THE EFFECT OF THE SHARE OF PSE MEAT ON PHYSICAL CHANGES IN COOKED HAMS

Jan Pyrcz, Ryszard Kowalski, Bożena Danyluk, Agnieszka Bilska, Waldemar Uchman
Institute of Meat Technology, University of Life Sciences in Poznań, Poland

ABSTRACT

PSE meat is characterized by its pale color, lack of firmness, and fluid (exudate) dripping from its cut surfaces. When cooked, this meat lacks the juiciness of normal meat. PSE meat is unsuitable for processed meats as well, as it results in products which have an undesirable pale color and are swimming in extra fluid. PSE condition results from an abnormally rapid drop in the pH of the carcass after slaughter. The aim of this research study was an attempt of technological optimization of quality of cooked hams produced with a share of PSE meat. The quality of experimental cooked hams were evaluated by determination: Lab colour, shear force and drip loss. The results of the performed investigations revealed that the 20% share of PSE meat in the material composition of experimental hams resulted in increased thermal drip and a deterioration of consistency in comparison to the reference sample produced from normal meat.

Key words: PSE meat, transglutaminase, quality.

INTRODUCTION

Progress in pig breeding has resulted in a situation when animals with a relatively high fleshing have appeared on the market [1,8]. However, usually increased meat content in the carcass is correlated with a deterioration of meat quality and the occurrence of numerous defects. The incidence of meat defects is on the one hand caused by some not completely clarified breeding factors and on the other hand by environmental condition (stress) and preliminary processing [4,8,11,12]. Meat industry addresses this problem by attempting to optimally utilize such meat in the production of meat products, without a deterioration of their quality.

The use of this kinds of meat create some technological problems and needs some specials proceedings to keep a good quality of final products. The critical factors are: colour, consistency, stability and mainly the shelf-life of products. The last mentioned factor, as the other ones, may be improved by addition of selected additives (hydrocolloids, soya isolate, animal protein, transglutaminase) [2,3,5,7,8] , by the keeping a proper technological procedure (selected of meat, tumbling etc.) [2,8] or use some modern technologies (packaging) [9,10].

The aim of this research study was an attempt of technological optimization of quality of cooked hams produced with a share of PSE meat.

MATERIAL AND METHODS

Experimental material consisted of cooked ham with the Polish brand name of "family ham". The formulation of experimental cooked hams contained a 20% share of ham muscles exhibiting the PSE type defect (pH₁ below 5.81), whereas the rest of the raw material consisted of ham muscles with normal parameters (pH₁ = 6.81, pH₂₄ = 5.79). The adopted experimental model consisted in the production of five experimental variants of cooked hams, differing in the quality of used meat as well as the addition of additives (tranglutaminase enzymatic preparation – Activa WM and κ-carrageenan). The types of experimental hams were as follows:

A – ham produced using traditional technology (reference sample, without PSE meat)
B – ham produced with a 20% share of PSE meat
C – ham produced with a 20% share of PSE meat and a 0.3% addition of transglutaminase enzymatic preparation (Activa WM, Ajinomoto)
D – ham produced with a 20% share of PSE meat and a 0.5% addition of transglutaminase enzymatic preparation (Activa WM, Ajinomoto)
E – ham produced with a 20% share of PSE meat and a 0.5% addition of κ-carrageenan.

Experimental cooked hams were produced under large-scale production conditions with a 25% addition of injection brine. Technology of their production met standards binding for this type of meat products.

The quality of experimental cooked hams was evaluated three days after their production was completed. The following attributes were investigated: jelly thermal drip was determined by measuring its weight, physical parameters of colour (L*, a*, b*) were determined using the reflection method with a Spectro-pen spectrophotometer [12], while tendeness was characterized by shear force using a universal testing machine, Instron 1140 with a Warner-Bratzler attachment.

RESULTS AND DISCUSSION

Analytical testing results indicate that the applied 20% share of PSE meat in the material composition of cooked ham did not differentiate trends of changes in the adopted quality attributes, i.e. jelly thermal drip and consistency (Table 1).

Table 1. Changes in physical quality attributes of experimental cooked hams (n = 9)

Ham type	Thermal drip [%]	Shear force [N]
A	3.90±0.09a	12.10±0.15a
B	5.66±0.07b	14.53±0.17b
C	5.77±0.11b	15.12±0.10b
D	5.90±0.13c	15.37±0.21b
E	4.02±0.08a	12.95±0.08a

c, b, c... different small letters ascribed to mean values show significant differences (p = 0.05)

The physical parameters of colour were also checked. The obtained results are present in Table 2.

Table 2. Changes in colour parameters of experimental cooked hams

Ham type	L*	a	b*
A	70.4±0.73c	6.8±0.39b	5.12±0.43a
B	65.2±0.67b	5.6±0.45a	5.53±0.39a
C	63.1±0.82a	5.4±0.64a	5.60±0.62b
D	61.8±0.91a	5.2±0.48a	5.67±0.71b
E	64.5±0.82a	5.8±0.52a	5.41±0.40b

c, b, c... different small letters ascribed to mean values show significant differences (p = 0.05)

Statistical analysis of testing results indicates that the applied factors of technological variation (material composition and the share of functional additives) significantly affected analyzed quality indexes of experimental hams (Tables 1, 2).

