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Physical and Chemical Properties, Oxidative Stability and Availability of Iron-Enriched Powdered Milk
Mendes, F.Q.1; Fazollo, A.1; Reis, D.T.C.1; Pilon, F.M.1; Marinho, J.S.2; Aquino, R.A.N.1; Oliveira, M.G.A.1
1 Departamento de Bioquímica e Biologia Molecular da Universidade Federal de Viçosa-MG; 2 Departamento de Biologia da Universidade Federal de Viçosa-MG
Anemia
due to lack of iron reaches approximately 36 % of world population; the
most vulnerable are children and expectant mothers. Bovine milk, food
often used for feeding children, has low rate and bioavailability of
iron. The objective of this work is to study the enrichment of powdered milk, principally intended for institutions (kindergartens and
schools) and nutritive supplement programs for feeding children.
Powdered milk was enriched with two different sources of iron: ferrous
sulfate and amino acid (glicine) chelate iron. Iron sources were added
before and after milk drying. 1.5 mg of iron per 100 ml of milk were
added to pasteurized milk C type, following a concentration of milk to
get a reduction of 50 % from its volume, and drying in spray-dyer. 12
mg of iron were added per 100 g
of powdered milk in order to obtain, after milk reconstitution, 1.5 mg
of iron per 100 ml of final product that is ready to use, equal to 15 %
of the recommended daily intake for children. Oxidative stability was assessed by the thiobarbituric acid (TBA) rate. Iron bioavailability was assessed by using an in vitro
method, based on iron solubility at pH 7,5, after digestion with
pepsine. Regarding the way of enrichment, differences were not found at
the level of 1% of probability, for the test t. Both technological
processes were simple and easy to perform in the laboratory.
Differences between the two sources of iron were not found at the level
of 1% of probability, for the test t, in terms of physical and chemical
characteristics of acidity, humidity, and lipids, proteins, lactose,
ash content and sediment rates. Oxidative stability of powdered milk
was greater when amino acid chelate iron was used and both sources
differed from the control (p<0,01), for the test t . Amino acid
chelate iron showed greater bioavailability in vitro (31,81 %) than ferrous sulfate (17,41 %), at the level of 1% of probability, for the test t. The bioavailability deduced in vivo,
was 15.45 % for amino acid chelate iron and 8.66 % for ferrous sulfate.
Amino acid chelate iron revealed better oxidative stability and better
bioavailability compared to ferrous sulfate, being a good source to
enrich powdered milk.
Support by CAPES
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