Effects of stimulation on tenderness of lamb with a focus on protein degradation

Abstract

Abstract. Past studies have identified that electrical stimulation systems not only affect the pH-temperature decline of lamb carcasses, but also affect the tenderness of the product. It is unknown whether these differences are due to the effects of an optimal pH-temperature decline path by which the occurrence of shortening is decreased and proteolytic enzyme activity is increased, or by another mechanism, such as disruption of the muscle myofibres. This study attempted to elucidate this by placing control and mid-voltage electrically stimulated samples of the M. longissimus thoracis et lumborum in a water bath to prevent shortening by imposing an even pH-temperature decline on all samples. In order to obtain a complete understanding of the effects of stimulation on the muscle, samples were taken for indicators of tenderness, myofibre degradation and protein breakdown. No effect of stimulation was seen on tenderness and structural degradation measures aside from the expected rapid lowering of muscle pH. Interesting relationships were observed, however, between the different methods of meat tenderness assessment, with muscle structural protein degradation, shear force and muscle fibre and myofibre breakdown comparisons. These results suggest that the effects of electrical stimulation seen in mid-voltage systems as applied in this study are due only to the prevention of shortening conditions.

Use of electrical stimulation and chilling to enhance meat tenderness of heavy lambs

“…The literature is not clear on the effect of ES on MFI in lamb. Past studies did not report any effect of ES on MFI (Kerth et al 1999;Martin et al 2006;Toohey et al 2008), while other studies found higher MFI following ES (Kadim et al 2009;Abbasvali et al 2012). Differential response to ES between studies may have arisen from inherent experimental conditions.…”

Effects of Medium‐Voltage Electrical Stimulation on Postmortem Changes in Fat‐Tailed Sheep

“…The MFI was higher in the treatment groups, the phenomenon that was previously addressed by Sonaiya and others (1982), Kerth and others (1999), and Martin and others (2006). MFI has been used as an indicator of PM proteolysis (Olson and others 1976; Lametsch and others 2007).…”

“…There were differences between the 5 times of ageing in MFI. The MFI increased in accordance to the ageing time (Sonaiya and others 1982; Martin and others 2006; Toohey and others 2008). The highest MFI was observed in the 5th treatment group, indicating that higher voltage/duration of ES was more effective on the MFI.…”

A Meta-Analysis of the Effectiveness of High, Medium, and Low Voltage Electrical Stimulation on the Meat Quality of Small Ruminants

“…When comparing the effect size of subgroups, ES meat aged for 1-3 days showed the greatest reduction in WBSF (−0.78) as compared with the other subgroups. Most of the studies in the database have reported a reduction in WBSF in meat subjected to ES followed by meat ageing [1,[32][33][34]50], although in approximately half the comparisons, the effects were statistically insignificant (Figure 1). Thus, using the statistical power of a meta-analysis, we demonstrated that ES was effective for improving tenderness of small ruminant meat.…”