TY - JOUR
T1 - Chlorophyll-bound magnesium in commonly and consumed vegetables and fruits
T2 - Relevance to magnesium nutrition
AU - Bohn, T.
AU - Walczyk, T.
AU - Leisibach, S.
AU - Hurrell, R. F.
PY - 2004
Y1 - 2004
N2 - Magnesium is bound as the central atom of the porphyrin ring of the green plant pigments chlorophyll a and b. It has been suggested that chlorophyll-bound magnesium may play an important role in magnesium nutrition because when iron is similarly bound in the porphyrin ring of heme, it is absorbed to a greater extent than non-heme iron. We have analyzed 22 frequently consumed fruits and vegetables for the chlorophyll content by high-pressure liquid chromatography and for magnesium with atomic absorption spectroscopy. Chlorophyll concentrations ranged from 6 μg/g (grape) to 790 μg/g (spinach) (median 63 pg/g). Magnesium concentrations ranged from 48 μg/g (grape) to 849 μg/g (spinach) (median 122 μg/g). In the green leafy vegetables, such as spinach and lettuce, chlorophyll-bound magnesium represented 2.5% to 10.5% of total magnesium whereas other common green vegetables, pulses and fruits contained <1% chlorophyll-bound magnesium. The chlorophyll content of spinach was further decreased by about 35% on thawing frozen spinach or on chopping fresh spinach, and this degradation increased to about 50% after boiling and steaming. Based on the present results and published food consumption data, we estimate that chlorophyll-bound magnesium represents a very low fraction of total magnesium intake in industrialized countries, less than 1% in the case for data obtained from Switzerland. Thus, chlorophyll-bound magnesium is of little relevance to magnesium nutrition.
AB - Magnesium is bound as the central atom of the porphyrin ring of the green plant pigments chlorophyll a and b. It has been suggested that chlorophyll-bound magnesium may play an important role in magnesium nutrition because when iron is similarly bound in the porphyrin ring of heme, it is absorbed to a greater extent than non-heme iron. We have analyzed 22 frequently consumed fruits and vegetables for the chlorophyll content by high-pressure liquid chromatography and for magnesium with atomic absorption spectroscopy. Chlorophyll concentrations ranged from 6 μg/g (grape) to 790 μg/g (spinach) (median 63 pg/g). Magnesium concentrations ranged from 48 μg/g (grape) to 849 μg/g (spinach) (median 122 μg/g). In the green leafy vegetables, such as spinach and lettuce, chlorophyll-bound magnesium represented 2.5% to 10.5% of total magnesium whereas other common green vegetables, pulses and fruits contained <1% chlorophyll-bound magnesium. The chlorophyll content of spinach was further decreased by about 35% on thawing frozen spinach or on chopping fresh spinach, and this degradation increased to about 50% after boiling and steaming. Based on the present results and published food consumption data, we estimate that chlorophyll-bound magnesium represents a very low fraction of total magnesium intake in industrialized countries, less than 1% in the case for data obtained from Switzerland. Thus, chlorophyll-bound magnesium is of little relevance to magnesium nutrition.
KW - Chlorophyll-bound magnesium
KW - Chlorophylls
KW - Magnesium
KW - Pigment degradation
KW - Vegetables and fruits
UR - http://www.scopus.com/inward/record.url?scp=10944253222&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2621.2004.tb09947.x
DO - 10.1111/j.1365-2621.2004.tb09947.x
M3 - Article
AN - SCOPUS:10944253222
SN - 0022-1147
VL - 69
SP - S347-S350
JO - Journal of Food Science
JF - Journal of Food Science
IS - 9
ER -