Konjac is a plant native to East Asia and has been used for centuries in traditional medicine and cuisine. The konjac plant produces a starchy tuberous root, also called a corm or block, which is used in various dishes and as a dietary supplement. Konjac noodles, also known as shirataki noodles, are made from the root of the konjac plant, while konjac chunks or blocks are made from the corm.

The main reason why konjac noodles are white is that they are made from refined konjac flour. The flour is obtained by washing and grinding the konjac root and then removing the impurities. The resulting flour is almost pure glucomannan, which is the main component of konjac. Glucomannan is a soluble fiber that is low in calories and has been shown to have various health benefits, such as reducing cholesterol levels and promoting weight loss.

On the other hand, konjac chunks or blocks are usually black because they retain more of their natural impurities, such as charcoal and minerals. The corm of the konjac plant contains charcoal, which gives it a dark color. Konjac blocks can be processed in various ways, but they usually retain some of the impurities, resulting in a dark color. Some manufacturers also add bamboo charcoal powder to the konjac block to enhance its appearance and nutritional value.

It’s worth noting that the color of konjac products can vary depending on the processing method and the manufacturer. Some konjac noodles may have a slightly yellow or brownish color, while some konjac blocks may be lighter or darker than others. The color doesn’t necessarily indicate the quality or nutritional value of the product.

In conclusion, konjac noodles are usually white because they are made from refined konjac flour, while konjac chunks or blocks are usually black due to the charcoal and other impurities they contain. The color doesn’t affect the taste or nutritional value of the products, but it can vary depending on the processing method and the manufacturer.