Dried Fruit Production

Five to eight kilogrammes of prepared fruit make one kilogramme of dried fruit, and the fruit decides the ratio rather than the dryer. Dried fruit production is an arithmetic business before it is a drying business: whoever knows their own fresh to dried ratio can price a sack of mangoes, and whoever does not is guessing. Uganda regulates the product under a compulsory standard, and a second one covers fried fruit.

How Much Fresh Harvest a Kilogramme of Dried Fruit Takes

Drying removes water and nothing else. Every gramme of sugar, fibre and mineral matter that was in the fruit is still in the finished slice, which means the weight you end up with is fixed by the fruit's dry matter and by the moisture you dry down to. Nothing in the equipment can improve it.

Write it out and the whole business plan falls out of one line. Dried weight equals fresh weight multiplied by the fruit's dry matter share, divided by the dry matter share of the finished product. Take 100 kilogrammes of prepared slices and dry them to 8 percent moisture, so the product is 92 percent dry matter.

Two things have to be measured separately, and mixing them is the commonest mistake in a dried fruit costing. The first is dressing loss: peel, stone, core and crown come off before drying, and for mango the stone alone is a large share of the fruit you paid for. The second is the drying loss above. Weigh the fruit as delivered, weigh the prepared slices, weigh the dried product, and you have both numbers for your own fruit and your own varieties. Do it once per variety and once per season.

The method for the moisture itself needs no laboratory. Weigh a small tray of prepared slices, dry them until the weight stops falling, weigh again, and the loss divided by the starting weight is the moisture on a wet basis. That is exactly how the published drying studies do it.

Two Ugandan Standards Split Dried Fruit From Fried Fruit

Uganda regulates this product by the process rather than by the fruit, and the split is cleaner than most people expect. Both halves sit in the bureau's schedule of legally enforced standards, in the edition read for this page, which is dated to the middle of last year.

Two neighbours in the same family are worth knowing about. Dried vegetables and herbs for food use have their own compulsory standard, US 889:2021, also a second edition, so a producer drying both fruit and herbs is under two documents. Dried tomatoes have a third, US 890:2011, separate again. And where a fruit surplus goes into a sugared preserve rather than a dry one, jams, jellies and marmalades are covered by US EAS 947:2019, which replaced a much older Ugandan jam standard.

The limit of this section has to be stated plainly. The schedule prints scopes, not specifications, and `unbs.go.ug` refuses automated access, so no moisture limit, defect tolerance, sampling plan or contaminant figure from any of those standards appears on this page. A scope is evidence. A specification nobody has read is not, and buying the document is the only way past that.

Dried Mango Has a Ugandan Standard and No Production Figure

Here is the oddity that ought to shape how a Ugandan mango dryer thinks. Uganda has a compulsory standard written for that exact product, US EAS 946:2019, Dried mango, covering dried mango from Mangifera indica intended for direct human consumption or for other use in the food industry. The state has a specification for a dried mango slice.

The same state files no mango production figure at all. Uganda's entries in the international crop production database run to five lines in total: cooking banana, an empty banana line, pineapple, a fruit aggregate, and a catch all called other fruits not elsewhere classified. There is no mango series, no avocado, no papaya, no orange, no lemon and no passion fruit. Everything outside pineapple and banana sits in that one residual line, which runs at about 7,900 hectares and 52,400 to 52,500 tonnes with every observation flagged as imputed, and whose six recent values span roughly 0.2 percent. A figure that barely moves across six years is a model being carried forward.

The blank is real rather than a failed search. The same file returns Uganda's pineapples, at about 1,000 hectares and 8,400 to 9,400 tonnes with the yields flagged as estimates, and returns an officially flagged cooking banana series above 11 million tonnes. Kenya files eleven of the items Uganda is missing, mangoes among them, and Tanzania files seven. So the gap is specific to Uganda rather than a hole in the dataset.

What follows for a processor is practical. There is no national tonnage to size a plant against, so supply has to be counted tree by tree and orchard by orchard, in the season you can actually buy. Orchard management and the varieties behind a usable drying harvest sit on mango farming in Uganda, and the pineapple guide covers the other crop this trade runs on.

Choosing Fruit Ripe Enough to Sell and Firm Enough to Slice

Maturity is the one raw material decision a dryer cannot undo. Underripe fruit dries to a pale, sour, leathery slice that no buyer wants twice. Fully soft fruit will not hold a slice on a tray, loses juice on the board, and is already carrying more mould than a firm fruit. The window that works sits between the two: sweet enough to taste right, firm enough to cut clean.

Sorting at the intake bench is where the money is protected. Rot, bruising, insect damage and soil all survive drying, and some of them concentrate as the water leaves. Every damaged slice that goes on a tray takes up the same dryer space as a good one and then has to be picked out of the finished product, which is the most expensive place to sort.

