A grain becomes flour. A raw pulse becomes soft after cooking. Rice and black gram become an airy fermented batter. Fresh ingredients become dry enough to keep in the pantry.
All four foods have been processed.
That word can sound suspicious on a package. We are often encouraged to imagine a simple divide: whole food on one side, “processed food” on the other.
But grinding, heating, fermenting and drying are not one nutritional event. They do completely different jobs.
Quick Clarity
Processing changes food—but “changed” does not automatically mean “damaged.”
Grinding changes particle size and structure. Heating can soften foods, change starches and proteins, improve safety and sometimes alter nutrient availability. Fermentation lets microorganisms transform components of food. Drying removes water and changes storage behaviour.
Each process can bring benefits, trade-offs or both. The useful question is therefore not simply “Is this processed?” but:
What process was used, why was it used, and what did it change?
Food processing is better understood as a set of tools than as a single quality ranking. Reviews of food processing describe outcomes ranging from improved safety, digestibility, palatability and shelf life to losses or transformations of certain nutrients, depending on the food and processing conditions.
One Ingredient Can Become Several Different Foods
Consider a grain.
Leave it intact and you have a whole grain.
Break it into coarse particles and its texture changes.
Grind it finely and you have flour.
Add water and heat and the starch behaves differently again.
Let a prepared batter ferment and microorganisms begin changing the food chemically.
Remove enough water and the final product may become far more shelf-stable.
Nothing about this sequence can be adequately described by the single word processed.
The same ingredient can behave differently in the kitchen because processing changes its physical structure, moisture, microbial activity and chemical environment. Those changes affect properties such as texture, cooking time, flavour, digestibility and storage.
That is the more useful mental model.
Eatwise Aha Moment
The important question is not how many processing steps a food has seen, but what each step actually does.
1. Grinding: Changing the Size and Structure
Grinding looks simple because nothing obvious has been added.
A millet grain becomes millet flour. Wheat becomes atta. Pulses can become dal flour. Spices become powders.
But mechanically reducing a food into smaller particles changes how much internal material is exposed.
Smaller particles generally create more surface area. In starchy foods, particle size and disruption of food structure can influence how readily digestive enzymes gain access to starch and protein. Experimental work with durum wheat has demonstrated that particle size can materially affect digestion behaviour in vitro.
Grinding Is Not Automatically the Same as Refining
This distinction matters.
Grinding means mechanically reducing particle size.
Refining can involve separating or removing particular anatomical fractions of a grain or ingredient.
A whole grain can therefore be ground into flour while retaining its components, while another flour may undergo additional separation steps.
So the fact that a food is “flour” does not, by itself, tell you how much of the original grain remains.
That is why a shopper should not use powdered versus whole as the only quality test.
What Grinding Can Change
Depending on the ingredient and degree of grinding, it can change:
- particle size;
- texture;
- mixing behaviour;
- cooking behaviour;
- surface area exposed to enzymes;
- the physical structure through which nutrients are released.
Research on starch-based foods shows that fine milling can disrupt structural barriers and influence starch digestion, although the effect varies with the food matrix and subsequent cooking or processing.
Grinding therefore changes form. Whether that change is desirable depends on what you are trying to cook and how the ingredient will ultimately be eaten.
2. Heating: Much More Than “Nutrient Loss”
Heating is probably the processing step most people perform every day.
Boiling dal.
Steaming idli.
Cooking rice.
Roasting grains.
Baking bread.
Heating changes food because heat supplies energy to physical and chemical transformations.
In starchy foods, one important example is starch gelatinisation. In the presence of sufficient water and heat, the organised structure of starch granules changes, which affects texture and digestibility. The extent of gelatinisation depends on factors including temperature, moisture, time and the surrounding food matrix.
Heat also alters proteins and can reduce the activity of some naturally occurring compounds that interfere with digestion. Studies of cooked legumes, for example, have reported reductions in compounds such as trypsin inhibitors and some phytate or tannin measures depending on the bean and cooking method.
And then there is safety.
Adequate cooking is a fundamental food-safety intervention because appropriate heating can destroy many harmful microorganisms. WHO's food-safety guidance therefore explicitly includes cook thoroughly among its core safer-food practices.
But Heat Is Not Always Nutritionally Neutral
Some heat-sensitive nutrients can be reduced during cooking or processing, particularly depending on temperature, duration, oxygen exposure, water use and whether cooking liquid is discarded.
At the same time, heating can improve digestibility, release some food components from the surrounding matrix and make foods safe or palatable enough to eat.
