Effects of high-intensity ultrasound and oil type on the Maillard reaction of d-glucose and glycine in oil-in-water systems

Hang Yu,Weibiao Zhou,Peter K C Ong,Yi-Xin Seow

doi:10.1038/s41538-017-0010-4

Hang Yu, Weibiao Zhou + Show 2 more

Open Access

https://doi.org/10.1038/s41538-017-0010-4

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Abstract

This study addresses the effect of high-intensity ultrasonic processing on four oil-in-water systems, using sunflower, peanut, olive and flaxseed oils, respectively, that contained an aqueous d-glucose and glycine Maillard reaction (MR) model system. The MR in the water phase was promoted as observed from higher depletion of reactants and higher amount of MR products (MRPs). A significantly higher amount of pyrazines was generated after ultrasonic processing, particularly in the sunflower and olive oil systems. These promotions were attributed to a well-mixing effect and a localised high temperature and pressure environment generated by the high-intensity ultrasound. However, upon 1 h of ultrasonic processing at 80 °C, a significant increase of oxidation was observed with high peroxide and p-anisidine values in the post-processed oils; meanwhile, the amount of unsaturated fatty acids decreased as well. As a result, some off-flavours were also detected in the post-processed oils, which affected the overall flavour profile of the MR systems.

Highlights

During food processing with heat, amino acids, peptides and some proteins are capable of reacting with reducing sugars to generate various coloured and odour-active compounds; this reaction has been named as Maillard reaction (MR)
Negroni et al.[10] studied xylose–lysine and glucose–lysine MR model systems in the presence of three oils, i.e., olive, canola and sunflower oils, and indicated that unsubstituted pyrazines were largely formed with olive oil, less with canola oil, and even less with sunflower oil
The iodine value (IV) of oil phase was significantly decreased compared with the raw oil, for all the types of oil except sunflower oil, for which no significant difference was observed between the raw and processed oils

Summary

Introduction

During food processing with heat, amino acids, peptides and some proteins are capable of reacting with reducing sugars to generate various coloured and odour-active compounds; this reaction has been named as Maillard reaction (MR). It is necessary to study the MR in the presence of oils to elucidate the relationship between the MR and lipid degradation in food systems as a result of processing.[1]. Recent studies showed that a number of MRs in model systems were promoted by high-intensity ultrasound in sample solutions.[4,5] Yu et al.[6] reported that the generation of flavour compounds was promoted by ultrasound with an intensity of 11.90 W cm−2 in a MR model system of Dglucose and L-serine. Studies of xylose–lysine, xylose–cysteine and glucose–methionine model systems supported such a finding.[7,8,9] high-intensity ultrasonic processing is a promising technology to promote the MRs. Different types of oil in oil-in-water MR systems would impact on final flavour profile. The reaction speed of the MR would be potentially accelerated due to the continuous removal of final MRPs from the water phase where the MR happens the most

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