The Chemical, Structural, and Biological Properties of Crude Polysaccharides from Sweet Tea (Lithocarpus litseifolius (Hance) Chun) Based on Different Extraction Technologies

Abstract

Eight extraction technologies were used to extract sweet tea (Lithocarpus litseifolius (Hance) Chun) crude polysaccharides (STPs), and their chemical, structural, and biological properties were studied and compared. Results revealed that the compositions, structures, and biological properties of STPs varied dependent on different extraction technologies. Protein-bound polysaccharides and some hemicellulose could be extracted from sweet tea with diluted alkali solution. STPs extracted by deep-eutectic solvents and diluted alkali solution exhibited the most favorable biological properties. Moreover, according to the heat map, total phenolic content was most strongly correlated with biological properties, indicating that the presence of phenolic compounds in STPs might be the main contributor to their biological properties. To the best of our knowledge, this study reports the chemical, structural, and biological properties of STPs, and the results contribute to understanding the relationship between the chemical composition and biological properties of STPs.

Microwave-Assisted Deep Eutectic Solvent Extraction, Structural Characteristics, and Biological Functions of Polysaccharides from Sweet Tea (Lithocarpus litseifolius) Leaves

“…The leaf of sweet tea has been approved as a new food material by the National Health and Family Planning Commission of China, which has also been utilized as an herbal tea to prevent and manage diabetes in the folk for a long history [ 1 , 2 ]. Generally, the leaf of sweet tea is rich in active ingredients, such as polysaccharides, flavonoids, phenolic acids, and triterpenoids [ 1 , 3 , 4 , 5 , 6 , 7 , 8 ]. Therefore, owing to these bioactive ingredients, it possesses multiple health benefits, such as antioxidant, anti-inflammatory, anti-diabetic, anti-cancer, anti-hypertensive, anti-microbial, cardioprotective, and hepatoprotective effects [ 1 ].…”

“…A large number of studies have shown that natural polysaccharides from edible and medicinal plants possess a variety of biological activities [ 9 , 10 , 11 , 12 ], which have attracted increasing attention in the functional food industry. However, the knowledge about the chemical structures and biological functions of sweet tea polysaccharides is still limited [ 5 ], which requires to be deeply investigated so as to promote its applications in the functional food industry.…”

“…A recent study has indicated that polysaccharides extracted from sweet tea leaves by microwave-assisted deep eutectic solvent extraction (MDAE) possess favorable biological activities [ 5 ]. Therefore, in order to further promote the potential applicability of MDAE for extracting bioactive polysaccharides from sweet tea leaves, the extraction conditions of MDAE were carefully optimized by using Box-Behnken Design in the present study.…”

Phenolic Content, Main Flavonoids, and Antioxidant Capacity of Instant Sweet Tea (Lithocarpus litseifolius [Hance] Chun) Prepared with Different Raw Materials and Drying Methods

“…Lithocarpus litseifolius [Hance] Chun, also popularly called "sweet tea", is a herbal plant with an evident sweet taste that has been accepted as a daily beverage in the south of China for more than 1000 years, and was approved as a new food material in China in 2017 [1,2]. The major bioactive components in sweet tea include flavonoids and polysaccharides; dihydrochalcones are the main flavonoids [3,4]. Until now, many health benefits have been reported of sweet tea, such as antioxidant, antihypertensive, antihyperlipidemic, antihyperglycemic, anti-inflammatory, antimicrobial, and anticancer effects [1,5].…”

Rapid monitoring of flavonoid content in sweet tea (Lithocarpus litseifolius (Hance) Chun) leaves using NIR spectroscopy

“…Lithocarpus litseifolius (Hance) Chun, which has abundant wild resources in the mountainous region of southern China, is commonly named as “sweet tea” [ 36 ]. Sweet tea has been listed as a new food resource by the National Health and Family Planning Commission of China since 2017 [ 9 ]. Its leaves, which function as tea, sugar and medicine, have been used as a traditional herbal medicine and tea, and it has the potential to become a functional food and food additive [ 26 ].…”