Cht x th

nh ngha cng ngh

Tn Trung Quc: cht x th

Tn ting Anh: cht x th

nh ngha: cellulose, hemicellulose, pectin v cht lignin.

Khoa hc ng dng: Khoa hc Thy sn (mt mn); thc n thy sn v phn bn (hai i tng)

Ni dung trn bng khoa hc quc gia v U ban ph duyt Cng ngh cng b

Cht x th l mt thnh phn chnh ca cc thnh phn t bo thc vt, bao gm c cellulose, hemicellulose, lignin, v cht sng v cc thnh phn. n thc phm c cha cht x th gip tiu ha, tng cng chc nng tiu ha, c mt li ch, nhng n nhiu s r rng l do khng c kh nng tiu ha v gy y hi.

Cht x th (si th, vit tt l CF, l tn c ca cht x, khng c.)

o bng phng php ca cht x th thc n thng thng, l nui mu l axit 1,25%, si kim cho mi 30 pht, cc carbohydrate khng ha tan cn li. Trong cellulose l mt -1, 4 trng hp trong polysaccharide ng nht ca ng; hemi-cellulose, glucose, fructose, xylose, mannose v arabinose polyme polysaccharide khng ng nht; lignin l mt polymer dn xut phenylpropyl, n l loi ng vt trong cc yu t hn ch chnh ca cht dinh dng. Trong phn tch ca phng php ny, mt s hemicellulose, cellulose v lignin c ha tan trong axit, kim, o hm lng cht x th thp, trong khi tng cc li tnh ton chit xut nit. ci thin th chng trnh phn tch cht x, Van Soest (1976) trnh by vi mt si cht ty ra trung tnh (Neutral si bt git, ch vit tt NDF), si cht ty ra axit (Acid Detergent Fiber, vit tt ADF), axit cht ty ra lignin (Acid Detergent Lignin, ch vit tt ADL) nh mt bin php ca thc n gia sc ch s vt liu si. Cht x th trong ch n ung trong khi cc hemicellulose, cellulose v lignin phn lp t tt c ra nh gi tt hn gi tr dinh dng ca thc n x th.

Ngoi ra, cht x th khng th c tiu ha v hp thu. Dinh dng trc nm 1970, ch c "cht x th", c s dng m t khng th c tiu ha, hp thu d lng thc phm, v ch bao gm cc b phn ca cellulose v lignin. Cht x th thng c coi l trn c th con ngi khng c vai tr ca dinh dng, v thm ch n rt nhiu cng nh hng n cc cht dinh dng c th trong thc phm, c bit l cho s hp thu nguyn t vi lng, gy bt li cho c th, khng c nghim tc. K t , thng qua mt lot cc nghin cu, c bit l gn y c pht hin, v nhn ra nhng ngi khng th tiu ha "khng dinh dng" vt cht, nhng n c lin quan cht ch n sc khe con ngi, m cn trong vic phng chng mt s bnh nh bnh tim mch ca con ngi, bnh tiu ng , to bn, ung th rut kt v ng mt vai tr quan trng, ng thi, cng nhn ra "cht x th" khi nim ca thut ng ny khng p dng, v do b loi b cht x.

Cht x th c li cho s pht trin ca rng

n cht x th phi cn thn khi nhai v nhai trn rng l mt massage mang li li ch v s kch thch, c th thc y s pht trin ca rng, nhai c th thc y s pht trin ca hm di, do rng ca tr sp xp gn gng, khun mt trang nghim, nhai c th tip tc kch thch tit nc bt, nc bt khng ch d nut, tiu ha thc n, nhng cng ng mt vai tr trong my git gim cht thi thc phm trong rng v rng xung quanh ni c tr, do lm gim t l su rng v bnh nha chu. Rau cht x th thng giu vitamin C cng cn thit cho qu trnh tng hp cc cht dinh dng y hc nha khoa ma trn. V vy, nu bn mun con c mt gn gng, hm rng trng, sau n t ngy nhiu rau cht x th bt u n.

Cc loi thc phm cht x th

Cc loi thc phm cht x th l thc phm mt trm g ram cha nhiu hn 2 gram cc loi thc phm cht x th, c ht ng, k, la min, la mch, yn mch, khoai m, khoai lang, khoai ty tre, u nnh, u H Lan, u xanh, u , u H Lan, u a, u, gi , cn ty, ti ty, ti ln, hoa hu, tuyt tng, t xanh, u H Lan, la hoang, mng tre, mng roi da, mng ty, hnh ty, m tc, c ci ng, to, l, nho, m, hng, to gai, du ty , tri cy c bo qun, m kh, mn kh, liu, ngy, ht d, qu c ch, u phng, nm, nm, nm, bng ng, c tm, to b, rong bin, rong bin, rong bin, mi trng thch. Tt c cc loi thc phm, cc cht x kh dy, kh tiu ha, hp th, s lm tng gnh nng cho d dy, v vy bnh nhn d dy nn n. Mt thnh phn chnh ca c ph c cht x th.

