Introduction of Lotus Root

Lotus root (scientific name Nelumbo nucifern), commonly known as lotus root, referred to as lotus root, “Er Ya”, also known as water hibiscus, lotus, lotus root, water Chi, water Hua, Zhu Hua, water rue, water Dan, Ze Zhi, Yu Huan, Jun Zi Hua, etc., is a kind of perennial persistent aquatic herbs to fat and tender rhizomes for food, is China’s very important aquatic vegetables, the “Divine Husbandman’s Classic of the Materia Medica” will be classified as a top quality.

Lotus root is mostly cultivated, widely distributed in China, Jiangsu, Zhejiang, Hunan, Hubei and other provinces for the production of superior. Lotus root has been a favorite food since ancient times. With the acceleration of the pace of life and the improvement of living standards, diet from food to nutritional health care type transformation, people’s demand for lotus root products is increasing.

Nutritional value of lotus root

Lotus root is rich in carbohydrates, protein, vitamins, minerals, tannin and so on. It has been determined that every 100g of lotus root contains 77.9-89g of water, 10-20g of starch, 1-2g of protein, 25-55mg of VC, as well as cotton seed sugar, fructose, rice sugar, sucrose and carotene, polyphenol compounds, calcium, phosphorus, iron and so on.

Lotus root has a high nutritional value, both as a fruit to eat, can also be used as a culinary delicacy, if the sugar pickled into preserves or made of lotus root powder, it is a unique flavor. Therefore, the lotus root is both a high-quality vegetable, but also has the characteristics of the best fruit, and set of nutrition and medicinal in one, has a good health function, can be called fruit, vegetables, medicine, all three are good.

Core processing technology of lotus root

During the processing of lotus root products, the most likely problem is discoloration. It is mainly enzymatic browning and non-enzymatic browning that causes discoloration. This is due to the fact that lotus root is rich in phenols, carbohydrates, proteins and other substances.

Discoloration will seriously affect the sensory quality and deep processing of lotus root products, so that its important industrial application value can not be better played out. Therefore, the color protection of lotus root is the core technology to carry out the processing of lotus root products and meet the market demand.

3.1 Enzymatic browning

Enzymatic browning of lotus root must have three conditions, i.e. appropriate phenolic substrate, phenol oxidase and oxygen.

The polyphenolic compounds in lotus root account for about 0.2% to 0.3% of the root, which mainly refer to the substances containing tannic acid (ellagic acid) components, and there are two main categories: one is catecholic acid, including D-epicatecholic acid, D-catecholic acid, neochlorogenic acid, etc; and the other is cryptochrome anthocyanin.

In the practice of controlling enzymatic browning, the possibility of removing the substrate pathway is very small, so the method of controlling the enzymatic browning of lotus root in processing mainly starts from controlling the enzyme and oxygen, and the main pathways are: passivating the activity of the enzyme (hot blanching, inhibitors, etc.); changing the conditions of enzyme action (pH value, water activity, etc.); isolating the contact of oxygen; and the use of antioxidants (ascorbic acid, SO2, etc.).

3.2 Non-enzymatic browning

Non-enzymatic browning mainly includes Merad reaction, VC’s own oxidative browning, discoloration of colorless flower pigments and browning caused by metal ions.

Heating promotes non-enzymatic browning, cooked lotus root will become gray, high temperature can accelerate this process.

Metal ions play a promotional role in discoloration, mainly polyphenol compounds and metal ions, especially with iron ions to generate iron tannins, so that the color of the lotus root becomes dark brown. Therefore, in the production and processing of lotus root, we should try to avoid contact with iron tools.

Tannins oxidize in the air, making the lotus root slowly turn brown, and combining with other metal ions will produce colored compounds. Because of tannin oxidation, it makes divalent iron ions oxidized to become trivalent iron ions. The color of the compound of divalent iron ion and tannin is not obvious, but after contacting with air, the color of the tannin compound which becomes trivalent iron ion becomes darker.

Prospect of Lotus Root Products

At present, the lotus root juice drinks and lotus root powder and other products in the market have products on the market, but still need to further improve the process, improve the quality, improve packaging, reduce costs, increase the variety of colors and colors, expanding the market share, and actively seek export channels, and strive to enter the international market at an early date.

China’s current exports of lotus root products are mainly salted lotus root, boiled lotus root, frozen lotus root and dehydrated lotus root, and later to further strengthen the dried lotus root, pickled lotus root, lotus root tea, canned lotus root, recreational lotus root slices, as well as lotus root health care products product development, in order to form a series of lotus root products, to the image of the green, health-care products and efforts to expand the market at home and abroad.

At the same time, develop corresponding standards and strengthen quality management. With the accession of WTO and the opening of the international market, our lotus root production and product standards should be in line with the international standards, and at the same time, we should strive to obtain HACCP, IS09000 series and other international quality certificates, so as to lay a good foundation for our lotus root products to enter the international market. The detection of heavy metals and pesticide residues should be especially strengthened when exporting lotus root products. In addition, when carrying out lotus root processing, the comprehensive utilization value of its resources should be fully considered so that lotus seeds, roots, leaves, stems and roots can be fully utilized; at the same time, attention should be paid to avoiding the loss of nutrients and flavor substances in the processing process, so as to make the products develop in the direction of greening and naturalization.