The effect of whole carcase medium voltage electrical stimulation, tenderstretching and longissimus infusion with actinidin on alpaca meat quality.

The effect on alpaca meat quality from applying medium voltage electrical stimulation (ES) in combination with tenderstretching (TS; pubic symphysis suspended) to whole carcases was investigated, along with the effect of actinidin infusion on alpaca longissimus (LTL) quality. Carcases (n = 36) were allocated to either no ES + achilles hung; or ES + TS. The left- and right-hand side LTL of each carcase was allocated to one of three infusion treatments; no infusion (control), infusion with water or infusion with enzyme. Processing treatments reduced LTL and semimembranosus shear force without negatively impacting colour or oxidation traits. Infusion with enzyme reduced LTL shear force relative to control and water treatments but resulted in reduced consumer acceptance. The use of TS with ES in commercial alpaca processing is supported. There was no advantage to infusing alpaca LTL with actinidin as results indicate a net negative effect on consumer acceptance of this novel meat.

The effects of season and post-transport rest on alpaca (Vicunga pacos) meat quality.

The effects of season (summer, autumn, winter and spring) and post-transportation rest on alpaca meat quality were investigated in 160 castrated male alpacas (23 ±â€¯1 month of age) over a 12 month period. Twice per season, animals were randomly allocated to consignment groups of 20, transported 4 h to slaughter and allocated to either of two treatment groups: (1) overnight lairage pre slaughter (Direct) and (2) seven day rest period with access to feed pre slaughter (Rested). At slaughter, blood was collected for the analysis of plasma cortisol and a longissimus core sample obtain pre rigor for glycogen content determination. Alpaca muscle moisture loss increased through summer and spring in the longissimus thoracics. Seasonal differences did not reflect pasture seasonality or muscle glycogen content. Resting alpacas for 7 days pre-slaughter reduced muscle glycogen content and tenderness. Drip loss and purge was greater for rested animals indicating that resting alpacas post transport is not advantageous to alpaca meat quality.

The effect of electrical stimulation and tenderstretching on colour and oxidation traits of alpaca (Vicunga pacos) meat.

The effects of tenderstretching (TS; carcase suspension by the pelvic bone) combined with medium voltage electrical stimulation (ES) on alpaca colour and oxidative traits was investigated. Castrated huacya alpacas were processed and treatments applied to the 36 split carcases, in a 2 × 2 factorial arrangement (Achilles hung; AH/TS and ES/non-ES). After 24 h chilling, colour stability analysis and thiobarbituric acid reactive substances evaluation (TBARS) was conducted on samples of longissimus and adductor femoris. An additional 30 cm of longissimus was prepared for TBARS evaluation and sensory assessment using an untrained consumer panel. Electrical stimulation increased lipid oxidation within the longissimus. However, overall oxidation levels were extremely low and as a result ES effects on oxidation were not detected at the consumer level. Therefore, the combined processing treatments did not dramatically impact alpaca meat eating quality or colour stability. Results also indicate that alpaca displays advantageous colour and oxidation traits when compared to other red meats.

Vitamin E concentration in alpaca meat and its impact on oxidative traits during retail display.

The longissimus thoracis et lumborum (LL), and adductor femoris (AF) muscles from 39 castrated, 23 (±1) month old huacaya alpacas were used to determine vitamin E content and the impact on lipid oxidation levels. At 24 h post death the LL and AF muscles were removed and sampled for meat quality analysis and subjected to simulated retail display. Vitamin E content of either muscle had no significant impact on colour stability or oxidation traits during retail display. This is thought to be due to the high levels of vitamin E (>5.4 mg/kg) in both muscles. Lipid oxidation levels were 0.2 mg MDA/kg higher in both muscles post retail display. However, overall differences in TBARS levels detected pre and post display were very low (<1.19 mg MDA/kg) and well below sheep threshold values of >3 mg MDA/kg. The mechanism behind why alpaca meat has such high vitamin E levels compared to other species requires further investigation.

Measurement of drip loss in alpaca (Vicugna pacos) meat using different techniques and sample weights.

Drip loss is an indicator of water holding capacity in fresh meat that can be measured using the bag method and the newer EZ method. However, to our knowledge, no previous study has investigated the application of these methods to assess drip loss of fresh alpaca meat. Over a year, 160 alpaca (Vicugna pacos) loins were sampled using the two different drip loss methods. There was no difference (P = 0.490) in drip loss percentage between the bag (3.39 ±â€¯0.24%) and EZ method (3.16 ±â€¯0.22%). The 24 h pH had a significant (P = 0.03) impact on drip loss percentages, such that as pH increased the drip loss percentage decreased. A greater (P < 0.001) drip loss was found using the bag method if the sample weighed 80 g (4.04 ±â€¯0.15%) compared to 60 g (3.38 ±â€¯0.12%).

The effect of combining tenderstretching and electrical stimulation on alpaca (Vicugna pacos) meat tenderness and eating quality.

The effect of combining tenderstretching (TS; carcase suspension by the pelvic bone) with medium voltage electrical stimulation (ES) during processing on the tenderness of alpaca muscles was investigated. Thirty-six split alpaca carcases were randomly allocated to treatments in a 2 × 2 factorial arrangement (Achilles hung/TS and ES/non-ES). Samples were collected from the m. longissimus thoracis (LT), m. adductor femoris (AF), m. semimembranosus (SM), m. semitendinosus (ST) and m. psoas major (TL) at 24 h post slaughter for shear force, sarcomere length, collagen and myofibre (particle size) measurement. Additional samples were taken from the m. longissimus lumborum (LL) for sensory assessment using an untrained consumer panel. Tenderstretching reduced shear force and variability within the alpaca AF, without negatively affecting the TL, while ES significantly improved TL and LT tenderness. Consumers were able to detect ES treated LL, rating ES samples higher for all sensory traits. Combining ES and TS maximizes alpaca carcase tenderness when considered on a multiple muscle basis.