Isitashi esingazweli, i-fiber entsha yezokudla, sidonse ukunakwa nocwaningo olukhulu. 1982, isazi sokusebenza komzimba saseBrithani u-Hans Englyst nabanye bathola ukuthi i-insoluble dietary fiber iqukethe isitashi, futhi bayiqamba ngokuthi i-ResistantStarch. Ngo-1992, i-FAO (Food and Agriculture Organization of the United Nations), esekelwe ocwaningweni lwe-Englyst kanye ne-EURESA (I-European Collaboration for the Study of Resistant Starch), yachaza ngokuthi "imikhiqizo yesitashi neyonakaliswa kwesitashi esingazweli engamuncwa emathunjini amancane abantu abanempilo." Ngokwemigomo ye-layman, isitashi esimelana nakho asimuncwa futhi sigaywe nge-enzymatically emathunjini amancane, kodwa singabhekana nokuvutshelwa ngama-fatty acids aguquguqukayo kukholoni yomzila wesisu somuntu. Ngakho-ke, isitashi esingazweli saziwa nangokuthi isitashi esimelana ne-enzyme kanye nesitashi esingagayeki.
Kunezigaba ezine eziyinhloko ze-RS kanje: RS1, RS2, RS3, and RS4.
I-RS1 (isitashi esifakwe ngokomzimba),okubhekisela kuzinhlamvana zesitashi eziba nomthelela wokuvimbela ngokomzimba ngenxa yokucubungula ngomshini futhi zikhiyelwe odongeni lweseli yesitshalo okuwenza angatholakali esenzweni se-amylase, atholakala kakhulu okusanhlamvu nemifino.
I-RS2 (ama-starch granules amelana),ibhekisela kulezo sitashi ezimelana ngokwemvelo nokugayeka kokudla. Itholakala kakhulu kumazambane aluhlaza, kubhanana kanye nesitashi sommbila oqondile{1} Ukumelana kwayo nokugaya kwe-enzymatic kungenxa yesakhiwo esiminyene futhi esiyingxenye yekristalu, futhi ukumelana kwayo kuyanyamalala lapho kuqedwa ukunamathisela.
I-RS3 (isitashi esivuselelwe),isho isitashi okunzima ukusihlephula i-amylase ngoba sicwebezela ngemva kokunamathisela nangesikhathi sokupholisa noma ukusigcina, esibizwa nangokuthi isitashi esikhulile. Kuyingxenye ebalulekile yesitashi esimelana nesitashi futhi kwakhiwa ngokushintsha kwesakhiwo samakhemikhali, i-polymerization kanye ne-crystal conformation yesitashi okubangelwa ukucubungula ukudla, ngakho-ke kuwuhlobo olubalulekile lwesitashi esingazweli. I-RS3 ivame ukutholakala elayisi elibandayo, isinkwa kanye nokudla okuthosiwe.
I-RS4 (isitashi esishintshwe ngamakhemikhali),isho i-enzyme-ingxenye yesitashi engazweli ekhiqizwa ngemva kokushintshashintsha kwe-starch molecule kanye nokwethulwa kwamanye amaqembu amakhemikhali asebenzayo, njenge-carboxymethyl isitashi,{1}}isitashi esihlanganisiwe, njll. Futhi, ibhekisela ekushintsheni kwesakhiwo samangqamuzana esitashi okubangelwa ukuguqulwa kwezakhi zofuzo{3}njengomphumela wokuhlanzwa kwenkanyezi{3} ukuguqulwa kwezakhi zofuzo noma izinguquko zesakhiwo samangqamuzana okubangelwa izindlela zamakhemikhali.
Uhlobo lokuhlukaniswa kwe-RS lusashintsha, kodwa i-RS1 ne-RS2 noma i-RS1 kanye ne-RS3 ngokuvamile -ukuba khona ekudleni okukodwa. Njengoba i-RS1 ne-RS2 zilahlekelwa iningi lazo ngesikhathi sokushisisa nokucubungula, abacwaningi basekhaya nabangaphandle njengamanje banesithakazelo esikhulu ku-RS3 ne-RS4, engangezwa ekudleni ukuze kuthuthukiswe ukusebenza kwayo.
Isitashi esingazweli futhi sithathwa njengefayibha yokudla, kodwa sisenezici ezihlukile ku-fiber yokudla, futhi sinemiphumela ebanzi yokusebenza komzimba womuntu. Ingakwazi ukwenza imisebenzi yayo yokwakheka komzimba ngokuthinta ukumuncwa kanye ne-metabolism yezinye izinto, kanye nokukhiqizwa kwezinto eziphilayo zesibili ngokuvutshelwa kukholoni.
