The purpose of this study was to extract proteins from lentils for
use in bread making to improve nutritional quality of bread. Three
solvents, distilled water, 0.7 M NaCl and 0.05 M NaOH solutions, were
used for extraction. Extractions were done at an alkaline pH near 10
for 30 min. Proteins were recovered by acid precipitation using 1 N
HCl. Macro-Kjeldahl determinations were run on the precipitated material
to determine protein content.
The results showed that extractions were effective using either
distilled water adjusted to pH 10.0 or 0.05 M NaOH. Protein recoveries
of 66.01-68.79% and 64.01-66.62% were obtained by these two procedures
respectively. These are simple methods that do not require sophisticated
equipment. Thus they would be practical and economical for use on a
large scale.
For bread supplementation studies, lentil proteins were extracted
by distilled water with pH of the slurries adjusted to pH near 10. The
extracted lentil proteins were used to replace white wheat flour at levels
of 0, 5, 7.5 and 10% on a dry weight basis. Breads were made using the
the straight dough method. Sodium-stearoyl-2-lactylate was used as a
dough conditioner. Specific volume, color, texture and protein content
of the breads were evaluated objectively. The breads were also
subjected to sensory evaluation for color, texture, moistness, flavor
and overall desirability.
Specific volume decreased as the level of lentil protein increased.
The control bread had the highest specific volume which was
significantly higher (p < 0.05) than the lentil supplemented breads.
Bread crumb became darker in color with increasing lentil protein
levels as shown by a decrease in Hunter L values. Hunter 'a'
values increased in breads with higher lentil protein contents but
there was little change in Hunter 'b' values.
Lentil proteins resulted in a decrease in crumb compressibility.
There was a linear relation between levels of protein replacement and
protein contents of the breads. The 5%, 7.5% and 10% lentil protein
replacements increased the protein contents of the breads from 11.44%
to 13.-2%, 13.80% and 14.59% respectively.
Although the lentil breads received lower sensory evaluation
scores than the control breads, they were judged as acceptable at the
5%, 7.5% and 10% substitution levels.
These findings are significant because the supplemented breads
have higher nutritional value. This would help reduce nutritional
deficiency problems especially in areas where protein malnutrition
exists. / Graduation date: 1983
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27471 |
| Date | 02 June 1982 |
| Creators | Idris, Nor Aini |
| Contributors | Anglemier, Allen F. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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