brief
communications
Relationships among crude fiber, neutral detergent fiber, in vitro dietary fiber, and in vivo (rats) dietary fiber in wheat foods1’2 R. M.
Saunders,3
Ph.D.,
and
E. Hautala,4
B.S.
ABSTRACT The in vivo dietary fiber contents of wheat milling fractions and wheat foods, determined in rat feeding experiments, were compared with dietary fiber values determined in vitro with pronase a-amylase digestion. Both types of dietary fiber values were compared with crude fiber and neutral detergent fiber values in the same materials. Regression analyses indicated close correlation amongst all values determined. It appears that laboratory analysis for crude fiber, neutral detergent fiber, or in vitro dietary fiber accurately predicts in vivo dietary fiber (rats) for wheat milling fractions when the laboratory result is adjusted by means of an appropriate regression equation. Am. I. Clin. Nuir. 32: 1188-1191, 1979.
The
possible
fiber5 stuffs
(or has
years
(1-4).
question
different chemical (5) and dures to
health-related
total been
indigestible reviewed
One
role residue) extensively
of dietary of foodin recent
in the dietary fiber is the validity of its measurement in foodstuffs, by in vivo, in vitro, or techniques. Goering and Van Soest Southgate (6) have published procemeasure
difficulty
“neutral
detergent
fiber”
and “unavailable carbohydrate,” respectively, whereas Hellendoorn et al. (7) have described an enzymatic procedure to measure “indigestible residue”. Each of these procedures provides a number that is assumed to be an approximate measure of dietary fiber, and such numbers are widely quoted in the literature. With one exception, to our knowledge, these values have not been interrelated to one another, to in vivo measurements of dietary
fiber,
nor
systematically
The American
Materials
Journal
of Clinical
Downloaded from https://academic.oup.com/ajcn/article-abstract/32/6/1188/4666276 by Washington University in St. Louis user on 02 July 2018
and methods
The wheat milling fast foods, and the indigestible residue earlier (9). Pronase
a-amylase Crude
were fiber
products,’ wheat breads and breakin vivo procedure to measure total (dietary fiber) have been described and crystalline procine pancreatic
purchased
was
Neutral detergent for wheat milling
from
measured by fiber (NDF)
fractions
Sigma, AOAC values
St. Louis,
Mo.
procedure (10). were determined
by the method
that
includes
‘From the Western Regional Research Center, Science and Education Administration, United States Department of Agriculture, Berkeley, California 94710. ‘Parts of this work were presented at Annual Meetings of the American Association of Cereal Chemists, 1976 and 1977.
to chemically
determined crude fiber-the figure that appears in food tables (8). The exception consists of an earlier report from this laboratory where crude fiber was closely correlated with in vivo dietary fiber in wheat products, measured in rats (9). In this paper values are determined for dietary fiber in wheat-based materials by an in vitro enzymatic procedure developed in 1188
this laboratory, and by a modified neutral detergent fiber technique. These values are compared with crude fiber and in vivo values determined earlier.
3Research Research
Leader, Chemist,
Cereals Nutrient
Research Unit. and Chemical
Analysis
Unit. ‘The fraction
term dietary fiber implies the total indigestible of the foodstuff, and includes indigestible soluble and insoluble polysaccharides, lignin, and unavaila-
ble
protein, ‘When after flour
fat, starch, and micronutrients. wheat is milled into flour, the residue left removal is termed millrun. In commercial millrun is usually further classified into subfrac-
practice, tions: germ, particles),
Nutrition
bran and
red
32: JUNE
(larger dog
particles),
shorts
(intermediate
(fines).
1979, pp. 1188-1191.
Printed
in
U.S.A.
TABLE I Crude fiber, techniques
neutral
detergent
in wheat
milling
fiber, fractions”
DIETARY
FIBER
and
fiber
dietary
IN
WHEAT
measured
by in vivo
and
Dietary Material
1189
FOODS
in vitro
fiber Crude
NDF In vitro
fiber
In vivo %
Bran
Shorts Germ
Red dog Flour AACC
bran’
49.66 41.97 26.47 19.33
(0.64)’
1.84
(0.06)”
45.42
(0.41)’
52.41 47.16 32.36 24.50 3.88 43.85
(1.00)’
(0.54)’< (0.36)’
(0.77)’ (0.76)’ (1.38y’
(0.45)” (0.14)” (0.39)’
“All figures on moisture-free basis. SD of sample is in determinations. ‘Average value for two determinations. d Average determination. ‘
communications
Relationships among crude fiber, neutral detergent fiber, in vitro dietary fiber, and in vivo (rats) dietary fiber in wheat foods1’2 R. M.
