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From Stevia Polyphenols to the Polyphenol Family Unlocking the New Code to Health
For a long time, stevia has garnered attention for its high content of steviol glycosides, a natural sweetener, making it an important sugar substitute in the food industry. Today, the legalization of stevia polyphenols undoubtedly paves new avenues for the application of stevia. With its antioxidant properties and various health benefits, stevia polyphenols are poised to become a new favorite in the food and health product sectors, potentially even surpassing the popularity of steviol glycosides.
Stevia polyphenols constitute 2%-4% of dried stevia leaves and mainly include active components such as chlorogenic acid, caffeic acid, and quercetin. Through extraction techniques, high-purity products can be obtained, with total polyphenol content reaching over 40%. These polyphenols are derived from stevia leaves and are produced through processes such as ethanol extraction, filtration, purification, concentration, and drying.
Plant polyphenols are secondary metabolites produced by plants during their growth process. They are a class of compounds containing multiple phenolic hydroxyl structures. Plant polyphenols have multiple benzene ring structures, each with one or more hydroxyl (-OH) groups, which endow them with strong antioxidant capabilities, allowing them to neutralize free radicals.
Based on their chemical structure, plant polyphenols can be divided into various types, mainly including flavonoids, proanthocyanidins, hydrolyzable tannins, and simple phenolic acids. Plant polyphenols are nutrients produced by photosynthesis in plants and play multiple roles within the plant, such as helping plants resist diseases and pests, forming pigments, providing structural support, and regulating growth cycles. Polyphenolic substances are typically stored in various parts of the plant, including the roots, stems, leaves, flowers, fruits, and skin.
Plant polyphenols are a class of natural compounds widely found in plants, with their content second only to lignin, cellulose, and hemicellulose. There are over 600 common plants in nature that are rich in polyphenols. In daily life, foods rich in polyphenols include fruits (such as apple skins and grape skins), vegetables, tea, coffee, seeds, grains, legumes, olive oil by-products, cocoa, herbs, and spices. The related extracts are very diverse, including apple polyphenols, pomegranate polyphenols, tart cherry polyphenols, blueberry anthocyanins, grape resveratrol, green tea polyphenols, coffee chlorogenic acid, and cocoa polyphenols in dark chocolate, among others.
In addition to stevia polyphenols, there are many other foods rich in polyphenols or primarily composed of polyphenols.
Sugarcane polyphenols are natural substances extracted from sugarcane, with the main components being total polyphenols, total flavonoids, and proanthocyanidins. These compounds have rich bioactivity and application value. Research has found that these polyphenols can effectively inhibit α-glucosidase and α-amylase in the small intestine, thereby slowing down the breakdown of carbohydrates in the digestive tract. This reduces the absorption rate of monosaccharides such as glucose and fructose, helping to control blood sugar levels. As a result, sugarcane polyphenols are primarily used in the development of low-GI (glycemic index) foods.
Catechins were approved as a new food ingredient in 2023 and can be used in beverages and confectionery. When used and consumed together with epigallocatechin gallate (EGCG) from the 2010 Announcement No. 17, the recommended total intake is ≤300 mg/day (calculated as total catechins). Catechins are the main polyphenolic compounds in tea leaves, accounting for 12% to 24% of the dry weight of tea leaves and 60% to 80% of the total tea polyphenols. They are primarily found in green tea, black tea, and oolong tea. In Japan, catechins are also well-recognized by consumers as a functional ingredient for “weight management.”
Tea polyphenols, also known as vitaphenols, are polyphenolic compounds primarily composed of catechins, extracted from tea leaves. As an antioxidant food additive, they are permitted for use in over 60 subcategories of food according to GB 2760, including oils, jams, nuts, pastries, meat products, seafood, canned foods, seasonings, beverages, and puffed foods.
Apple polyphenols are mainly derived from apple skins, particularly those of unripe green apples, which are rich in these compounds. The polyphenol content in unripe apples is about ten times that of ripe apples. Apple polyphenols include various phenolic substances such as chlorogenic acid, catechins, epicatechins, apple condensed tannins, phloridzin, phloretin, and anthocyanins.
Grape seeds, a by-product of the wine and juice industries, have a total polyphenol content of 60-70%. The main components include catechins, epicatechins, and proanthocyanidins, with proanthocyanidins (OPC) being the core active ingredient. Grape seed polyphenols are well-recognized in the market and have long been a star ingredient in the oral beauty market.
Lychee polyphenols are a class of polyphenolic compounds extracted from lychees. Various parts of the lychee, such as the flesh, seeds, and peel, contain multiple polyphenolic substances. The main polyphenols in lychee fruit include protocatechuic acid, catechins, chlorogenic acid, caffeic acid, epicatechins, syringic acid, p-coumaric acid, rutin, and ferulic acid.
In addition to the application of single polyphenol ingredients, polyphenol combinations have also become a promising direction for some companies. For example, full-spectrum polyphenol supplements may include pomegranate extract, quercetin, turmeric, bitter orange (fruit), green tea (leaf extract), grape extract (skin and seed), organic blueberry extract, apple extract, aronia berry extract, olive extract (fruit), acai berry (fruit), noni (fruit), alfalfa (whole plant), hawthorn berry powder, and celery extract (seed).
In summary, plant polyphenols, as natural antioxidants, have a wide range of application prospects. Whether it is stevia polyphenols or other polyphenol-rich foods, their applications in the food and health product sectors are continuously expanding, providing more choices for a healthy lifestyle. Natural Field has been deeply involved in the health industry for twenty years, focusing on meeting customers’ health needs. The company not only offers various polyphenol products but also provides one-stop solutions based on customer requirements.
