In vitro assessment of the effectiveness of non-nutritive sorbent materials as binding agents for boar taint compounds

Abstract

Boar taint, an off-odor and an off-flavor in the meat from some uncastrated male pigs, is due to high levels of the testicular steroid hormone, androstenone, and the indole, skatole. Thus far, there are no known methods for controlling both androstenone and skatole through dietary means. We tested the adsorbent agents, cholestyramine (CH), activated carbon (AC), tween-60 (Tween), bentonite (BNT) and polyvinylpolypyrrolidone (PVPP) for binding androstenone, estrone (E 1 ), estrone sulfate (E 1 S) and skatole from buffer solutions in an in vitro system. The goal was to determine the potential utility of these binding agents as feed additives to control boar taint. Michaelis-Menten analysis was utilized to determine the effectiveness of the adsorbents. At pH 7.4, E 1 S was bound to AC and CH with the highest B max (maximum binding), whereas Tween and AC had the greatest B max for E 1 . The B max for skatole at pH 7.4 was highest for AC, CH and PVPP. AC had a higher B max for androstenone than CH and Tween. The B max values at pH 3.0 with E 1 S for AC and CH were essentially 100%, whereas the binding of Tween to E 1 S at pH 3.0 decreased by 49.5% from binding at pH 7.4 (P , 0.05). The Ad int values, which represent efficiency of binding, illustrated that AC bound E 1 , androstenone and skatole with greater efficiency than the other binding agents at pH 7.4, whereas AC bound E 1 S as efficiently as CH. We conclude that AC was the most effective adsorbent agent for binding E 1 , E 1 S, androstenone and skatole in vitro, followed by CH, Tween, PVPP and lastly BNT. These adsorbent agents may be useful for binding boar taint compounds in in vivo studies to decrease the risk of boar taint.

Nutritional Influences on Skatole Formation and Skatole Metabolism in the Pig

“…Studies with the addition of complex clay minerals to the diet of pigs to bind skatole to prevent the absorption were published, but were not successful in all studies [ 91 , 100 ]. Similar approaches with more advanced additives, which should bind skatole and thus reduce the absorption rate, were carried out as in vitro studies, were not proven to be effective in vivo , but may be promising [ 101 ].…”

Effect of the use of entire male fat in the production of reduced salt fermented sausages

“…Therefore, skatole concentration can be reduced through the addition in the diet of certain carbohydrates (inulin, raw potato starch, etc), enzymes (Øverland, Kjos, Fauske, Teige, & Sørum, 2011) or sorbent material (Jen & Squires, 2011). However, androstenone concentration cannot be easily reduced; the only way known so far is through genetic selection or manipulation; unless inmunocastration is carried out.…”

Preliminary Test of the Reduction Capacity for the Intestinal Adsorption of Skatole and Indole in Weaning Piglets by Pure and Coated Charcoal

“…Thus, variations between in vivo and in vitro can occur [ 17 ]. This difference was also obvious in the study by Jen and Squires, whereby they found less skatole reduction by activated carbon in fat and plasma in vivo [ 18 ] than in vitro [ 28 ].…”

“…The reduction in skatole and indole was calculated from the difference of initial and end content in %. In contrast to in vitro studies with charcoal, e.g., Jen and Squires [ 28 ], the feed, its transition time and digestion were neglected as our study aimed to prove the feasibility of the charcoal coating and the difference between pure and coated charcoal. Therefore, caecum and colon chyme were used—without any further modification—for skatole and indole adsorption.…”