H.N. Zerby

Consumer perceptions of pork eating quality as affected by pork quality attributes and end-point cooked temperature

The study evaluated the interactive and individual effects of fresh pork loin (n=679) ultimate pH (pH), intramuscular fat (IMF), Minolta L* color (L*), Warner-Bratzler shear force (WBS), and four cooked temperatures (62.8 degrees C, 68.3 degrees C, 73.9 degrees C, and 79.4 degrees C) on consumer (n=2280) perception of eating quality (n=13,265 observations). Data were analyzed using ordered logistical regression. Predicted mean responses were consistently near or under five on the 1-8-point end-anchored scale, indicating a neutral perception of pork eating quality regardless of fresh quality or cooked temperature. Responses improved as IMF and pH increased and WBS decreased, whereas L* did not contribute significantly to variation in responses. Increasing IMF resulted in a very small incremental improvement in responses, but was of practical size only when comparing the least (1%) to the greatest (6%) levels. Loin pH and WBS were primary contributors to consumer perceptions, whereby an incremental increase in pH (0.20 unit) and decrease in WBS (4.9 N) resulted in a 4-5% reduction in the proportion of consumers rating pork as >or= 6 (favorable) on the 8-point scale. No interactions between quality and temperature effects were observed. Increased cooked temperature was negatively (P<0.05) associated with Overall-Like and Tenderness ratings, but the incremental effect was small. Juiciness-Like and Level responses decreased by 0.50 units as temperature increased across the range. Consumer responses favor pork with lower WBS, greater pH and IMF, and pork cooked to a lower temperature.

Effect of visual marbling on sensory properties and quality traits of pork loin.

Pork loins (N=53) were selected from a commercial packing plant to determine the influence of subjective marbling score on sensory attributes and eating quality properties. The pork loins were obtained from commercially raised hybrid barrows (average carcass weight=67.7 kg), originating from nine cooperating herds, and fed similar diets throughout the finishing period. Carcass quality measurements, trained sensory panel analyses, fatty acid composition, thiobarbituric acid-reactive substance (TBARS) index, and cholesterol content were assessed and analyzed on the individual pork loins. With an increase in marbling level, there was a corresponding decrease in drip loss (P=0.049) and observed increases in pH (P=0.001), sensory tenderness (P=0.001), and sensory juiciness scores (P=0.017). The most notable results demonstrated that protein concentrations were reduced as marbling levels amplified (P=0.012). The increase in marbling score was observed to be a significant source of variation in polyunsaturated fatty acid (PUFA) concentrations. Linoleic and arachidonic acids decreased in both raw and cooked samples as marbling score increased. The data demonstrated that visual marbling score does have an influence on sensory properties and pork quality.

Prerigor infusion of lamb with sodium chloride, phosphate, and dextrose solutions to improve tenderness

Combinations of sodium chloride, phosphate, and dextrose solutions were infused prerigor into lamb carcasses to evaluate effects on tenderness, palatability, color change and microbiological growth during simulated retail display. Each carcass (n=48) was randomly assigned to one of the following: (1) deionized water (dH(2)O), (2) 2% NaCl (S), (3) 3% dextrose (D), (4) 0.5% tri-polyphosphate (P), (5) 2% NaCl and 3% dextrose (SD), (6) 2% NaCl and 0.5% tri-polyphosphate (SP), (7) 0.5% tri-polyphosphate and 3% dextrose (PD), and (8) 2% NaCl, 0.5% tri-polyphosphate, and 3% dextrose (SPD). The right side was pumped to 120% its original green weight and the corresponding left side served as the paired control in a nested design. The SD, SP and SPD solutions improved (P<0.05) Warner-Bratzler shear force values (WBS), sensory panel evaluations for tenderness, decreased cook loss, and increased ultimate pH when compared with their corresponding controls. In addition, no adverse affects on color or microbiological growth were observed for any of the treatments.

Carcass merit and meat quality in Suffolk lambs, Katahdin lambs, and meat-goat kids finished on a grass-legume pasture with and without supplementation.

The experiment evaluated traditional U.S. sheep (Suffolk), hair sheep (Katahdin), and meat goat (Boer crossbred; Goat) carcass and meat quality parameters when finished on pasture with and without supplemental whole cottonseed (Gossypium hirsutum L.). Supplemented animals had greater ribeye area (P<0.01), body wall thickness (P<0.001), and lean quality score (P<0.05) than unsupplemented animals. Whole cottonseed increased fatty acids (FA) 18:1 trans-10, 18:1 trans-12, 18:2, and Omega6:Omega3 ratio and decreased FA 18:1 trans-11, 18:3, and Omega3 in longissimus muscle (LM). Katahdin LM had greater (P<0.001) intramuscular fat compared to Suffolk and Goat. Goat LM had less (P<0.001) FA 14:0, 18:0, 18:1 t11, 18:3, 20:3n-6, and saturated FA when compared to Suffolk or Katahdin. Carcass weights from pasture-finished sheep and goats would be acceptable for most ethnic markets in the USA. Omega6:Omega3 ratios in chevon and lamb were within the guidelines for meats that can improve human diets and health.

Carcass parameters and meat quality in meat-goat kids finished on chicory, birdsfoot trefoil, or red clover pastures.

This study was conducted during the 2009 and 2010 grazing seasons to assess carcass parameters and chevon (goat meat) quality when meat-goat kids (n=72) were finished on pastures of red clover (Trifolium pratense L.; RCL), birdsfoot trefoil (Lotus corniculatus L.; BFT), or chicory (Cichorium intybus L.; CHIC). Final live weight (P<0.05) and carcass weight (P=0.10) were greater when goats were finished on RCL compared to CHIC with BFT being intermediate. Ribeye area, backfat thickness, body wall thickness, internal fat score, and leg score were not different (P>0.10) among treatments when adjusted for the covariate of carcass weight. Finishing meat-goat kids on RCL, BFT, or CHIC impacted concentrations of fatty acids (FAs) 18:1 trans-10, 18:1 cis-11, 18:2, 18:3 polyunsaturated fatty acids (PUFAs), omega-6, omega-3, and PUFA:saturated fatty acid ratio in longissimus lumborum samples. Finishing meat-goat kids on CHIC, RCL, or BFT pastures produced carcass weights acceptable for most ethnic markets in the USA.

Meat goat kids finished on alfalfa, red clover or orchardgrass pastures: carcass merit and meat quality.

This experiment was conducted in 2005-2007 to evaluate carcass and chevon (goat meat) quality parameters when meat-goat kids (n=72) were finished on alfalfa (Medicago sativa L; ALF); red clover (Trifolium pratense L.; RCG); or orchardgrass (Dactylis glomerata L.; OGR) pastures. Carcass conformation score was greater (P=0.08) when meat-goat kids were finished on ALF compared to OGR with RCG intermediate. Chevon meat samples from goats finished on the three pasture treatments did not differ in ash, intramuscular fat, or crude protein content or in concentrations of omega6 and omega3 fatty acids, or the omega6 to omega3 ratio. Goats finished on OGR had higher (P<0.001) 18:1 trans-11 fatty acids (FA) compared to ALF or RCG. Overall, meat-goat kids finished on ALF, RCG, or ORG produced desirable carcass weights for most niche markets in the USA. Chevon is a low-fat meat option with high desirable fatty acids for human diets.