Reduction of Off‐Flavor Generation in Soybean Homogenates: A Mathematical Model

Abstract

The generation of off-flavors in soybean homogenates such as n-hexanal via the lipoxygenase (LOX) pathway can be a problem in the processed food industry. Previous studies have examined the effect of using soybean varieties missing one or more of the 3 LOX isozymes on n-hexanal generation. A dynamic mathematical model of the soybean LOX pathway using ordinary differential equations was constructed using parameters estimated from existing data with the aim of predicting how n-hexanal generation could be reduced. Time-course simulations of LOX-null beans were run and compared with experimental results. Model L2, L3, and L12 beans were within the range relative to the wild type found experimentally, with L13 and L23 beans close to the experimental range. Model L1 beans produced much more n-hexanal relative to the wild type than those in experiments. Sensitivity analysis indicates that reducing the estimated Km parameter for LOX isozyme 3 (L-3) would improve the fit between model predictions and experimental results found in the literature. The model also predicts that increasing L-3 or reducing L-2 levels within beans may reduce n-hexanal generation.Practical Application: This work describes the use of mathematics to attempt to quantify the enzyme-catalyzed conversions of compounds in soybean homogenates into undesirable flavors, primarily from the compound n-hexanal. The effect of different soybean genotypes and enzyme kinetic constants was also studied, leading to recommendations on which combinations might minimize off-flavor levels and what further work might be carried out to substantiate these conclusions.

Response Surface Analysis for Acceptability Assessment of Micronutrient Fortified Un-Stabilized Soymilk from Sprouted Soybeans

“…Bibliography sponsible for spoilage [1,3]. Also dehulling may have removed offflavour [31] associated with soymilk from underholed beans. The choice of using unsaturated soybean oil in the fortification may have contributed to the desirable flavour and good mouth feel [3] thereby increased acceptability.…”

Recombinant Lipoxygenases and Hydroperoxide Lyases for the Synthesis of Green Leaf Volatiles

“…2 Notably, aldehydes (hexanal and nonenal) and ketones have also been reported to be responsible for off-flavor in stored soybeans, and thus, soybean breeds deficient in LOX genes have been studied to reduce the off-flavors associated with LOX activity. 366,367 4.1. Recombinant LOXs and HPLs for the Production of GLVs.…”

The kinetics of thermal generation of flavour

“…Just one interesting examples is given. Mellor used mathematics to model the generation of hexanal from the lipoxygenase pathway in soybeans and demonstrated which soybean genotypes to select in order to minimise off‐flavours.…”