Update on PSE in Poultry Meat. Christine Z. Alvarado, Ph.D. Department of Animal and Food Sciences Texas Tech University

Transcription

1 Update on PSE in Poultry Meat Christine Z. Alvarado, Ph.D. Department of Animal and Food Sciences Texas Tech University

2 Meat Quality Attributes influenced by postmortem muscle metabolism: Color Water Holding Capacity Texture Ferket and Foegeding, 1994; Pearson, 1994

3 Meat Quality ale, Soft, Exudative accelerated postmortem glycolysis protein denaturation Hedrick et al., 1989; Lawrie, 1998

4 Meat Quality Combination of events: Rapid postmortem decline in muscle ph High carcass temperatures (early postmortem) Bendall and Wismer-Pederson, 1962; Penny, 19

5 Meat Quality Pale, Soft, Exudative Meat Pale color Soft texture Low water holding capacity = reduced yields and poor quality

6 Protein Denaturation Myofibrillar proteins Water holding capacity / gel strength Sarcomplasmic proteins Color Bendall and Wismer-Pederson, 1962; Penny, 1969

7 Protein Denaturation Protein denaturation can cause low strength (poor) gels to form resulting in softer (mushy) texture. Example: Pale, SOFT, Exudative meat

8 Protein Denaturation Poor slice ability PSE meat

9 Deli Loaves and Rolls Made with PSE Turkey Meat Excessive Purge

10 Pale color Low WHC

11 Problems with PSE Broiler Meat Lost yield (sometimes hidden) Problems in further processing equipment (e.g. automatic breast deboner) Variation in color

12 Economic Implications 4The use of PSE meat in cooked products can cost a processing plant $2-4 million/year in lost meat yield alone. 4Estimate does not factor in: hpackaging costs hrework labor hmultiplier effect

13 PSE Incidence in Poultry Ranges from 5-40% 20-25% is background (genetic?) Remainder varies with day, week, or season (environment?) Genetic and environmental factors not distinctly separated

14 Factors Influencing PSE Meat Genetic PSE Environmental Ryanodine Receptor (RyR) Antemortem Postmortem

15 Porcine Stress Syndrome genetic disorder (autosomal recessive) linked to the ryanodine receptor gene single point mutation induced by halothane and succinylcholine induced by stress Malignant Hyperthermia in other species Hall et al., 1966; Harrison et al., 1968; Webb and Jordan, 1978; Fujii et al., 1991

16 The Ryanodine Receptor Single Point Mutation Cytosine (C) to thymine (T) at nucleotide 1843 Substitution of cysteine for arginine in position 615 Abnormal calcium release Observed in swine and humans PSS/MH No evidence to support or refute mutation in avian species Fujii et al., 1991

17 Halothane Screening - +

18 The Ryanodine Receptor Isoforms Mammalian hα located in skeletal muscle hβ located in cardiac muscle and brain Avian hα and β located in skeletal muscle hgenetic difference found but currently being studie Percival et al., 1994

19 Antemortem Stress Factors Stresses associated with PSE meat in swine hrapid Growth hpreslaughter handling practices htransportation henvironmental temperatures Poultry are subjected to similar conditions Cassens et al., 1975; Backstrom and Kaufmann, 1995; D Souza et al., 1998; Maribo et al., 1998

20 Rapid Growth Fast growing/heavier birds More susceptible to heat stress hhigher body temperature hgreater metabolic heat production hhigher mortality Greater incidence of muscle abnormalities Muscles may outgrow life support system Bohren et al., 1982; Sosnicki and Wilson, 1991; Hunt et al., 1999; Mahon, 1999; Mills et al., 1999

21 Antemortem Stress Factors Transportation Physiologically stresses poultry No increase in PSE incidence associated with 3 h of transportation prior to slaughter May be dependent on duration and other conditions Kannan et al., 1997; Freeman et al., 1984; Kannan et al., 1998 Gregory, 1994; Cashman et al., 1989; Owens and Sams, 1999

22 Antemortem Stress Factors Chronic heat stress Higher incidence of PSE meat in turkeys Heat stressed turkeys exhibited: hlower muscle ph hhigher L* values hhigher drip loss hhigher cook loss McCurdy et al., 1996; McKee and Sams, 1997

23 Postmortem Factors Chilling Rates Slow or inadequate chilling increases PSE Problem in turkeys due to size Postmortem temperature is the most important factor influencing overall meat quality McKee and Sams, 1998; Alvarado and Sams, 2002; Alvarado and Sams, 2003

24 Objectives To evaluate the relationships between muscle chilling rates, ph decline, color, water holding capacity, and texture, in turkey carcasses To develop a time and temperature range for chilling turkey carcasses to decrease meat quality problems associated with PSE meat.

