What moisture, water activity and microbial limits should freeze-dried passion fruit meet?
Write four numbers into the contract and most passion fruit problems never reach your dock: moisture ≤5.0%, water activity (aw) ≤0.30, total plate count ≤104 CFU/g and Salmonella not detected in 25 g. Those are the limits FruitBuys partner facilities release to.
Passion fruit needs them more than most fruits. It is acidic, rich in soluble fibre and full of seeds, and all three pull humidity out of the air faster than a mango or pineapple cube does. A lot that leaves Vietnam at aw 0.35 can still look fine on the COA and arrive as a soft, fused block.
Which limits belong in the contract, and which on the release sheet?
Put the same figures in both, and make water activity the one you sign on. Moisture tells you how much water is in the cube. Water activity tells you how freely that water moves, which is what decides whether the cube stays crisp and whether anything can grow. Two lots at 4.5% moisture can sit on either side of aw 0.30, depending on how much sugar and fibre they carry and how well they were sealed.
| Parameter | Limit | What it protects |
|---|---|---|
| Moisture | ≤5.0% | You pay for fruit solids, not water; crisp bite |
| Water activity | ≤0.30 | No softening, caking or mould in the sealed bag |
| Total plate count | ≤104 CFU/g | Ready-to-eat use as a topping or inclusion |
| Yeasts & moulds | ≤102 CFU/g | No spoilage once the pack is in the market |
| E. coli | <10 CFU/g | Hygiene of handling and water |
| Salmonella | Not detected / 25 g | Release condition for ready-to-eat food |
| Fines (bottom of bag) | ≤3% (20 mm) to ≤5% (10 mm) | Usable yield on your line |
| Foreign matter | Visual sorting + metal detection | Consumer safety |
Water activity is measured to ISO 18787:2017, and the US FDA guide on water activity in foods sets out why low-aw foods do not support pathogen growth.
The commercial point is simpler. At aw ≤0.30 the cube stays porous: it snaps, does not pack into the teeth, and the seeds crack open to release their oil and the full passion fruit aroma without any added flavouring. Let a lot pass at 4.5% moisture but aw above 0.30, and after two months at sea the corners of every bag start to cake. That is a whole container written down for the lack of one line in the contract. Get it right and the bag that leaves Cat Lai still snaps when your customer opens it in Rotterdam or Dubai.
Which tests travel with every container?
On full-container orders, every lot ships with a third-party COA covering moisture, water activity, total plate count, yeasts & moulds, E. coli and Salmonella. The methods are the standard ones your own lab will recognise: ISO 6579-1 for Salmonella and ISO 16649-2 for E. coli, both run at ISO/IEC 17025 accredited laboratories in Vietnam.
Trial and LCL orders ship with the in-house release log (moisture, aw and sensory per batch) plus the baseline report below. If your QA policy needs an independent COA on a trial lot, FruitBuys arranges it at net lab cost and credits the fee in full against your first container order. Lab turnaround is 3–5 working days, so build it into the booking date rather than the sailing date.
Of everything on this list, aw is the line buyers skip most and regret first. Ask for it as a measured figure on the COA, not a “pass”.
What does the baseline report cover?
Heavy metals and mycotoxins do not change lot to lot the way moisture does; they reflect the growing area and the process. FruitBuys covers them through periodic third-party surveillance. The most recent baseline report on freeze-dried passion fruit, from an independent ISO/IEC 17025 accredited third-party laboratory, returned:
| Parameter | Result | Limit of quantification |
|---|---|---|
| Lead (Pb) | Not detected | 0.05 mg/kg |
| Arsenic (As) | Not detected | 0.03 mg/kg |
| Aflatoxin total | Not detected | 2 µg/kg |
| Aflatoxin B1 | Not detected | 0.5 µg/kg |
| E. coli | <10 CFU/g | – |
| Salmonella | Not detected / 25 g | – |
Those detection limits sit below the EU maximum levels in Regulation (EU) 2023/915 on contaminants in food, which is the yardstick most European QA teams use. The full report is available on request. If your market or customer needs cadmium, pesticide multi-residue or extended microbiology such as Listeria, FruitBuys coordinates the panel with an accredited lab before the container is stuffed.
Why does freeze-dried passion fruit soften faster than other fruits?