Tc ng tiu th cht x th v m ng

Cc cht x th nh vy gi l cht x. Cc loi thc phm c cha cht x ch n ung ch yu l ng cc, rau, tri cy, u v nh vy. l tip tc chia thnh cht x ha tan v cht x khng ha tan. Nu trc y, ko cao su v cht kt dnh, c th c ha tan trong nc, cc chnh

c tm thy trong tri cy, yn mch, la mch v mt s loi u. V nht l cht x khng ha tan nh cellulose v hemicellulose. Nht trn th trng c b sung cc loi thc phm c cha cht x th khng ha tan cht x ng cc v cc loi ng cc nh ng, la m, cm, cm go v nh vy ng chng hn. Hm lng cht x th t dinh dng, v khng d tiu ha, nhng n c kh nng bo ph, cholesterol, bnh tiu ng v cc bnh khc cao ng vai tr trong vic phng nga v iu tr.

Cc loi thc phm cht x th nn c ngi tiu dng chnh ca ngi ln v ngi gi, nhng cng theo khi n dinh dng c khuyn co cho lng cht x th mi ngi mt ngy no l 2035 gram, n nhng s lm gim vic s dng cc cht dinh dng khc t l. Ngoi ra, cht x th c th tng khi lng phn gim thi gian lu li d lng thc n ng rut trong c th, do tn sut i tiu tng tc. V vy, tr em, v chc nng tiu ha km, tiu chy, ngi ta thng khng n.

Cc cht x th c gi l, c ngha l, chng ta thng ni rng cht x. l cc carbohydrate trong mt lp hc ca polysaccharides khng tinh bt, ch yu l t thnh t bo thc vt. Cht x rt kh c tiu ha v hp th bi c th, v kt cu ch yu l th, dinh dng trong nhng nm u c bit n nh cht x th.

Cc loi thc phm c cha cht x ch n ung ch yu l ng cc, rau, tri cy, u v nh vy. Ch yu l tri cy, yn mch, la mch v mt s loi u. V nht l cht x khng ha tan nh cellulose v hemicellulose. Nht trn th trng c b sung cc loi thc phm c cha cht x th khng ha tan cht x ng cc v cc loi ng cc nh ng, la m, cm, cm go v nh vy ng chng hn.

C th lm gim lng ng trong mu v cholesterol

Hm lng cht x th t dinh dng, nhng khng tiu ha, thi gian rt di, mi ngi ngh g v nh hng sc khe ca n. Nhng vi cc tiu chun ngy cng cao ca cuc sng, cu trc ch n ung ca ngi dn ngy cng tr nn "Ty ha" --- n tht hn v nhiu hn na, nhng n nhiu rau qu v thc phm t hn v lng cht x ch n ung s tr nn t hn v t hn, c nhiu bnh lin quan n li sng, chng hn nh bo ph, cholesterol cao, tiu ng v nh vy. Ti thi im ny, n c pht hin, cht x th ca cc bnh ny c th ng mt vai tr trong vic phng v iu tr.

Nghin cu dinh dng hin i cho thy, n cc loi thc phm cht x th c bn u im ln: Th nht, ci thin chc nng tiu ha, c th ngn nga to bn, ngn nga ung th rut kt, th hai l ci thin p ng ng huyt, lm gim lng ng trong mu sau n v gip iu tr bnh tiu ng; Th ba, gim nng cholesterol trong huyt tng, ngn nga tng lipid mu v bnh tim mch, kim sot trng lng Th t, gim t l mc bnh bo ph.

20 gram mi ngy l

Cc loi thc phm cht x th nn l nhm ngi tiu dng chnh cho ngi ln v ngi gi, bi v h lm vic, cuc sng cng thng, v vt l l do, nhng ngi b bo ph, tng lipid mu, bnh tiu ng hn. Nhng cng ch khi n ung, dinh dng khuyn ngh cho lng cht x th l 20-35 gram mt ngi mi ngy, n nhng s lm gim vic s dng cc cht dinh dng khc.

Ngoi ra, cht x th c th tng khi lng phn gim thi gian lu li d lng thc n ng rut trong c th, do tn sut i tiu tng tc. V vy, tr em, v chc nng tiu ha km, tiu chy thng xuyn l tt hn khng n