The technology stream has a saying: What is the difference between ordinary food and organic food?
Organic food refers to agricultural and sideline products and their processed products that come from the organic agricultural production system, are produced and processed according to the corresponding standards of organic agriculture, and have been certified by an independent organic food certification agency. Its main feature is not the use of synthetic substances, such as pesticides, fertilizers, growth regulators, feed additives, genetic engineering products. However, in view of the quality and food safety of organic food, there are still disputes in the academic circles. Some people even think that there are "three problems" (can not be seen, tasted and measured) between organic food and ordinary food. In order to reveal the differences in nutritional quality and safety between organic food and common food, this paper reviewed a large number of literatures, combined with our research data, and introduced the research progress of organic food at home and abroad from three aspects of sensory quality, nutritional value and safety. On the whole, organic food tastes better, and the pesticide residue is 0-1/3 of ordinary food; the nitrate content of organic fruits and vegetables is 50%-80% less than that of ordinary fruits and vegetables. In addition, the dry matter content of organic agricultural products is about 7%-20% higher than that of ordinary food. The content of anthocyanins, isoflavones, carotenoids and other phenolic compounds with anti-cancer and anti-oxidation in organic fruits and vegetables is significantly higher than that in ordinary foods, and the content of vitamin C is higher, which is 30%-68% higher than that of ordinary fruits and vegetables. Organic animal products contain more polyunsaturated fatty acids that are beneficial to human health. In terms of element content, a large number of elements P, Fe, Mg and trace elements Zn, Cu and Cr in organic agricultural products are higher. This study found that there are obvious differences in quality and safety between organic agricultural food and ordinary food, which can provide an important theoretical basis for the healthy development of organic food industry.
Key words: organic food; common food; quality; safety
The "National Standard for Organic Products (GB/T19630)" jointly issued by the General Administration of Quality Supervision, Inspection and Quarantine of China and the National Standardization Administration of China has the following basic requirements for the production process of organic food: 1) Do not use organisms and their products obtained by genetic engineering; 2) Do not use chemically synthesized pesticides, fertilizers, growth regulators, feed additives and other substances; 3) Follow natural laws and ecological principles, adopt a series of sustainable agricultural technologies to maintain a sustainable and stable agricultural production system.
In developed countries in Europe and America, the consumption of organic food accounts for 3%-5% of the total food consumption. The price of organic food is higher than that of ordinary food because of its natural source, rich nutrition, high quality, safety and environmental protection, and relatively more artificial input. In developed countries, the price of organic food is 40-60% higher than that of ordinary food; in China, the price of organic food is 2.5-3 times that of ordinary food.
China feeds 22% of the world's population with less than 7% of the world's per capita arable land, but consumes 35% of the world's total chemical fertilizers and 70% of agricultural water resources. At the same time, the long-term acceptance of pesticides and fertilizers by crops will also threaten the quality and safety of agricultural products. Excessive pesticide residues and heavy metal content will seriously endanger human health.
However, the development of organic agriculture in China is still facing serious problems. Mainly manifested in the emphasis on certification, light process management, the market to fake, hit the consumer confidence. More importantly, consumers do not understand organic food and lack the necessary knowledge in food consumption, resulting in the slow development of organic food industry. Even for the quality of organic food and food safety, academic research conclusions are not uniform. In April 2009, the European Union's "Low Input Food Quality" report summarized five years of research and showed significant differences in grain and livestock quality between organic and conventional production systems. Mainly reflected in (1) organic food contains higher levels of beneficial nutrients, such as vitamins, polyunsaturated fatty acids, antioxidants, etc.;(2) organic food heavy metals, mycotoxins and pesticide residues are lower (Niggliet al.2009). On the contrary, in 2012, Stanford University Spangler and others reviewed 223 research reports to analyze the differences in vitamin content and nutrient content in organic food and non-organic grains, fruits and vegetables, meat, poultry, eggs, and milk from a nutritional perspective. "There is no sufficient evidence to prove that organic food is more nutritious and more beneficial to human health".
The original text will provide consumers with organic and conventional agricultural products in food nutritional quality and safety of scientific and objective answers, for the healthy development of organic food industry to provide a theoretical basis, to ensure food safety has a certain practical reference significance.
Difference of Sensory Quality between Organic Food and Common Food
Sensory indicators of agricultural products, such as appearance, color, taste, smell, uniformity, etc., are the most intuitive indicators to describe and judge product quality. The content of plant metabolites is closely related to the taste and flavor of agricultural products. Compared with ordinary food, organic food has natural color and better taste, and consumers eat the most natural taste. Part of the results found that organic planting patterns can improve the total sugar or soluble sugar content of agricultural products, especially melons and fruits, and improve the taste of agricultural products.
Generally, organic vegetables and fruits are slightly inferior to ordinary fruits and vegetables in appearance. They are different in length, size and color. They are not as bright as ordinary fruits and vegetables and even have some insect bites. However, organic fruits and vegetables do not use pesticides and grow according to natural laws. They will inevitably encounter insect bites and have some damage in appearance. This is a normal phenomenon and does not affect eating. On the contrary, because of this, organic fruits and vegetables taste more pure.
Studies have found that organic pork has more lean meat and firmer meat; organic chicken meat is harder and tastes better. Organic farming allows poultry to grow in the natural environment, breathe fresh air, and partially eat natural foods (such as insects, earthworms, seeds, tender leaves, etc.). The meat is relatively delicate and compact, and the quality of the eggs produced is better.
