Starch Lipids of Barley and Malt

Abstract

Barley and malt starches were compared with respect to their lipid content and composition. The starch lipids were first fractionated into internal and surface lipid fractions followed by lipid class and fatty acid analyses of each fraction. Barley starch contained 13 mg/g lipids, of which 9.3 mg were internal lipids and 3.7 mg were surface lipids. The total lipid content of malt starches varied between 11 and 13 mg/g of starch. However, malt starch contained only 1 mg of surface lipids; therefore, the internal lipid contents were as high as or even higher than those in the corresponding fraction of barley starch. Lipid class analyses suggested that the ability for hydrolysis of starch surface lipids was increased in malt. The hydrolysis occurred during the malting or the isolation process, resulting in reduced surface lipid content in malt starch. However, no reduction in the portion of polyunsaturated fatty acids was seen; therefore, lipid oxidation could not have been responsible for the lower content of malt starch surface lipids. Also, not only was the content of starch internal lipids higher in malt, but the composition of these lipids was different when compared to barley starch. The increase in starch internal lipids during malting may be due to transportation and reacylation of free fatty acids that had been liberated by hydrolysis from surface lipids.

Physicochemical, thermal and rheological properties of starches isolated from malting barley varieties

“…Lipids content in of the analyzed starches ranged between 0.21 (for BS8 starch) and 0.61 (for BS9 starch) g per 100 g of starch dry mass (Table 1). According to Kaukovirta-Norja et al (1997) starch lipids significantly affect water holding capacity of starch and its solubility in water, as well as its pasting temperature. Moreover, Tester (1997) found that lipids content of waxy, normal and highamylose barley starches increased with increase in temperature at which the plant was growing.…”

Neutral lipids in non‐starch lipid and starch lipid extracts from Portuguese sourdough bread

“…Conversely, SL are structurally bound within the starch granules, and can be extracted from flour only upon disruption of said granules. These type of lipids do not appear to significantly affect dough features, so they will have a minor influence upon baking; in fact, they are tightly bound (as inclusion compounds) to amylase, so they will hardly be available for reaction with proteins -at least during dough mixing [2,5,27,28,32]. Moreover, the extent of lipid binding increases throughout dough mixing and baking, so the lipid extractability (and the ratio NSL/SL) tends to change [33].…”

“…The composition in neutral lipids (NL) of cereal extracts is traditionally determined after isolation of lipid classes via TLC, and involves addition of an internal standard to each fraction, trans-esterification of acylglycerols and SE fractions, and quantification of the corresponding fatty acid methyl esters by gas liquid chromatography (GC) [3,23,32,34]. Furthermore, SPE [35] and HPLC [23,[35][36][37][38][39][40][41][42][43][44] have been successfully used for analysis of NL.…”

The influence of non-starch polysaccharide on thermodynamic properties of starches from facultative wheat varieties

“…Particularly potent effectors are lipids that either bind to the surface or are incorporated into amylose-lipid inclusion complexes (AML) [4][5][6][7]. The presence of lipid complexes in starch granules is observed as a hydrophobic nucleus situated within helices formed by amylose chains.…”