Study of the role of sugar fatty esters in explaining differences in the malt composition of barley analysed using vibrational spectroscopy and chemometrics

Abstract

Extensive research has been conducted for understanding starch structure and composition in relation to grain composition and quality. However, less effort has been dedicated to studying the main role of other non-structural carbohydrates and their interactions with other molecules such as glycolipids and lipopolysaccharides. The formation of complexes between amylose and lipids has also been highlighted, indicating that these complexes can modulate the different biochemical, chemical and physical properties of different cereal grains. Recent studies also suggested that other sugars (e.g., sucrose) can be associated with lipids in the form of lipopolysaccharides, glycol-glycerolipids or sugar esters having an important role in food properties (e.g. gelatinization of starch, formation of emulsions). The aim of this study was to investigate the presence of sugar fatty esters in barley malt using mid-infrared (MIR) spectroscopy. The results from this study indicated the existence of correlations between the area in the MIR related to esters (1800-1600 cm À1 ) and malt extract, showing statistically significant (p < 0.05) correlations (R 2 ¼ 0.36) in barley varieties that yield high malt extract (>83%). The results of this study also indicated that sugar fatty esters or esters might play a role in explaining differences in malt composition between different barley varieties. Fig. 2 Second derivative of the mid-infrared spectra of the creamy layer in each of the barley samples analysed. Panel A: fingerprint range (700-1800 cm À1 ); Panel B: carbonyl ester regions (1700-1760 cm À1 ). 6154 | Anal. Methods, 2015, 7, 6152-6157 This journal is

Mid-Infrared Spectroscopy as a Rapid Tool to Qualitatively Predict the Effects of Species, Regions and Roasting on the Nutritional Composition of Australian Acacia Seed Species

“…The ATR-MIR spectra and the relevant MIR features found in the set of AS samples analyzed are presented in Figure 1 . The MIR spectra of the samples displayed frequencies in the MIR spectra range related to structural and non-structural carbohydrate (900 to 1240 cm −1 ), proteins (1500 to 1700 cm −1 ), and lipids (2800 to 2950 cm −1 ) [ 18 , 22 , 23 , 24 , 25 ]. The MIR band region around 1744 cm −1 was reported to be associated with phosphodiesters [ 18 , 23 , 24 , 26 ].…”

“…The MIR spectra of the samples displayed frequencies in the MIR spectra range related to structural and non-structural carbohydrate (900 to 1240 cm −1 ), proteins (1500 to 1700 cm −1 ), and lipids (2800 to 2950 cm −1 ) [ 18 , 22 , 23 , 24 , 25 ]. The MIR band region around 1744 cm −1 was reported to be associated with phosphodiesters [ 18 , 23 , 24 , 26 ]. In addition, the region between 900 and 1500 cm −1 is characterized by the presence of bands derived from the aromatic O-H bend, the aromatic C-H in plane bend, and the C-O stretch of phenolic compounds [ 27 , 28 ].…”

“…In addition, the region between 900 and 1500 cm −1 is characterized by the presence of bands derived from the aromatic O-H bend, the aromatic C-H in plane bend, and the C-O stretch of phenolic compounds [ 27 , 28 ]. Moreover, the MIR spectra showed specific peaks associated with amide-I (C-O stretch, C-N stretch) around 1641 cm −1 and with starch around 1045 cm −1 , or lipids and fatty acids (aliphatic CH 2 groups) at 2852 and 2926 cm −1 [ 18 , 22 , 23 , 24 , 25 , 29 ].…”