Onions and garlic are the main crops grown in many areas in Hai Duong. In That Hung, ward of Kinh Mon town, nearly 100% of farmers grow onions and garlic as the main crops that take them the main income from agriculture. According to Mr. Tuyen, a resident in That Hung, if there was no need for rice straw to cover the soil line of onions and garlic, many people would not grow rice, because it does not bring profit after deducting expenses. For example, in 2022, a pole of garlic gave an income of 13-15 million VND if sold freshly right after harvesting and 20-25 million VND if sold at this time of the year. However, the prices of onions and garlic are not always as high as this year. Mr. Tuyen said that in years of heavy rain, onions and garlic were flooded, so the garlic yield was low, causing the onions and garlic's price to increase; meanwhile, when the harvest were plentiful, the price, however, decreased. It can be said that onions and garlic are bringing great income to many rural areas in Hai Duong, which may promote the expansion of garlic growing area in the near future. If the potential or demand for onions and garlic is not fully exploited, the value of this crop may decrease.
Onions and garlic are grown in the autumn-winter period. After rice is harvested, the entire rice-growing area in That Hung is converted to grow onions and garlic. The time to harvest onions and garlic is around February of the lunar calendar. About 50% of the harvested onions and garlic is sold immediately to traders after it is picked up, 50% of the harvested onions and garlic is brought back to farmers house to be used as seed and gradually sold at a good time of the year.
Figure 1. The onion and garlic as seeds of Mr. Vu Trung Tuyen - a farmer in Phuong Hoang residential area, That Hung ward, Kinh Mon town, Hai Duong.
Onions and garlic seeds need to be stored for about 7 months from harvest time to the next planting season (around August of the lunar calendar). To preserve onions and garlic, people need to spray pesticides to prevent the growth of insects that damage onions and garlic seeds. In the traditional method of preserving onions and garlic, the harvested onions and garlic’s leaves are cut, tied into bundles, hung on the trellis in a well-ventilated and low-humidity place to dry the skin and preserve. Farmers often leave onions and garlic seeds on the terrace for preservation. In this way, onions or garlic are always kept in a dry state due to the ventilation conditions in the storage place. The major threat to stored onions and garlic is insects since they eat and make the seeds soften and shrivel. In addition, storage onions and garlic are also damaged by mold and rotten due to microorganisms. Some farmers also store garlic for sale as food in a similar way; Although ensuring the isolation time of pesticides and onions or garlic has a peel that will peel off when used. However, this will lead to the risk of food poisoning during processing; pesticides are also chemicals that are not used for food preservation due to legal reasons. If this preservation method is used for a long time or occurs any food safety problems, consumers may distrust the quality of onions and garlic products, whether or not they are preserved by pesticides. It is essential to have other preservation methods that are suitable for food hygiene and safety, which in the long run can save the primary livelihood of many farmers in Hai Duong and other provinces
According to studies, in onions (Allium cepa L.), a plant belonging to the genus of Allium, is rich in sugar, vitamins A, B, and C, mineral salts, Na, K, P, Ca, Fe, S, Si, H3PO4, acetic acid, allyl and propyl disulfide, volatile oil, glucokinin, oxidase and diastase. Studies show that the fresh leaf juice and the volatile component of the plant (onion essential oil) have strong antibacterial effects against Streptococcus hemolyticus, Salmonella tryphi, Shigella flexneri, Shigella shiga, Coli bethesda, and Bacillus subtilis. The active ingredient, odorin, has a strong inhibitory effect on Staphylococcus aureus. According to traditional medicine in many countries, onions are used to treat dysentery, ulcers, wounds, scars, asthma, diuretics, and drugs to support diabetes, etc. In general, onions and garlic contain many antioxidants, antibiotics and vitamins, therefore they have many potential applications in medicine and health care. Onion and garlic juice can be used to treat sore throats, coughs, beautify the skin, enhance health, antioxidant capacity, and eliminate toxins, etc. If these applications are developed and spreaded, they will help the demand for onions and garlic increase sharply, contributing in solving the problem of bumper crop but low price for onions and garlic, especially when the growing area of onions and garlic is being expanded. Currently, onions and garlic are mainly used in the form of fresh bulbs or fried for example, as seasoning. In order to diversify products and develop potential applications of onions and garlic in the field of health care and beauty, thereby helping to increase the demand for onion and garlic consumption, it is necessary to increase the value of onions and garlic. That will help to facilitate the expansion of the onion and garlic growing area and to increase income for farmers in Hai Duong in particular and in agricultural sector across the country in general.
Phuong Khiem Limited Company is an enterprise operating in the field of food processing in Hai Duong. Since 2019, this business has processed garlic health care products such as garlic wine, garlic molasses, peeled garlic; the company also collaborates with FPT Digital Retail Joint Stock Company, which owns the Long Chau pharmacy system, in developing some garlic products such as paste gallic and garlic C tablets. Such processing products, if successful, will create more outputs for onions and garlic products. In order to produce clean, safe products and avoid contamination risks, Phuong Khiem Company buys fresh garlic from farmers and preserves raw garlic for production in storages without using pesticides. However, the company's raw garlic is quickly damaged. According to Mr. Tran Dinh Khiem, director of the company, said that in some years, his company has to discard 30 tons of garlic due to rotten and flat occurrences in storage. It can be seen that a method of preserving onions and garlic to ensure food hygiene and safety is an urgent need not only for farmers but also for companies operating in the field of food processing that use onions and garlic as raw materials.
Figure 2. Some garlic products of Phuong Khiem Company Limited in Kinh Mon town, Hai Duong province (left – garlic wine; right – fermented garlic and honey).
1. Roldan E, Sanchez-Moreno C, de Ancos B, Cano MP. Characterization of onion (Allium cepa L.) by-products as food ingredients with antioxidant and antibrowning properties. Food Chem. 2008;108:907-16.
2. Borah P, Banik BK. Diverse Therapeutic Applications of Onion. Arch Pharmacol Ther. 2018; 1(1):14-16.
Ngo Duy Sa - Faculty of Food Science and Technology