Seaweed costs only 5 yuan for a large bag, while nori only gets you a few sheets, yet they taste very similar. So, what's the actual difference between them?
Actually, seaweed and nori are the same type of food. The seaweed we commonly eat mainly consists of two varieties: *Porphyra haitanensis* and *Porphyra yezoensis*. In northern China, *Porphyra yezoensis* is predominant, while in the south, it's *Porphyra haitanensis*. Nori is processed from *Porphyra yezoensis*. The reason for its higher price is mainly because nori undergoes processing and sorting, requiring steps like rinsing, crushing, high-temperature steaming and pressing, dehydration, and baking, which naturally increases the cost. However, nori has a better appearance and texture than regular seaweed.
Regular consumption of seaweed and nori is very beneficial for health. They are top-tier "iodine-rich foods." While grains are a daily staple, the plant protein in grains lacks lysine. Lysine is an essential amino acid, and without it, the protein utilization from staple foods is significantly reduced. The lysine content in seaweed and nori is about five times that of rice, instant noodles, refined flour, and dried noodles. If we add some seaweed to our noodles, have a bowl of seaweed soup with rice, or pair wontons with seaweed when eating a large pancake, we can easily achieve a "protein complementary effect," thereby upgrading the protein quality of our staple foods.
Seaweed itself is highly nutritious and is known as a "treasure trove of vitamins." Its fat content is relatively low, accounting for only 1%-2% of its total nutrients, but the content of EPA, an unsaturated fatty acid beneficial for nervous system development, makes up 52% of that fat. Coupled with a large amount of essential minerals and vitamins for the human body, long-term consumption of nori can improve microcirculation, enhance immunity, delay aging, and reduce the incidence of cancer and cardiovascular diseases. Therefore, dried nori can be considered a decent snack. However, dried nori has a high salt and MSG content, so it's not suitable for long-term, continuous consumption. It's best not to eat more than one or two ounces at a time.