Raisins

Raisins are dried grapes and therefore can be found in supermarkets almost all year round. They are dried shortly after harvest and can then be stored for a long time. You can buy them loose in large bags, in small portion packs for lunchboxes, or already mixed into mueslis and baked goods. Because they are dry, they last longer than fresh fruit – similar to dried apricots or dates. Still, they retain their flavor best when stored in a cool, dark place.

Where do raisins come from?
Most raisins come from warm, sunny countries, because grapes need a lot of sun to become sweet. Important growing regions are:

You can imagine it like this: grapes are like small water balloons that slowly shrink in the sun. In warm regions the sun is stronger and dries the grapes more quickly and evenly. Therefore many raisins come from these countries and are then shipped around the world.

What varieties are there?
There are several typical types of raisins that differ in color, taste and size. The main ones are:

How are they dried?
Raisins can be dried in various ways: either in the sun, on drying racks, or mechanically in drying facilities. Sun drying is traditional and inexpensive, mechanical drying is faster and more controlled. Those who want natural raisins without additives look for the words “no additives” or “natural” on the packaging.

Variants when buying
There are also organic raisins, where chemical treatment is avoided, and oil-treated or sugared variants that have a more specific taste. In trade you can also find ready-made raisin mixes with nuts, chocolate or other dried fruits – practical for on the go.

In short: raisins are widely available, mostly come from sunny countries and come in many forms – light or dark, small or large, with or without seeds. That way you can easily find the variety you like best, whether for baking, muesli or simply as a snack.

Raisins are dried grapes and are among the oldest preserved fruits. By removing water, sugars, minerals and secondary plant compounds become concentrated, giving raisins a high energy density and characteristic chemical composition. Common raw materials are seedless grape varieties such as Thompson Seedless, and red and dark varieties are also used.

Chemical composition and nutritional values
Raisins consist mainly of carbohydrates, predominantly the monosaccharides glucose and fructose, which occur as reducing sugars. Typical nutritional values per 100 g lie in the range: energy ~290–310 kcal, carbohydrates 65–80 g (of which simple sugars 50–65 g), fiber 3–5 g, protein 2–4 g and fat <1 g. Minerals are comparatively concentrated; in particular potassium (often 700–900 mg/100 g), iron (1–3 mg/100 g) and calcium (variable) are relevant. Vitamins, especially water-soluble ones like vitamin C, are largely lost during drying, while heat- and oxygen-stable secondary plant compounds such as phenols, flavonoids and levels of resveratrol are partially retained.

Processing methods
Drying is carried out classically outdoors (sun drying) or industrially using heated or forced-air dryers. Grapes are often pretreated before drying:

Browning during drying is based both on enzymatic oxidation of phenols and on non-enzymatic processes such as the Maillard reaction between amino acids and sugars. Target water activity (aw) for microbiologically stable products is below approx. 0.6, which prevents growth of most pathogenic microorganisms.

Quality, shelf life and safety
Raisins are relatively shelf-stable due to their low water activity if stored cool, dry and airtight. Nevertheless, spoilage and quality loss can occur due to:

Health aspects
Due to the high proportion of free sugars, raisins are energy-dense and excessive consumption can contribute to weight gain. At the same time they provide quickly available energy, fiber and minerals such as potassium, which can have positive effects on cardiovascular functions. Antioxidant phenolic compounds may potentially contribute to reducing oxidative stress, although in vivo effects depend on amount and matrix. The glycemic index of raisins is generally rated moderate to medium; portions should be portioned for diabetics.

Uses and practical tips
Raisins are used both as a snack and in baked goods, mueslis, sauces and savory dishes. For rehydration, hot water or soaking solutions with acid or alcohol are sufficient. For best quality raisins should be stored cool, protected from light and in airtight containers.