Available online at www.sciencedirect.com MEAT SCIENCE Meat Science 78 (2008) 185–193 www.elsevier.com/locate/meatsci

Carcass composition and yield of Alaskan reindeer (Rangifer tarandus tarandus) steers and effects of electrical stimulation applied during field slaughter on meat quality

E. Wiklund a,b,*, G. Finstad b, L. Johansson c, G. Aguiar b, P.J. Bechtel d

a AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand b Reindeer Research Program, University of Alaska Fairbanks (UAF), P.O. Box 757200, Fairbanks, AK 99775-7200, USA c Fja¨rdhundragatan 32, Uppsala, Sweden d USDA-ARS, Subarctic Agricultural Research Unit, UAF, Fairbanks, AK 99775-7220, USA

Received 19 February 2007; received in revised form 1 June 2007; accepted 2 June 2007

Abstract

Twenty six adult reindeer steers (>3 years old) were used in a study to evaluate the effect of electrical stimulation (ES) on the quality of hot-boned, rapidly frozen shoulder meat and of the striploin (M. longissimus, LD) from carcasses held at +3 C for 48 h. Carcass yield and composition was determined from the left carcass half from which the shoulder meat was not removed. The shoulder meat was pro- cessed frozen into cubed, sliced or ground products. Proximate composition of the LD, meat color and water-holding capacity were very similar for the ES (n = 15) and non-electrical stimulation (NES; n = 11) groups. Ultimate pH and shear force values were significantly lower in the ES meat (LD), however a trained sensory panel could not detect differences between the two groups in any of the measured sensory attributes. Consumer preference tests demonstrated that ES increased tenderness in the cubed and sliced products made from field slaughtered reindeer shoulder meat. ES in combination with hot boning and processing of boneless frozen meat can be used in field slaughter systems for reindeer to improve meat quality and to increase the potential value of the carcass. 2007 Elsevier Ltd. All rights reserved.

Keywords: Meat quality; Low voltage stimulation; Carcass composition; Shear force; Trained sensory panel; Consumer test

1. Introduction regulated field slaughter system for the majority of reindeer slaughtered in Alaska. The field slaughtered reindeer meat Alaska has a small red meat industry but given its large can be marketed locally provided animals are slaughtered grazing and forage crop base the potential economic out- on snow when ambient temperature is below 0 C, car- put could be significant. The Alaskan reindeer industry casses are allowed to freeze in the field and the meat is has produced meat for subsistence and local use and at not thawed until in the hands of the consumer (Alaska times has been an important export commodity (Stern, Department of Environmental Conservation, 2003). Ambi- Arobio, Naylor, & Thomas, 1980). Currently, the reindeer ent air temperatures during field slaughtering are usually industry uses both a typical USDA inspected system for a below À10 C so instant chilling and freezing of the car- small number of animals slaughtered annually and a state- casses inevitably occurs. The requirement to keep the field slaughtered reindeer meat frozen (Alaska Department of Environmental Conservation, 2003) limit the diversity of * Corresponding author. Address: AgResearch Limited, Ruakura techniques available for value added processing due to Research Centre, Private Bag 3123, Hamilton 3240, New Zealand. Tel.: +64 7 8385152; fax: +64 7 8385625. the presence of bone in the frozen carcass. However, if E-mail address: [email protected] (E. Wiklund). the bones are removed prior to freezing the meat can be

0309-1740/$ - see front matter 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2007.06.004 186 E. Wiklund et al. / Meat Science 78 (2008) 185–193 sliced, cubed and ground while still frozen. Potential prob- reindeer carcasses on sensory and mechanical tenderness lems include compromised meat quality due to the rapid as well as water-holding properties of the striploin (M. lon- freezing of pre-rigor meat. gissimus) was determined. Another purpose of this study Electrical stimulation accelerates post-mortem glycolysis was to determine carcass yield and composition to illus- and rigor onset, so that rapid cooling or freezing of car- trate the proportion of primal and less valuable cuts in typ- casses may be carried out soon after slaughter without risk ical slaughter animals from the Seward Peninsula, Alaska. of the muscles cold shortening (Davey & Chrystall, 1980). This technique has also been adopted in commercial 2. Material and methods slaughtering as a method of meat tenderisation in beef, lamb and goat carcasses (Chrystall & Hagyard, 1976; 2.1. Animals Davey, Gilbert, & Carse, 1976; Geesink, van Laak, Bar- nier, & Smulders, 1994; Savell, Smith, Dutson, Carpenter, A total of 26 castrated reindeer bulls (>3 years old) were & Suter, 1977). Studies on red deer (Cervus elaphus)dem- included in the study. Reindeer were gathered just outside onstrated that electrical stimulation applied to the car- Nome on the Seward Peninsula, Alaska, and shot in the casses accelerated the rate of tenderisation (Chrystall & field. After bleeding, carcasses were randomly allocated Devine, 1983; Drew, Crosbie, Forss, Manley, & Pearse, to either an electrical stimulation treatment (ES; n = 15) 1988; Wiklund, Stevenson-Barry, Duncan, & Littlejohn, or a no electrical stimulation treatment (NES; n =11). 