a UV light.
text: I cannot speak to the stability of vitamins under UV.
answer_details: author: cooking.stackexchange.com/users/14401/SAJ14SAJ
score: 1
sents: text: UV light will destroy bacteria etc.
text: On direct contact only They are used in commercial food storage to self clean all the surfaces of the food storage system and containers placed within it Food should be in light proof containers if the UV light is very strong, or there will be some surface degradation For a domestic fridge, this is most likely a marketing gimmick, though it may help reduce odors etc.
text: if the owner doesn't clean the fridge very well or often?
answer_details: author: cooking.stackexchange.com/users/3203/TFD
score: 1
sents: text: Is it a sub zero?
text: Sub zero uses a uv light to filter the air
text: every 20 minutes not light up the entire fridge.
text: It is taking bacteria and odors as well as ethelyne gas out of the air circulated in the fridge.
text: This is not a new concept
text: Revco corporation introduced this at least as far back as the 60's in their bilt-in Gourmet line.
text: They continued it until they stopped making home refrigeration in the late 70's or early 80's.
text: They continue to make lab refrigeration so they probably continue to use uv air filtration.
answer_details: author: cooking.stackexchange.com/users/58663/John Plant
score: 1

Summary of the answers:
UV light will sterilise the surface of food and destroy bateria, extending the lifetime of some foods. Similar technology is used in fish tanks and for sterilising drinking water. Containers should be clear and light proof for this to be effective, and only the surfaces exposed to the light will be sterilised.
UV light is used as a method of sterilization. However, it only works on direct contact and thus its use is limited. It also causes plastic to deteriorate over time. Practising good sanitation may be a better method of removing bacteria.