So the simple equation:
heat = nutrients destroyed
is not scientifically useful.
The more accurate question is:
What food, what temperature, how long, how much water—and for what purpose?
Processing Is Often a Trade-Off, Not a Score
This is an important principle.
A raw pulse may retain certain heat-sensitive compounds better than a cooked one.
But that does not make raw pulses automatically preferable.
Cooking can dramatically alter texture, digestibility and safety.
Likewise, an intact grain and a ground grain are not simply a “good” and “bad” version of the same ingredient. Their structures and culinary purposes differ.
Food processing should therefore be judged by function and consequence, not by how close the food looks to its raw state.
Eatwise line
Processing is a verb, not a verdict.
3. Fermenting: Letting Microorganisms Transform Food
Fermentation introduces another kind of transformation.
Instead of relying only on mechanical force or heat, fermentation involves microorganisms and their enzymes acting on components of the food.
They may use available carbohydrates and produce acids, gases, alcohols or other metabolites depending on the fermentation.
These changes can influence:
- acidity;
- flavour and aroma;
- texture;
- leavening;
- microbial ecology;
- digestibility;
- certain vitamins and antinutritional compounds.
FAO and WHO have long recognised fermentation as a food-processing and preservation technology with potentially important food-safety implications, while also emphasising that the benefits and risks depend on how fermentation is carried out.
A Familiar Indian Example: Idli Batter
Idli shows beautifully why processing steps should not be examined in isolation.
Rice and black gram are soaked.
They are ground.
The batter is mixed.
Microorganisms ferment it.
Then the batter is steamed.
Research on idli fermentation confirms microbial succession, acid production and leavening during fermentation of the rice–black gram batter.
So what is idli?
Ground food?
Fermented food?
Heated food?
It is all three.
Trying to classify it with a simplistic processed/unprocessed label tells us very little about what actually happened to the ingredients.
Fermentation Can Change Nutrient Accessibility—But Avoid the Halo
Fermentation is sometimes marketed as if it automatically transforms every food into a nutritionally superior product.
That goes too far.
Depending on the organism, substrate, conditions and subsequent processing, fermentation can alter phytate, protein digestibility, B vitamins and mineral bioaccessibility. Recent food-science studies continue to show that these effects are highly process- and food-specific rather than universal.
A fermented food may therefore have valuable functional characteristics.
But fermented is still a description of a process—not a guarantee that every fermented product is healthier, nutritionally complete or appropriate for everyone.
And fermentation does not eliminate the need for hygienic preparation and safe handling.
4. Drying: Removing Water Changes More Than Weight
Think about fresh chilli and dried chilli.
Fresh herbs and dried herbs.
Fresh fruit and dried fruit.
A freshly prepared ingredient and a dehydrated powder.
The most obvious difference is water.
Removing water changes weight, texture, concentration and storage behaviour.
Drying has long been used to preserve foods because reducing available moisture makes conditions less favourable for microbial growth and many deteriorative reactions. Modern drying systems range from sun and hot-air drying to freeze-drying, spray drying and newer controlled technologies.
Less Water Does Not Mean Sterile
This distinction is especially important.
Low-moisture foods may prevent microorganisms from multiplying readily, yet some microorganisms can remain alive for long periods.
FAO/WHO risk assessment work specifically notes that outbreaks have occurred in low-moisture foods and that pathogens may persist even when they cannot grow normally in the product.
So:
dry = lower moisture
does not mean:
dry = microbiologically risk-free.
Drying Can Also Change Quality
The drying method matters.
Time, heat exposure, oxygen, tissue structure and moisture removal rate can influence colour, flavour, texture and retention or accessibility of different compounds. Some drying systems preserve heat-sensitive components better than others.
Again, the process name alone is not enough.
The Surprising Part: Processes Interact
A food rarely experiences only one transformation.
Consider a simple cereal or pulse product.
It may be:
cleaned → soaked → ground → fermented → heated → dried
Each stage changes what the next stage has to work with.
Grinding changes particle structure before fermentation.
Fermentation changes acidity and chemistry before heating.
Heating changes starch and protein structure.
Drying changes moisture after cooking.
Food scientists therefore often think in terms of a process chain, not isolated labels.
That is also a useful way for shoppers to think.
Instead of asking:
“Is this minimally processed?”
ask:
“Which processing steps were used, and did they serve a useful purpose?”
The Eatwise Four-Question Processing Check
1. What Was Physically Changed?
Was the food merely cleaned, cut or ground?
Was part of it removed?
