Konjac Production——A Rising Industry for the 21st Century

Konjac, known also as elephant’s-foot of devil tongue, represents a group of perennial herbal plants in Amorphophallus genus of Araceae family. There are altogether about 170 species of konjac in the world, distributed mainly in Asia and Africa. China is rich in the resources of konjac germplasm and boasts of 20-odd species, of which 13 can be found only in this country.

Konjac in China is distributed mainly in the mountainous and plateau regions south of the Qinling Mountains. Yunnan, Guizhou, Sichuan Basin, southern Shaanxi, western Hubei and the mountainous regions in Hunan are chief producers of konjac in China.

The Chinese are the earliest nation to study and utilize this plant. Konjac was first recorded as a disease-curing herb in shen Nong Record of Materia Medica in Western Han Dynasty (206 B.C.-08 A.D.). In the subsequent dynasties of Yuan, Ming, Qing, various records have been kept about konjac being used as a medicine, or as a food in famine years. In the famous classic Compendium Materia Media, a detailed description is given about the ecological environment of the plant and its cultivation, and about its curing functions, administering methods and processing and cooking procedures. In A Comprehensive Dictionary of Chinese Traditional Medicines, a dictionary published in contemporary time, the functions of konjac for detoxification, germ-suppression, phlegm liquefication and asthma soothing, and blood stasis alleviation are re-affirmed. The traditional utilization method of konjac in China as a food is to process its fresh tuber or dried chips into a curd. However, such a traditional procedure has a great disadvantage of losing part of its health-building function as a result of heavy alkalization.

The component of economic value in konjac is the glucomannan contained in its corm (tuber). It can be seen from its anatomical structure that there are many glucomannan-containing idioblasts in the corm. Removing the starch and other substances surrounding the idioblasts will result in konjac power, or crude konjac glucomannan (KGM). The process of crude KGM production consists mainly of two steps: drying by dehydration and konjac power processing.

The harvested fresh konjac tuber is first washed clean and peeled, followed by slicing. Drying by dehydration is achieved in special kind of oven-drying equipment in which the konjac slices are subjected to high temperature color fixing and low temperature drying. Then the dried slices are broken and made into fine powder in another kind of special equipment and the starch, fiber and other impurities are removed. When the konjac powder is further purified and finely subdivided, a better product, konjac gum, will result, which has a better quality and is more convenient for uses.

KGM is a high molecular polysaccharide, characterized by many good physicochemical properties, such as water solubility, and thickening, stabilizing suspending, gelling, film-forming, and binding ability. Therefore, konjac can be utilized in a variety of ways.

The main component of crude KGM is a good quality soluble semi-cellulose, which contains few calories. It is shown in the clinic tests carried out by West China Medical University and other prestigious medical institutions that the health-promoting effect of konjac consists in its food fiber regulating the nutrient balance in the human body. It helps prevent constipation, reduce the levels of cholesterol and triglyceride in the serum, alleviate hyperlipemia, lower blood sugar level and lose weight.

Crude KGM can be made into konjac cakes by bulking, gelatinizing and adding coagulant, and into konjac noodles with the help of a porous mould. Different varieties of konjac food can be produced by different combinations of moulds and ingredients, such as konjac cakes, konjac noodles, konjac bars, konjac cubes, konjac balls and the like.

Crude KGM can also be made into various styles of meat-imitating food, such as vegetarian squid, vegetarian fish, vegetarian shrimp, vegetarian animal stomach, and vegetarian kidney. It can also be made into various delicious dishes with different cooking methods: frying, roasting, boiling, and stewing.

Owing to its values as a food and a medicine, konjac can be processing into light delicious functional food, which is in conformity with a new trend in customer preference in the present world. And konjac food is regarded as an “ideal health-promoting food”.

Crude KGM is widely applied as a thickening or stabilizing agent in the production of jelly, jam, fruit juice, vegetable juice, ice cream and other cold drinks or solid drinks, and as flavoring agents. As an adhesive, it is also used in the making of noodles, meat balls, ham sausage, bread and cakes so as to improve their strength and keep them fresh.

The unique physicochemical properties of crude KGM help its application in the industries of drilling, paper-making, construction material, textile printing, daily-use chemicals and environmental protection.

Konjac, owing to its wide field of application, is a highly cost-efficient economic crop with great potentiality on domestic and international markets. The konjac industry has been expanding very rapidly in China, covering the sectors of large-scale cultivation, mechanized dehydration, crude KGM and konjac gum production and konjac food processing. Konjac industry has become one with considerable scale, having a hundred products and an annual output of US$100,000,000. It has contributed to the aid-the-poor drive and developing the local economy in the mountainous regions of southern China and to earning foreign exchange for the country through export. This newly emerging industry will have an even brighter future with the improvement of the material life of mankind and of the health care of the society. It is expected that it will be a rising industry in the 21­­­­­­­­st century.

The Chinese Konjac Association

Add: china, Chongqing, Beibei  Zip: 400716

Tel: 86-23-68250731,  13709418585

Fax: 86-23-68250733

E-mail: zgmyxh@126.com

    Web: www.konjac.org