Three things work together. The pulp carries natural organic acids and sugars that bind water readily. The seeds and pulp bring about 20 g of fibre per 100 g, and that fibre holds moisture like a sponge. And the porous structure freeze-drying leaves behind gives humid air a very large surface to reach.
Raw material adds a seasonal swing. Central Highlands pulp runs from about 13 to 17 °Brix and pH 2.8–3.2 between the dry and rainy season. Higher-sugar, rainy-season fruit dries to a cube that is a little more hygroscopic, which is why FruitBuys releases on aw as well as moisture all year rather than relaxing the limit in the wet months. The same natural acidity works for your formulators: at around pH 3.0, the fruit carries its own sourness, so many cereal and confectionery recipes can cut back added citric acid and keep a cleaner label.
What this means on your side: soft vacuum and a desiccant sachet in every foil bag, bulk bags of 1–5 kg sized to one production batch, and storage at ≤25 °C and RH ≤60%. Packaging and loading are covered in detail in how freeze-dried passion fruit should be packed and loaded. In a wet base such as yogurt, the cube will soften whatever its aw at release; the format guide shows how R&D teams keep it crisp.
How is foreign matter kept out of a seed-in cube?
Through three layers of control, each aimed at a different risk. First, the fruit is selected and opened, and the seed-in pulp is passed through a mesh screen before it is frozen into slabs; grit, peel fragments and anything that does not belong in the pulp stay on the screen. Second, the line sorts the diced cubes visually before packing. Third, every sealed bag passes a metal detector as the final control point.
The screen does the heavy lifting on non-metal contaminants, because it works on liquid pulp where nothing can hide inside a dried piece. For a seed-in product, the most common query from a new customer is a seed mistaken for a foreign body; the black seeds are part of the product and appear in the ingredient line. If your customer’s specification calls for X-ray inspection on top of this, raise it at RFQ stage so the facility and cost are agreed before the contract.
Use this table to set your specification
| Your situation | What to write into the spec |
|---|---|
| Retail snack or topping, ready to eat | All six COA parameters per lot; aw ≤0.30 as the acceptance figure |
| Ingredient for a heat-treated product (bakery filling, sauce) | Same limits; micro limits still apply because the cube is handled dry in your plant |
| EU destination | Add pesticide multi-residue to the pre-stuffing panel |
| Private label with a long printed date | Add an accelerated shelf-life study on your final pack |
| Trial or LCL order | Release log + baseline report; independent COA at net lab cost, credited to your first container |
This is the check every buyer should run, including with us: measure aw on arrival from the second sealed pouch of the pre-shipment sample and compare it with the COA. A gap of more than a few hundredths points to a sealing or storage problem worth raising before the next lot. The sample process is set out in how to make sure the bulk shipment matches the approved sample.
Why conventional and not organic?
Vietnam’s passion fruit comes from Central Highlands smallholder networks, and certified organic fruit (EU or USDA Organic) is available only in small, scattered volumes that cannot carry a container programme on cost or continuity. FruitBuys supplies conventional passion fruit and controls the risk organic buyers usually worry about through the destination market’s pesticide limits: a multi-residue panel against the EU MRLs runs before stuffing on EU-bound containers. For a brand that needs a steady year-round supply at container scale, that is the route that keeps both the specification and the price stable. If your label must carry an organic logo, this product is not the one to build it on.
Get the specification for your QA file
Send your destination market and application. FruitBuys returns the full product specification, the COA template for a container lot and the latest baseline report, so your QA team can approve the supplier before the sample lands. Full product details are on the freeze-dried passion fruit page.
FAQ
What water activity should freeze-dried passion fruit have?
At or below 0.30 at release. Above that, the cubes soften and start to stick together in the bag.
Is moisture or water activity more important?
Water activity. It decides texture and microbial stability; moisture alone can pass while aw drifts above 0.30.
Which tests come with each container?
A third-party COA for moisture, water activity, total plate count, yeasts & moulds, E. coli and Salmonella. Heavy metals and aflatoxin are covered by periodic baseline reports.
Is freeze-dried passion fruit ready to eat?
Yes. It is released against ready-to-eat microbial limits, including Salmonella not detected in 25 g.
Are the black specks foreign matter?
No. They are passion fruit seeds and part of the product. Metal detection runs on every packed bag.
