To evaluate the saponification of two fat raw matters, ovine suet and residual of African palm oil (Elaeis guineensis), by means of the use of sodium hydroxide, potassium and calcium, with the purpose of protecting these fats from the bovine ruminal degradation, an experiment according to a completely random design, with factorial arrangement 3 x 2 was conducted. A bromatological analysis of the obtained soaps, evaluation of consistency and profitability by means of cost-benefit indicator was carried out. The variance analysis showed significant interaction among the studied factors. The dry matter was higher in the residual of palm oil soaps treated with calcium, sodium and potassium (P d» 0001). Likewise, ash was higher in these soaps (P d» 0001).It was higher with the potassium hydroxide. This hydroxide allowed soaps with higher (P < 0, 0002) protein concentrations (with both fat sources).The higher concentration of fat was in the ovine suet soaps (P d» 0001).The calcium hydroxide saponification acted in an optimum way in the consistency of residual palm oil and ovine suet soaps. The cost benefit showed higher values (1.25) in the residual palm oil soaps protected with calcium. It is concluded that the studied saponification methods (sodium, potassium and calcium hydroxide) allowed an appropriate nutrients concentration in the obtained soaps, high contribution of fat in ovine suet, adequately hardness in calcium soaps, acceptable levels of in vitro solubility and high profitability for calcium soaps.

Para evaluar la saponificación de dos materias primas grasas, sebo ovino y residuos de aceite de palma africana (Elaeis guineensis), mediante la utilización de hidróxido de sodio, potasio y calcio, con el propósito de proteger estas grasas de la degradación ruminal bovina, se condujo un experimento según diseño completamente al azar, con arreglo factorial 3 x 2. Se realizó análisis bromatológico de los jabones obtenidos, evaluación de consistencia y rentabilidad mediante el indicador beneficio-costo. El análisis de varianza mostró interacción significativa entre los factores estudiados. La materia seca fue mayor en los jabones de residuos de aceite de palma tratados con calcio, sodio y potasio (P d 0001). Igualmente, la ceniza resultó superior en estos jabones (P d 0001). Fue más elevada con el hidróxido de potasio. Este hidróxido permitió jabones con más altas (P < 0.0002) concentraciones de proteína (con ambas fuentes de grasa). La mayor concentración de grasa se encontró en los jabones de sebo ovino (P d 0001). La saponificación con hidróxido de calcio actuó de manera óptima en la consistencia de los jabones de residuos de aceite de palma y sebo ovino. El beneficio-costo indicó valores más altos (1.25) en los jabones de residuos de aceite de palma protegidos con calcio. Se concluye que los métodos de saponificación estudiados (hidróxido de sodio, potasio y calcio) permitieron una adecuada concentración de nutrientes en los jabones obtenidos, alto aporte de grasa en sebo ovino, dureza adecuada en los jabones de calcio, aceptables niveles de solubilidad in vitro y alta rentabilidad para jabones de calcio.

The supplementation with bypass fat is an alternative to increase the energetic density in fitting ration to dairy cows (Tyagi 2010) that have an energy negative balance after parturition (Gallardo 2011), because fats are inert in the rumen and digestible in the intestinal tract.

Four types of inert fats have been informed: recovered with proteins, hardness hydrogenated fats, seeds and calcium salts of fatty acids (Cabrera and Carpio 2007).

The calcium salts of fatty acids are obtained by saponification.During this process, free fatty acids are join with calcium ions. These compounds showed high melting point and solubility in pH lower at 5.5.Therefore, they are not dissociated in the rumen and dissolved in the ruminal liquid. The abomasums show pH from 2 to 2.5 that can be dissociated by means of the release of fatty acids and calcium molecules, compounds that can be digested in the intestine (Salvador et al. 2009).

The saponification is a chemical reaction between a fatty acid and a base, in which it is obtained the acid salt as a main product (Mateos et al. 1996).The bases or alkaline can be sodium salts or potassium (Bernardini and González 2009 and Bas 2001) and of calcium (InfoCarne 2008 and Herrera and Calleja 2011).All have a caustic power (García 2002 and García and Cruz 2011) and could give similar results, as protection of fatty acids against ruminal degradation.

In a previous research study, the ovine suet and palm oil residuals were characterized, abundant elements in Ecuador. The poor use of these resources contributes to the environmental pollution. The contents, relatively high, of unsaturated fatty acids present in palm oil residuals and ovine suet, could be used in the dairy cows diet, but this required to protect these fats from ruminal degradation, so they were transform into bypass fats.

The objective of this research was to evaluate three saponification methods (sodium, potassium hydroxide and calcium) on two types of fats(ovine suet and palm oil residuals), with the purpose of protecting them to the bovine ruminal degradation.

The research was carried out in the Chemical Sciences Laboratory, belonging to Facultad de Ciencias Pecuarias de la Escuela Superior Politécnica de Chimborazo, in Ecuador. This facility is located at 2,754 m o.s.l, with annual average temperature of 13.36 ºC and annual precipitation of 490.8mm, according to reports from the Meteorological Annual (ESPOCH 2011).

T1: Ovine suet saponificated with KOH
T2: Oil palm residuals saponificated with KOH
T3: Ovine suet saponificated with NaOH
T4: Oil palm residuals saponificated with NAOH
T5: Ovine suet saponificated with Ca (OH)₂
T6:Oil palm residuals saponificated with Ca(OH)₂

The soaps, once obtained, were subjected to a bromatological analysis (DM, minerals, fat, protein, fiber and NFE) according to AOAC 2005.The consistency was evaluated with a non parametric scale, from 1 to 4 points. Profitability was analyzed by means of cost benefit indicator(C/B=totals income/ totals cost).

