Break the situation of edible oil import dependence and improve the self-sufficiency rate of oil and oil

China is a major importer of oilseeds, and the Central Document No.
1 in 2022 proposed to vigorously implement the soybean and oilseed production capacity improvement project, so that the "oil bottle" can be filled with as much Chinese oil
as possible 。 In order to promote the research and industrial innovation and development of lipid science and health-related fields, at the 6th International Symposium on Lipid Science and Health, jointly organized by the Institute of Oil Crops of the Chinese Academy of Agricultural Sciences and Northwest A&F University, the participating experts and scholars made special reports and discussions on cutting-edge academic topics such as lipid science and health, including the development of insect oil and oil, improved oil extraction process, etc.
, so as to improve the self-sufficiency rate of oil and solve the problem
of dependence on imports of edible oil.

The gap between supply and demand is large, and net imports are rising year by year

China is a major country in the global oil production, consumption and trade, and the scale of domestic oil crop planting is second only to grain
.

According to data from the National Bureau of Statistics, China's oil production has developed rapidly, and the planting area of oil crops (including rapeseed, soybeans, peanuts, sunflowers, sesame, and flax) in China reached 350 million mu in 2020 (accounting for about 7% of the world), an increase of 1.
6% over 2019; The total output of oil crops is about 57 million tons (accounting for about 20% of the world), an increase of about 2.
6% over 2019, and rape, peanuts and soybeans account for 94.
2%
of China's total oil crop production.

In 2019, China's edible vegetable oil output was 23.
84 million tons, accounting for 10.
5% of the world's edible oil production, ranking second in the world; From the perspective of the composition of edible and consumed vegetable oils, the main edible oil varieties include soybean oil, rapeseed oil, palm oil, peanut oil, etc
.

From the perspective of production scale, the planting area of oil crops in the country is second only to the three major cereal grain crops
of rice, corn and wheat in scale.
From the perspective of varieties, the sum of the planting area and total output of rapeseed, soybean and peanut in the country accounts for more than 90% of oil crops, and is the main body
of oil production and utilization.
From the perspective of quality, all kinds of oilseeds have cultivated high-oil varieties, soybeans and peanuts have cultivated high-protein varieties, and rape and peanuts have cultivated high-oleic acid varieties
.
From the perspective of production area distribution, winter rapeseed in the Yangtze River Basin, soybeans in the northeast region, peanuts in the Huanghuai region, and sunflowers in the arid and saline-alkali areas in the north are the concentrated production areas and advantageous production areas
for oil crop planting.

"Although China's oil production has generally maintained a growth trend, with the accelerated growth of consumer demand, domestic vegetable oil faces the practical problem
of low self-sufficiency rate and high import dependence.
" Huang Fenghong, a researcher at the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, said that in 2021, the total consumption of vegetable oils and fats in the country was 42.
545 million tons, and the consumption of edible oil increased by 37.
08 million tons (accounting for 17.
7% of global consumption), three times
that of 2000.
Since 2010, China's edible oil consumption growth is significantly higher than that of developed countries, and the per capita consumption of oil and oil has increased simultaneously, and China's per capita edible oil consumption in 2021 is 30.
1 kg, exceeding the world's
per capita edible oil consumption of 27 kg in 2021.

Due to the large gap between production and demand, China's oilseeds and edible vegetable oils are highly dependent on the international market
.
Taking palm oil as an example, the demand side is domestic, and the supply side is almost entirely dependent on imports
.
The price of oilseeds fluctuates frequently, and the stable and healthy development of the industry faces high uncertainty
.

Huang Fenghong introduced that after 1999, China canceled the quota restrictions on soybeans, reduced tariffs, the price difference between domestic and foreign soybeans was obvious, and China's oil product imports soared
.
In 1998, China's oilseed imports were 4.
61 million tons, which increased to 6.
94 million tons in 1999, 1.
5 times that of the previous year, and reached 108 million tons by 2020, 15 times
that of 2000.
Soybean imports are 5.
1 times that of domestic production, sesame is 2.
3 times; rapeseed imports are increasing year by year, reaching 3.
11 million tons in 2020; and peanut imports in 2020 exceed domestic production
.

In 2021, the self-sufficiency rate of edible oil continued to decline, and in 2021, the total domestic crushed oil was 37.
08 million tons, of which 11.
5 million tons of domestic oil (rape, peanuts) accounted for 31%, imported oil crushed 17 million tons (soybeans, rapeseed) accounted for 46%, imported vegetable oil 8.
58 million tons (palm oil, rapeseed oil, etc.
) accounted for 23%, and import dependence was as high as 70%.

Therefore, the task of expanding the production of soybeans and oilseeds and increasing the self-sufficiency rate of domestic edible vegetable oil has become more and more urgent.

Use scientific methods to increase the rate of self-sufficiency

In 2022, the Central Document No.
1 proposed to vigorously implement the soybean and oil production capacity improvement project, so that the "oil bottle" can be filled with as much Chinese oil
as possible.
The Ministry of Agriculture and Rural Affairs has proposed expanding soybean oil production as a major political task
that must be completed next year.

