Evaluation of some objective methods for measuring pork quality

Relationship Between the Subjective and Objective Assessment of Pork M. semimembranosus and Classification of Further Processed Pork Quality

Pale, soft, exudative (PSE) pork poses many problems for ham processors with the colour and texture of the final product being of major concern. As visual assessment is the primary, and often the only, method used by these producers, they require objective methods of assessing the quality of the raw material prior to production of hams. This study was conducted to establish the relationship between objective colour measurements and subjective (visual) methods of assessing pork meat quality and to ascertain the ability of objective colour measurements (CIE L* and percentage reflectance) to accurately segregate porcine muscles according to quality, prior to ham production. Pork topsides (M. semi-membranosus and M. adductor) were visually assessed by experienced industry personnel, from a large ham producing company, as being ‘pale’ (n 489) or ‘good’ (n 625) in colour. CIE L* and percentage reflectance (%R) were then recorded on all muscles. Pearson’s correlation coefficients confirmed a significant relationship between visually assessed meat and both L* (r 0.71) and reflectance (r 0.71). CIE L* above 57 and%R below 43% correctly classified 75% of the ‘pale’ topsides. CIE L* below 53 and%R above 53% correctly classified 75% of the ‘good’ topsides. Muscles were processed and colour, texture, sliceability and water holding capacity of the resulting ham products were determined. Hams produced using ‘pale’ topsides had significantly higher (p 0.001) CIE L* and b* values and lower%R (p 0.001), moisture content (p 0.001) and water holding capacity (p 0.05). The textural characteristics of the hams were significantly different (p 0.05) and those produced using ‘good’ meat had greater cohesiveness, chewiness, gumminess and springiness. This study indicates that these objective methods may have potential in the classification of topsides prior to ham processing.

Utilization of carrageenan, citric acid and cinnamon oil as an edible coating of chicken fillets to prolong its shelf life under refrigeration conditions

AIM

The present study was conducted to determine efficacy of edible coating of carrageenan and cinnamon oil to enhance the shelf life of chicken meat stored under refrigeration conditions.

MATERIALS AND METHODS

Chicken breast was coated with carrageenan and cinnamon oil by three methods of application viz., spraying brushing and dipping. The coated meat was evaluated for drip loss, pH, thiobarbituric acid number (TBA), tyrosine value (TV), extract release volume (ERV), Warner-Bratzler shear force value (WBSFV), instrumental color, microbiological, and sensory qualities as per standard procedures.

RESULTS

There was a significant difference observed for physicochemical parameters (pH, TBA, TV, ERV, drip loss and WBSFV) and microbiological analysis between storage periods in all the samples and between the control and treatments throughout the storage period but samples did not differed significantly for hunter color scores. However, there was no significant difference among three methods of application throughout the storage period though dipping had a lower rate of increase. A progressive decline in mean sensory scores was recorded along with the increase in storage time.

CONCLUSION

The carrageenan and cinnamon edible coating was found to be a good alternative to enhance the shelf life of chicken meat under refrigeration conditions. It was also observed from study that dipping method of the application had comparatively higher shelf life than other methods of application.

The relationships between initial pH, reflectance and exudation in pig muscle

Using data collected from several hundred pigs, the relationships of drip loss during storage, and reflectance, to pH(45) in the M. longissimus dorsi (LD) were both found to be biphasic. Muscles with a lower pH(45) lost more drip and were paler. Below pH 6·1, however, decreasing pH(45) had only a small effect on the weight of drip lost but a large influence on reflectance. In contrast, above pH 6·1, increasing pH(45) had a large influence on drip loss but only a small effect on reflectance. There was also a biphasic relationship between drip loss and reflectance with the discontinuity at 9·9% drip. Differences in pH(u) explained less than 15% of the variation in exudation and reflectance.

The relationship between reflectance (EEL value) and colour (L*) in pork loins

The relationships between reflectance values measured with an EEL reflectometer, and C1ELAB L* a* b* coordinates measured with a tristimulus meter, were determined using 572 samples of pork m. longissimus dorsi. These samples covered the muscle colour/condition range from extreme pale, soft, exudative (PSE) to extreme dark, firm, dry (DFD). There was a good (r = 0·91) and slightly curvilinear relationship between L* value and reflectance, the other relationships being significantly poorer. Based on these findings, pork loins with L* values between 49 and 60 would on average have consistently good visual appeal using criteria in the Meat and Livestock Commission blueprint for quality pork.