The bromatological analysis considered the percentage content of DM, from which was calculated the content of minerals, protein, fat, fiber and NFE.

For the consistency determination, punctuation scale from 0 to 4 was applied, where:

1=doughy soaps

2= soft soaps

3=half hard soaps and

4=firms or hard soaps

Duncan (1995) test was used for mean comparison in necessary cases. The non parametric measure was carried out according Conover (1999).

The statistical analysis showed the significance of the studied factors interaction (fat x saponification methods).The bromatological contents of the different studied fats are showed in table 1.

The soaps made with oil palm residuals (92.28% with calcium, 86.25% with sodium and 84.21 % with potassium) showed the highest (P d» 0001) DM content regarding to those formulated with ovine suet (calcium 82.89, sodium 81.16 and potassium 79.38%).

The potassium hydroxide, as saponificate material, allowed obtaining soaps with high protein concentration (3.68% in ovine suet and 3.37% in oil palm residuals). It fallows the sodium hydroxide (3.10%to ovine suet and 2.44% to oil palm residuals).Soaps with low protein concentration (P<0.0002) corresponded to the calcium hydroxide (1.87% in ovine suet and 1.81% in oil palm residuals).

The ovine suet soaps showed higher fat concentration(sodium 89.13%, potassium 86.38 %and calcium 85.98%) regarding the soaps made with oil palm residuals(calcium 78.67%, sodium 74.91% and potassium 68.36%).

The ovine suet soaps did not showed fiber presence. Those of oil palm residuals protected with sodium showed the higher (P<0.0001) fiber levels (4.72%), fallow by those formulated with oil palm residuals and protected with potassium (3.72%).Those made with oil palm residuals, protected with calcium (1.2%) were in last position .

Regarding to the content of nitrogen free extract, all soaps showed similar values, did not exits statistical differences (P e» 0.1).

Table 2 shows the results of consistency. Calcium hydroxide acted optimally and similar in soap consistency; the sodium and potassium hydroxide allowed optimal hardness, only when they acted in the ovine suet.

As reference to the profitability possible to obtain in protected fats elaboration from oil palm residuals and ovine suet, cost- benefit indicator was used , whose value are showed in table 3.

The calcic soaps of oil palm residuals showed the highest values (1.25) in cost benefit indicator. Fallow by the calcic soaps of ovine suet (1.17) and the sodium ones, formulated with oil palm residuals (1.13).The fulfilled analysis was partial because they were not considered in this values the effects in animal production.

The rule of the Standardization National Institute of Ecuador (SIN 1981) establish that the soaps made with animal fat and oils should contain, at least, 65% of dry matter, parameter that has taken as reference to consider the success of chemical process applied to oil palm residuals and ovine suet. The higher dry matter concentration in the soaps of oil palm residuals could be due to solid residuals presence that constitute the raw matter, coming from residuals of palm fruit.

The soaps of oil palm residuals showed higher ash concentration regarding to those of ovine suet, probably due to that the raw matter of oil palm residuals contain more ash than the ovine suet. Consequently, ash content showed direct relation with the ones of raw matters. It is known that ashes are an indicator of mineral content and have structural functions (P, Ca, Mg, Fe) and electrolytic (Na, K, Ca, Mg) that acted in the osmotic pressure, equilibrium and membrane permeability and tissues. It also takes part,in catalyst functions (Na, Mn, Cu, I, Se).Because of this, is very important that food destined to animals diet contribute important amount of minerals to the ration. Murillo et al. (2013) informed decrease of the interval conception parturition in supplemented cows with mineral concentrate and oil palm regarding to non supplemented cows. This shows that the energy supplement cannot act if it is with minerals contribution that, by general, is relatively low in suets. In oil palm residuals do not happen in that way, in which the ash contribution was significantly higher regarding to ovine suet.

The higher bromatological concentration of fat in the ovine suet soaps are logics if the levels of this element presents in raw matter are considered regarding to oil palm residuals. The results of this study suggest that the bromatological characteristic of the studied soaps depends on the used raw matter, especially regarding minerals, fat and fiber.

Regarding consistency (table 2), calcium hydroxide permitted the soaps optimum hardness, indistinctly of the raw matter on which it acted, can be used in saponification process, be of oil palm residuals or ovine suet. Otherwise, the use of sodium and potasium hydroxidesis not recommended for the saponification of oil palm residues, since soft soaps are get that could have conservation problems, fundamentally in the mixture of the raw materials used in the elaboration of concentrates.

The profitability calculation, in function of cost- benefit indicator, allows affirming that the fats elaboration protected from the ruminal degradation, would be profitable if it is used the calcium hydroxide as saponificate element. The lower profitabilities were observed when using potassium hydroxide, in whose values can influence, in a decisive way, the chemical reagent cost.

It is concluded that the procedures used to saponificate the raw matter studied, were appropriate. An adequate dry matter concentration, high ash concentration (especially in oil palm residuals), important energy contribution (especially in ovine suet), appropriate hardness (especially with calcium) and high profitability (especially to calcium soaps) were observed. The results suggest that the bromatological characteristic of soaps depends on the raw matter particularities, especially regarding to minerals, fat and fiber.

It is recommended the use of calcium hydroxide as saponificated element for ovine suet and oil palm residuals, because with it was obtained the best hardness of soaps and the highest profitability levels. It should be complemented the viability study of applied procedures by means of in situ degradability and in vivo digestibility.

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