Characterization of Asparagus Lignin by HPLC

Abstract

Lignin is the cell wall component most frequently associated with hardening. Its characterization and quantification are very important to understand the biochemical modifications related to the changes in texture of vegetables such as asparagus (Asparagus officinalis), in which this organoleptic attribute is a very important quality factor. In this study, asparagus lignin from the basal sections of fresh and stored spears was analyzed using 2 methods, the traditional (Klason lignin) and the recently developed derivatization, followed by reductive cleavage (DFRC) method. The latter is a simple and reproducible technique for lignin characterization based on a degradation procedure that produces analyzable monomers and dimers by cleaving alpha- and beta-aryl ethers in lignins. The primary monomers derived from DFRC degradation of lignins are essentially p-coumaryl peracetate, coniferyl peracetate, and sinapyl peracetate. To evaluate the efficiency of the DFRC method, our investigations have been carried on distinct sample types, including wood (data not shown), straw, and asparagus samples. The results have confirmed that lignin composition is affected by plant nature. It has been found that whereas wood samples mostly contain coniferyl units, plant foods, such as straw and asparagus, contain both coniferyl and guaiacyl units.

Green and White Asparagus (Asparagus officinalis): A Source of Developmental, Chemical and Urinary Intrigue

“…In white asparagus, so far the focus has been on the total phenolic content [96] and specifically, ferulic acid derivatives [65,102]. Here, it was shown that an increased level of ferulic acids is associated with post-harvest spear hardening [65], and that post-harvest storage temperature plays an important role in cell wall hardening [4,6,102,103].…”

“…Harvesting has a direct impact on the metabolism of plant materials, as it can lead to the activation of plant defence and stress mechanisms and eventually senescence and decay, leading to the production of several protective secondary (volatile and non-volatile) metabolites and proteins [101]. The impact of cultivation conditions, harvesting and storage of asparagus on its antioxidant capacity have been thoroughly examined [14,64,65,96,102,103]. In white asparagus, so far the focus has been on the total phenolic content [96] and specifically, ferulic acid derivatives [65,102].…”

Differences in the Structural Chemical Composition of the Primary Xylem of Cactaceae: A Topochemical Perspective

“…The estimation of lignin composition has been made through different methods: pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) (Klap et al, 2000), nuclear magnetic resonance (NMR) (Jin et al, 2007; Weng et al, 2010; Marques et al, 2016; Reyes-Rivera et al, 2018), Fourier transform infrared (FTIR) (Li et al, 2015; Reyes-Rivera et al, 2015; Reyes-Rivera et al, 2018), and high-performance liquid chromatography (HPLC) (Jaramillo-Carmona et al, 2008; Kline et al, 2010; Reyes-Rivera et al, 2015). For this reason, in this paper, Klason lignin is used directly to perform infrared (FTIR) spectrum readings, due to Reyes-Rivera et al (2018) finding consistent values when comparing these with other methods such as Py-GC/MS and NMR.…”

Combined application of wounding stress and extrusion as an innovative tool to obtain carrot powders with modified functional properties

“…Regarding the effect of extrusion processing on lignin content, an increase (35.32%) was detected only in CC extruded at 100°C with the expansion screw configuration ( Table 2). The cross-linked structure of lignin polymers makes it a highly insoluble material, where small fractions are solubilized by chemical treatments (Jaramillo-Carmona et al 2008). In the case of WSC samples, extrusion did not affect the content of soluble lignin.…”