Polysaccharides are formed by many monosaccharides linked by past bonds Polymer compound 。 One molecule of polysaccharide can generate hundreds, thousands or even tens of thousands of monosaccharide molecules after hydrolysis. Therefore, the polysaccharide relative molecular mass They are very large, usually above tens of thousands of carbon units. Polysaccharides are widely distributed in the biological world. Some polysaccharides are substances that constitute the skeleton of animals and plants, such as cellulose, chitin, etc; Some polysaccharides, such as starch and glycogen, are nutrient reserves in animals and plants; Glycoproteins, proteoglycans, glycolipids and other molecules with important physiological functions in organisms all contain polysaccharides or oligosaccharides. Some natural polysaccharides, such as starch, glycogen and cellulose, produce only one monosaccharide glucose after hydrolysis, which is called homopolysaccharide or homopolysaccharide; Another kind of polysaccharide, such as Hyaluronic acid 、 chondroitin sulfate , dermatan sulfate, heparin and other proteoglycans, and the final hydrolysate is more than two monosaccharides or monosaccharides derivatives, which are called heteropolysaccharides. Because proteoglycans contain a large number of repeated disaccharide structural units, they are also called glycosaminoglycans. [2] Terpenoid It is a type derived from methylglutaric acid, and the basic carbon frame has two or more isoprene Compounds of unit structure. Terpenes are widely found in the biological kingdom, higher plants, fungi and bryophytes, with a total of about 30000 species. A considerable number of terpenoids have bitter taste, and the bitter taste of Chinese herbal medicine is mostly due to its existence, so it was once called "bitter element". Terpene compounds have a wide range of types, different properties and diverse pharmacological activities, such as antifertility genkwa ester A, oleanolic acid that promotes liver cell regeneration, antibacterial andrographolide, anti-tumor paclitaxel, anti-inflammatory borneol, and paeoniflorin that dilates coronary arteries. The scientific research team led by Tu Youyou won the Nobel Prize in Biology and Medicine for the first time in China for the discovery of the antimalarial component artemisinin, which is a terpene compound. [3] Sterols are unsaponifiable substances in lipids, which are easy to crystallize in organic solvents. Generally, sterols have one structure Cyclopentane phenanthrene Ring. There is a methyl between the AB ring and the CD ring of cyclopentane phenanthrene, which is called angular methyl. Cyclopentane phenanthrene with angular methyl group is called "steroid". [4] Phytosterol Soluble in oils and oil solvents (such as ether, chloroform, acetone, etc.), each plant contains more than one sterol, often a mixture of several sterols, and wheat and corn germ oil contains many sterols. [4] Alkaloids are a large class of important natural compounds, which are widely found in natural plants, animals and microorganisms. They have many structural types and strong biological activity. Many of them have been widely used in clinical as common drugs, such as berberine (berberine) Tetrahydropalmatine , scopolamine (atropine), reserpine, camptothecin, quinine, vincristine, matrine, homoaconitine, morphine, etc. Alkaloid natural ingredients have a wide range of biological activities, such as analgesia, tumor inhibition, blood pressure reduction, antibacterial, antiviral and other effects. Some alkaloids are both active and toxic components, such as Aconitum alkaloids 。 The distribution of alkaloids in nature has certain regularity, for example, diterpene alkaloids are mainly distributed in Aconitum and Delphinium of Ranunculaceae, and rare in other families and genera. [5] Nucleic acid is one of the most basic substances in organism. According to different chemical composition, nucleic acids can be divided into Deoxyribonucleic acid And RNA. DNA is the main material to store, copy and transmit genetic information. RNA is all living things protein synthesis The indispensable part can also be used as the genetic material of some viruses. Nucleic acid plays a decisive role in a series of important life phenomena such as growth, heredity and variation. [6] Protein is a biological macromolecule with relatively stable conformation and certain biological functions, which is condensed by many α amino acids through amide bond (or peptide bond) according to a certain sequence. Protein is the carrier of life, and it is impossible for any living organism to leave protein. Protein has important biological significance in life activities and ethnic reproduction, and bears a strong function. [7]
① Structure and function: protein is a component of biological tissues and cells, and plays a role in protection and Sertoli cell Such as protein in biological membrane. [7] ② Catalytic function: Almost all biochemical reactions in the organism are catalyzed by enzymes, and most enzymes are proteins. [7]
③ Motor function: the contraction and relaxation of muscles of higher animals are determined by Actin And myosin, resulting in body movement, respiration, digestion and blood circulation. [7] ④ The development of embryo and larva of storage functional organism needs nutrition, and the nutrition provider is protein, such as Ovalbumin , gliadin in seeds, etc. [7] In addition to the above functions, it also has such functions as hemoglobin It can be said that proteins participate in the growth, reproduction, heredity and variation of organisms. [7] Natural bioactive substances have anti-inflammatory, anti-cancer, antioxidant and other physiological activities, and are widely distributed in a variety of animals and plants, marine organisms and microorganisms. Fruits and vegetables are an important part of daily food. At present, the main functional factors identified include dietary fiber, fruit oligosaccharides Phytosterol 、 Carotenoids , flavonoids, diallyl disulfide Resveratrol 、 Isothiocyanate , limonene, etc. For example, apples are