2001) and had no negative effects on water-holding capac- Electrical stimulation was applied within 5 min post-stun- ity of the meat (Wiklund et al., 2001). Reindeer meat (M. ning/bleeding, followed by removal of the viscera and hide. longissimus) has been found to be extremely tender regard- Meat from the right shoulder was boned out from the less of ultimate pH and to reach optimal tenderness with- warm carcasses in the field at approximately 45 min post- out ageing (Wiklund, Barnier, Smulders, Lundstro¨m, & slaughter, packed into individual plastic-lined cardboard Malmfors, 1997). As early as 3 days post-mortem, shear boxes and left to freeze at ambient temperature. The ambi- force values in the reindeer meat samples were only 2– ent temperature during the field slaughter varied between 3 kg/cm2, which was very low compared with measured À18.6 CandÀ24 C, and the meat in the boxes was frozen shear force values in beef (values around 10 kg/cm2) after in the field after on average 8.2 h post-mortem (varying the same ageing time (Barnier, Wiklund, van Dijk, Smul- between 5.5 and 10 h post-mortem). The carcasses minus ders, & Malmfors, 1999). No reports are available on the the right side shoulder were immediately transported by effects of electrical stimulation on mechanical or sensory truck (10 minutes transport at ambient temperature), to a tenderness or other meat quality attributes in reindeer meat processing facility in Nome and hung in a chilling meat. room (+3 C) to avoid freezing in the field (simulating an Reindeer meat is a very exclusive product even in the inspected slaughter). Temperature in M. longissimus (LD, countries where it is produced and is in high demand and at the last rib) and in M. biceps femoris (BF) was measured often on the menu in the more luxurious restaurants but at 3, 4, 5, 6, 7, 8 and 48 h post-mortem. At 2 days post- otherwise difficult to buy for the ordinary consumer. There slaughter carcasses were boned and both the right and left are traditional ways of processing and preparing reindeer loins (LD) were removed, loins from each side were ran- meat, i.e. in the Fennoscandian countries primal and lower domly allotted for either sensory evaluation (one loin) or quality cuts from the carcass are first separated and the analysis consisting of determination of water-holding lower quality cuts are then frozen and thin sliced to a capacity, proximate analysis, meat color and tenderness stir-fry type product. In rural Alaska, the tradition is to measurements (one loin divided in five parts; four samples cut up the whole carcass in cubes for ‘‘stew’’ meat, though for water-holding capacity measurements and one sample ground meat products have become increasingly popular. for tenderness, color and proximate analysis. Samples were It is essential for reindeer meat producers, abattoir man- randomly allocated to each measurement). All samples agers and wholesale distributors to have knowledge about were vacuum-packaged and frozen at À20 C until analysis carcass composition and the yield of primal and lower except those for determination of water-holding capacity. quality cuts to estimate the potential market value of a car- These samples were either frozen to measure freeze/thaw cass to develop business strategies. Earlier work has loss or vacuum-packaged and chilled (+3 C) for 1, 2 and described carcass composition and yield of reindeer bulls, 3 weeks to measure drip loss (purge). cows and calves from Nunivak Island, Alaska (Renecker, Renecker, & Mallory, 2005). However, this study did not 2.2. Electrical stimulation include castrated bulls (steers) which is the most common reindeer category destined for slaughter in Alaska. Electrical stimulation of the 15 ES carcasses was per- The major purpose of the study was to evaluate the use formed via a low voltage beef stimulator (Jarvis BV80, Jar- of electrical stimulation and hot boning in a field slaughter vis, Connecticut, USA) with the following specifications: setting and the further processing of frozen meat to rectangular pulses with 5 ms duration, 70 ms pulse period improve the quality of less tender reindeer cuts (shoulder and an output of 80 V peak to peak. A 2500 W gas- meat). In addition, the effect of electrical stimulation of powered generator at the field slaughter site powered the E. Wiklund et al. / Meat Science 78 (2008) 185–193 187 stimulator. Carcasses were stimulated in a lying position on brachii, M. supra spinatus and M. infra spinatus with bone the snow and all of them were resting on their left side. The and shank). stimulation equipment was hooked up via battery clips attached to the nasal septum and a fleshy region of the 2.5. Shear force, color and drip loss skinned right rear hock. Current was applied for 20 s within 5 min post-stunning/bleeding. For shear force measurements steaks (2.5 cm thick) were cut from the loin samples and cooked on a George Fore- 2.3. Temperature and pH man grill (Salton, Lake Forest, IL, USA) to a core temper- ature of 70 C. Internal temperature was monitored with Temperatures in the LD (at the last rib) and BF were copper–constantan thermocouples (Type T, Omega Engi- measured with a digital thermometer (Comark, DT 300, neering, Stamford, CT, USA) and a Barnant scanning dig- Beaverton, OR, USA). Ultimate pH values were measured ital thermometer (Model 692-0000, Barnant Co., in the lab in connection with the proximate analysis by Barington, IL, USA). Cores of 1.3 cm were cut parallel homogenizing 2 g of meat in 20 ml of room tempered to the muscle fibers and these cores were sheared at 4 C deionized water. The pH values were registered on a Beck- using a TAXT Plus texture analyzer (Texture Technolo- man 350 pH meter (Beckman Coulter Inc., Fullerton, CA, gies, NY, USA) instrument equipped with a Warner-Brat- USA) equipped with a combination pH electrode (Beck- zler blade attachment at a head speed of 3.5 mm/s. man Futura 511080, Beckman Coulter Inc., Fullerton, Tenderness values were registered as maximum shear force CA, USA). (peak height). Objective color (L, a and b values) was determined with 2.4. Carcass yield and composition a Hunterlab Colorflex (CFLX-45, Hunter Associates Lab- oratory Inc., VA, USA). A 0.5-cm slice was removed from Yield of commercial cuts utilized only the intact left car- the sample to expose a fresh surface to air and the slice was cass half and used a protocol developed for this study, allowed to bloom for 15 min prior to color measurement. based on earlier moose (Alces alces) and reindeer carcass