The BACIS Archives

[ BNB - 96121 ]

• Book discussion: "The Maillard Reaction"

INTRODUCTION

BACIS read for you The Maillard Reaction. Consequences for the Chemical and Life Sciences, edited by Raphael Ikan and published by John Wiley & Sons, Chichester (1996). We find this a valuable book for every scientist working in flavour chemistry.
The advertisement for and the blurb of this book read as follows (emphasis by BACIS):

The Maillard Reaction was first observed by Louis-Camille Maillard and describes a reaction between proteins and carbohydrates. In food, the Maillard Reaction is responsible for changes in the flavour, colour, nutritive value and the formation of mutagenic compounds. The Maillard Reaction has also been detected in mammalian organisms.
This book presents the latest advances and technologies in a series of reviews on topics including the impact of the Maillard Reaction on aging, its generation of aromas, geochemical aspects, anti-carcinogenic effects, microwave induced reactions and the biological recognition of its products.

It is a pity that a good book is advertised in such a contradictory and controversial way. Is it true that on the one hand the Maillard Reaction is responsible for the formation of mutagenic compounds and that, on the other hand, it has impact on anti-carcinogenic effects ? To the best of our knowlegde mutagenic compounds can have carcinogenic effects and carcinogenic compounds all have mutagenic effects.

DISCUSSION

We found the most excellent chapters in the book the two following:

Thermal Generation of Maillard Aromas, by Chi-tang Ho; 26 pages with 75 references.
This chapter is a must for every organic chemist working in aroma research.

Genotoxicity of Maillard Reaction Products, by Jon W. Wong and Takayuki Shibamoto; 30 pages with 102 references.
This chapter is not only very interesting for people working in flavour chemistry but also for the toxicologist in general. The authors demonstrate in a table 22 studies between 1979 and 1995 about Maillard model systems used to study mutagenicity. Of these 22 studies 18 dealt with the formation of mutagenic compounds and only four studies discussed no mutagenicity and anti-mutagenic effects.
It seems worthwile to cite here the final conclusion of Wong and Shibamoto:

The Maillard reaction is responsible for the formation of mutagenic compounds formed in several degradation pathways or by Maillard intermediates combining with other chemical constituents in foods. The diversity of the mutagens ranges from simple dicarbonyl compounds and heterocyclic volatiles to heterocyclic aromatic amines. The advanced analytical developments and genotoxic testing techniques used to identify and quantify such compounds in foods and to assess their mutagenicity have provided information to establish relationships between dietary intake and carcinogenesis. Research in these areas is improving and continues to be assessed.

In the index of the book we find anti-carcinogens cited only once (p. 106) and carcinogens three times (pp. 131, 140, 176), while an important part on carcinogenesis on page 153 is not in the index and also the word-combination of mutagenic and cancer occurs more often in the book than the index suggests.

CONCLUSION

The Maillard Reaction is a must for every food scientist. The advertisement for the book, however, is misleading. During the Maillard or non-enzymatic browning reaction in food, mutagenic compounds are formed and these compounds can be carcinogenic.