Fruit for drying and fruit for a bottling line are not competitors so much as the same purchase split at the bench. A processor who can do both has somewhere for every grade to go, which is the whole argument for handling drying and juicing in one building. The wet route is covered on fruit juice processing.

Peeling, Slicing and the Thickness That Sets Drying Time

Peeling and slicing are hand operations at Ugandan scale, and both feed straight into the arithmetic at the top of this page. Thick slices hold water in the middle long after the surface feels dry, which is how a batch comes out of a dryer that passes a touch test and then moulds in the sack. Thin slices dry evenly and fast and are easier to break. Consistency matters more than any particular thickness, because a tray of mixed slices cannot be finished at one time: the thin ones burn while the thick ones are still wet.

Work clean. Peeled fruit is exposed flesh, and the surfaces it touches between the peeling knife and the tray decide most of what the finished product carries. A board on the ground is the worst of them. Raised, washable surfaces, washed hands and covered trays are the whole hygiene system at this scale, and they cost nothing but discipline.

Browning starts within minutes of the knife. Some of that is the fruit's own enzymes reacting with air, which is why a slice left on the bench darkens before it ever reaches the dryer. Getting cut fruit onto a tray and into moving warm air quickly is a colour decision, not just a throughput one.

Five Drying Methods, Measured Side by Side

Most pages compare drying methods by description. One East African study compared five of them with instruments, drying mango and pineapple slices simultaneously under all five, with air temperature and weight logged every thirty minutes until constant weight. The experiment ran outdoors in Arusha, Tanzania, at an institute of science and technology, with a co author based at a Ugandan research institute, so read it as East African physics rather than a Ugandan field trial.

Three readings come out of that table and each one is worth acting on. First, the three cheap methods are indistinguishable. Open sun, black cloth and white cloth all sat within about two degrees of ambient and all took about sixteen hours, so a cloth over the trays buys dust protection and not drying speed. Second, an enclosed cabinet is where the step change happens: the solar cabinet ran 5.8 degrees above open sun and cut the time by roughly a third. Third, the improved unit, which added metallic solar concentrators in series and a greenhouse cover, ran 7.7 degrees above the cabinet and 13.5 degrees above open sun, and brought mango down to six hours. Those temperature gaps reconcile by addition against the stated means, which is the check that a table has not been mangled in extraction.

Sixteen hours against six is not a convenience difference in a Ugandan climate. Drying ran from eight in the morning to six in the evening, so a sixteen hour method needs two days and a night in between, and the night is when a partly dried tray takes moisture back out of the air and grows the mould that finishes it. A method that completes inside one day removes that risk entirely, which is the real argument for a cabinet rather than the tarpaulin.

One caution about relying on any single study. The proximate composition table in that paper, as extracted, gives moisture values for the dried products that sit at or above the fresh samples, which cannot be right for material that has just lost water. That column is unusable and nothing from it appears here. The drying times and air temperatures come from the results text and reconcile internally, so they are published and the composition table is not.

The Moisture a Dried Fruit Has to Reach for Storage

The same study dried its slices until they reached 8 percent moisture or below, which it describes, citing postharvest literature, as the optimum safe storage moisture for most fruit types. That is the number to work to in the absence of a specification you have bought, and it is a fruit figure with nothing to do with grain.

That last point matters because the wrong number travels easily. A cereal moisture ceiling of 13 or 13.5 percent belongs to maize grading tables and has no application to a mango slice, which will mould at that moisture. Dried fruit is a lower moisture product than any grain, the documents are unrelated, and a figure carried across from one to the other is a spoiled batch. If maize is what you are drying, the reconciled cereal figures and the reason two editions disagree sit on the maize drying guide, not here.

Under drying and over drying both cost, in different currencies. Leave moisture in and the product moulds, ferments or cakes in the bag, and the loss arrives weeks later at the buyer. Take too much out and the slice goes brittle, breaks into fragments and dust in handling, and you have sold dry matter as breakage. Both errors are invisible on a tray, which is why the weight based check above beats the touch test.

Sulphites, Colour and What Ugandan Additive Rules Control

A bright orange dried mango slice usually got that way with help. Sulphur dioxide and sulphite salts hold colour during drying and in store, and they are the reason imported dried fruit looks brighter than a farm dried slice. Two facts about them belong on this page and a third does not.

The first is that sulphites are food additives, and Uganda runs additives through one legally enforced document that decides which additive belongs in which food and under what conditions. The second is that an additive has to be declared, and declaring it means naming it rather than calling it a preservative in general. The third, the permitted level, is not published here, because that standard was not read for this page and a figure invented or borrowed from another country's rules would be worse than no figure. Get it from the standard and from the additive supplier's own container.

What a processor can decide without any number is whether to use them at all. A sulphite free dried mango is darker, and some buyers read darker as older or poorer. That is a market conversation, not a quality fact: the honest position is to let the slice be the colour the fruit dried to and say so, or to use the additive within its permitted conditions and declare it. What cannot be done is to use it and stay quiet.

