Mung Beans (Green Gram)
Sortex Mung Beans (Colour Sorted)
Optical colour sorting for mung beans: what it removes, what it costs, and when the premium is justified.
"Sortex" is used across the pulses trade as a generic term for optical colour sorting, regardless of which manufacturer built the machine. The principle is the same in every case: product is fed in a thin, even stream past camera arrays, each grain is assessed against an accepted colour range, and grains falling outside it are ejected by a burst of compressed air.
On mung beans this is a powerful step, because the defects that survive mechanical cleaning are almost entirely colour defects. Weathered seed, stained seed, mould-marked seed, off-shade seed and foreign seed of a different colour are all invisible to a screen and a gravity table and obvious to a camera. Running a sorting pass typically lifts purity from the 98% range into the 99.5% range and tightens every visual parameter alongside it.
The cost is the reject fraction. An optical sorter does not repair anything; it removes. Everything ejected leaves the contracted lot, and the tighter the setting the more sound grain is ejected along with genuine defects. That yield loss, plus the processing time, is what a Sortex premium pays for — which is why sorting intensity is set against the contract rather than run at one fixed level.
What optical sorting removes
- Discoloured, weathered and stained seed.
- Mould-marked and heat-damaged seed.
- Off-shade and off-variety seed within the same size range.
- Remaining foreign seed distinguishable by colour.
- Visible insect-damaged seed where the bore hole or staining is detectable.
When Sortex is worth specifying
Retail packing is the clearest case. Where the bean reaches a consumer through a transparent pack, colour and uniformity are the product, and a machine-cleaned lot will generate complaints regardless of its purity figure.
Premium repacking and distribution is a second case, particularly in the Gulf, where consistency between shipments is part of what the buyer is selling.
Sprouting buyers are a distinct case. They need viable seed, and while sorting improves presentation it does not establish germination — that is tested separately on the actual crop.
Setting the intensity
A light pass protects yield while removing the obvious defects. An aggressive pass produces a very clean sample at a materially higher reject fraction and therefore a higher price per tonne of accepted product. Neither is right in the abstract — the correct setting is the one that meets the contract at the lowest cost, which is why the target parameters should be stated rather than left to a default.
Specification
Typical specification
Mung Beans (Green Gram) — Sortex
Machine cleaned and optically colour sorted
- Product
- Whole mung beans, colour sorted
- Origin
- Tanzania, Kenya, Ethiopia
- Crop year
- Stated on contract
- Moisture
- 12% max
- Purity
- 99.5% min
- Foreign matter
- 0.1% max
- Admixture
- 0.5% max
- Damaged and discoloured
- 0.5% max
- Broken and split
- 0.5% max
- Insect damaged
- 0.5% max
- Immature and shrivelled
- 0.5% max
- Size
- 3.2 mm and above
- GMO status
- Not genetically modified
Notes on specific parameters
- Crop year — Contract on a specific crop year; it materially affects colour, cooking behaviour and insect load.
- Size — Other bands on request.
- GMO status — There are no commercially cultivated genetically modified varieties of this crop.
- Specification suited to repackers, retail packers and buyers with a high visual standard.
- Germination testing for sprouting buyers is arranged separately and is crop-dependent.
Specifications shown are indicative contract parameters used across the trade. They are not laboratory results and are not a guarantee attaching to any particular lot. The specification that governs a shipment is the one written into its contract, agreed against the buyer’s requirement and, where appearance matters, against an approved sample.
Frequently asked questions
What does Sortex actually mean?
It is a generic trade term for optical colour sorting, used regardless of equipment manufacturer. Product passes camera arrays in a thin stream and grains outside the accepted colour range are ejected by compressed air.
Does Sortex improve germination for sprouting?
No. Sorting improves appearance and purity by removing off-colour seed; it does not make seed viable. Where sprouting quality is required, germination is tested on the actual crop and agreed as a separate parameter.
Why does Sortex product cost more?
Because of the reject fraction. Everything the sorter ejects leaves the contracted lot, and tighter settings eject more sound grain alongside genuine defects. The premium pays for that yield loss and the additional processing time.
Request mung beans (green gram) availability
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- Origin
- Specification
- Crop year
- Quantity
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