25 Materials and Methods 48 Male Nicholas Turkeys processed in 2 trials Bled, scalded, picked, eviscerated Chilled at 0, 10, 20, 30 C Deboned

26 Materials and Methods Sample Analyses Temperature of the fillets ph L* Value Gel Strength % CL Expressible Moisture

27 Temperatures of Turkey Pectoralis from Various Chilling Times and Temperatures Carcass Temperature (C) a Pooled SEM = Time Postmortem (min) a b 0 C 10 C 20 C 30 C a b c d

28 ph of Turkey Pectoralis Chilled at Various Rates a 0 C 10 C 20 C 30 C ph Pooled SEM = a ab b Time Postmortem (min) a ab b

29 Muscle Temperature and ph Decline from Turkey Lobes a a Pooled SEM = ph b Carcass Temperature (C) b

30 Relationship of Muscle Temperature and L* Value from Turkey Lobes L* Value b Pooled SEM = 0.31 a a a Carcass Temperature (C)

31 Means of Meat Quality Parameters for deboned turkey breast fillets Temperature ( C ) Parameter Pooled SEM L* Value (24 h) Drip Loss 0.23 b 0.24 b 0.27 b 0.40 a 0.02 Cook Loss Exp. Moist. Gel Strength b b b a ab Means with different superscripts are significantly different (P<0.05)

32 Conclusion There is a chilling time and temperature relationship which can be a factor in the development of PSE meat. Therefore, processors should implement a proper chilling regime in order to maintain acceptable meat quality. Carcass Temperature recommendations < C at 0.75 h PM < C at 1.5 h PM Alvarado and Sams, 2003,200

33 Strategies to Improve PSE Meat Adjustment of ph or ionic strength use ingredients to restore protein function High ph phosphates (Pre-rigor and PM) Increased ph Decreased Cook loss Improved color by 24 h PM3

34 Objectives To determine the effects of pre-rigor marination with sodium phosphates on ph, color, and WHC in both normal and pale broiler breast fillets

35 Materials and Methods Poultry Research Center (3h PM): Injected (15% solution, 25 PSI) ph 9 (0.9% NaCl, 0.45% PO4) ph 11 (0.9% NaCl, 0.45% PO4) Vacuum tumbled (25 mm Hg, 30 min, 14 RPM) ph Lab* value Marinade pick-up/ retention Cook Loss Expressible moisture Sensory TBARS

36 Measurements from Normal and Pale Fillets Marinated with a ph 9 Solution ph (2h) ph (24h) L* (2h) L* (24h) EM (%) CL (%) Normal 6.30 a,x 6.12 a,y b,x b,x b a Pale 6.09 b,x 6.00 b,x a,x a,y a a Pooled SEM a, b Means in a column differ ( P < 0.05) x, y Means in a row and within the same parameter differ (P < 0.05)

37 Measurements from Normal and Pale Fillets Marinated with a ph 11 Solution ph (2h) ph (24h) L* (2h) L* (24h) EM (%) CL (%) Normal 6.30 a,x 6.28 a,x b,x b,x b a Pale 5.95 b,x 6.22 a,y a,x a,y a a Pooled SEM a, b Means in a column differ ( P < 0.05) x, y Means in a row and within the same parameter differ (P < 0.05

38 Sensory Measurements from Marinated Fillets Treatment ph 9 ph 11 Hedonic Scale Value

39 TBARS Measurements from Marinated Fillets Pale TBARS TBARS TBARS (Day 0) (Day 2) (Day 4) ph ph Normal TBARS TBARS TBARS (Day 0) (Day 2) (Day 4) ph ph

40 Shelf-life Measurements from Marinated Normal Fillets 8 Log CFU/ml Day 0 Day 3 Day 6 Day 9 1 4

41 Shelf-life Measurements from Marinated Pale Fillets 8 Log CFU/ml Day 0 Day 3 Day 6 Day 9 ph 9 ph 11

42 Conclusion High ph phosphates Increased ph Decreased Cook loss Improved color by 24 h PM Impacts to industry: higher yield, increased consumer acceptability

43 Strategies to Improve PSE Meat Sort meat based on color or meat ph direct PSE meat to non-problem products away from products with no or low amounts of salts and phosphates

44 Sorting Breast Fillets Based on Color easy and rapid human eye optical scanning equipment Based on Meat ph more complicated currently used in pork and beef industry

45 Conclusions Long-term strategies genetic typing screening tests selective breeding Short-term strategies reduce environmental stress sort meat control flow/distribution of PSE meat

46 Questions? Christine Alvarado, Ph.D. International Center for Food Industry Excellence Animal and Food Sciences Texas Tech University