Physical and chemical properties, antioxidant capacity, and total phenolic content of xyloglucan component in tamarind ( Tamarindus indica ) seed extracted using subcritical water

Abstract

Tamarind kernel powder was utilized as raw material for xyloglucan component extraction. The main aims were to determine the potential of applying subcritical water in xyloglucan component extraction and to investigate effects on yield and properties of extracted xyloglucan components. Ratio of tamarind kernel powder to water for all extractions was 1:20 (w/v) with extraction temperatures of 100–200°C. Extracted xyloglucan component samples were determined for their color, pasting property, viscosity, water absorption index (WAI), water solubility index (WSI), molecular weight, antioxidant capacity, and total phenolic content. It appeared that xyloglucan components extracted by subcritical water, especially in cases where severe conditions were applied, had greater color intensity and WSI than conventional method but less holding strength, setback from trough, final viscosity, WAI, antioxidant capacity, and total phenolic content. Subcritical water extraction at 175°C provided the highest production yield of 62.28% which was remarkably higher than conventional method. Practical applications Tamarind seed, an economic by‐product from the commercial utilization of tamarind fruit and pulp, contains a high proportion of xyloglucan. Xyloglucan in tamarind seeds is deemed as a natural, non‐toxic, and edible polysaccharide. Currently, it is utilized in food industry as a gelling agent due to its gel forming capability over a wide pH range and heat stability. This study demonstrated that the subcritical water extraction technique was an effective method for tamarind seed xyloglucan extraction because it provided apparently higher extraction yield than conventional extraction method. The xyloglucan component powder manufactured in this work can be used as a food additive; however, suitable applications for the xyloglucan component extracted using the subcritical water extraction technique must be considered based on its physical, chemical, and functional properties.

Extraction of xyloglucan from tamarind industrial waste by different methods and their potential application in the food sector

“…The extraction pressure range is 250–500 MPa for 5–15 min. The HPP‐treated mixture is subjected to the same protease enzyme and alcohol precipitation process (Limsangouan et al ., 2019).…”

“…Therefore, enzyme hydrolysis is used in HWE, increasing the yield and purity of obtained XG. Limsangouan et al (2019) reported that XG is extracted from defatted TKP by dissolving in distilled water, boiling, followed by enzyme hydrolysis with protease and then centrifuged, filtered, precipitated with ethanol and dried.…”

“…The properties of subcritical water cause higher yield through the degradation of the primary cell wall in tamarind kernel powder. However, the SWE produced XG in a darker colour, reduced molecular weight, and altered physical, chemical, and antioxidant properties than that produced through other methods (Limsangouan et al ., 2019).…”

Tamarind seed: Composition, applications, and value addition: A comprehensive review

“…Therefore, a novel process, such as subcritical water extraction, is required to upgrade the xyloglucan production process (Limsangouan et al, 2019). Limsangouan et al (2019) used a subcritical water extraction method in xyloglucan production. They reported maximum yield as 62.28% at an extraction temperature of 175°C, which was higher as compared with the methods followed by other researchers.…”

“…and converted into powder.The utilization of boiling for the extraction of xyloglucan has some limitations such as longer extraction time, use of a large amount of solvents, lower extraction yield, and alteration in the properties(Kulkarni et al, 2017). Therefore, a novel process, such as subcritical water extraction, is required to upgrade the xyloglucan production process(Limsangouan et al, 2019). Limsangouan et al (2019) used a subcritical water extraction method in xyloglucan production.…”