Analysis of the Barley Malt Rootlet Proteome.

Ramamurthy Mahalingam

doi:10.3390/ijms21010179

Abstract

Barley seeds are one of the main ingredients of the malting industry for brewing beer. The barley rootlets that are separated from the kilned seeds at the end of the malting process and used as animal feed are one of the byproducts of this industry. In this study, the proteome of rootlets derived from two stages of the malting process, germination and kilning, from a popular malting barley variety were analyzed. A label-free shotgun proteomics strategy was used to identify more than 800 proteins from the barley rootlets. A high coverage and high confidence Gene Ontology annotations of the barley genome was used to facilitate the functional annotation of the proteins that were identified in the rootlets. An analysis of these proteins using Kellogg Encyclopedia of Genes and Genomes (KEGG) and Plant Reactome databases indicated the enrichment of pathways associated with phytohormones, protein biosynthesis, secondary metabolism, and antioxidants. Increased levels of jasmonic acid and auxin in the rootlets further supported the in silico analysis. As a rich source of proteins and amino acids use of these by-products of the malting industry for animal feed is validated. This study also indicates rootlets as a potential source of naturally occurring phenylpropanoids and antioxidants that can be further exploited in the development of functional foods.

Highlights

Barley (Hordeum vulgare L.) is the fourth-largest cereal cultivated around the world
This study indicates rootlets as a potential source of naturally occurring phenylpropanoids and antioxidants that can be further exploited in the development of functional foods
Malt rootlets, called as chits, are germs that appear during the malting process of barley, which are separated before the brewing process and are used as a byproduct for animal feed

Summary

Introduction

Barley (Hordeum vulgare L.) is the fourth-largest cereal cultivated around the world. Barley is used for feed and in the malting industry. In the United States of America (USA), a significant part of harvested barley is used for malt and beer production. The barley malting process involves three consecutive stages—steeping, germination, and kilning, which have been described in detail [1]. Temporal proteome analyses of the seeds from these different stages have been reported earlier [2]. Malt rootlets, called as chits, are germs that appear during the malting process of barley, which are separated before the brewing process and are used as a byproduct for animal feed

Methods

Results

Conclusion