daily meals Flavanol and Xanthone alcohol The main source of, has the function of improving immunity, anti-oxidation; Longan polysaccharide can regulate and improve immunity, memory, anti-oxidation, anti-tumor and other health functions; Resveratrol contained in grape fruits and seeds can inhibit lipid oxidation; Flavonoids in nuts have the effects of inhibiting platelet aggregation, bacteriostasis and anti-tumor. The main bioactive substances in vegetables are Carotene 、 Organic sulfur compounds The lycopene, anthocyanin, etc. in polysaccharides and flavonoids can significantly promote human health and prevent diseases. For example, pumpkin polysaccharides have many health functions such as dietotherapy and disease prevention; The active chemical components in Momordica charantia, such as triterpenoids, steroids, alkaloids, proteins, organic acids and sugars, have the functions of reducing blood sugar and lipids, regulating enzyme activity, anti-virus, anti-tumor, etc. [8] In addition Soybean isoflavone 、 saponin , polypeptides, oligosaccharides, lecithin and other major functional factors, with anti-cancer, immune regulation, cardiovascular protection, anti free radicals, blood lipids and other effects; Tea tea polyphenols 、 Tea polysaccharide Tea γ - aminobutyric acid and other bioactive substances have high health functions; The effects of edible fungi on anti-tumor, immune regulation, anti-virus, anti-bacterial, anti-inflammatory and blood lipid are closely related to their rich active ingredients such as polysaccharides, triterpenoids, polypeptide amino acids, etc; Marine organisms also contain a variety of anti-tumor, anti-virus, antioxidant bioactive substances. [8] Some functional foods also use fungi. For example, the medicinal wine produced in China will put different animal and plant parts together for processing, and add fungi at the same time; Ganoderma lucidum is used to make medicinal liquor; Using bisporus to make puffed food, etc. There are also some magical creatures in China, the most distinctive one is Cordyceps sinensis. Cordyceps is caused by the fungus parasitism in the insect body until the insect body dies, and the fungus occupies the insect body, drilling out of the ground and looking like grass. Due to the particularity of its formation, cordyceps also contains some active factors that are extremely beneficial to human body. At present, China has developed many functional products related to it, such as cordyceps wine, cordyceps jelly and cordyceps herbal diet. [9]
The key of functional food is that the natural bioactive substances contained in it can regulate human physiological functions. In order to achieve multidisciplinary basic research and innovative product development, it is necessary to constantly develop and tap new functional food raw materials. The resources of bioactive substances in animals and plants are very huge. Modern advanced science and technology are used to comprehensively carry out resource identification and evaluation, including the identification of functional ingredients and active substances, the exploration of physiological activity mechanism, etc., and to dig deeply into the resources of plant cultivated species, related species, and wild species, so as to enrich, protect, and innovate the use of homologous plants of medicine and food. While making deep use of resources to research and develop efficient and special functional food, it is also necessary to carry out research on the functional genetic background and fine variety breeding of high-yield, high-quality and total nutrient plant resources to meet the needs of daily diet. [8]
Optimization of extraction and separation process
The ultimate purpose of extraction and separation is to remove impurities and retain the biological activity and stability of natural bioactive substances to the maximum extent, that is, to explore the best conditions of extraction methods, optimize harmless green separation process and purification technology, and provide technical guidance for in-depth development of preparation process improvement, characteristic application, modified products, and special functional food development, Give better play to the green and health functions of functional food. Modern science and technology such as low-temperature crushing technology Ultrafine grinding technology Supercritical extraction technology; Membrane separation technology Molecular distillation technology , nanotechnology, etc; In pursuing the consumption trend of scientific nutrition and green food, aseptic packaging technology should also be adopted according to the characteristics of plant varieties Microcapsule technology , drying technology (freeze drying and sublimation drying) and other new technologies to produce functional food with high content, high activity, high purity and high stability. [8] The active substances extracted from various animals and plants are generally mixtures of various components. On the basis of separation and purification, modern scientific methods and experimental means should be used to conduct in-depth research on the structure, efficacy and mechanism of their components. First of all, the physical and chemical properties, medicinal efficacy, structure-activity relationship and dose effect relationship of various natural bioactive substances are systematically studied by means of modern biotechnology with cell engineering, genetic engineering and enzyme engineering as the main body. The mechanism of action and possible side effects are discussed from the molecular, cellular and organ levels, and the efficacy of functional factors Safety and stability. Secondly, study the combined effect and mechanism of a variety of natural bioactive substances, including the synergy, antagonism or independent performance among a variety of natural bioactive ingredients, to provide a theoretical basis for the deep processing and comprehensive development of resources from multiple levels and aspects, and also to provide a basis for the formulation of functional food management norms. [8]
