So far, we have studied Japanese dried foods from various perspectives including history, associated traditions, and food characteristics. In this blog, let’s study the nutritional differences between fresh and dried forms of some food items.
What is the difference between fresh and dried foods? Dried foods are made by exposure to the sun, so obviously they contain less water than fresh foods. Due to the lower water content, nutrients are more highly concentrated; when comparing both, per 100 grams of product weight, dried foods supposedly contain more energy, protein, minerals, etc. than fresh foods. Well, then, is the difference between fresh and dried foods just water content?
The above table is a nutritional comparison between fresh and dried foods. You can see that each pair of fresh and dried items contains different amounts of water, and there are differences in the nutritional values of dried foods that are not simply because of lower water content. Take a look at the values in bold type. For instance, look at the wakame row. Dried wakame has more potassium and calcium, and far more dietary fiber than raw wakame, whose difference in value is greater than the difference in water content. Further, when comparing fresh and kiriboshi daikon, dried daikon contains far greater amounts of minerals, vitamins, and dietary fiber than the fresh daikon even when taking differences in water content into account. Dried persimmons, which are too astringent to eat in their fresh form, become a sweet, delicious, and healthy food containing lots of minerals and dietary fiber after drying.
Though not shown in the table, dried foods obviously contain more umami elements like amino acids and nucleic acids. For example, Katsuobushi contains lots of inocinic acid, which is known as an umami element but which doesn’t exist in living bonito. When bonito die, inocinic acid is synthesized by the effect of the enzyme in its muscles. Drying and processing bonito at the right time gives katsuobushi its rich inocinic acid content.
In oriental medicine, foods are categorized into “yin” (which decreases body heat) and “yang” (which increases body heat) types and advise maintaining healthy by eating the appropriate yin and yang foods. Dried foods, which have been fully exposed to the sun have mostly “yang” or “medium” properties, which means that they improve your metabolism and help boost the immune system. While it has been said that “colds may lead to all kinds of diseases,” yang foods are said to be effective in preventing colds and cancer.
Long ago, when people didn’t have means of preserving raw foods like today’s freezing and refrigeration technologies, they showed wisdom and used the natural energy of sunlight on dry foods so they were able to preserve foodstuff for sustaining themselves in times of food shortage. And now, these dried foods, a product of our ancestors’ wisdom, provide modern people with something much more valuable than just preserved foods.
As we have seen, dried foods are not simply products from which water has been removed but also products containing lots of nutrients and umami elements. We hope that you will pursue your interest in dried foods – which contain a lot of natural energy, are healthy, safe, and delicious foodstuff – and use them in your everyday diet.
Reported by Yukari Aoike, Sugahara Institute