Drip loss (purge) and freeze/thaw loss was measured by studies (Hansson & Malmfors, 1978; Wiklund, Hansson, the following procedure: (1) the combined weight of meat & Malmfors, 2000). Definitions of the cuts presented in and vacuum pack was recorded before opening; (2) at Table 1 are as follows: semiboneless leg (major part of opening, any surplus drip on the meat was removed using the hindquarter of the carcass without shank, pelvic bone, a paper towel and the drip-free weight of the meat vertebrae and flank muscles but including the M. gluteus recorded. The combined dry bag (average weight of 25 medius, M. quadriceps femoris, M. biceps femoris, M. sem- empty vacuum bags) and drip-free meat weights were sub- itendinosus and M. semimembranosus); saddle (M. longissi- tracted from the unopened package weight to obtain the mus with bone); striploin (M. longissimus); tenderloin total drip weight. Drip weight was then expressed as a pro- (M. psoas major); topside (M. semimembranosus); and portion (%) of the original weight of meat packed. forequarter (neck, chuck and shoulder including M. triceps 2.6. Processing of frozen shoulder meat

Table 1 The frozen and boxed shoulder meat was shipped to the Carcass characteristics, yield and composition (means ± standard devia- tion) in reindeer steers included in the study (n = 26) University of Alaska, SFOS Fishery Industrial Technology Center located in Kodiak, Alaska. The frozen meat was Trait removed from the boxes and tempered in a cold room Live weight, kg 104 ± 11.2 (+2–4 C) to a temperature of À3 C before being either Carcass weight (Cw), kg 56.9 ± 6.6 Dressing (%) 54.7 ± 2.4 ground (Brio Grinder model G58463; Brio Manufacturing Hindquarter, kg 21.8 ± 2.4 Company, Ohio, USA) though a plate with 4 mm diameter Hindquarter, % of Cw 38.5 ± 1.7 holes, sliced (Urschel Comitrol model 1700; Urschel Labo- Forequarter, kg 22.7 ± 3.0 ratories Inc., Indiana, USA) using the 0.75 inch head (giv- Forequarter, % of Cw 39.8 ± 1.9 ing slices of approx. 5 mm thickness) or cubed (Koch Dicer Semiboneless leg, kg 15.4 ± 1.8 Semiboneless leg, % of Cw 27.2 ± 1.3 model SR-1; Koch Equipment, Missouri, USA) to approx- Saddle, kg 7.6 ± 1.1 imately 1 cm · 0.75 cm cubes while still frozen. The Saddle, % of Cw 13.4 ± 1.1 ground, sliced and cubed meat samples were then vac- Topside, kg 3.6 ± 0.4 uum-packaged and transported to Fairbanks and kept fro- Topside, % of Cw 6.3 ± 0.4 zen until sensory evaluation. Striploin, kg 1.9 ± 0.3 Striploin, % of Cw 3.4 ± 0.4 Tenderloin, kg 0.8 ± 0.1 2.7. Proximate analysis Tenderloin, % of Cw 1.4 ± 0.1 Bone, kg 17.3 ± 2.4 Moisture content was determined using AOAC method Bone, % of Cw 30.2 ± 2.7 952.08, ash with AOAC method 938.08 (AOAC, 1990) and 188 E. Wiklund et al. / Meat Science 78 (2008) 185–193 lipid content according to Folch, Lees, and Stanley (1957). preparation of the meat samples took place on the day of The nitrogen content was determined in triplicate using the each test and just prior to the tasting sessions. Leco FP-2000 Nitrogen Analyzer (LECO Corporation, St. At each of the test sessions the consumers were pre- Joseph, MI, USA). The protein content was calculated as sented with two samples (meat from ES and NES car- percent nitrogen · 6.25. casses), each coded with a random three-digit number. Together with the meat samples, a questionnaire was pre- 2.8. Sensory evaluation sented with the following instructions; ‘‘In front of you are two samples. Please test the samples from left to right 2.8.1. Trained panel and determine which sample is the most tender. Circle The work was performed at the Cooperative Extension the corresponding number on the score sheet. You must Service, Food Product Development Kitchen (University make a choice, even if it is only a guess. You may re-taste of Alaska Fairbanks). A descriptive test, conventional the samples as often as you wish until they are consumed’’. profiling (ISO 6564, 1985), was carried out by a selected Space was provided for the consumers to specify additional and trained sensory panel (ISO 8586-1, 1993) consisting remarks on the meat samples. of seven members. The panel members were trained in sessions where reindeer meat samples from animals in 2.9. Statistical analysis both treatment groups (ES and NES) and from different meat cuts from the carcasses were presented. The meat The statistical analyses were carried out with the Statis- cuts were selected to represent the typical variation in sen- tical Analysis System (SAS Institute, 2003) using the GLM sory attributes (particularly tenderness) in reindeer meat and originated from the shoulder (M. infraspinatus), the stiploin (M. longissimus), the topside (M. semimembrano- sus) and the outside (M. biceps femoris). The sensory training was performed in accordance with ISO 6564 (1985). All assessments were carried out in a sensory lab- oratory with separate booths equipped with Compusense five, an automated data collection system (Compusense Inc., 2004) and under normal white light (ISO 8589, 1988). Upon thawing, the loin samples were put in a refrigera- tor at +3 C for 17 h. The meat was cooked in a conven- tional oven at 150 C to a core temperature of 70 C. Internal temperature in each loin was monitored with cop- per–constantan thermocouples (Type T, Omega Engineer- ing, Stamford, CT, USA) and a Barnant scanning digital thermometer (Model 692-0000, Barnant Co., Barington, IL, USA). At every session, the panel members were served meat samples from 7 to 9 animals at the same time, each sample consisting of one slice of meat. Samples were placed in plastic cups coded with three-digit numbers and were served to the panel members in randomised order, at room temperature and in two replicates. The following attributes were selected and unanimously agreed upon during panel training; tenderness, juiciness, bloody flavor, gamey flavor and sweet flavor. An unstructured continuous line scale from 0 (low intensity) to 10 (high intensity) was used.