Was its particle size changed dramatically?
This tells you more than the generic word “processed.”
2. Was Heat Used—and Why?
Was the purpose cooking, safety, texture, roasting, drying or shelf stability?
Heating is not one uniform treatment.
3. Was Biology Involved?
If the food was fermented, what kind of product is it and how is the fermentation controlled?
“Fermented” should not automatically be interpreted as either beneficial or risky.
4. What Does the Final Food Look Like?
Read the ingredient list and nutrition information where relevant.
Processing method and formulation are separate questions.
A ground single-ingredient grain flour and a highly formulated snack can both be “processed,” yet they are clearly not the same type of food.
The Eatwise Perspective: Purpose Before Processing Fear
At Eatwise, the useful hierarchy is not:
raw → minimally processed → processed → bad
It is:
Preferred When
Processing performs a clear culinary, safety, digestibility, preservation or functional job and the final food remains understandable.
Acceptable Alternative When
A more intensive process genuinely improves convenience, stability or usability without creating a misleading impression about the food.
Case-by-Case When
The impact depends strongly on the ingredient, process intensity, formulation, serving pattern or intended use.
Requires Verification When
A package makes specific claims about a processing method—such as exact temperatures, nutrient preservation or superior bioavailability—without adequate evidence.
Eatwise Would Question
Any marketing message suggesting that all processing is harmful or, at the opposite extreme, that one fashionable process automatically makes a food nutritionally superior.
Both erase the distinctions that actually matter.
Your Kitchen Has Always Been a Processing Space
Return to the kitchen.
Grinding spices before cooking.
Heating dal until it softens.
Allowing an idli batter to ferment.
Drying ingredients for storage.
These are not exceptions to “real food.”
They are ways humans turn ingredients into food that can be cooked, eaten, stored and enjoyed.
Processing does change food.
Sometimes it makes nutrients less stable.
Sometimes it makes components more accessible.
Sometimes it improves safety.
Sometimes it creates texture or flavour.
Sometimes it simply makes an ingredient usable.
The useful skill is not learning to fear the word processed.
It is learning to ask what the process did.
Eatwise Clarity Summary
Grinding changes particle size and physical structure.
Heating can change starches and proteins, improve cooking quality and safety, while also altering some nutrients.
Fermentation uses microorganisms to transform food and can change flavour, acidity, structure and nutrient accessibility.
Drying removes water, changes concentration and texture and can extend shelf stability, but does not make food sterile.
Several of these processes often occur in the same food.
The effect of processing therefore depends on the ingredient + process + intensity + purpose + final food, not simply on the number of steps.
When I next see the word “processed,” I will identify what processing was actually used and what purpose it served before deciding what I think about the food.
Frequently Asked Questions
Does grinding destroy nutrients?
Not automatically. Grinding primarily changes particle size and structure. Nutritional effects depend on what is retained or removed during milling, how fine the particles become and what happens to the food afterwards. Fine grinding can also alter digestion behaviour by increasing structural disruption and accessibility.
Is cooked food less nutritious than raw food?
There is no universal answer. Heating can reduce some heat-sensitive compounds, but it can also improve safety, digestibility and availability of certain food components. The effect depends on the food and cooking method.
Is fermented food always healthier?
No. Fermentation can produce useful changes in flavour, acidity, texture, nutrient accessibility and preservation, but its effects depend on the food, microorganisms, fermentation conditions and subsequent processing.
Does drying remove nutrients?
Drying removes water first and foremost. Nutrient retention varies with the compound and drying conditions. Heat, oxygen exposure, duration and drying technology can all influence the final food.
Does “minimally processed” automatically mean better?
No. The degree of processing alone cannot tell you whether a food is safe, nutritionally suitable or appropriate for a particular purpose. Processing method, formulation, portion and dietary context all matter.
References & Further Reading
- World Health Organization. Five Keys to Safer Food Manual.
- World Health Organization. Food Safety. Updated 4 June 2026.
- FAO/WHO. Fermentation: Assessment and Research — Household Technology to Improve Food Safety.
- Van Boekel, M. et al. A Review on the Beneficial Aspects of Food Processing. Molecular Nutrition & Food Research.
- Li, C. Recent Progress in Understanding Starch Gelatinization. Carbohydrate Polymers.
- Mandhania, M.H. et al. Diversity and Succession of Microbiota during Fermentation of the Traditional Indian Food Idli. Applied and Environmental Microbiology.
- FAO/WHO. Ranking of Low-Moisture Foods in Support of Microbiological Risk Management.
