Mejoramiento del valor nutritivo de frutos secos de guasima (guazuma ulmifolia) con urea e hidróxido de sodio (Improving the nutritive value of dried fruits of guazuma ulmifolia with urea and sodium hydroxide)

Resumen
Se recolectaron frutos secos de la guásima Guazuma ulmifolia para evaluar cambios en la composición química y DIVMS (digestibilidad in vitro de materia seca) aplicando los tratamientos alcalinos siguientes: TST (testigo), TUR (frutos tratados con 4 p.100 de urea) y THS (frutos tratados con 4 p.100 de NaOH). Diez muestras de 500 g, fueron sometidas a cada tratamiento durante 21 días, en frascos de vidrio y a temperatura ambiente. Un incremento de pH y cenizas (p<0,05) fue observado con los álcalis. La PB (proteína bruta) aumentó sólo en TUR (113 g/kg-" MS) vs84 g y 83 g del testigo y con NaOH, respectivamente. Los componentes de la pared celular decrecieron con los tratamientos (p<0,05)
sin embargo, la celulosa no mostró cambios significantes. Con los álcalis aumentó la DIVMS 68,5 (g/kg-1 MS) con urea y 174 g con NaOH respecto al testigo. Con ambos tratamientos hubo reducción en los componentes de las paredes celulares, propiciando un aumento en la DIVMS de los frutos de guásima. Este efecto, unido al aumento de PB, hacen atractivo el uso de ambos álcalis para el tratamiento de estos frutos.
Abstract
The wild plant foliage species represent an alternative to traditional cattle feeds. The guásima Guazumaulmifolia, awild tree species that is found in abundance in tropical areas, produces palatable fruit and foliage for cattle. This experimentwas conducted toevaluatetheeffectofalkaiitreatmentonthechemical composition and IVDMD of thedriedfruitsof guasima. Samples of 500 g of fruits were treated with the following alkali: TST (control), TUR (4 p.100 urea), and THS (4 p.100 NaOH). Ten samples pertreatment were placed in glass flasks and stored during 21 d at room temperature. Lateron, the samples were dried at 65°C by 48 h and were analyzed by threefold. An increase of pH and ashes was observed using the alkalis (p<0.05). CP was increased in TUR (113 g/ kg-1 DM) vs 84 g and 83 g of control and THS, respectively. The components of cell walls decreased with both treatments (p<0.05)
however, cellulose did not showed significant changes. With the alkali the IVDMD was increased (g/kg-1 DM)68.5withureaand 174 g with NaOH respect to control. The changes in CP, fiber components and IVDMD suport the use of both urea and NaOH to treat guasima fruit. WithNaOH, the IVDMD was higher than urea. It would possible to use the NaOH treatment to improve the nutritive value of fruit, and add urea in the integral diet.