Tsarin ruwa

Tsarin ruwa

Ana amfani da tsarin Atwater, mai suna bayan Wilbur Olin Atwater, ko abubuwan da aka samo daga wannan tsarin don ƙididdige yawan kuzarin abinci . An samar da tsarin sosai daga binciken gwaji na Atwater da abokan aikinsa a ƙarshen karni na 19 da farkon shekarun 20th a Jami'ar Wesleyan a Middletown, Connecticut . Amfani da shi ya kasance sanadin jayayya akai-akai, amma an ba da shawarar wasu hanyoyi. Kamar yadda yake tare da lissafin furotin daga jimlar nitrogen, tsarin Atwater al'ada ne kuma ana iya ganin iyakokinsa a cikin samuwarsa.

Fitowa

Samuwar makamashi (kamar yadda Atwater ke amfani da shi) yayi daidai da amfani da zamani na kalmar makamashi mai narkewa (ME).

$${\text{Metabolisable Energy}}=\left({\text{Gross Energy in Food}}\right)-\left({\text{Energy lost in Faeces, Urine, Secretions and Gases}}\right).$$

A mafi yawan binciken da aka yi a kan mutane, an yi watsi da hasara a cikin ɓoye da iskar gas. Babban makamashi (GE) na abinci, kamar yadda aka auna ta hanyar calorimetry na bam yana daidai da jimlar zafin konewa na abubuwan da aka haɗa - furotin (GE _p ), mai (GE _f ) da carbohydrate (GE _cho ) (ta bambanta) a cikin tsarin kusanci.

$${GE}={{GE}_{\mathrm {p} }+{GE}_{\mathrm {f} }+{GE}_{\mathrm {cho} }}.$$

Atwater yayi la'akari da darajar makamashin najasa haka.

$${GE}^{\mathrm {F} }={{GE}_{\mathrm {p} }^{\mathrm {F} }+{GE}_{\mathrm {f} }^{\mathrm {F} }+{GE}_{\mathrm {cho} }^{\mathrm {F} }}.$$

Ta hanyar auna ma'auni na samuwa ko a cikin ƙamus na zamani bayyananniyar narkewa, Atwater ya samo tsarin ƙididdige asarar makamashin faecal.

$${\text{Digestible energy}}={{GE}_{\mathrm {p} }(D_{\mathrm {p} })}+{{GE}_{\mathrm {f} }(D_{\mathrm {f} })}+{{GE}_{\mathrm {cho} }(D_{\mathrm {cho} })},$$

inda D _p, D _f, da D _cho ne bi da bi da digestibility coefficients na furotin, mai da carbohydrate lissafta kamar yadda