2.8.2. Consumer preference tests Three paired-comparison consumer tests (cubed meat, sliced meat and ground shoulder meat from ES vs. NES carcasses) were performed in collaboration with the Coop- erative Extension Service (CES) on the UAF campus in Fairbanks using a total of 625 consumers to evaluate the cubed, sliced and ground shoulder meat. The cubed meat Fig. 1. Temperature decline in M. longissimus (LD; 1a) and M. biceps was cooked in the vacuum bags in a water bath to an femoris (BF; 1b) from reindeer from two treatments; electrically stimulated end temperature of 74 C. The slices and ground meat (ES; n = 15) or non-stimulated (NES; n = 11) included in the study (least- was roasted on an oven tray until well done (74 C). All squares means), measured at 3, 4, 5, 6, 7, 8 and at boning (48 h post-mortem). E. Wiklund et al. / Meat Science 78 (2008) 185–193 189 and MIXED procedures. The model for comparing carcass Table 3 characteristics and composition, meat ultimate pH, tender- Chemical composition of M. longissimus (LD) in reindeer from two ness, color, drip loss, and chemical composition included treatments; electrically stimulated (ES; n = 15) or non-stimulated (NES; n = 11) included in the study (least-squares means and standard errors) the fixed effect of treatment group. Significance was defined a as P 6 0.05. For the trained panel work, the model Trait ES group NES group Degree of sign. included the random effects animal and panel member, as Moisture (%) 72.0 ± 0.6 71.8 ± 0.7 n.s. well as the fixed effect of treatment group. The consumer Ash (%) 1.2 ± 0.1 1.1 ± 0.1 n.s. Protein (%) 23.6 ± 0.5 23.6 ± 0.6 n.s. tests were set up as three separate paired comparisons Fat (%) 2.7 ± 0.3 2.8 ± 0.4 n.s. (one-sided directional difference tests) with the null hypoth- a n.s. = P > 0.05; *P < 0.05. esis being H0: Tenderness ES samples = Tenderness NES samples and the alternate hypothesis being Ha: Tenderness ES samples > Tenderness NES samples (Mielgaard, Civille, & Carr, 1999). Table 4 Consumer preference for processed (cubed, sliced and ground) hot boned 3. Results and frozen reindeer shoulder meat (M. triceps brachii, M. supra spinatus and M. infra spinatus) from electrically stimulated (ES) or non-stimulated 3.1. Carcass characteristics and composition, pH and (NES) animals included in the study temperature Question Which of these two samples is the most tender? Number Preference Preference Degree of The carcass characteristics, including yield and compo- participants ES NES signa sition, for the reindeer steers are illustrated in Table 1. Cubed meat 203 114 89 * Temperature decline in M. longissimus (LD) and Sliced meat 205 130 75 *** M. biceps femoris (BF) were very similar for both treat- Ground meat 217 119 98 n.s. ment groups (Fig. 1) indicating no effect of electrical Total 625 stimulation on carcass cooling rate. The ES carcasses a n.s. = P > 0.05; *P < 0.05; *** P < 0.001. had significantly lower ultimate pH in LD compared with the NES carcasses although the difference was only 0.07 pH units (Table 2). 3.3. Sensory evaluation 3.2. Color, shear force, drip loss and chemical composition 3.3.1. Trained panel The LD from the ES carcasses was significantly more No significant differences between the two treatment tender than LD from the NES carcasses when measured groups (ES and NES) were found when comparing the sen- as shear force values (Table 2). No differences were found sory attributes of the meat (LD). Sensory scores (least- in meat color values, drip loss or freeze/thaw loss between squares means and standard errors) indicated that all sam- the two treatment groups (Table 2). ples were tender (values from 6.2 to 6.6 ± 0.4), juicy (value The analysis of proximate composition (moisture, ash, 6.2 ± 0.3 for both groups), had low scores for game flavor fat and protein) showed no differences between the LD (value 3.0 ± 0.4 for both groups), bloody flavor (values samples from the ES and NES groups (Table 3). from 4.6 to 4.7 ± 0.6) and sweet flavor (3.1–3.3 ± 0.3).

3.3.2. Consumer tests In the consumer tests of the cubed (P < 0.05) and sliced Table 2 meat (P < 0.001), the ES meat was significantly more ten- Meat quality characteristics in M. longissimus (LD) in reindeer from two der compared with the NES meat (Table 4). No significant treatments; electrically stimulated (ES; n = 15) or non-stimulated (NES; difference was found when comparing the ground meat, n = 11) included in the study (least-squares means and standard errors) however a tendency (P < 0.10) towards ES meat being a Trait ES group NES group Degree of sign. most tender was observed (Table 4). Ultimate pH 5.58 ± 0.01 5.65 ± 0.01 *** Shear force (kg) 1.68 ± 0.05 1.84 ± 0.06 * 4. Discussion Color L-value 19.4 ± 0.3 18.8 ± 0.4 n.s. Color a-value 15.7 ± 0.3 15.6 ± 0.4 n.s. Color b-value 12.8 ± 0.2 12.3 ± 0.3 n.s. Reindeer in Alaska originate from Chukotka in Russia where they were selected and used for meat production. Drip loss (%) 1 week 3.7 ± 0.5 4.1 ± 0.6 n.s. Even though this sub species is the same as the Fennoscan- 2 weeks 4.9 ± 0.4 5.1 ± 0.5 n.s. dian reindeer (Rangifer tarandus tarandus), the Alaskan 3 weeks 6.4 ± 0.6 5.2 ± 0.7 n.s. animals are heavier and have a stockier body shape (Fins- Freeze/thaw 7.1 ± 0.6 7.6 ± 0.6 n.s. tad & Prichard, 2000). Alaskan reindeer herders typically a n.s. = P > 0.05; *P < 0.05; ***P < 0.001. manage and slaughter adult steers (Alaska Agriculture Sta- 190 E. Wiklund et al. / Meat Science 78 (2008) 185–193 tistics, 1990–2006), whereas the Fennoscandian reindeer 30 industry uses the strategy of slaughtering more calves to topside enhance meat production from the herds (Danell, 1998; 25 silverside Helle & Kojola, 1993). As an example 33,457 animals or knuckle 63.8% of the total number of slaughtered reindeer (52,409 20 animals) in