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Microbiology

Food microbiology and shelf-life testing

Microbiological testing answers two different questions with two different test designs: is a pathogen present in this batch, and how long does the product stay safe and acceptable. A pathogen test is a snapshot; a shelf-life study is a series of tests over the storage period you want to claim.

Two questions
Safety now · shelf life later
Sample needed
3 retail units minimum
Incubation
Fixed by method, cannot be shortened
Common use
FSSAI file, buyer audit, label claim

Organisms we test for

Which organisms belong on your panel depends on the product, its water activity and how it is stored. We will propose a panel rather than sell you all of them.

Organism / countWhat it indicatesTypical samples
Total plate countGeneral hygiene of process and raw materialMost foods, water, swabs
Yeast and mould countSpoilage risk and storage problemsBakery, spices, dry mixes, juices
Total coliformsPost-process contamination or poor waterDairy, RTE foods, water, ice
Escherichia coliFaecal contamination — hygiene failureWater, RTE foods, produce
Salmonella speciesPathogen; absence required in a defined weightMeat, egg, dairy, spices
Listeria monocytogenesPathogen that grows at refrigeration temperatureChilled RTE, dairy, seafood
Staphylococcus aureusContamination from handling personnelRTE foods, sweets, bakery
Bacillus cereusToxin risk in starchy food held warmRice dishes, cooked staples
Clostridium perfringensTemperature abuse during coolingBulk cooked meat and gravies

What to send us

Quantity
At least three sealed retail units per batch. For a shelf-life study, enough units to cover every pull point plus spares
Container
Original sealed packaging. Loose samples must come in a new sterile pouch, never a reused container
Hold time
Chilled and frozen products must arrive at their storage temperature — a thawed sample is a different sample
Full collection instructions →

How a shelf-life study is designed

We agree the storage condition and the pull points first — for example day 0, 15, 30, 60 and 90 at ambient — then test microbiological and relevant chemical markers at each point. You send enough units at the start to cover every pull. A real-time study takes as long as the shelf life you want to claim; accelerated studies can indicate a direction but do not substitute for real-time data on a label claim.

Questions about this test

What should a restaurant test?

For food service the useful panel is water, ice, a swab of food-contact surfaces and one or two high-risk ready-to-eat items. It is far cheaper than testing every dish and it is what an auditor actually asks to see.

Can I get a 6-month shelf life claim in a month?

Not honestly. A real-time study takes six months. An accelerated study at elevated temperature can give an early indication for internal decisions, but printing a date on a pack based on it alone is a risk you are carrying, not us.

A batch failed. What now?

Test to find where it came in rather than retesting the same batch hoping for a better number. Raw material, process water, surfaces and personnel are the four usual routes, and each has a different fix.

Request this testAsk on WhatsAppUpdated 16 September 2026