Physicochemical, Rheological, Structural, Antioxidant, and Antimicrobial Properties of Polysaccharides Extracted from Tamarind Seeds

Abstract

In this study, the polysaccharides were firstly extracted from the tamarind seeds in which the crude polysaccharides have been extracted once by hot water extraction. The structure was characterized by FTIR, SEM, and X-ray diffraction after removing protein and small molecule impurities. Furthermore, the rheological and bioactivity of tamarind seed polysaccharides (TSP) were also investigated. The results indicated that the yield of the obtained polysaccharide was 3.42%. TSP was mainly composed of glucose (45.09%), galactose (22.80%), and xylose (28.89%), while it contained characteristic structure of polysaccharides, such as –OH, pyranose, and uronic acid at 3,418, 1,150, and 1,040 cm−1 respectively, which demonstrated that it was a uronic acid heteropolysaccharide. Moreover, the XRD pattern revealed the amorphous behavior of TSP, and it was found to consist of films or “sheets” reflected by SEM. The flow behavior testing confirmed its pseudoplastic character, and the flow behavior index (n) was between 0.4539 and 0.9201. The DPPH radical scavenging activity of TSP was 40.34% at 10 mg/mL. Furthermore, TSP displayed moderate hydroxyl radical scavenging and anti-bacterial activities, owing to its special structure and composition. Overall, our results suggested that TSP could be used as a food ingredient with anti-oxidative and antibacterial activities, which provides useful information on the potential utilization of TSP in the food industry.

Characterization and Antioxidant and Antibacterial Activities of Carboxymethylated Tamarind Seed Polysaccharide Composite Films Incorporated with ε-Polylysine and Their Application in Fresh-Cut Green Bell Pepper Preservation

“…As shown in Figure a, the control group exhibited a significant scavenging effect on the DPPH experiment with a free-radical clearance ability of 78.02%. Previous studies by Ren et al have reported the excellent antioxidant properties of TSPs . After modification, CTP still maintains considerable antioxidant activity.…”

“…The XRD pattern of the composite film is depicted in Figure b. A distinct diffraction peak is observed for the CTP membrane at 2θ = 20.34, indicating that CTP exhibits characteristics of a semicrystalline or semicrystalline polymer . Upon addition of ε-PL, the crystalline diffraction peak shifts to 19.34°.…”

“…Previous studies by Ren et al have reported the excellent antioxidant properties of TSPs. 4 After modification, CTP still maintains considerable antioxidant activity. However, the addition of different concentrations of ε-PL did not lead to a significant improvement in the free-radical clearance ability.…”

“…This not only results in a waste of resources but also has negative environmental impacts. 4 Thus, recycling tamarind seeds helps to improve the sustainability of the food industry and reduce environmental pollution. Tamarind seed polysaccharide (TSP) is a neutral polysaccharide isolated from the seed endosperm of tamarind.…”

“…However, the seeds are discarded as a byproduct. This not only results in a waste of resources but also has negative environmental impacts . Thus, recycling tamarind seeds helps to improve the sustainability of the food industry and reduce environmental pollution.…”