Sweden 2004/2005 were calves (National Board 15 of Agriculture, 2006). The present values for live weights % and carcass weights from Alaskan reindeer steers were notably higher than values reported for adult Swedish rein- 10 deer (Wiklund et al., 2000) and for reindeer slaughtered on Nunivak Island, Alaska (Renecker et al., 2005). The pres- 5 ent data were in good agreement with a recent study of sea- sonal variation in live weights, carcass weights and carcass 0 Reindeer Reindeer Moose Beef heifers Rusa deer composition of adult reindeer bulls and steers from the steers calves and bulls Seward Peninsula (Wiklund, Finstad, & Bechtel, 2005). Similar carcass composition values to those of the pres- Fig. 2. Hindquarter meat cuts as a percentage of hind leg weight from reindeer steers (present study); reindeer calves (Wiklund, unpublished ent study for reindeer have been reported for Swedish adult data); moose (Hansson & Malmfors, 1978); beef (Hansson & Malmfors, reindeer bulls by Wiklund et al. (2000). In the same study it 1978); and Rusa deer (Sookhareea et al., 2001). The hindquarter cuts are: was found that reindeer carcasses had lower fat contents topside (M. semimebranosus); silverside (M. biceps femoris and M. semi- and higher bone contents than red and fallow deer or tendinosus); and knuckle (M. quadriceps femoris). domestic species (Wiklund et al., 2000), results that were in good agreement with those in the present study. Surgical and chemical castration of deer has been demonstrated to High ultimate pH values in meat from ruminants (beef affect animal live weight gain and carcass composition, cattle, reindeer, red deer and fallow deer (Dama dama)) mainly fat content (Drew, Fennessey, & Greer, 1978; Freu- have been related to pre-slaughter handling stress denberger et al., 1991; Mulley & English, 1985), therefore (Malmfors, Lundstro¨m, & Fabiansson, 1983; Pollard, further studies of carcass composition and meat quality Stevenson-Barry, & Littlejohn, 1999; Warriss, 1990; Wikl- attributes in Alaskan reindeer bulls and steers are being und, Andersson, Malmfors, & Lundstro¨m, 1996)and carried out. The variation in muscle/meat distribution poor nutritional status of the animals (Gregory, 1996; between different deer species was described by Goosen, Pollard et al., 2002; Wiklund et al., 1996). The reindeer Fennessey, and Pearse (1999), where a hybrid animal (cross in the present study were shot in the field after a mini- between red deer and Pe`re David’s deer (Elaphurus davidi- mum of pre-slaughter handling and the measured meat anus) was demonstrated to have relatively more meat in the pH values thus indicated that all animals were exposed hind leg primal cut compared with red deer. Generally, the to a stress-free slaughter and that they were in good most valuable cuts from a carcass originate from the strip- physical condition. loin, tenderloin and hindquarter. To illustrate the species When carcasses are cooled quickly, they have the differences in hindquarter composition, literature values potential to be affected by cold-induced shortening and/ for the three main cuts from the hindquarter (topside; or toughening (Savell, Mueller, & Baird, 2005). Muscle M. semimembranosus, silverside; M. biceps femoris and temperature and pH relationships at the moment of rigor M. semitendinosus and knuckle; M. quadriceps femoris) onset have been proposed to determine the degree of cold from reindeer, moose, Rusa deer (Cervus timorensis russa) shortening (Hannula & Puolanne, 2004). The susceptibil- and beef carcasses are compared in Fig. 2. Rusa deer had ity to cold shortening has been demonstrated to vary a very high percent of meat in the hindquarter (topside between different types of muscle fibers (Bendall, 1973) 21.5%, silverside 25.4% and knuckle 18.7%) compared with and consequently beef, lamb and deer meat (where most the other species (Sookhareea, Taylor, Dryden, & Wood- muscles are dominated by red muscle fibers) was thought ford, 2001). As shown in Fig. 2 the topside of the reindeer to be more sensitive to cold shortening than pork (Savell hindquarters was the largest cut (16.4% of the hindquar- et al., 2005). There are economic advantages for rapid ter), while in moose the largest cut was the knuckle carcass chilling, which include reduced cooling time, (15.3%) and in beef the silverside (14.4%). The hindquar- increased carcass processing rate and decreased shrink ters and forequarters in the present study represented and drip losses; however rapid chilling may reduce meat approximately equal proportions of the whole carcass tenderness (Aalhus, Janz, Tong, Jones, & Robertson, (hindquarter 38.8%; forequarter 40.2%). The economical 2001). Using treatments like electrical stimulation and value of the reindeer carcass would increase considerably pelvic suspension (i.e. hanging the carcass from the obtu- if value could be added to the forequarter. This is challeng- rator foramen) offer meat processors the opportunity ing in the field slaughter situation where the carcasses have to counteract most or all the effects of cold shortening to be frozen in the field and cannot be thawed before pur- (Savell et al., 2005). The combination of electrical stimu- chase by the consumer. lation and rapid/blast chilling has been recommended as E. Wiklund et al. / Meat Science 78 (2008) 185–193 191 a means to reduce chilling times and shrink losses while Littlejohn, 2006; Wiklund et al., 2001) and fallow deer producing meat of as good or slightly superior quality and lamb meat (LD) purge values of 2.0–2.6% after 3 compared with conventionally cooled beef carcasses (Aal- weeks of storage (Wiklund, Mulley, Hutchison, & Little- hus et al., 2001; Li et al., 2006). Meat from bison (Bison john, 2004) were lower than the purge values of 5.2 and bison bison) carcasses exposed to conventional chilling (0– 6.4% after 3 weeks of storage found in the present study. 