Pomegranate is the most visible fruit on an autumn table. A great deal gets said about its nutritional value, but less about where that value comes from and why it depends on season.
What is its nutritional profile?
A hundred grams of pomegranate seeds is around 83 calories.
Carbohydrate is 19 grams, of which 14 are sugars.
Fibre is 4 grams, a high figure among fruits.
Most of that fibre comes from the kernels inside the seeds.
Vitamin C is 10 milligrams per hundred grams, around 12 percent of the daily requirement.
Vitamin K is present too: 16 micrograms, 14 percent of the daily requirement.
Potassium is 236 milligrams.
Folate is 38 micrograms.
But the real value of pomegranate does not lie in its vitamins and minerals.
Its polyphenol content is what separates it from other fruits.
What are punicalagins?
That is a polyphenol group specific to pomegranate.
They occur almost nowhere else.
Punicalagins belong to the ellagitannin class.
Their antioxidant capacity is very high; in laboratory measurements they give stronger results than green tea and red wine.
But those compounds are not distributed evenly through the fruit.
The highest concentration sits in the skin and the white membranes between the seeds.
They occur at lower levels in the seeds themselves.
Commercial juice production therefore presses the whole fruit; skin and membrane pass into the juice.
That raises the juice's punicalagin content while bringing an astringent taste.
| Part | Punicalagins | Anthocyanins | Fibre |
|---|---|---|---|
| Skin | Very high | Moderate | High |
| White membrane | High | Low | High |
| Seed (fleshy part) | Low | High | Low |
| Kernel | Low | None | Very high |
| Pressed juice | High | High | None |
Where do the anthocyanins come from?
The red colour of pomegranate comes from anthocyanins.
Those compounds concentrate in the fleshy part of the seeds.
They have antioxidant effects and rise in direct proportion to the intensity of the colour.
A pomegranate with deep red seeds carries more anthocyanin than one with pale pink seeds.
Colour is also an indicator of ripeness.
The seeds of an unripe pomegranate are pale and its taste sour.
The quantity of anthocyanin rises markedly during ripening.
That explains why season matters.
Pomegranate picked early carries less anthocyanin and less sugar.
What does season change?
Pomegranate is harvested between September and December.
The heaviest period is October and November.
Fruit picked then is fully ripe.
Pomegranate picked early — at the start of September — has not completed its ripening.
Its sugar is low, its acidity high and its polyphenol content not fully developed.
Those fruits are generally picked for long transport and storage.
Pomegranate found out of season comes either from cold storage or from abroad.
The anthocyanin content of stored fruit falls over time; three months of storage brings a loss of 15 to 25 percent.
Punicalagins are more stable; the loss is smaller.
The highest nutritional value nonetheless lies in fresh fruit picked in season.
That is the concrete argument for eating pomegranate in season.
What separates the seeds from the juice?
That is a frequent question.
Pomegranate seeds contain fibre; the juice does not.
A hundred grams of seeds carries 4 grams of fibre; the same quantity of juice carries none.
Fibre slows the absorption of sugar.
That is an important difference for blood sugar.
A glass of juice — 250 millilitres — contains the juice of around three pomegranates.
The sugar comes to about 30 grams.
Taking the same sugar from the seeds requires eating three pomegranates, which is difficult in practice because of the fibre.
Eating the seeds therefore brings a natural limit on the portion.
On the other hand the juice contains the polyphenols of the skin and membranes.
In that respect it is richer than the seeds.
Both have their place; seeds for daily eating, juice at intervals.
How should pomegranate molasses be judged?
Pomegranate molasses is produced by reducing the juice.
Water evaporates and sugar and acid concentrate.
The result is an intensely sour and sweet syrup.
Polyphenols are partly preserved, though the heat treatment causes some loss.
Anthocyanins are heat-sensitive, which is why the molasses turns dark brown.
Punicalagins are more resistant.
The label should be read: genuine molasses contains only pomegranate juice.
Some products add sugar, glucose syrup and acidifiers.
Those are sold as "pomegranate sauce" and belong to a different category.
Genuine molasses uses around five kilograms of fruit for a kilogram of product, which explains the price difference.
It is used as a source of acidity in salads, marinades and meat dishes.
How is a pomegranate chosen?
There are four criteria.
The first is weight. Of two fruits the same size, the heavier is juicier.
That is the most reliable indicator.
The second is the skin. It should be taut and slightly angular.
A round, slack fruit has not ripened.
As a pomegranate ripens the seeds swell and press the skin from within, creating that angular appearance.
The third is colour. Shades from deep red to burgundy indicate ripeness.
But it varies by variety; some stay yellowish.
The fourth is sound. A metallic note when tapped lightly indicates full seeds.
Small cracks in the skin are not a problem; they can even indicate high ripeness.
Soft patches, however, are the beginning of decay.
How is pomegranate stored?
Pomegranate is a long-keeping fruit.
It lasts one to two weeks at room temperature.
A month somewhere cool and dark.
Up to two months in a fridge; it should sit in the vegetable drawer without a bag.
Moisture gathers in a bag and mould begins.
Extracted seeds keep five days in the fridge.
They should sit in an airtight container.
The seeds can be frozen; they are frozen in a single layer on a tray and then bagged.
They keep six months.
Thawed seeds soften and are unsuitable for eating fresh.
But they can be used in juice, sauces and desserts.
Pomegranate juice keeps three days in the fridge and six months frozen.
Juice frozen in ice cube trays allows portioned use.
Molasses keeps six months in the fridge once opened; its high sugar and acid make spoilage unlikely.
