Fermented Tofu, Tofuyo

Fermented tofu (soybean curd) is widely distributed in East and Southeast Asia. It is known in mainland China and Taiwan as toufu-ru, toufu-ju, furu, rufu, sufu, funan, fuyu, tou-yu, tauzu, in the Philippines as tafuri, in Malaysia as tau ju, in Thailand as tau-fu yee, and in Vietnam as chao or dau-phu-nyu. In Japan, fermented tofu, known as tofuyo, is found only in Okinawa Prefecture (Shurtleff & Aoyagi, 1975; Su, 1986; Yasuda, 1983b, 1994). Surprisingly, fermented tofu is not found in mainland Japan and Korea, which are located in East Asia. In most Western scientific literature, Chinese fermented tofu has been introduced as sufu. However, the term sufu is not familiar to most Chinese people, while furu or toufu-ru seems to be more commonly known. In Japan, fermented tofu has been introduced as “nyufu” (rufu) or “funyu” (furu) (Ohta, 1965). According to Su (1986), sufu is prepared by overgrowing soybean curd with a mold of the genus Actinomucor, Mucor, or Rhizopus and further fermented in a salt-brine/rice-wine mixture. During fermentation, the mold and rice wine mixture imparts additional flavor to the product. Sufu is usually comprised of red, pale yellow or white colored blocks (2 to 4 cm2 and 1 to 2 cm thick). Commercial products of both white sufu (furu) and red sufu (rufu) made in Taiwan are shown in Fig. 1. Pale yellow or white sufu are untreated, whereas red sufu is colored with red koji which is prepared by growing the mold Monascus anka or Monascus purpureus on cooked rice. Other additives are frequently incorporated into the brine solution, imparting either additional color or flavor to the various types of sufu. Sufu is consumed directly as a condiment (for example, as a seasoning for hot breakfast rice: gruel or Chinese bread) or is cooked with vegetable or meats. Sufu adds zest to the bland taste of a rice-vegetable diet. These descriptions are very interesting in comparison with the following description of tofuyo from Okinawa. Tofuyo is a fermented tofu indigenous to Okinawa Prefecture, Japan. It is a low-salt vegetable cheese product prepared from tofu by the action of microorganisms. It is nutritionally rich, with high quality of protein, fat, and other nutrients. Tofuyo is a creamy cheese-like product with a mild flavor, fine texture, and good taste. Traditionally, tofuyo is directly consumed as a dish eaten with awamori, a traditional distilled liquor in Okinawa, or as cakes served at teatime for ladies (Fig. 2). Red furu was brought to Okinawa from Fujian, China, and was introduced during the period of the Ryukyu dynasty, around the 18th century. Because the product was brined and had a strong taste, it was initially unpalatable to the Okinawan people in its original form. Therefore, it was re-created using awamori instead of salt by cooks in the dynasty for a more palatable taste that was milder in flavor. It was named tofuyo. Its other beneficial