2 C for 24 h) and blast chilling (À20 Cand3msÀ1 air It should be noted that the red deer studies (Wiklund velocity for 2 h) with or without ES was significantly et al., 2006; Wiklund et al., 2001) were performed within more tender after ES compared to the NES treatment the practices of the New Zealand venison industry where (Janz, Aalhus, & Price, 2001). The present reindeer LD fresh meat is stored and transported at À1.5 C while in samples were all very tender regardless of ES or NES the fallow deer/lamb study (Wiklund et al., 2004) and in treatment, though ES samples were significantly more the present study samples were stored at +2–3 C. tender than NES samples. Earlier studies have reported Objective color values as determined by the Hunter equally low shear force (high tenderness) values for rein- chromameter were not different (p > 0.05) between ES deer meat (Rincker et al., 2006; Wiklund et al., 1997). and NES samples for L, a,andb values. The Hunter L val- The present results support earlier conclusions that rein- ues in the present study of 18.8 and 19.4 were slightly lower deer meat (LD) does not require a period of ageing to than values reported by McDougall, Shaw, Nute, & be tender (Barnier et al., 1999; Wiklund et al., 1997) Rhodes (1979) for venison from farmed young red deer. and consequently electrical stimulation would not practi- The lower Hunter L, a, and b values of the reindeer meat cally increase the rate of meat tenderization in primal are consistent with a product that is darker in appearance, cuts like the striploin. The potential positive effects of and has less red and yellow color than beef (Rincker et al., ES on tenderness in tougher reindeer meat cuts (like 2006). Other investigators have compared the effects of ES shoulder meat) must therefore be balanced against the on Minolta L, a,andb meat color values and reported ES risk of ‘over-tenderizing’ the already very tender primal beef to be paler (higher L values) and also redder (higher a cuts. The fact that individual muscles exhibit different values) than NES beef (Eikelenboom, Smulders, & Rude´- pre-rigor behaviours was highlighted in a study of hot- rus, 1985; Hector, Brew-Graves, Hassen, & Ledward, boned ES treated beef (White, O’Sullivan, Troy, & 1992). ES treatment was associated with some loss of color O’Neill, 2006). In this study (White et al., 2006) it was stability during retail display of red deer meat (Wiklund concluded that mechanisms other than the prevention et al., 2001), although this effect of ES was shown to be of shortening could be involved in the ES induced tender- neutralized by manipulation of rigor temperature (Bekhit, ization of meat and that a variation in fiber type compo- Farouk, Cassidy, & Gilbert, 2007). sition and physical dimensions of the muscles might The significant difference in mechanical tenderness impact on the ES regimes. (shear force) between the two treatment groups showed The procedure of hot boning was developed to remove that the ES treated meat (LD) was slightly more tender meat cuts from the carcass before chilling or freezing. than the NES meat (Table 2), however with all shear force However, excised muscle removed pre-rigor is more suscep- values being below 2 kg the marginal difference between the tible to shortening due to the loss of muscle–bone attach- groups could not be picked up by the trained panel. Sen- ment and rapid freezing would enhance the likelihood of sory scores for tenderness and juiciness in reindeer meat cold shortening (Savell et al., 2005). When meat freezes (LD) have been reported to be high (Renecker et al., before the onset of rigor then, on thawing, the muscle 2005; Rincker et al., 2006; Wiklund, Johansson, & Malmf- shortens severely and becomes very tough after cooking, ors, 2003), and the present results are in agreement with a phenomenon called thaw rigor (Warriss, 2000). If thaw previous studies. In the present experiment three different rigor occurred in the processed reindeer meat samples in products were prepared (thin sliced, cubed and ground the present study that would have happened just before meat) from field slaughtered lower quality cuts (shoulder cooking the meat, as the meat samples were frozen until meat) and the consumers confirmed ES treatment to cooking. The effects of shortening/contraction would prob- increase tenderness in the cubed and sliced meat products ably have been less in the processed samples, where the (Table 4). These results are somewhat in contrast to the meat structure was mechanically broken compared with study by Toohey & Hopkins (2006) who concluded that the effects whole pieces of meat. Further, it has been sug- ES was not sufficient to ensure eating quality of hot- gested that the effects of thaw rigor might be reduced dur- boned/rapidly frozen sheep meat. ing frozen storage of meat (Warriss, 2000). Results from the consumer test in the present study suggest application 5. Conclusions of low voltage ES may have ameliorated the effects of any shortening/toughening of hot-boned reindeer meat. Results from this study demonstrate that ES increased Values for drip loss (purge) during storage of fresh tenderness in hot-boned cubed and sliced products made chilled reindeer meat have not been reported. However, from field slaughtered reindeer shoulder meat. Loins from purge values of 0.6–3.7% for red deer LD samples after 3 carcasses conditioned for 48 h prior to boning and freezing weeks of storage (Wiklund, Sampels, Manley, Pickova, & were similar in color and tenderness although ES did result 192 E. Wiklund et al. / Meat Science 78 (2008) 185–193 in slightly lower shear force values. The ES technique in and New Zealand wapiti-type