Impact of the hydrodyne process on tenderness, microbial load, and sensorycharacteristics of pork longissimus muscle

Paired, boneless pork loin muscles were obtained from 76 market hogs to eva luate tenderness, meat quality characteristics, sensory attributes, and mic robial characterization of pork muscle exposed to the Hydrodyne Process (H) compared with untreated control (C) loin. A subset of 16 paired loins was randomly selected for use in sensory evaluation and microbial characterizat ion. Loins were vacuum packaged and immersed in a heat shrink tank prior to the H treatment. The Hydrodyne treatment exposed the loin to the pressure equivalent of a 150-g explosive, generating a pressure distribution of appr oximately 703 kg/cm(2) at the surface of the samples. Meat quality assessme nts taken following treatment included subjective color, firmness/wetness, marbling scores (1 to 5 scale), Minolta reflectance and color readings, dri p loss, and lipid content. The P-value for statistical significance for mai n effects and interactions was set at <.05 in all analyses. Administration of H resulted in a 17% improvement in Warner-Bratzler shear force (2.6.9 vs 3.24 kg), with the shear force similar at two end-point cooking times (11 and 16 min) corresponding to approximately 75 and 83 degrees C, respectivel y. No differences between H and C were observed for color score, firmness s core, Minolta L*, Minolta Y, or drip loss on uncooked samples. The H loins had lower marbling scores (P < .05) and intramuscular lipid (P < .05) conte nt than the paired C loin. Sensory evaluation on the randomly selected (n = 16) paired loins samples showed no improvement in Warner-Bratzler shear fo rce. Sensory panelists were also unable to detect a difference between H an d C loins for both initial and sustained tenderness scores. No differences between H and C loins were found for pork flavor, off-flavor, cohesiveness, or number of chews before swallowing, but Ii loins had a significantly low er juiciness score and more cooking loss than C loins. Microbial analysis r esults showed no differences in coliform bacteria counts, aerobic plate cou nts, and no detectable levels of Escherichia coli bacteria in any loins. Th e findings support the ability of the Hydrodyne procedure to improve tender ness without impacting other muscle quality attributes of pork.