Relationship Between Blocked Lysine and Carbohydrate Composition of Infant Formulas

Abstract

The quantity of blocked lysine in spray-dried infant formulas in Italy was calculated by the furosine method. This quantity was then correlated with the composition of the carbohydrate fraction. In formulas containing only lactose as carbohydrate its presence in large quantities (6.7-7.5 g/l00 mL of formula as fed), with a lysine-rich protein fraction, may lead to amino acid blocking of >20%. In formulas in which lactose was substituted with low-DE maltodextrin a reduction of lysine blocking was possible. Addition of glucose may result in high levels of blocked lysine.

Modifications of structures and functions of caseins: a scientific and technological challenge

“…In a general way, the extent of lactosylation depends on several factors such as (1) intensity of heat treatments, (2) type and structure of the considered protein (van Boekel 1998;Scaloni et al 2002), (3) lactose/protein ratio (Evangelisti et al 1994), and (4) environmental conditions like pH. The literature describing the reaction of lactosylation and its effects on casein micelles is relatively poor.…”

Comparative LC–MS/MS profiling of free and protein-bound early and advanced glycation-induced lysine modifications in dairy products

“…For the determination of Amadori products, the indirect furosine method is commonly applied. Furosine, generated at a constant percentage upon acid hydrolysis of Amadori products, was monitored chromatographically in raw, pasteurized, UHT and skim milk, as well as in infant formulas [23][24][25].…”

Non-Enzymatic Degradation Pathways of Lactose and Their Significance in Dairy Products

“…In general, low molecular weight reactants tend to react more readily than high molecular weight reactants, partially as a result of steric hindrance in the latter. Thus, glucose is more reactive than lactose and contributes to the increased rate of browning in lactose-hydrolysed milks (Lea, 1948;Evangelisti et al, 1994). Colour intensity produced in model systems may be ranked according to the reacting sugars as follows: xylose>arabinose>fructose>glucose>maltose>lactose (Yang and Shin, 1980).…”