Peter de Kok - Academia.edu (original) (raw)

Papers by Peter de Kok

Research paper thumbnail of Flavor Aspects of Pulse Ingredients

Cereal Chemistry Journal

Pulses (Fabaceae) have regained interest for their high protein level. However, food application ... more Pulses (Fabaceae) have regained interest for their high protein level. However, food application of pulses and pulse ingredients is hampered by several issues around their off-flavor. Off-flavors in pulses are partially inherent and partially produced during harvesting, processing, and storage. Generally, volatile off-flavor compounds in pulses belong to the categories of aldehydes, alcohols, ketones, acids, pyrazines, sulfur compounds, and others, and off-taste is strongly correlated to the presence of saponins, phenolic compounds, and sometimes alkaloids. No systematic studies have been performed on the identification of the off-flavor compounds present in pulses in relation to their contribution to the overall perception of the pulses. This review article aims to provide a concise overview highlighting the most important aspects of the knowledge available on the off-flavor compounds present in various pulses, their possible origins, and the technologies available to prevent, reduce, or mask these off-flavor compounds. Rather than attempting to make a full inventory of the literature in the field, this paper addresses the most relevant topics referring to a selected set of relevant papers on each topic to substantiate the observations and conclusions that may guide the reader toward additional literature.

Research paper thumbnail of Regio- and stereo-selective hydride uptake in model systems related to 3-carbamoyl pyridinium compounds

Journal of the Chemical Society, Chemical Communications, 1985

Research paper thumbnail of Molecular mechanics calculation of geometries of NAD+ derivatives, modified in the nicotinamide group, in a ternary complex with horse liver alcohol dehydrogenase

European journal of biochemistry / FEBS, Jan 15, 1988

The geometry of seven NAD+ analogues bound to horse liver alcohol dehydrogenase (LADH) modified o... more The geometry of seven NAD+ analogues bound to horse liver alcohol dehydrogenase (LADH) modified only in their nicotinamide group, have been studied using AMBER molecular mechanics energy-minimization procedures. Starting geometries were taken from X-ray crystallographic data for NAD+/Me2SO/LADH reported by Eklund and co-workers. In this study the NAD+ analogues were encaged by the constituent amino acids of the enzyme within a range of 0.6 nm from the initial NAD+/Me2SO/Zn2+ complex. The calculational method used is able to rationalize individual substituent effects and to evaluate the essential interactions between NAD+ analogue, enzyme, Me2SO and Zn2+ without the necessity of additional X-ray data. The results presented here demonstrate that the reactivity of NAD+ derivatives as reported in literature can be qualitatively related to the position of the pyridine moiety in the active site.

Research paper thumbnail of Flavor Aspects of Pulse Ingredients

Cereal Chemistry Journal

Pulses (Fabaceae) have regained interest for their high protein level. However, food application ... more Pulses (Fabaceae) have regained interest for their high protein level. However, food application of pulses and pulse ingredients is hampered by several issues around their off-flavor. Off-flavors in pulses are partially inherent and partially produced during harvesting, processing, and storage. Generally, volatile off-flavor compounds in pulses belong to the categories of aldehydes, alcohols, ketones, acids, pyrazines, sulfur compounds, and others, and off-taste is strongly correlated to the presence of saponins, phenolic compounds, and sometimes alkaloids. No systematic studies have been performed on the identification of the off-flavor compounds present in pulses in relation to their contribution to the overall perception of the pulses. This review article aims to provide a concise overview highlighting the most important aspects of the knowledge available on the off-flavor compounds present in various pulses, their possible origins, and the technologies available to prevent, reduce, or mask these off-flavor compounds. Rather than attempting to make a full inventory of the literature in the field, this paper addresses the most relevant topics referring to a selected set of relevant papers on each topic to substantiate the observations and conclusions that may guide the reader toward additional literature.

Research paper thumbnail of Regio- and stereo-selective hydride uptake in model systems related to 3-carbamoyl pyridinium compounds

Journal of the Chemical Society, Chemical Communications, 1985

Research paper thumbnail of Molecular mechanics calculation of geometries of NAD+ derivatives, modified in the nicotinamide group, in a ternary complex with horse liver alcohol dehydrogenase

European journal of biochemistry / FEBS, Jan 15, 1988

The geometry of seven NAD+ analogues bound to horse liver alcohol dehydrogenase (LADH) modified o... more The geometry of seven NAD+ analogues bound to horse liver alcohol dehydrogenase (LADH) modified only in their nicotinamide group, have been studied using AMBER molecular mechanics energy-minimization procedures. Starting geometries were taken from X-ray crystallographic data for NAD+/Me2SO/LADH reported by Eklund and co-workers. In this study the NAD+ analogues were encaged by the constituent amino acids of the enzyme within a range of 0.6 nm from the initial NAD+/Me2SO/Zn2+ complex. The calculational method used is able to rationalize individual substituent effects and to evaluate the essential interactions between NAD+ analogue, enzyme, Me2SO and Zn2+ without the necessity of additional X-ray data. The results presented here demonstrate that the reactivity of NAD+ derivatives as reported in literature can be qualitatively related to the position of the pyridine moiety in the active site.