cong dung cua yen

Duoc si Phan Duc Binh hoi Duoc hoc Viet Nam
Yen sao hay to chim yen la loai thuc pham tu
lau da duoc xep vao hang “cao luong my vi”. The nhung no bo duong nhu the nao ma
gia ban lai dat nhu vang?
Yen sao (con duoc goi la
to yen, hai yen, yen thai, quan yen) la to
cua loai chim yen bien. Co may loai yen thuoc ho vu yen Apodidae cho to an duoc:
Collocalia linchi Horsfi.; C. innominata Hume.; C. francia merguiensis Hart.; C.
francica germaini Oustalet…
Cac loai chim yen song o hai dao doc bien, tu Quang Binh den Ha Tien. Than nho,
canh dai nhon, duoi ngan, mo cong. Long duoi va long canh co mau den hay xam,
bung mau trang. Chim yen to co tren duoi 10g. Yen bay rat khoe, thuong kiem an
tren mat nuoc. Chim yen lam to tren cac vach da cheo leo hiem tro va lam to bang
nuoc mieng cua chung.
Theo dong y, to yen co vi ngot, tinh binh,
tac dung vao cac kinh phe va vi. Co tac dung duong am, bo phe, tieu dam, tru ho
dinh suyen. Dung trong cac chung ho hen, khai huyet, suy nhuoc co the. Ngoai ra,
to yen con dung de tiem voi tao tau, hat sen,
hoai son, nhan sam, duong quy, ky tu… lam thuoc bo duong cho nguoi gia yeu. Lieu
dung 6 – 12g/ngay. De lam thuoc hoac lam mon an, nguoi ta ngam
to yen vao nuoc am trong hai gio cho no ra,
nhat bo tap chat va long chim neu co, roi rua sach, de rao. Cho yen vao tiem
chung (chung cach thuy) voi ga ac, ga gio, bo cau va gia vi hay cac vi thuoc noi
tren. Cung co the chung voi duong phen de an.
Theo luan an tien si duoc khoa tai dai hoc Duoc khoa Sai Gon nam 1972 cua TS
Huynh Huu Tao, co ba nhom yen sao phan bo
theo vung dia ly: yen sao quanh vung Cu Lao
Cham (Quang Nam – Da Nang). Yen sao quanh
vung Quy Nhon va yen sao quanh vung Nha Trang – Cam Ranh. Tuy theo tinh chat va
kich co, to yen chia lam ba loai: quy hiem nhat la yen huyet (to yen mau do hay
hoi do, gia dat vi hiem gap). Yen quan (la loai to yen tot nhat, to to, trang,
moi to nang tu 10 – 12g). Thu nhi la yen thien (to yen nho hon, mau xanh nhat
hay vang nhat). Thu ba la yen dia (to yen nho, xau, mau xam hay luc nhat).
Yen sao rat giau chat khoang, ke ca khoang
vi luong (xem bang). Thanh phan chat dam trong
yen sao cung rat cao: yen trang Da Nang (55%), yen huyet Da Nang (54,4%),
yen trang Nha Trang (53,8 %), yen huyet Nha Trang (56,9%), yen trang Quy Nhon
(54,4%), yen trang Singapore (56,3%).
Nghien cuu chi tiet hon thanh phan chat dam, cho thay
yen sao khong chua cac protein va axit
alginic cua rong tao. Dieu nay chung minh yen
sao lam bang nuoc mieng chim yen chu khong phai rong tao. Yen sao cung khong
chua hong cau va cac hem cua huyet ma chua rat nhieu sat. Yen huyet vi vay khong
phai do mau chim yen ma do thanh phan sat trong da co mau do cua suon nui tao
nen. Thanh phan bot duong duoc nghien cuu sau cho thay chua nhieu galactose
trong mucoprotein, khong chua cac duong len men, chung to to yen duoc lam hoan
toan bang nuoc mieng chim. Yen sao khong
chua chat beo.
Tom lai, chim yen dung nuoc mieng de lam thanh
yen sao, co thanh phan rat giau chat dam va khoang chat, glucosamin thien
nhien (la yeu to can thiet tao nen sun khop) nen rat bo duong, de tieu hoa hap
thu, tuy gia thanh qua dat.