male deer. Journal of the Science of Food combination with the right processing methods can be used and Agriculture, 43, 245–259. in field slaughter systems for reindeer to significantly Drew, K. R., Fennessey, P. F., & Greer, G. J. (1978). The growth and carcass characteristics of entire and castrate red stags. Proceedings: increase the quality and potential value of e.g. forequarter New Zealand Society of Animal Production, 38, 142–144. meat. Eikelenboom, G., Smulders, F. J. M., & Rude´rus, H. (1985). The effect of high and low voltage electrical stimulation on beef quality. Meat Acknowledgements Science, 15, 247–254. Finstad, G. L., & Prichard, A. K. (2000). Growth and body weight of free- range reindeer in western Alaska. Rangifer, 20, 221–227. The authors wish to thank the Davis’ family of Nome, Folch, J., Lees, M., & Stanley, G. H. S. (1957). A simple method for the Heikki Muhonen and Chuck Stites for all their assistance isolation and purification of total lipids from animal tissues. Journal of and cooperation in connection with the slaughter, butcher- Biological Chemistry, 226, 497–509. ing and collection of samples. We are also grateful to Freudenberger, D. O., Wilson, P. R., Purchas, R. W., Barry, T. N., Moss, Heather Averett for laboratory analysis and Kamolluck B. A., & Trigg, T. E. (1991). Effects of immunization against LHRH on body growth, scrotal circumference and carcass composition in Trateng for her invaluable assistance during the sensory yearling red deer stags. Proceedings: New Zealand Society of Animal sessions with the trained panel. During the consumer tests Production, 51, 63–65. the help of Suzanne Worker, Margo Kramer and Becky Geesink, G. H., van Laak, H. L. J. M., Barnier, V. M. H., & Smulders, F. Knight was greatly appreciated. Financial support for this J. M. (1994). Does electrical stimulation affect the speed of ageing or work was provided by the United States Department of ageing response?. Sciences des Aliments 14, 409–422. Goosen, G. J., Fennessey, P. F., & Pearse, A. J. (1999). Carcass Agriculture (USDA; New Crops Opportunities IV, grant composition of male and female red deer and hybrids with Pe`re no. G00001355) and by the Reindeer Research Program, David’s deer. New Zealand Journal of Agricultural Research, 42, University of Alaska Fairbanks. 483–491. Gregory, N. G. (1996). Welfare and hygiene during pre-slaughter References handling. Meat Science, 43S, S35–S46. Hannula, T., & Puolanne, E. (2004). The effect of cooling rate on beef tenderness: The significance of pH at 7 C. Meat Science, 67, Aalhus, J. L., Janz, J A. M., Tong, A. K. W., Jones, S. D. M., & 403–408. Robertson, W. M. (2001). The influence of chilling rate and fat Hansson, I., & Malmfors, G. (1978). Meat production from moose (Alces cover on beef quality. Canadian Journal of Animal Science, 81, alces L). Swedish Journal of Agricultural Research, 8, 155–159. 321–330. Hector, D. A., Brew-Graves, C., Hassen, N., & Ledward, D. A. (1992). Alaska Agriculture Statistics. (2006). US Department of Agriculture. Relationship between myosin denaturation and the colour of low- Palmer Alaska. voltage-electrically stimulated beef. Meat Science, 31, 299–307. Alaska Department of Environmental Conservation. (2003). Regulations Helle, T., & Kojola, I. (1993). Reproduction and mortality of Finnish for reindeer slaughtering and processing (18 AAC 32.600) and semi-domesticated reindeer in relation to density and management regulations for reindeer for retail sale to or at a market (18 AAC strategies. Arctic, 46, 72–77. 31.820). State of Alaska, USA. ISO 6564. International Organisation for Standardization. (1985). Sensory AOAC (1990). Official methods of analysis (15th ed.). Arlington, VA, analysis – methodology – flavour profile methods. ISO 6564:1985 (E), USA: Association of Official Analytical Chemists. Geneve, Switzerland. Barnier, V. M. H., Wiklund, E., van Dijk, A., Smulders, F. J. M., & ISO 8586-1. International Organisation for Standardization. (1993). Malmfors, G. (1999). Proteolytic enzyme and inhibitor levels in Sensory analysis – general guidance for the selection, training and reindeer (Rangifer tarandus tarandus L) vs. bovine longissimus muscle, monitoring of assessors – Part 1: Selected assessors. ISO 8586-1:1993 as they relate to ageing rate and response. Rangifer, 19, 13–18. (E), Geveve, Switzerland. Bekhit, A. E. D., Farouk, M. M., Cassidy, L., & Gilbert, K. V. (2007). ISO 8589. International Organisation for Standardization. (1988). Sensory Effects of rigor temperature and electrical stimulation on venison analysis – general guidance for the design of test rooms. ISO 8589:1988 quality. Meat Science, 75, 558–563. (E), Geveve, Switzerland. Bendall, J. R. (1973). The biochemistry of rigor mortis and cold- Janz, J. A. M., Aalhus, J. I., & Price, M. A. (2001). Blast chilling and low contracture. In Proceedings: 19th European meeting of meat research voltage electrical stimulation influences on bison (Bison bison bison) workers, Paris, France (pp. 1–27). meat quality. Meat Science, 57, 403–411. Chrystall, B. B., & Devine, C. E. (1983). Electrical stimulation of deer Li, C. B., Chen, Y. J., Xu, X. L., Huang, M., Hu, T. J., & Zhou, G. H. carcasses. New Zealand Journal of Agricultural Research, 26, 89–92. (2006). Effects of low-voltage electrical stimulation and rapid chilling Chrystall, B. B., & Hagyard, C. J. (1976). Electrical stimulation and lamb on meat quality characteristics of Chinese Yellow crossbred bulls. tenderness. New Zealand Journal of Agricultural Research, 19, 7–11. Meat Science, 72, 9–17. Compusense Inc. (2004). Compusense five, release 4.6-SP2. Compusense Malmfors, G., Lundstro¨m, K., & Fabiansson, S. (1983). Influence of Inc., Guelph, Ontario, Canada. handling systems on meat quality of beef. In Proceedings: 29thEuro- ¨ Danell, O. (1998). Optimal production. In Proceedings: 10th Nordic pean Congress of Meat Research Workers, Salsomaggiore, Italy (pp. conference on reindeer research, Kautokeino, Norway. Rangifer Report, 70–75). 