Lars Kristensen* & Mari Ann Tørngren
To clarify the effect of androstenone, skatole and indole levels in the neck fat of entire males on the perceived boar taint in processed whole meat cuts (ham, Danish flank roll and smoked streaky bacon).
Materials and method
At a local slaughter house boars were screened using the Danish skatole method, and 30 carcasses with skatole equivalents between 0.25 ppm and 0.50 ppm were selected for smoked cooked ham, and 30 castrates were used as reference. For production of Danish flank roll and smoked streaky bacon, 28 carcasses were selected in respect to the following four skatole equivalent groups: (1) < 0.10 ppm, (2) 0.20-0.25 ppm, (3) 0.26-0.50 and (4) >0.65 ppm including 20 castrates as reference. Samples from the neck fat were analysed for skatole, indole and androstenone using an HPLC method.
- Smoked ham: topsides (M. semimenbranousus) were cured, smoked and cooked to five different core temperatures from 70°C to 90°C. The hams were stored at 0°C and reheated to either 23°C or 65°C before sensory analysis.
- Danish flank roll: flanks (M. rectus abdominis) were brine-injected, spiced, rolled, put in sausage casings and heat treated at 80°C to 72 °C core temperature and chilled.
- Streaky bacon: pork bellies were derinded, brine-injected, drained and smoked according to a 9-step smoking program (130 min, 54-60°C). The bacon was then sliced, vacuum-packed and stored at 0°C before cooking.
Smoked ham: androstenone and skatole levels in the neck fat varied between 0.10 and 3.5 ppm and 0.015 and 0.51 ppm, respectively. Boar taint-related sensory attributes in the ham were highly affected by serving temperature and androstenone, but no effects of skatole, indole and core temperature were observed. Urine odour, sweat odour and pungent flavour were the sensory attributes most affected by androstenone and serving temperature.
Danish flank roll: androstenone and skatole levels in the neck fat varied between 0.37 and 6.25 ppm and 0.036 and 1.13 ppm, respectively. Skatole and skatole equivalents were highly correlated (r=0.97175), whereas skatole and androstenone were only slightly correlated (r=0.4596). High model correlations were obtained for manure (0.94091), urine (0.93395) and meat flavour (0.90505).
Smoked streaky bacon: results in progress.
Cooked smoked ham
- Androstenone has a major effect and should be below 0.4 ppm in the neck fat to eliminate perceived boar taint
- Variation in skatole is not reflected in boar taint
- Core temperature in the range of 70°C-90°C has no effect on perceived boar taint
- Cooked smoked ham should be served cold to minimize perceived boar taint
Danish flank roll
- Androstenone and skatole have a major effect on perceived boar taint
- Manure flavour is the most intense attribute, whereas manure aftertaste is the most critical attribute.
Androstenone content should be below 2.1 ppm (if skatole content < 0.05ppm), and skatole content should be below 0.3 ppm (if androstenone content < 0.2 ppm).