| Abstract | Zrno kukuruza najvažniji je izvor energije te predstavlja najzastupljenije krmivo u hranidbi svinja. Energija zrna kukuruza deponirana je u obliku škroba čija je visoka probavljivost i iskoristivost neophodna za održanje života, rast, obnovu tkiva, zdravlje i proizvodnju. Najveći dio zrna kukuruza čini endosperm čiji se brašnavi i caklavi dio razlikuju u svojstvima te njihov omjer kao i morfologija utječu na probavljivost škroba. Cilj ovog istraživanja bio je utvrditi utjecaj svojstava brašnavog i caklavog endosperma na in vitro kinetiku ilealne probavljivosti škroba cijelog zrna kukuruza u modelu koji oponaša sustav probave u želucu i tankom crijevu svinja. Istraživanje je provedeno na 30 hibrida kukuruza u kojima je, manualnom disekcijom, određen udio caklavog i brašnavog endosperma. U dijelovima endosperma potom je određen sadržaj amiloze, zeina, te škrobnih i neškrobnih lipida. Koeficijenti probavljivosti izračunati su za 0, 15, 30, 45, 1, 2, 3, 4 i 5 sati inkubiranja in vitro procedure probavljivosti cijelog zrna, a brzina probavljivosti škroba izračunata je prema kinetici prvog reda. Probavljivost suhe tvari analiziranih hibrida u prosjeku je iznosila 83,36%, dok su se koeficijenti probavljivosti značajno razlikovali između hibrida što upućuje na to da razlike u njihovim svojstvima utječu na in vitro kinetiku brzine probavljivosti škroba. Nadalje, hibridi su se razlikovali u brzini probavljivosti škroba (P < 0,01; 0,73 – 1,63 1/h). Istraživanjem je utvrđena negativna korelacija (P < 0,05) između sadržaja amiloze, zeina, škrobnih i neškrobnih lipida i parametara in vitro probavljivosti škroba, dok model linearne regresije sa četiri varijable (sadržaj zeina i škrobnih lipida u caklavom te zeina i amiloze u brašnavom endospermu) može predvidjeti više od 64% varijabilnosti brzine probave škroba. |
| Abstract (english) | Maize grain is the main energy source and it represents the most common feed in swine nutrition. The energy of maize grain is deposited in form of starch whose high digestibility and utilization is necessary for life maintenance, growth, tissue regeneration, health and production. Endosperm compromises majority of maize kernel and its floury and vitreous parts are different in characteristics whereas their ratio and morphology affect starch digestibility. The aim of this research was to determine the impact of floury and vitreous endosperm traits on in vitro digestibility kinetics of starch from whole maize kernel in a model imitating digestive system in the stomach and small intestine of the swine. The research was conducted on 30 maize hybrids in which the portion of vitreous and floury endosperm was determined by manual dissection. Subsequently, in endosperm parts, contents of amylose, zein, starch and non-starch lipids were determined. The digestibility coefficients were calculated after 0, 15, 30, 45, 1, 2, 3, 4 and 5 hours of incubation in an in vitro procedure for whole grain digestion and starch digestibility rate was calculated according to the first order kinetics. The dry matter digestibility of analysed hybrids was 83,36% on average while digestibility coefficients varied significantly between hybrids suggesting that the differences between their traits have an impact on in vitro digestibility kinetics of starch. Furthermore, hybrids varied in starch digestibility rate (P < 0.01; 0.73 – 1.63 1/h). In this research, negative correlation (P < 0.05) was determined between contents of amylose, zein, starch and non-starch lipids and parameters of in vitro starch digestibility, while a linear regression model with four variables (contents of zein and starch lipids in vitreous and zein and amylose in floury endosperm) can predict more than 64% variability of starch digestibility rate. |
