<b>Evaluation of resistance of the Nile tilapia (Oreochromis niloticus) skin in longitudinal, transversal and diagonal position after tanning with chromium salts and retanning with different tanning substances</b> - DOI: 10.4025/actascianimsci.v28i3.54

Abstract

The objective of this experiment was to evaluate the resistance of the Nile tilapia (Oreochromis niloticus) skin in longitudinal, transversal and diagonal sections after tanning with chromium salts and re-tanning with different tanning substances. Skins were distributed in a totally randomized design, 3 by 3, with three re-tanning techniques (T1 = with 4% chromium salts; T2 = 6% vegetal tannins; T3 = with 6% synthetic tannins) coupled with three removal positions (P1 = longitudinal position; P2 = transversal position and P3 = diagonal position), with 6 replications per treatment in triplicate. Hide was considered the experimental unit. The EMIC dynamometer was used for traction, lengthening and progressive tearing resistance. Hide thickness ranged from 1.00 to 1.20 mm with no difference in re-tanning techniques. Although no significant difference in traction existed with regard to re-tanning techniques, there was a higher significant difference with regard to transversal position removal of proofs (11.92 N/mm2). Re-tanning technique and position did not affect progressive tearing, which ranged from 24.47 to 29.12 N/mm. Hide in the transversal position had greater elongation of technique, albeit no difference occurred in T2 technique for longitudinal position. Greater resistance to traction and elongation occurred in re-tanned hide with chromium salts, while re-tanning and position did not affect progressive tearing