Preparation, characterisation and antioxidant activities of litchi (Litchi chinensis Sonn.) polysaccharides extracted by ultra‐high pressure

Abstract

Summary Litchi (Litchi chinensis Sonn.) is a fruit containing many nutrients. Based on a three level, three‐variable Box‐Behnken design, response surface methodology, was used to optimise the process of ultra‐high pressure (UHP) assisted extraction of litchi polysaccharides (LCP). The optimal extraction conditions were as follows: pressure 460 MPa, treatment time 17 min and liquid–solid ratio 15. The experimental yield for extracting LCP was 12.01% under the optimal conditions. The LCP had a high polysaccharide and low protein content. GC results showed that LCP was composed of rhamnose, fucose, mannose and galactose with the corresponding molar percentages of 7.89, 46.45, 9.71 and 19.63. Infrared analysis showed that LCP had a typical spectrum of an α‐configuration pyranose ring. Antioxidant activity analysis revealed that LCP possessed a strong reducing power and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging activity and could protect against the damage of hydroxyl radicals. The investigations demonstrated that UHP could be a valuable way to separate polysaccharides from litchi pulp, and LCP may be potentially developed to an antioxidant for food industries.

Extraction optimization and antioxidant activity of Phyllanthus urinaria polysaccharides

“…According to the slopes of the regression equations, it can be calculated that the RP and TAOC of the polysaccharides were equivalent to 93.62% and 93.55% of TBHQ, respectively. Compared with other polysaccharides, the RP of Phyllanthus urinaria polysaccharides (absorption of 0.463 at 95 μg/mL) was higher than that of litchi polysaccharides (absorption of 0.320 at 1000 μg/mL) (Gao et al, 2017) and polysaccharides from tobacco waste (absorption of 0.377 at 1000 μg/mL) (Jing et al, 2016); meanwhile, the TAOC of Phyllanthus urinaria polysaccharides (absorption of 0.451 at 115 μg/mL) was higher than that of Trapa quadrispinosa polysaccharides (absorption of 0.510 at 400 μg/mL) (Raza et al 2017).…”

Structural characterisation and immunomodulatory effects of polysaccharides isolated from Dendrobium aphyllum

“…There are many advantageous properties of polysaccharides, including nontoxicity, lack of side effects, improvement of immunity and antitumour, antidiabetic, hypolipidemic and antioxidant properties Yao et al, 2017). As polysaccharides are safe as functional food sources and have become more popular in recent years, it is important to conduct a value-oriented inquiry about D. aphyllum polysaccharides (Gao et al, 2017;Wee et al, 2017).…”

Pericarp and seed of litchi and longan fruits: constituent, extraction, bioactive activity, and potential utilization

“…The Smith degradation analysis identified 8.7% (1→2)-glycosidic linkages, 83.3% (1→3)-glycosidic linkages, and 8.0% (1→6)-glycosidic linkages in the polysaccharides. Biological analysis indicated that these various polysaccharide fractions from litchi fruit pericarp tissues exhibited strong antioxidant ability and anti-glycated activity (Yang et al, 2006(Yang et al, , 2009aGao et al, 2017), suggesting that litchi polysaccharides could be explored as a new and potential alternative antioxidant.…”

“…Recently, application of green technology, such as ultrasonic extraction and high-pressure extraction, has been reported for extraction of bioactive constituents from various litchi and longan fruit tissues (Prasad et al, 2009b(Prasad et al, , 2009c(Prasad et al, , 2010a(Prasad et al, , 2010bYang et al, 2009c). Prasad et al (2009b) and Gao et al (2017) reported that application of high-pressure extraction had higher extraction efficiency in terms of extraction yield, compound content, and antioxidant activity from litchi and longan pericarps and seeds, compared with the conventional and ultrasonic extraction. Furthermore, Zhang RF et al (2017) have optimized the ultra-high pressure assisted extraction procedures of procyanidins from litchi pericarps, which greatly increased the extraction yield and bioactive activity of the extract.…”