2, 19. McDougall, D. B., Shaw, B. G., Nute, G. R., & Rhodes, D. N. (1979). Davey, C. L., & Chrystall, B. B. (1980). Condition for an efficient post- Effect of pre-slaughter handling on the quality and microbiology of mortem electrical stimulation. Annales de Technologie Agricole, 29, venison from farmed young red deer. Journal of the Science of Food 547–561. and Agriculture, 30, 1160–1167. Davey, C. L., Gilbert, K. V., & Carse, W. A. (1976). Carcass electrical Mielgaard, M., Civille, G. V., & Carr, B. T. (1999). Sensory evaluation stimulation to prevent cold shortening toughness in beef. New Zealand techniques (3rd ed.). New York, USA: CRC Press. Journal of Agricultural Research, 19, 13–18. Mulley, R. C., & English, A. W. (1985). The effects of castration of fallow Drew, K. R., Crosbie, S. F., Forss, D. A., Manley, T. R., & Pearse, A. J. deer (Dama dama) on body growth and venison production. Animal (1988). Electrical stimulation and ageing of carcasses from red, fallow Production, 41, 359–361. E. Wiklund et al. / Meat Science 78 (2008) 185–193 193

National Board of Agriculture. (2006). Statistics of Swedish reindeer White, A., O’Sullivan, A., Troy, D. J., & O’Neill, E. E. (2006). Effects of slaughter 2004/2005. Available from: http://www.sjv.se. electrical stimulation, chilling temperature and hot-boning on the Pollard, J. C., Littlejohn, R. P., Asher, G. W., Pearse, A. J. T., Stevenson- tenderness of bovine muscles. Meat Science, 73, 196–203. Barry, J. M., McGregor, S. K., et al. (2002). A comparison of Wiklund, E., Andersson, A., Malmfors, G., & Lundstro¨m, K. (1996). biochemical and meat quality variables in red deer (Cervus elaphus) Muscle glycogen levels and blood metabolites in reindeer (Rangifer following either slaughter at pasture or killing at a deer slaughter plant. Tarandus Tarandus L) after transport and lairage. Meat Science, 42, Meat Science, 60, 85–94. 133–144. Pollard, J. C., Stevenson-Barry, J. M., & Littlejohn, R. P. (1999). Wiklund, E., Barnier, V. M. H., Smulders, F. J. M., Lundstro¨m, K., & Factors affecting behaviour, bruising and pH in a deer slaughter Malmfors, G. (1997). Proteolysis and tenderisation in reindeer premises. Proceedings: New Zealand Society of Animal Production, (Rangifer tarandus tarandus L) bull longissimus thoracis muscle of 59, 148–151. various ultimate pH. Meat Science, 46, 33–43. Renecker, T. A., Renecker, L. A., & Mallory, F. F. (2005). Relationships Wiklund, E., Hansson, I., & Malmfors, G. (2000). Composition and between carcass charactieristics, meat quality, age and sex of free- quality of reindeer (Rangifer tarandus tarandus) carcasses. In Proceed- ranging Alaskan reindeer: A pilot study. Rangifer, 25, 107–121. ings: 46th International congress of meat science and technology, Buenos Rincker, P. J., Bechtel, P. J., Finstad, G., van Buuren, R. G. C., Killefer, Aires, Argentina. J., & McKeith, F. K. (2006). Similarities and differences in composi- Wiklund, E., Mulley, R. C., Hutchison, C. L., & Littlejohn, R. P. (2004). tion and selected sensory attributes of reindeer, caribou and beef. Effect of carcass suspension method on water holding capacity of M. Journal of Muscle Foods, 17, 65–78. longissimus from fallow deer (Dama dama) and lamb. In Proceedings: SAS Institute (2003). SAS System for Windows, release 9.1. Cary, NC: 50th International congress of meat science and technology, Helsinki, SAS Institute. Finland. Savell, J. W., Mueller, S. L., & Baird, B. E. (2005). The chilling of Wiklund, E., Finstad, G., & Bechtel, P. J. (2005). Seasonal variation in carcasses. Meat Science, 70, 449–459. carcass quality of reindeer (Rangifer tarandus tarandus) from the Savell, J. W., Smith, G. C., Dutson, T. R., Carpenter, Z. L., & Suter, D. A. Seward Peninsula, Alaska. In Proceedings: 51th International congress (1977). Effect of electrical stimulation on palatability of beef, lamb and of meat science and technology, Baltimore, USA. goat meat. Journal of Food Science, 42, 702–706. Wiklund, E., Johansson, L., & Malmfors, G. (2003). Sensory meat quality, Sookhareea, R., Taylor, D. G., Dryden, G. McL., & Woodford, K. B. ultimate pH values, blood parameters and carcass characteristics in (2001). Primal joints and hind-leg cuts of entire and castrated Javan reindeer (Rangifer tarandus tarandus L) grazed on natural pastures or rusa (Cervus timorensis russa) stags. Meat Science, 58, 9–15. fed a commercial feed mixture. Food Quality and Preference, 14, Stern, R. O., Arobio, E. L., Naylor, L. L., & Thomas, W. C. (1980). 573–581. Eskimos, reindeer and land. Agricultural and Forestry Experimental Wiklund, E., Sampels, S., Manley, T. R., Pickova, J., & Littlejohn, R. P. Station, University of Alaska Fairbanks. Bulletin, 59, 205. (2006). Effects of feeding regimen and chilled storage on water holding Toohey, E. S., & Hopkins, D. J. (2006). Eating quality of commercially capacity, colour stability, pigment content and oxidation in red deer processed hot boned sheep meat. Meat Science, 72, 660–665. (Cervus elaphus) meat. Journal of the Science of Food and Agriculture, Warriss, P. D. (1990). The handling of cattle pre-slaughter and its effect on 86, 98–106. carcass and meat quality. Applied Animal Behaviour Science, 28, Wiklund, E., Stevenson-Barry, J. M., Duncan, S. J., & Littlejohn, R. P. 171–186. (2001). Electrical stimulation of red deer (Cervus elaphus) carcasses – Warriss, P. D. (2000). Meat science – an introductory text. United effects on rate of pH-decline, meat tenderness, colour stability and Kingdom: CABI Publishing, CAB International. water holding capacity. Meat Science, 59, 211–220.