This post is one part of my research proposal about Tempeh. I am interested in researching benefits of Tempeh because tempeh is one of most popular Indonesian food. It is relatively cheap and has many beneficial effects for health. Not much Indonesian people know the beneficial effects of tempeh. Hopefully this study will brings goodness for everyone.
Tempeh is
Indonesian traditional food, which is made by fermented soybean. It is one of
alternatives source of protein and relative cheaper than animal source of
protein. The texture is soft and has a unique flavor. It uses Rhizopus oligoporus to ferment the soybean.
Basically, tempeh
is made from soybean. In 100 grams of soybean, it contains protein almost 40%.
Not only macro and micronutrients, soybean also contains isoflavone. Isoflavone
is one of phytoestrogen which refers to plant-derived compounds that show
estrogen-like biological activity. It is structurally and functionally similar
to 17β-estradiol. There are
three groups of phytoestrogen: genistein, daidzein, and glycitein (24).
Tabel 1. Nutrition composition
in 100 grams of tempeh
Nutrients
|
Value per 100 g
|
Unit
|
Energy
|
201
|
kcal
|
Protein
|
20.80
|
g
|
Total lipid
(fat)
|
8.80
|
g
|
Carbohydrate
|
13.50
|
g
|
Vitamin A
|
0.0
|
IU
|
Vitamin B1
|
0.19
|
mg
|
Vitamin C
|
0.0
|
µg
|
Calcium
|
155
|
mg
|
Iron
|
4.00
|
mg
|
Phosphorus
|
326
|
mg
|
Source: Daftar
Komposisi Bahan Makanan, 2013
Compared to unprocessed
soybean, tempeh has higher protein efficiency (PER) ratio and vitamin B.
Trypsin inhibitor and phytic acid in soybean also decreased in tempeh because
of R. oligoporus fermentation (25). Fermentation in tempeh also increase the
availability of isoflavone aglycones. Aglycone form is changed by hydrolysis of
the isoflavone glucoside by β-glycosidase enzyme during fermentation process (26). Soy isoflavone has many beneficial effects to
human health. Genistein, one of soy isoflavon, has anti-diabetic effects on
β-cell proliferation, glucose-stimulated insulin secretion and protection
against apoptosis, independent of its function as an estrogen receptor agonist,
antioxidant, and tyrosine kinase inhibitor (27). Isoflavones are thought to exert both
estrogenic and antiestrogenic effects, depending on the tissue. Isoflavones may
block the estrogen receptor, thereby having an antiestrogenic effect on uterine
and breast tissue where excess estrogen may promote tissue proliferation.
Conversely, isoflavones may bind to the estrogen receptor and stimulate estrogen
activity in other tissues, thereby having an estrogenic effect. It has been
hypothesized that soy isoflavones exert a proestrogenic effect on menopausal (28). Soy food consumption is effective in relieving
menopausal symptoms and it also associated with lowering risk of breast and
endometrial cancer in observational studies (29).