It is necessary to establish a big food concept, ask for oil and fat from plants, animals and microorganisms, consolidate the foundation of food security in an all-round way, and ensure that the Chinese's rice bowl is firmly in our hands
.
Huang Fenghong said: "It is necessary to adjust the structure in a down-to-earth manner, expand the planting of soybeans and oilseeds, see measurable results, and deal with the uncertainty
of the external environment with the certainty of stable domestic production and supply.
" ”

"The key to improving market competitiveness is to increase oil content
.
" Cai Guangqin, a researcher at the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, said that unlike food crops, oil is the main product of oil crops, and oil production is the most important indicator to measure oil crops, and the oil content of promoted varieties is about 42%-45%, which is 4%-6%
lower than that of major rapeseed producing countries such as Canada.

"The genetic mechanism of oil content is not clear, which is one of the key bottlenecks restricting the development of
China's rapeseed industry.
" Cai Guangqin introduced that the accumulation of matter (oil and protein, etc.
) during the development of oil plant seeds is a dynamic change process, among which, the net accumulation of oil has a tendency to increase first and then decrease, and how to crack the degradation of oil seriously affects the net accumulation of oil seed oil of oil plant is a key scientific problem
.

Oil degradation is an important biological phenomenon in plant life-sustaining activities, such as providing energy for seed germination, coping with abiotic stress, and affecting the accumulation of oil during seed development
.
"However, the metabolic regulation of oil catabolism is still unclear, so the mining and identification of key genes for oil degradation regulation is of great significance
for the genetic improvement of oil content in oil crops such as rapeseed.
" Cai Guangqin said
.

In developing seeds, oil synthesis and degradation occur at the same time, and it is difficult to find the key genes
for oil degradation.
Among the germinated seeds, oil degradation is the mainstay, which provides the most important energy for the completion of seedlings in the later stage, and it is easier to study
the degradation mechanism of oil.

Through the screening of seed germination rate and sugar-free medium seedlings, AHL4
, a key transcription factor in the regulation of lipid degradation, was identified.
AHL4 inhibits lipid catabolism
by inhibiting the expression of specific genes involved in triacylglycerol hydrolysis and fatty acid oxidation.
The oil content of seeds of AHL4 overexpressed strains increased by 4.
5%-6.
7% compared with wild type, and the linoleic acid content in seeds of AHL4 overexpressed strains was significantly higher than that of wild type
.
Cai Guangqin said that this study provides a new strategy
for the genetic improvement of oil yield of rapeseed and even other oil crops, which can inhibit the degradation of oil during seed development.

Insect protein, as one of the alternative protein sources, has been well known to the public and used in beverages, snacks, protein bars and other food branches
。 Insect fat also has high development value, insect oil is mainly unsaturated fatty acids, good digestion performance, rich in trace elements, low sugar content, insect lipids and oils can be used as high-quality nutritional blended edible oil, but also can be used in the pharmaceutical industry and other industries, such as mealworms can be used as health care products added oil, cosmetic additives and transformer oil, silkworm chrysalis oil can be used to prepare cholesterol-lowering drugs, lubricating oil, etc
.
, the value of edible insects is more excavated.

At present, more than 1 million species of insects have been known in the world, of which more than 3,650 species of insects have been identified for edibles, and more than
800 species of edible insects are presumed to be in China.
The content of lipids in insects varies with the life history of insects, but in general, insects are rich in fat, and many insects have a fat ratio of 30% or even more than
40%.
In addition, insects also contain some fat-soluble vitamins, such as vitamin A, vitamin D, vitamin E, etc
.
"Insect lipids are important components in insects, and the development of insect lipids is of great significance
.
" Professor Wang Jun of Jiangsu University of Science and Technology introduced
.

Silkworm pupae are rich in n-3 unsaturated fatty acids, such as α-linolenic acid, which are essential
for human health.
However, due to the unique properties of lipids, proteins and other components present in insects, although the process of extracting oil by pressing method is simple and the production scale is flexible, the oil production efficiency is low
.
At present, most of the leaching methods used have low labor intensity and high production efficiency, but the amount of organic solvents used is large, the safety is poor, and the environment is not friendly
.
The water enzyme method is based on the water generation method, using biological enzymes to destroy the cell structure and promote the release of oil under specific conditions, which has the advantages of
mild extraction conditions, green and safe, and can separate oil and protein products at the same time.

Wang Jun's team improved the water enzymatic method by using magnetic nanoparticle immobilization enzyme and other methods to achieve greener, safer, efficient and economical extraction of insect oil
.
The results show that the catalytic performance is significantly improved, the extraction time is reduced by 2 hours compared with the improved hydroenzymatic method, only 4 hours, the temperature required for the process is reduced from the original 80 degrees Celsius to 50 degrees Celsius, and there is no need to repeatedly extract multiple times, the solvent used is water, and the solvent can be reused
after centrifugation.
The enzymatic extraction rate before the improvement was 70%, and the enzymatic extraction rate after the improvement was 93.
13%, and the oil lifting effect was significantly improved
.

(Wang Jiayi, Liu Yanfang)

China Food News(Version 02, December 12, 2022)

(Responsible editor: Gao Jiaodi).