Frequently Asked Questions

FAQ - FRESH+™ Products

An ethylene scrubber is an air purifier that removes ethylene gas from the air. Ethylene gas is naturally produced by fresh produce and potentially other sources (such as combustion and forklift batteries) in the cold storage environment. For a long time, the only ethylene scrubber type available was the pellet-type ethylene scrubber, utilizing potassium permanganate pellets to oxidize ethylene. The FRESH+™ Ethylene Scrubber product line uses a next generation technology called photocatalytic oxidation, which is more effective, environmentally friendly, and does not require constant maintenance like pellet-type ethylene scrubbers do.
Ethylene scrubbers are used in various settings to extend the shelf life of fruits and to protect other ethylene-sensitive items like certain vegetables and floral. For example, scrubbing ethylene in fruit storage prevents the "snowball effect" of ethylene from shortening the shelf life of fruit. In floral storage, ethylene scrubbers help slow senescence and reduce abscission. In mixed storage with fruits and vegetables, it is important to reduce ethylene to protect cruciferous vegetables and other highly sensitive items, which can have a variety of negative effects from ethylene.
The air re-circulates through the unit, continuously killing bacteria and mold and oxidizing ethylene, converting it to very small amount of carbon dioxide and water (humidity). All purification is done within the scrubber so nothing is released to the room. The science behind the reaction that is taking place is advanced chemical engineering, but the use of an advanced technology like PCO provides an elegant solution that is quite simple to install, operate and maintain.
No, there are no special requirements. The equipment will work in your regular storage environment, either CA or air storage, and while air-tight facilities desirable from an energy perspective, they are not required for effective ethylene control with FRESH+™.
No, there is no ozone created or used in FRESH+™. This frequently causes confusion because UV lamps can be used to generate ozone. Our UV lamps are designed to block the wavelengths responsible for ozone generation so it is completely ozone free. Ozone is not recommended for occupied spaces. Please see the US EPA's comments regarding the safety of ozone in occupied spaces.
No, FRESH+™ is an ethylene scrubber, removing ethylene from the storage environment. 1-MCP, on the other hand, is a chemical application that binds the ethylene receptors on the surface of the fruit. Trials and field tests have demonstrated that using FRESH+™ Ethylene Scrubbers is just as effective as 1-MCP. FRESH+™ Ethylene Scrubbers are safe for organic produce. Once product is removed from the ethylene-controlled environment (or the ethylene scrubbers are turned off), the normal ripening process resumes. This is beneficial especially in the case of items where aroma and softening are desirable eating qualities (peaches, nectarines, pears, apricots, etc). For a detailed comparison of FRESH+™ versus 1-MCP, please contact us.
FRESH+™ Ethylene Scrubbers offer the lowest total cost of ownership of any ethylene removal system on the market. Compared to pellet-type systems, FRESH+™ has a higher initial cost. but the ongoing cost of consumables and labor add up quickly and typically cost 2x's as much as FRESH+™ Ethylene Scrubbers over the life of the equipment. Compared to other PCO systems, FRESH+™ Ethylene Scrubbers are less expensive and provide 6-8 air changes per day as recommended by postharvest and HVAC-R experts. Other PCO systems typically specify < 1 air change per day, inadequate for significant ethylene reduction. FRESH+™ Ethylene Scrubbers are made in the USA with the highest quality components for years of dependable service. For a detailed cost comparisons of FRESH+™ versus other alternatives, please contact us.
Installation of the EC-60 is as simple as plugging the unit into a 120V outlet inside the storage room. As an option, it can be mounted on the wall or ceiling to save space or mounted on a cart for use in multiple rooms. Other models designed for larger commercial and industrial warehouse applications are supplied with uni-strut brackets for easy installation and are hardwired for 240V connection.
The only "regular" maintenance item is replacement of a pre-filter ($10-50 depending on the model). Catalyx's engineers can provide guidelines but initially, it should be monitored closely until you can establish standards for your facility. The lamps and PCO filter should be replaced every 2 years. These items are fairly inexpensive and the change out is not difficult. For exact costs, please contact us for quote.

FAQ - Ethylene Gas

Ethylene is a naturally occurring hormone that is emitted from fresh fruit, vegetables, and floral items. Ethylene gas is necessary in initiating the ripening process. And in fact, ethylene gas is used as a natural treatment to ripen certain commodities such as bananas, tomatoes, and avocados. However, ethylene damage can occur when produce is stored for longer periods for marketing purposes so removing ethylene can be beneficial in certain cases. Many fruit, vegetables and floral items are susceptible to ethylene damage in varying degrees. UC Davis has agreat website that has data for each fruit, vegetable and floral item for which data is known. You can check it out here. Contact us for more additional information about specific commodities as some have a higher value proposition for ethylene scrubbing than others.

In large retail and food service distribution centers:, the primary source of ethylene gas is from ripening rooms in proximity to produce and floral storage areas.  Throughout the produce supply chain, other sources include:

  • combustion sources
  • injured and damaged produce
  • during the normal ripening of ethylene-producing crops:
  • Apples, apricots,avocados, bananas (ripening), cantaloupes,cherimoya, figs,guavas, honeydew,kiwifruit ripe,melons,mamey, mangoes,mangosteen,nectarines, papayas,passion fruit, peaches,pears, persimmons,plantains, plums,prunes, quinces,rambutan, tomatoes.

Source: USDA Tropical Products Transport Handbook,  Agriculture Handbook No. 668

Most if not all fruit, vegetables, cut flowers and live plants are ethylene-sensitive to varying degrees.  Most experts recommend to keep ethylene below 1 ppm for most items and as low as 50 ppb for kiwi and floral.  Recently completed research with FRESH+™ Ethylene Scrubbers in tomato storage demonstrated a doubling of shelf life (+7-10 days at grower on-site storage) when levels were kept below 200 ppb.  Similarly, other research indicates even items previously thought to be unresponsive to ethylene gas can demonstrate significant extension in shelf life when ethylene levels are maintained at < 100 ppb (strawberries, cabbage, and more).   Ethylene gas is also a food source for mold.  Removing ethylene gas from produce storage reduces mold both directly (by the action of the UV-C) and indirectly (through the reduction of ethylene gas). For site-specific recommendations, please contact us. 

There are two primary means of reducing the effects of ethylene.

  • The first is to remove ethylene from the storage area –called ethylene scrubbers. There are a number of styles on the market including a potassium permanganate pellets filter system, ozone-based systems and FRESH+™'s PCO-based system (like FRESH+™).
  • The other primary means is primarily for use by growers as it must be applied within days of harvest to be effective. It is a chemical treatment applied to the surface of fresh produce which binds the ethylene receptors on the surface of the fruit rendering the ethylene inactive. Eventually, the receptors re-form and the 1-MCP needs to be reapplied or the effects will "wear off". FRESH+™ works continuously to protect fresh produce from the harmful effects of ethylene and it's also safe for organics.

There are advantages and disadvantages to each alternative. Each case should be evaluated for the right mix of ethylene control for the expected marketing period. Sometimes, for extra long storage periods, very high ethylene production and/or very ethylene-sensitive commodities, it may make sense to employ multiple ethylene control measures. For a quick overview of how the alternatives stack up, please see "The Business Case for Ethylene Control" or contact us for more details.

Fresh Plus International can help you evaluate the options when it comes to ethylene control and food safety. As a family business, our reputation is more important to us than "getting the sale" so you can count us for objective information to help you make an informed decision. Contact us today for a no-obligation evaluation and price quote.