What types and characteristics do specialty rice varieties have?

I. The concept of specialty rice II. Types and characteristics of specialty rice 1. Colored rice 2. Aromatic rice 3. Special-purpose rice I. The concept of specialty rice Specialty rice refers to rice with specific genetic traits and special uses, mainly distinguished from ordinary rice by the particularity of its use. Specialty rice generally includes three categories: colored rice, aromatic rice and special-purpose rice. Although its varieties account for only about 10% of rice germplasm resources, it has received widespread attention at home and abroad because of its special nutritional, health-care and processing-and-utilization characteristics. The concept of specialty rice was first expounded by the Chinese scholar Zhao Zesheng. In 1989, when he gave an academic report titled "The Role of Specialty Rice in High-Quality Staple Food and Food Structure" at the Faculty of Agriculture of Osaka Prefecture University in Japan, he first proposed that specialty rice refers to rice with special traits, and these traits are heritable, and the rice milled from it has higher utilization value and greater social and economic benefits. This concept was recognized after extensive discussion by experts attending the "First China Specialty Rice Academic Symposium" in 1992. In 1995, the publication of the monograph "China Specialty Rice", edited by Zhao Zesheng and others, marked the initial establishment of China's specialty rice disciplinary system. II. Types and characteristics of specialty rice 1. Colored rice Colored rice refers to rice whose brown rice (caryopsis) carries color. Because anthocyanins accumulate in large amounts in the pericarp and seed coat, the brown rice appears green, yellow-brown, brown, coffee-colored, red, red-brown, purple-red, purple-black, jet-black and other colors. Usually, the red-brown pigment of red rice accumulates in the seed coat, while the purple pigment and black pigment of purple rice and black rice accumulate in the pericarp. At present, colored rice consists overwhelmingly of red rice and black rice, but no variety with colored endosperm has yet been found. Colored rice can be eaten directly, cooked into porridge, made into cakes, made into flatbreads, brewed into wine, and used in dietary therapy and medicinal therapy; natural pigments can also be extracted from it for use in the food industry. (1) Black rice and purple rice Black rice and purple rice are a special type of rice resource. In China they are mainly distributed in Yunnan, Guizhou, Guangxi, Guangdong, Shaanxi, Sichuan, Fujian, Hunan, Jiangsu and other provinces, and the grain quality is mostly of the glutinous type. The grain surface is black, purple or brown, and the endosperm is white. Black rice and purple rice are usually eaten as brown rice and have extremely high nutritional value. They also have high medicinal value. For example, some black glutinous rice and purple rice in Yunnan and Guizhou provinces not only nourish and strengthen the body but also have the medicinal effect of promoting bone reunion and tissue regeneration. Guangxi's Donglan ink rice has a high content of black rice pigment and is also soluble in water, and has the function of improving body immunity. Because black rice and purple rice varieties have a long planting history, a wide distribution range, complex geographical environments and greatly differing climates, they have formed diversity of varieties. In type they are divided into indica, japonica, lowland, upland and glutinous, but most are black glutinous or purple glutinous. Famous varieties include Shaanxi Yangxian black rice, Yunnan Xishuang black glutinous rice, Lincang black glutinous rice, Dehong purple rice, Lijiang purple rice, Baoshan purple rice, Shiping purple rice, Mojiang bone-reunion glutinous rice; Guizhou's Huishui black glutinous rice, Tunli black glutinous rice, Gaozi black glutinous rice; Guangxi Rongxian black glutinous rice, Longcun black glutinous rice, Donglan ink rice; Fujian's Yunxiao purple rice; Guangdong Shaoguan black glutinous rice; Hunan Xiangxi black glutinous rice; Jiangsu Changshu duck-blood glutinous rice, etc. (2) Red rice. Among the traditional varieties in China's Henan, Yunnan, Guizhou, Guangxi, Jiangxi, Jiangsu, Fujian, Hunan, Shaanxi, Shanxi and other provinces there are some red rice varieties, including indica, japonica, non-glutinous and glutinous. Famous varieties include Yunnan's Hongyundang, Shanxi's red aromatic rice and red aromatic grain, Shaanxi's Pingli Sanlicun, Jiangxi's dwarf willow-strip red, etc. Among them, Shaanxi's Pingli Sanlicun has pinkish-red grain color, is glutinous, has extremely long grains and is aromatic; it is a precious variety of the Ankang region, and its main planting areas are in the Pingli and Zikang county area, also including Chang'an willow-leaf rice, Baoji red rice, Zhen'an red millet, Xunyang Sanlicun, etc. As a special commercial rice, red rice has great value, and can also be used as a raw-material rice for brewing, red pigment and aromatic beverages. The grain quality of red rice is mostly of the semi-glassy type. (3) Green rice and yellow rice. China's rich rice resources contain some green rice and yellow rice varieties, but there are very few domestic research reports, so only the green rice and yellow rice varieties of Shaanxi are introduced here. For example, Shangnan County's red-shell rice turns light green after the grain matures, is sticky, and most grains are semi-transparent with excellent grain quality. Varieties of this kind include Shangnan County's Baiganzi, Gangquan cold-water valley rice, etc.; yellow rice is represented by Yangxian aromatic rice, whose grain color is light yellow, bright with no chalkiness, semi-transparent, of excellent grain quality and aromatic; such varieties are relatively few. The pigment contained in green rice is extremely unstable and often fades during storage. 