The promotional thrust in India of a particular product which is globally marketed, reads some thing like this: "consumption of this product makes children taller, stronger, sharper than other kids". Interestingly the promoters roped in some professionals in the ads to make the claim all the more convincing. What is this product? A distinct category of beverages popular in India under the category ' Malted Milk' containing malt extract and milk solids. It also claims A-Z nutrition to pre-school children guaranteeing 100% of daily needs of 'key' nutrients, promoting sleep if consumed at bed time and increased growth and alertness amongst children. While in India such claims go unchallenged, UK Authorities have termed these claims as 'unsubstantiated'!
No doubt the combination of malt and milk can be a good base for an attractive product with high sensory quality. Malted milk was originally developed in 1873 by a UK entrepreneur, after shifting to America, by name James Horlick and the product was patented in 1883. Originally marketed under the name 'Diastoid', it was later branded as 'Malted Milk'. There are many variants of malted milk and generally they contain about 7% fat, 70% carbohydrates ( starch and sugars), 12% proteins and other ingredients. The process of manufacture involves blending of milk, malt extract and sugar, drying the blend under vacuum and milling to desired particle size. Some use spray drying also. The malt extract used is not an active malt preparation with diastatic activity but made from roasted malted cereals by extraction and vacuum concentration into 78%-80% solids thick syrup. It contains about 1-3% fructose, 30-42% maltose, 15% maltotriose, 7-10% glucose and rest higher saccharides, all of them reducing sugars. The typical flavor associated with malt extract is due to aldehydes and pyrazines generated during roasting of the malt before extraction.
Coming to the nutrition part, any food scientist worth his salt knows that malt extract owes its color to Maillard reaction, first discovered by the French Biochemist Louis-Camille Maillard, that is triggered by presence of reducing sugars and amino acids present in proteins at temperatures of 235C-255C that exists in the kilns used for roasting. But even at lower temperatures like ambient conditions the reaction takes place, albeit slowly. For every 10C rise in temperature, the reaction rate increases 2-3 times. When such a material like malt extract and milk are mixed and heated even at lower temperatures, the Maillard reaction is bound to be accelerated. What are the consequences of Maillard reaction on the nutrition of a product like Malted Milk?
Protein-reducing sugar reaction generally contributes to deterioration and loss of nutritional value of proteins during processing and storage, a fact well known to food scientists. More disturbing is the reported involvement of Maillard reaction products causing chemical aging of long-lived proteins in human tissues. Products of sequential glycation and oxidation of proteins, known as glycoxidation products accumulate in these long-lived proteins with advancing age and at an accelerated rate in diabetes. The precise implication of these artifacts on the health of consumers is still not well understood, raising uncertainties regarding their real nutritive impact. Reduced availability of Lysine and some of the essential amino acids and formation of inhibitory chemicals or anti-nutritional compounds during processing and storage may be of real concern when any judgment is made regarding the relevance of malted milk products as a regular item of consumption in the diet. Probably milk consumed alone may be more nutritious than the so called malted milk. Viewed in this context the health claims by the malted milk industry are not vindicated by science and hence will remain unsubstantiated unless such claims are validated by studies as per international protocols.
The purpose of this blog is not to indict any brand of products in the market but to focus on the inadequacies of data based on which special nutritional claims can be made. Probably stoichiometrically the Maillard reaction may not be affecting very significantly the absolute quantum of protein available and the artifacts produced may not be as harmful as they are thought to be. But the scientific arguments based on existing data as articulated above, do support the theory that Maillard reaction is not desirable if nutritional value is the main concern in products like malted milk.