Hydrothermal treatment and malting of barley improved zinc absorption but not calcium absorption in humans.
OBJECTIVE
To study whether hydrothermal treatment or malting of barley (cv. Blenheim) improves zinc and calcium absorption in humans.


METHODS
: Two groups of 10 and 12 healthy subjects, respectively, were in a period of 2 months in a fasting state, served two single meals each containing porridge or breakfast cereals prepared from processed or unprocessed (control) barley (60 g). The meals included 200 g of milk, extrinsically labelled with (65)Zn and (47)Ca. Whole-body retention of both minerals was measured.


METHODS
The study was carried out at the Department of Radiation Physics, Sahlgrenska University Hospital, Göteborg.


METHODS
The subjects were recruited among students at the Göteborg University. None dropped out.


METHODS
The activities of (65)Zn and (47)Ca were measured by whole-body counting four to five times over a 4-week period after each meal.


RESULTS
Zinc absorption from hydrothermally treated barley porridge, containing 28 mg P as inositol tri- to hexaphosphates (InsP(3)-InsP(6)), was significantly higher (P<0.001) than from control porridge containing 111 mg P as InsP(3)-InsP(6), 25.2+/-6.9 vs 11.0+/-2.5% (n=12). Calcium absorption did not differ (P>0.05), 21.1+/-6.8 vs 19.5+/-4.7% (n=12). Zinc absorption from breakfast cereals of malted barley with phytase activity and containing 70 mg P as InsP(3)-InsP(6,) was significantly higher (P<0.05) than from flakes of barley, containing 108 mg P as InsP(3)- InsP(6) and no phytase activity, 22.9+/-5.8 vs 14.8+/-4.6% (n=10). The calcium absorption was 21.3+/-6.5 vs 18.5+/-4.3% (n=10) and did not differ significantly (P>0.05).


CONCLUSIONS
Improvements of zinc absorption in breakfast meals can be achieved by optimised hydrothermal treatment or malting of barley. Calcium absorption was not influenced in the meals in this study.


BACKGROUND
Supported by Semper AB, Sweden, Oy Lahden Polttimo, Finland, the SL-Foundation, Sweden, Swedish National Board for Industrial and Technical Development (NUTEK), the Nordic Industrial Foundation, Swedish Council for Forestry and Agricultural Research (SJFR, project no 50.0306/97).
Fredlund
K
K
Department of Food Science, Chalmers University of Technology, Box 5401, SE 402 29 Göteborg, Sweden. mlw@fsc.chalmers.se
Bergman
E-L
EL
Rossander-Hulthén
L
L
Isaksson
M
M
Almgren
A
A
Sandberg
A-S
AS
D000293:Adolescent; D000328:Adult; D001682:Biological Availability; D002118:Calcium / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002132:Calcium Radioisotopes; D002523:Edible Grain; D005260:Female; D005511:Food Handling / Q000379:methods*; D001467:Hordeum / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D008875:Middle Aged; D010833:Phytic Acid / Q000494:pharmacology; D015032:Zinc / Q000008:administration & dosage / Q000493:pharmacokinetics*; D015037:Zinc Radioisotopes
D002132:Calcium Radioisotopes; D015037:Zinc Radioisotopes; D010833:Phytic Acid; D015032:Zinc; D002118:Calcium