2. Aromatic rice Aromatic rice refers to rice whose grains contain fragrance. The grains, brown rice and milled rice of aromatic rice have a fragrant aroma that makes people feel comfortable, and the cooked rice is fragrant and delicious. The stems and leaves of many aromatic rice varieties also emit a strong fragrance; when the wind blows along them, the fragrance spreads for ten li. The main component reported in the fragrance of aromatic rice is 2-acetyl-1-pyrroline, which is a carbonyl compound and easily volatilizes and decomposes. When aromatic rice is steamed or cooked into porridge, the whole house is filled with a delicate fragrance, greatly increasing appetite. A small amount of aromatic rice can also be added to ordinary rice to make mixed aromatic rice, with the same effect. Aromatic rice is deeply loved by people for its rich aroma, crystal-clear grains and fragrant cooked rice. It has high economic value and contains abundant protein, various amino acids, alkaloids, vitamin B1 and vitamin B2 as well as various nutrients essential to the human body, and has certain nourishing and medicinal effects. According to Li Shizhen's "Compendium of Materia Medica", aromatic rice can "moisten the heart and lungs, harmonize with all medicines, and when taken for a long time makes the body light and prolongs life". Sweet rice balls, rice cakes and rice wine made with aromatic rice taste excellent. And in successive dynasties aromatic rice was kept as tribute rice, exclusively for the imperial household and high officials to enjoy. China's aromatic rice includes distinctions of indica, japonica, non-glutinous and glutinous, and the pericarp also differs as white, red, brown, purple and black, with producing areas across 15 provinces and regions from north to south. Famous varieties include Shaanxi's Yangxian aromatic valley, Cunmi, Cunxiangmi and Hanzhong black aromatic glutinous rice; Yunnan Jinghong County's large aromatic glutinous rice, Haodage, aromatic purple glutinous rice; Guizhou's white-haired aromatic valley and red aromatic valley; Guangdong's Luofu aromatic rice; Jiangxi's Longnan aromatic grain and Jishui aromatic glutinous rice; Jiangsu's Suyu glutinous rice; Zhejiang's aromatic japonica glutinous rice; the aromatic japonica and aromatic japonica glutinous rice of Shanghai's Qingpu County and Songjiang County; Anhui's Sixian Jiagou aromatic rice; Shandong's Qufu aromatic rice, Linyi large aromatic rice and white-shell aromatic rice; Henan's Huixian aromatic glutinous rice and Xixian aromatic rice; Sichuan's Liangshan rice and Tianquan County's Shibadao aromatic rice, Luxian aromatic valley, etc. 3. Special-purpose rice Special-purpose rice refers to rice specially used for food-industry processing, such as wine rice, soft rice, parboiled rice, pastry rice, canned rice, giant-embryo rice, feed rice, etc. (1) Wine rice Wine rice is rice specially used for brewing wine and can be divided into two types, namely japonica wine rice and glutinous wine rice. China's wine rice is usually glutinous rice, while Japan's wine rice is japonica rice. The characteristics of wine rice are: high brown rice yield, milled rice yield and head rice yield, amylose content lower than 2g/100g, protein content of 5-6g/100g, low fat content, large milled grains, mostly round, milky white throughout, glossy, strong water absorption, and starch granules easily enzymatically hydrolyzed. (2) Soft rice. Soft rice is an indica-type high-quality rice unique to Yunnan Province. Its grain quality is between glutinous and non-glutinous rice. Its cooked rice is soft yet refreshing, and after cooling it does not harden or retrograde, and it is suitable eaten both cold and hot, hence the name. Cooked soft rice keeps you full after eating, and rice noodles made from it do not break easily. Some varieties are aromatic, and the varieties are diverse, with red and white types, as well as transparent, semi-transparent and powdery-white varieties. They are mainly distributed in parts of Yunnan's Dehong Prefecture and Baoshan region, as well as Gengma, Yunxian, Shuangjiang, Yongde and other places in the Lincang region, mostly concentrated between 800-1000m above sea level. After soft rice varieties are planted in other places, it is often difficult to maintain their original excellent quality. Soft rice varieties were mainly formed through the interaction of the dietary habits of ethnic minorities and special natural conditions. Their botanical characteristics differ from those of general indica rice varieties, and their yield is relatively low. Recently, Guangdong, Hunan and other regions have successively bred some new soft rice varieties with higher yields according to market demand.