Difference of Sensory Quality between Organic Food and Common Food
1. Dry matter
Dry matter is the component of plant photosynthesis products accumulated in plants. It refers to the quality of the remaining organic matter after the organism is fully dried at a constant temperature of 60-90°C. It is an important indicator to measure the accumulation of organic matter and the amount of nutrients in plants. Including starch, cellulose, protein, fat, inorganic minerals, etc. Numerous studies have found that organic fruits and vegetables contain more dry matter.
2. Protein and amino acids
Protein is the material basis of life and the basic organic matter of cells. It is composed of more than 20 kinds of amino acids in different proportions. Eight of these are necessary for the human body, but must be supplied by food protein. Under the organic planting mode, the supply of nitrogen fertilizer is not as sufficient as that of conventional chemical fertilizers, and nitrogen is an essential element for nucleic acid and protein synthesis. Therefore, the protein content of general organic agricultural products is lower than that of ordinary agricultural products.
Lipid differences were mainly concentrated in animal meat and dairy products. Polyunsaturated fatty acids have important physiological functions for the human body, which can regulate the body's lipid metabolism, treat and prevent cardiovascular and cerebrovascular diseases. The analysis of the fatty acid composition of organic beef, mutton and chicken found that the beef, mutton and chicken in the organic mode contained higher polyunsaturated fats than those in the conventional production.
4. Phenolic compounds and antioxidants
Phenolic compounds are a class of plant secondary metabolic compounds composed of one or more aromatic rings combined with one or more hydroxyl groups, including flavonoids (anthocyanins, flavonols, flavonoids, etc.), terpenoids (carotenoids, xanthophylls) and nitrogen-containing compounds (glycosides, amines, alkaloids, etc.).
A large number of studies have proved that organic fruits and vegetables contain a wide variety of phenolic compounds and antioxidants. These substances have positive effects on enhancing human immunity, scavenging free radicals in the body, preventing cancer, and regulating immunity.
Vitamins are essential nutrients to maintain the normal physiological functions of the human body and are divided into two categories: water-soluble and fat-soluble vitamins. Water-soluble vitamins mainly include vitamin C, which is an essential nutrient for the human body and an antioxidant. The vitamin C needed by the human body is mainly obtained from fresh fruits and vegetables. Studies have shown that the vitamin C content of organic fruits and vegetables is higher than that of conventional fruits and vegetables.
Difference of harmful substances between organic food and ordinary food
Studies have shown that organic fruits and vegetables have lower nitrate content than conventional fruits and vegetables, especially in leafy vegetables, about 50% lower
2. Heavy metals
On the whole, organic planting mode reduces the content of heavy metals in agricultural products, because organic agriculture forbids the use of chemical fertilizers, pesticides and feed, which reduces the infection of harmful substances.
Mycotoxins (mycotoxin) are secondary metabolites produced by fungi, which have strong toxicity, carcinogenic, teratogenic and mutagenic effects, including aflatoxin (AF), zearalenone (ZEN), deoxynivalenol (DON), HT-2 toxin, T-2 toxin and so on. The organic model uses compost without pesticides and antibiotics, which may increase the probability of plants being attacked by microorganisms and pathogens.
4. Pesticide residues
According to the China Rural Statistical Yearbook, in 2013, the output of 335 pesticide companies above designated size reached 3.19 million tons, and about 1000 kinds of synthetic substances were used as pesticides, fungicides, herbicides and other pesticides. Excessive pesticides pose a great threat to food safety. China's fruits and vegetables use a large amount of pesticides and use them many times. Although the state explicitly stipulates that highly toxic and highly toxic pesticides should not be used in food production, they are still used in actual production. Excessive pesticide residues will bring carcinogenic, teratogenic and mutagenic hazards, and have an enrichment effect in the food chain. Organic food production process prohibits any chemical synthesis of pesticides, so organic food pesticide residues are low.
5. Pathogenic bacteria
According to the definition of the World Health Organization, all pathogenic factors that enter the human body through food intake, causing the human body to suffer from infectious or toxic diseases, are called food-borne diseases. It is mainly caused by foodborne pathogens of plant and animal origin. Due to the prohibition of the use of pesticides, the number of pathogenic bacteria in organic agriculture may increase. If the organic fertilizer is not fully decomposed, it may become a potential source of intestinal infectious diseases.
problems and prospects
Organic food has advantages in nutritional quality and safety, especially in vitamin C, vitamin E, polyphenols and antioxidants content is much higher than ordinary food.
In terms of scientific research, it is necessary to strengthen the research on the quality of organic food, especially the comprehensive and detailed display of pesticide residues, nitrate content, heavy metal content and other aspects of consumer concern.
Consumers have a distrust attitude towards organic food, mainly because they do not fully understand the quality of organic food, which requires scientific research to reflect the real quality differences. From the results of this paper, organic food and ordinary food is not the existence of "three not" (can not see, taste, can not be measured) problem, but in the sensory phase, nutrients, heavy metal residues, pesticide residues and so on there are obvious differences. Producers can stand the test as long as they carefully produce according to organic standards. Consumers consume at a reasonable price and drive the enthusiasm of producers and investors, and the organic food industry can develop and grow.
Source: Ecological Home, Author: Yu Xiaofan, Jiang Gaoming