Description
Soybean Flour
Soy flour is extracted from ground soybeans which enhance protein,
provides moisture to baked goods and provides basis for soymilks
and textured vegetable protein. It improves taste as well as
texture of foods and also lowers fat absorption in fried foods. Soy
flour tastes from beany flavor to sweet and mild flavor.
Health Benefits of Soy Bean Flour
Soy flour is an excellent source of soy protein, bio active
components such as isoflavones and dietary fiber. This ingredient
is a great source of iron, potassium and B vitamins. It has a
bio-active component which provides relief from menopausal symptoms
such as hot flashes, prevent breast cancer, prostate cancer,
colorectal cancer and maintain healthy bones. The profile and
content of bio-active components differs from product to product
that depends on how the soy protein is processed and how much soy
protein is found in the food. It is the healthy source of protein
due to high quality of protein containing all amino acids essential
for growth.
1. Cardiovascular health
An epidemiological association between soy intake and reduced
cardiovascular disease risk is well supported by a number of
publications.
2. Antiatherosclerotic effects
The hypothesis that soy protein consumption has antiatherosclerotic
effects is supported by the epidemiological association between soy
protein intake and reduced cardiovascular disease risk. A number of
reports from a variety of animal models indicate that soy protein
intake can reduce development and final size of experimentally
induced atherosclerosis.
3. Kidney Disease
An area for possible clinical application of soy proteins is that
of hyperlipidemias secondary to kidney disease, particularly the
nephrotic syndrome. In this condition, changing from an animal to a
vegetarian soy diet markedly reduces serum cholesterol and also
reduces urinary protein excretion. A recent study by Teixeira et
al. concluded that a soy protein isolate-based diet compared to one
based on casein can improve both serum lipids and nephropathy
biomarkers in Type II diabetic patients with nephropathy. A change
to a soy diet may favorably influence the progression of renal
disease.
4. Prevention of Breast Cancer
In addition to its antiestrogenic effects such as suppressing
estrogen levels and prolonging menstrual cycles, isoflavone may
contribute to breast cancer risk reduction by its effect on cancer
cell growth inhibition. These are either antiestrogenic or
nonhormal effects since isoflavone inhibits ER-positive and
ER-negative breast cancer cell growth. Since most of the effects
are observed in the supraphysiological concentrations, further
studies are needed to elucidate the effect in more physiological
environments in in vitro, in vivo, and human studies. Coexistence
of estrogen and other substances and high concentrations achieved
by heavy isoflavone intake may interact to reduce cancer risk.
5. Anticancer activity
Soybeans are known as a low risk food for cancer, and a correlation
between the intake of soybean foods and the morbidity of cancer,
especially colon and prostate cancers, has been reported in an
epidemiological survey. Chemical carcinogenesis is a multistage
process that includes initiation, promotion, and progression, and
many food plants show potent inhibitory effects against
carcinogenic promotion. Maeda et al. found that the
promotion-inhibitory effect of food plants, especially carrot leaf,
oilseed rape, and beans (soybeans, black soybeans, azuki
[red]beans), correlated closely with the alkyl peroxide radical
scavenging effect. The anticancer effects of the soybean may
mutually involve saponins, protease inhibitors, isoflavones, and
inositol**-phosphate, although there are few reports on the
individual anticancer effects of these substances. Konoshima et al.
investigated the Epstein-Barr viral antigen activity of
triterpenoid saponins of the bean family and reported the antigen
activity facilitatory effect of soyasaponin Be (ketone function at
C**2), one of the soybean saponins, and a protective effect on Raji
cells.
6. Antiviral activity
Viruses are infectious particles in which DNA or RNA (the viral
genome) is wrapped in a protein capsid. Once DNA viruses invade
nonpermissive cells, they are incorporated into the genome of the
host cells and replicated or become a plasmid that is replicated.
This often causes genetic changes in onpermissive cells. RNA
viruses infect permissive cells, causing genetic changes in the
cells. It has recently been revealed that the continuous synthesis
of viral protein after these genetic changes causes cell
transformation (neoplastic transformation) leading to
cancerization, so the antiviral effects of food are now attracting
research interest. The human immunodeficiency virus (HIV), a
retrovirus, invades helper T-cells (Th cells) by binding to their
membrane protein (CD4). This means there may be two ways to protect
against HIV infection: inhibition of reverse transcriptase or
binding to Th cells. When the inhibitory effects of Group A
(bis-desmoside saponins), Group B (monodesmoside saponins, hydroxyl
group at C**2), and Group E (monodesmoside saponins, ketone
function at C**2) saponins on HIV infection are compared, Group B
saponins show an inhibitory effect that is severalfold greater than
that of other saponins. In particular, soyasaponin Bb shows the
highest effect, providing almost complete inhibition of cell
degeneration and of viral antigen expression caused by HIV. Since
soybean saponins themselves do not act directly on HIV, the
inhibitory effect of soyasaponin Bb on HIV infection does not
provide direct inhibition of the reverse-transcriptional activity
of HIV but may protect T4 cells from contact with HIV. The general
characteristics of soybean saponins include bubble formability, or
the surfactant effect. Group B saponins have greater inhibitory
effect on HIV infection than Group A saponins (which have higher
bubble formability), suggesting that this inhibitory effect is not
derived from the physical characteristics of saponins.
7. Inhibitory effects on liver disorders
The liver is an important organ that has roles in storing
nutrients, producing bile, regulating blood flow, and breaking down
alcohol and pharmaceuticals. Excessive intake of alcohol and drugs
and viral infections may cause liver disorder (hepatitis), leading
to serious liver diseases such as cirrhosis and liver cancer.
Soybean saponin fractions have an inhibitory effect on these
disorders. Ohminami et al. reported that Group A saponins, or
bis-desmoside saponins, have this effect, and Miyao et al. reported
the liver-damaging effect of Group B saponins, or monodesmoside
saponins. Five Group B saponins have been isolated from soybeans.
Soyasaponin Bb, the predominant saponin, effectively inhibits liver
disorders induced by carbon tetrachloride, suggesting the
usefulness of soybean intake.
8. Hypocholesterolemic activity
- Isoflavones are compounds with weak estrogenic and
antiestrogenic activity, abundant in the Asian diet and present in
varying amounts in different soy preparations. Individuals have
highly variable gastrointestinal absorption of isoflavones (in some
cases close to nil), and absorption is highly dependent on the
individuals gut microflora. Nevertheless, a recent meta-analysis of
clinical trials concluded that soy isoflavones have
hypocholesterolemic activity — contradicting an earlier
meta-analysis that reported no association between changes in
cholesterolemia and dietary isoflavones.
- Soy protein and isoflavones may be needed for
maximal cholesterol-lowering effect of soy protein
preparations and that soy protein should be consumed with a low
saturated fat and low cholesterol diet to maximize its
effectiveness. It remains, however, difficult to suggest plausible
mechanisms whereby soy isoflavones might exert any additional
hypocholesterolemic effects to those of the protein. Soy
isoflavones at best provide only a minor additional
hypocholesterolemic effect above that of the protein, though they
may induce additional effects beneficial to cardiovascular disease
risk, such as stimulating apo AI production.
