Scanning electron micrographs of Semitendinosus beef muscles raw, 120 h post-mortem, submitted to pre-injection tumbling 8.5 rpm–0.5 h, injected to 130% (over original
weight) and then submitted to post-injection tumbling 8.5 rpm–5 h. Transversal views: a) T5 (control), arrows indicate gaps among fibre bundles and between fibres; b) T4 (NaCl
1.25%); c) T2 (MWPC 1.88%+NaCl 1.25%), arrows indicate gaps among fibre bundles and between fibres; d) T3 (STPP 0.25%+NaCl 1.25%), arrows indicate the presence of material
onto the fibres