Comparative study of some analytical methods to quantify lignin concentration in tropical grasses

Autor(es)

Velasquez, Alejandro V. ^[1] ; Martins, Cristian M. M. R. ^[1] ; Pacheco, Pedro ^[1] ; Fukushima, Romualdo S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Nutr & Prod Anim, Fac Med Vet & Zootecnia, Ave Duque Caxias, 225, BR-13630900 Pirassununga, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES; v. 32, n. 11, p. 1686-1694, NOV 2019.
• Citações Web of Science: 0

Resumo

Objective: Lignin plays a relevant role in the inhibition of cell wall (CW) structural carbohydrate degradation. Thus, obtaining accurate estimates of the lignin content in tropical plants is important in order to properly characterize the mechanism of lignin action on CW degradation. Comparing conflicting results between the different methods available for commercial use will bring insight on the subject. This way, providing data to better understand the relationship between lignin concentration and implications with tropical forage degradation. Methods: Five grass species, Brachiaria brizantha cv Marandu, Brachiaria brizantha cv Xaraes (MG-5), Panicum maximum cv Mombaca, Pennisetum purpureum cv Cameroon, and Pennisetum purpureum cv Napier, were harvested at five maturity stages. Acid detergent lignin (ADL), Klason lignin (KL), acetyl bromide lignin (ABL), and permanganate lignin (PerL) were measured on all species. Lignin concentration was correlated with in vitro degradability. Results: Highly significant effects for maturity, lignin method and their interaction on lignin content were observed. The ADL, KL and ABL methods had similar negative correlations with degradability. The PerL method failed to reliably estimate the degradability of tropical grasses, possibly due to interference of other substances potentially soluble in the KMnO4 solution. Conclusion: ADL and KL methods use strong acid (H2SO4) and require determination of ash and N content in the lignin residues, therefore, increasing time and cost of analysis. The ABL method has no need for such corrections and is a fast and a convenient method for determination of total lignin content in plants, thus, it may be a good option for routine laboratory analysis. (AU)

• Processo FAPESP: 13/07430-0 - Estudos objetivando aperfeiçoar o método lignina brometo de acetila na quantificação do teor de lignina em plantas forrageiras tropicais
• Beneficiário: Romualdo Shigueo Fukushima
• Modalidade de apoio: Auxílio à Pesquisa - Regular