:: SAS and Engineering - Particle and gas phase air filtration and ventilation ::

Ethylene Gas Postharvest Ethylene Gas Removal:

Perishable fruit, vegetables & ornamentals begin to lose quality as soon as they are harvested. Many of these products are transported to markets in refrigerated transport, and if they are handeled correctly, it is possible to slow their rate of quality loss. Product condition, at the market, reflects the cumulative quality losses at each step in the handling chain.

There are four environmental conditions that can be managed in order to get good quality produce to the market. These are:

Temperature
Humidity
Ethylene Gas Concentration
Atmospheric Composition

Our products are designed specifically for Ethylene control.

Undesireable effects of Ethylene:

Accelerated ripening & softening of fruits
Accelerated senescence & loss of green colour in some immature fruits.
Russet spotting on lettuce.
Formation of bitter principle (isocoumarin) in carrots.
Induction of stress metabolites i.e. Isomeamarone in sweet potatoes.
Sprouting of potatoes - either stimulation or retardationdepending on concentration and duration of exposure to ethylene.
Abscission leaves.
Toughening of asparagus.

Abbreviated storage life & reduced quality of cut flowers.

Physiological disorders in flowering bulbs.

Ethylene impact on cut flowers and bulbs:

Shortens the life span of cut flowers
Inhibits the development of immature flower bulbs. Causes partial / completeflower absorbtion.
Retards the growth of the plant.
Causes growth abnormalities such as excessive leafiness and stimulates growth of daughter bulbs.

The impact of Ethylene:
Ethylene production and sensitivity levels of fresh produce, flowers & nursery stock.

Fruits & Vegetables	Rate of Ethylene production	Level of Ethylene Sensitivity	Principle reaction to Ethylene gas
Apples	VH	H	Scald, Lose Crunch
Apricots	H	H	Decay
Asian Pears	H	H	Decay
Asparagus	VL	M	Toughness
Avocados	H	H	Decay
Bananas	M	H	Decay
Berries	VL-L	L	Mold
Broccoli	VL	H	Yellowing
Brussel Sprouts	VL	H	Yellowing
Canteloupe	H	M	Decay
Carrots	VL	L	Bitterness
Chard	VL	H	Decay
Cherimoya	VH	H	Decay
Cherries	VL	L	Softening
Cucumbers	L	H	Yellowing
Grapefruit	VL	M	Mold
Grapes	VL	L	Mold
Kiwi Fruit	L	H	Decay
Lemons, Lime	VL	M	Mold
Lettuce, Leafy Greens	VL	H	Russet Spotting
Mangoes	M	H	Decay
Melons	M	H	Decay
Nectarines	H	H	Nectarines
Onions, Garlic	VL	L	Odour, Sprouting
Oranges	VL	M	Mold, Rind Breakdown
Papaya	H	H	Decay
Passion Fruit	VH	H	Decay
Peaches	H	H	Decay
Pears	H	H	Decay
Persimmons	L	H	Decay
Plums, Prunes	M	H	Decay
Potatoes	VL	M	Sprouting
Quinces	L	H	Decay
Tomatoes	M	H	Shrink, Decay
Watermelons	L	H	Lose Firmness
Floral & Nursery Commodities
Cut Flowers (Carnations)	VL	H	Sleepiness, Leaf Curl
Cut Flowers (Roses)	VL	H	Premature Opening

Classification of Ethylene sensitivities
VL - VERY LOW
L - LOW (3 - 5ppm)
M - MEDIUM (0.5 - 3ppm)
H - HIGH (0.01 - 0.5ppm)
VH - VERY HIGH

We offer the supply of potassium permanganate impregnated activated alumina pellets & filters for postharvest ethylene gas removal.

Typical Specifications:

Shape	Spherical
Size	>5,69mm<10% 5,69 - 2,36mm 85% <2,36mm<5%
Colour	Purple
Bulk Density Potassium	800kg/m3 at 15% moisture
Permanganate	8% by weight (dry)
Moisture Content	20% Maximum

Comparisons of available media:

	S.A.S H.C. Spheres	Surface Coated Spheres	Chemical Impreg Caron
Preferred Media Feature Carries a UL Class - 1 Rating	YES	YES	YES
Built in colour indicator to determine available chemistry content throughout	YES	YES	NO
Non-combustible	YES	YES	NO
Active chemistry per unit weight	VERY HIGH	VERY LOW	HIGH
Uniformity of flow-path through packed bed	VERY UNIFORM	UNIFORM	UNIFORM
Extends useful life of media bed	YES	NO	YES
Absorbed pollutants will not outgas	WILL NOT	CAN	WILL
Shape of individual unit	UNIFORM	UNIFORM	IRREGULAR
*Relative humidity recommended usable above 90 ambient**	YES	YES	NO
Easy disposal of spend media	YES	YES	NO