Saunders,3
Ph.D.,
and
E. Hautala,4
B.S.
ABSTRACT The in vivo dietary fiber contents of wheat milling fractions and wheat foods, determined in rat feeding experiments, were compared with dietary fiber values determined in vitro with pronase a-amylase digestion. Both types of dietary fiber values were compared with crude fiber and neutral detergent fiber values in the same materials. Regression analyses indicated close correlation amongst all values determined. It appears that laboratory analysis for crude fiber, neutral detergent fiber, or in vitro dietary fiber accurately predicts in vivo dietary fiber (rats) for wheat milling fractions when the laboratory result is adjusted by means of an appropriate regression equation. Am. I. Clin. Nuir. 32: 1188-1191, 1979.
The
possible
fiber5 stuffs
(or has
years
(1-4).
question
different chemical (5) and dures to
health-related
total been
indigestible reviewed
One
role residue) extensively
of dietary of foodin recent
in the dietary fiber is the validity of its measurement in foodstuffs, by in vivo, in vitro, or techniques. Goering and Van Soest Southgate (6) have published procemeasure
difficulty
“neutral
detergent
fiber”
and “unavailable carbohydrate,” respectively, whereas Hellendoorn et al. (7) have described an enzymatic procedure to measure “indigestible residue”. Each of these procedures provides a number that is assumed to be an approximate measure of dietary fiber, and such numbers are widely quoted in the literature. With one exception, to our knowledge, these values have not been interrelated to one another, to in vivo measurements of dietary
fiber,
nor
systematically
The American
Materials
Journal
of Clinical
Downloaded from https://academic.oup.com/ajcn/article-abstract/32/6/1188/4666276 by Washington University in St. Louis user on 02 July 2018
and methods
The wheat milling fast foods, and the indigestible residue earlier (9). Pronase
a-amylase Crude
were fiber
products,’ wheat breads and breakin vivo procedure to measure total (dietary fiber) have been described and crystalline procine pancreatic
purchased
was
Neutral detergent for wheat milling
from
measured by fiber (NDF)
fractions
Sigma, AOAC values
St. Louis,
Mo.
procedure (10). were determined
by the method
that
includes
‘From the Western Regional Research Center, Science and Education Administration, United States Department of Agriculture, Berkeley, California 94710. ‘Parts of this work were presented at Annual Meetings of the American Association of Cereal Chemists, 1976 and 1977.
to chemically
determined crude fiber-the figure that appears in food tables (8). The exception consists of an earlier report from this laboratory where crude fiber was closely correlated with in vivo dietary fiber in wheat products, measured in rats (9). In this paper values are determined for dietary fiber in wheat-based materials by an in vitro enzymatic procedure developed in 1188
this laboratory, and by a modified neutral detergent fiber technique. These values are compared with crude fiber and in vivo values determined earlier.
3Research Research
Leader, Chemist,
Cereals Nutrient
Research Unit. and Chemical
Analysis
Unit. ‘The fraction
term dietary fiber implies the total indigestible of the foodstuff, and includes indigestible soluble and insoluble polysaccharides, lignin, and unavaila-
ble
protein, ‘When after flour
fat, starch, and micronutrients. wheat is milled into flour, the residue left removal is termed millrun. In commercial millrun is usually further classified into subfrac-
practice, tions: germ, particles),
Nutrition
bran and
red
32: JUNE
(larger dog
particles),
shorts
(intermediate
(fines).
1979, pp. 1188-1191.
Printed
in
U.S.A.
TABLE I Crude fiber, techniques
neutral
detergent
in wheat
milling
fiber, fractions”
DIETARY
FIBER
and
fiber
dietary
IN
WHEAT
measured
by in vivo
and
Dietary Material
1189
FOODS
in vitro
fiber Crude
NDF In vitro
fiber
In vivo %
Bran
Shorts Germ
Red dog Flour AACC
bran’
49.66 41.97 26.47 19.33
(0.64)’
1.84
(0.06)”
45.42
(0.41)’
52.41 47.16 32.36 24.50 3.88 43.85
(1.00)’
(0.54)’< (0.36)’
(0.77)’ (0.76)’ (1.38y’
(0.45)” (0.14)” (0.39)’
“All figures on moisture-free basis. SD of sample is in determinations. ‘Average value for two determinations. d Average determination. ‘
