Release of Bound Lipids in Cereal Starches Upon Hydrolysis by Glucoamylase

Abstract

Cereal Chem. 74(1):1-6The raw starch granules from corn, rice, and wheat were hydrolyzed by practically pure glucoamylase (Rhizopus niveus). The bound lipids remaining in the residual starches were investigated, of which the major components of the lipids, free fatty acids (FFA) in corn starch, FFA and phospholipids (PL) in rice starch, and PL in wheat starch were determined. In each case, the bound FFA and PL were decreased to some extent during the initial stage of hydrolysis. During the later stages, the FFA continued to gradually decrease, while the level of PL stabilized. It was interesting that some of the bound lipids were released from the granules upon glucoamylase hydrolysis, differing from the model amylose-lipid complexes. Furthermore, the structures of the residual starches were investigated. The blue value and λ max of the starches were increased by partial hydrolysis of the starch granules using practically pure glucoamylase. Two gel-permeation chromatography analyses revealed that the relative amount of amylose fraction was increased by glucoamylase hydrolysis, and also that the increments were reduced by the defatting of bound lipids. The results suggest that the increase in amylose fraction is attributable to the existence of bound lipids in the granules.

Effect of temperature, moisture and lipid content on the rheological properties of rice flour

“…Corn oil was used because of the affinity between this product and the lipids found in rice. Kitahara, Tanaka, Suganuma, and Nagahama (1997) determined that the majority of fatty acids found in corn are present in rice in similar quantities, i.e., linoleic, palmitic and oleic. The importance of the type of fatty acids added lies in the fact that they affect the formation of the amilose-lipid complexes, which in turn influence the viscosity of RF (Zhou, Robards, Helliwell, & Blanchard, 2002).…”

Effect of the addition of fatty acids on rice starch properties

“…For example, complexation impacts on the formation of resistant starch (Kitahara, Suganuma, & Nagahama, 1996;Kitahara, Tanaka, Suganuma, & Nagahama, 1997) and yields of resistant starch (Mangala, Udayasankar, & Tharanathan, 1999) were increased significantly by the removal of lipids from rice starch. Complexes formed between amylose and long-chain, saturated monoglycerides were generally more resistant to in vitro digestion than complexes with shorter chains or more unsaturated monoglycerides (Guraya, Kadan, & Champagne, 1997).…”

Fatty Acids and Bioactive Lipids of Potato Cultivars: An Overview

“…Their presence and interaction within starch granules strongly influence starch behavior towards gelatinization, retrogradation, swelling, viscosity and leaching of soluble carbohydrates during different technological processing i.e. cooking, baking and extrusion 17,18 .…”