Packaging and Storage That Stops Dried Fruit Taking Up Moisture Again

A dried slice spends the rest of its life trying to get its water back. Ugandan air is humid for most of the year, so an open sack in a store will pull moisture until the product reaches equilibrium with the room, and the mould follows. Everything about packaging dried fruit is about that one problem.

Cool the product before it goes into any container. Warm slices sealed in a bag give up water vapour that condenses on the inside of the film, which puts free water on the surface of a product you just spent a day drying. Let the trays come down to room temperature first, in a covered space rather than out in the open.

Then seal properly, keep the sealed units small enough that a customer finishes one rather than reopening it repeatedly, and store off the floor and away from walls in a dry room. Sacks on a concrete floor take up moisture from below whatever the room feels like. Container materials, seals and what each does to storage life are worked through on the agricultural product packaging guide.

What Gets a Dried Fruit Lot Rejected by Buyers

Finding those buyers is its own piece of work, and the routes into supermarkets, tourist outlets and exporters are different from selling fresh fruit at a market. That is covered on how farmers can find produce buyers.

Sizing a Dryer Against Your Own Harvest

Dryer capacity is set by tray area and by how many batches a day the method allows, and the second is where the study above earns its place. A cabinet that finishes mango in six hours can take a second load the same day; a tarpaulin that needs sixteen hours cannot. So the same tray area gives roughly double the throughput under a hot cabinet, before any consideration of quality.

Work backwards from the harvest instead of forwards from the machine. Count the kilogrammes of fruit that arrive on your busiest week, apply your own dressing loss to get prepared slices, divide by the tray area a batch holds, and that is the number of batches the week demands. Then check whether your method can run them. A dryer sized for the average week idles for most of the season and then fails in the peak, which is when the fruit is cheapest and the reason for drying it is strongest.

Where one grower's harvest cannot fill a worthwhile unit, sharing one across a group changes the arithmetic without changing the physics, and the same logic applies to the sorting bench and the sealing machine. What a group has to settle before it buys anything is who owns the unit, who schedules it in the peak week, and who carries a batch that spoils.

Frequently Asked Questions About Dried Fruit Production in Uganda

How much fresh fruit do I need for a kilogramme of dried fruit? For prepared slices, somewhere between about 4.6 and 7.7 kilogrammes depending on how much water the fruit was carrying, drying to 8 percent moisture. From whole fruit it is worse again, because peel, stone and crown come off first. Measure your own by weighing fruit in, slices prepared and product out, once per variety and once per season.

What moisture should dried fruit reach? The published drying work uses 8 percent or below, described as the safe storage level for most fruit types. Do not use a grain figure: a cereal moisture ceiling near 13 percent belongs to grading tables for maize and will mould a mango slice.

Is a solar dryer worth building instead of drying on a tarpaulin? On the measured evidence, yes, and the reason is time rather than temperature. Open sun, black cloth and white cloth shade all took about sixteen hours for mango, which means two days with a night in the middle. A solar cabinet took about nine hours and an improved unit about six, both inside one day, which removes the overnight moisture pickup that spoils batches.

Which standard applies to my dried fruit? If you dried it, the dried fruits standard. If you fried or baked it, the fruit chips and crisps standard, whose scope excludes anything dried and whose counterpart excludes anything fried or roasted. Dried herbs and dried tomatoes each have a separate standard again.

Do I have to use sulphur to keep the colour? No. A sulphite free slice is darker and that is a market question rather than a safety one. If you do use an additive, its permitted conditions come from Uganda's general standard for food additives and it has to be named on the label. No level for it appears on this page because that standard was not read here.

How much does a dryer cost and what can dried mango be sold for? Both move too much to print. Dryer prices depend on size, materials and whether it is fabricated locally, and the selling price depends on the buyer, the pack size and whether the product is graded. What is worth doing before either is the ratio calculation above, because it tells you the fruit cost inside a kilogramme of product, and no selling price means anything without it.

Can I dry fruit and sell it without any registration? A packaged food product carrying a label, a brand and a shelf life is a regulated product in Uganda, under a compulsory standard and the labelling rules for prepackaged foods. Confirm what applies to your product and your scale with the bureau before printing anything, since the position can change and the schedule is revised.

Why did my dried mango go mouldy in the bag when it felt dry? Almost certainly uneven moisture. Thick slices keep water in the centre after the surface is dry, and a few wet slices raise the humidity inside a sealed bag until the whole lot is at risk. Slice to one thickness, dry to constant weight rather than to the touch, and cool before sealing.

No price for a tray, a mesh screen, a roll of cover material or a sealing machine belongs on this page, because every one of them tracks an importer and a season. Ask two local suppliers, and ask the bureau for the current edition of whichever standard your product falls under. The rest of the cluster sits on the value addition hub, and the fried route, which lands under a different standard, is covered on banana chips production.