Effect of iron and lactose supplementation of milk on the Maillard reaction and tryptophan content

Abstract

New liquid UHT milks supplemented with iron (0.9-1.4 mg/100 ml), vitamin C (1-7 mg/100 ml), lactose (2-4 g/100 ml) and linoleic acid (200-400 mg/100 ml), named growth milks, have recently become available to satisfy the specific nutritional needs of children aged 1-3 years. But the iron-vitamin C mixture could activate the lactose-induced Maillard reaction and tryptophan (Trp) oxidation in proteins. We have therefore examined the Amadori product and Trp concentrations of these milks. Forty-two commercial growth milks from five firms were analysed for the Maillard reaction and the soluble protein Trp content and compared with 64 UHT milks. The furosine concentration of total proteins was two to four times higher in 'growth' milks than in standard UHT milks, indicating a proportional loss of available lysine. The Trp fluorescence of undenatured proteins soluble at pH 4.6 was almost three times lower in 'growth' than in standard milks and Trp concentration 36% lower suggesting destruction of this oxidation-sensitive amino-acid. The mechanism of Trp destruction remains to be elucidated, and the roles of iron and Amadori products determined.

The interaction of metal ions with Maillard reaction products in a lactose–glycine model system

“…The presence of Cu 2+ and other transition metal ions in Maillard model systems affected the rate of formation of both melanoidins and precursors of melanoidins (Birlouez-Arragon et al, 1997;Hayase et al, 1996;Rendleman & Inglett, 1990). In general, two protons were released for each Cu 2+ -ion that was bound (Rendleman & Inglett, 1990).…”

“…The development of the non-enzymatic browning in food products and the nature of the compounds formed in the different stages of the Maillard reaction depend on the presence of other reactive compounds in the food system: for example, oxidizing or reducing agents, such as ascorbate (Zidertman, Gregorski, Lopez, & Friedman, 1989) or sulphite (Swales & Wedzicha, 1992) and mineral elements, especially metal ions with variable valence (Birlouez-Arragon, Moreaux, Nicolas, & Ducanze, 1997;Cheng & Kowakishi, 1993;Hayase, Shibuya, Sato, & Yamamoto, 1996;Kawakishi, Okawa, & Uchida, 1990;Rendleman & Inglett, 1990).…”

Formation and reduction of carcinogenic furan in various model systems containing food additives

“…In contrast, another study showed increased furan formation from a linoleic acid model system with the addition of butyl hydroxytoluene (BHT) (Mark, Pollien, Lindinger, Blank & Mark, 2006). The presence of metal ions in the Maillard reaction affects the rate of formation of Maillard reaction products (Birlouez-Arragon, Moreaux, Nicolas, & Ducanze, 1997;Cottier & Descotes, 1991;Hayase, Shibuya, Sato, & Yamamoto, 1996;Rendleman & Inglett, 1990). However, the mechanism of metal incorporation into the Maillard reaction is http://dx.doi.org/10.1016/j.foodchem.2014.10.128 0308-8146/Ó 2014 Elsevier Ltd. All rights reserved.…”

Microwave Processing: Current Background and Effects on the Physicochemical and Microbiological Aspects of Dairy Products

“…The authors found that the best way to minimize NFC formation and nutrient degradation was to use high energy for a short time, similar to that obtained with the UHT process for conventional heating (Laguerre et al., ). CML is used to measure the overall contribution of various substrates, including lactose, vitamin C, and aldehydes derived from the Maillard reaction (Birlouez‐Aragon, Moreaux, Nicolas, & Ducauze, ; Fu et al., ), and it has been reported to be well correlated with the extent of lysine blockage in milk (Leclère, Birlouez‐Aragon, & Meli, ).…”