Analyzed physical quality attributes, i.e. jelly thermal drip, consistency and colour at cross-section, indicate that the production of cooked ham with a share of PSE meat constitutes a significant technological problem. A 20% share of PSE meat in the material composition of experimental ham (ham B) results in a deterioration of its quality, i.e. an increase in both jelly thermal drip loss even by 45% and in hardness to approx. 20% in comparison to the reference sample (ham A). In turn, the application of adopted additives in the technological process (an enzyme transglutaminase and κ-carrageenan) significantly differentiates the investigated quality attributes. Results show that the enzymatic transglutaminase preparation at a concentration of 0.3 and 0.5% deteriorates (i.e. increases) jelly thermal drip from approx. 2 to 4% and consistency increases from approx. 4 to 5%, while the addition of carrageenan improves the quality of hams produced with the addition of PSE meat (Table 1).

The deterioration of quality in hams produced with the addition of an enzyme transglutaminase (hams C and D) is a disputable problem. It is assumed that the image of changes observed in these hams was probably caused by a large number of forming cross-linkage bonds between protein chains, which limit the capacity to attach water molecules to their polar groups [5,7].

Under normal large-scale production conditions, i.e. using only defect-free meat (red, firm, normal – RFN), an enzyme transglutaminase causes a considerable improvement of consistency and contributes to increased binding capacity of water (brine) added in the technological process of cooked ham production [5,7].

The adopted technological variation factors (material composition and functional additives) result also in a differentiation of physical colour parameters (L*, a*, b*) of experimental hams. The highest value of colour brightness (L*=70.4 units) was found for experimental cooked hams produced from RFN muscles, in the production of which only a traditional curing brine was applied (experimental ham variant – A). Significantly lower (p=0.05) brightness values were recorded for hams with 0.3 and 0.5% additions of transglutaminase preparations (variants C and D) and κ-carrageenan (variant E).

The highest value of the red colour share was found in case of hams produced from normal meat (6.8), while the lowest value of the red colour share was recorded for a sample with a 0.5% content of transglutaminase preparation. All hams produced with a share of PSE meat showed similar values of parameter a*, which for these variants (B, C, D, E) ranged from 5.2 to 5.8 units.

It was found that parameter b* assumed values ranging from 5.12 for ham produced from normal meat to 5.67 units for products with a share of PSE meat. Results of measurements of parameter b* confirm literature reports, showing a higher share of yellow in the colour of products from PSE meat in comparison to those from normal meat [8].

CONCLUSIONS

In conclusion it may be stated that a 20% share of PSE meat in the material composition of experimental hams resulted in increased thermal drip and a deterioration of consistency in comparison to the reference sample produced from normal meat. Transglutaminase preparations applied as functional additives did not improve the quality of products from PSE meat. Only carrageenan resulted in a reduction of thermal drip loss and an improvement of shear force in relation to the sample containing a share of PSE meat and produced using traditional brine

REFERENCES

1. Borzuta K., Pospiech E., 1999. Analiza korzyści związanych ze wzrostem mięsności tuczników oraz strat spowodowanych pogorszeniem jakości mięsa [Analysis of profits connected with an increase of fleshing in fatteners and losses connected with a deterioration of meat quality]. Gosp. Mięs. 9, 36-40 [in Polish].

2. Fischer K., 2001. Fleischfehler müssen nicht sein. 1. Bedingungen zur Produktion von Fleisch guter sensorischer und technologischer Qualität [Conditions of production good sensoric and technological quality products from meat]. Fleischwirtschaft 10, 21-24 [in German].

3. Kaczmarek-Duszek J., Bilska A., Krysztofiak K., Uchman W., 2008. The effect of selected technological additives on improvement of shelf-life of ground meat. Acta Sci. Pol., Technol. Aliment. 7(2), 51-61.

4. Knaflewska J., Pospiech E., 2007. Quality of assurance systems in food industry and health security of food. Acta Sci. Pol. Technol. Aliment. 6(2), 75-85.

5. Kuraishi C., Sakamoto J., Soeda T., (1998). Application of transglutaminase for meat processing. Fleischwirtschaft, 78, 656-662.

6. Materiały reklamowe Ajinomoto [Adwertizing materials of Ajinomoto], Japan, http://meat-n-more.info/test/englisch/activa/activawm/actwm0.htm

7. Nakahara C., Nozawa H., Seki N., 1999. A comparison of cross-linking of fish myofibrillar proteins by endogenous and microbial transglutaminase. Fish. Sci. 65,138.

8. O'Neill D.J., Lynch P.B., Troy D.J., Buckley D.J., Kerry J.P., 2003. Effects of PSE on the quality of cooked hams. Meat Sci. 64, 2: 113-118.

9. Otles S., Yalcin B., 2008. Inteligent food packaging. Logforum 4, 4, 3.

10. Otles S., Yalcin B., 2008. Smart food packaging. Logforum 4, 3 ,4.

11. Pospiech E., 2001. Analiza możliwości przetwarzania mięsa o obniżonej jakości [Analysis of processability of inferior quality meat]. Mięso Wędl. 34-37 [in Polish].

12. Strzyżewski T., Bilska A., 2008. Zależność pomiędzy wartością pH mięsa a jego barwą [Correlation between pH values of meat and its colour] Nauka Przyr. Technol., 2, 2, 12 www.npt.up-poznan.net/volume2/issue2 [in Polish].

 

Accepted for print: 15.02.2009

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Jan Pyrcz
Institute of Meat Technology,
University of Life Sciences in Poznań, Poland
Wojska Polskiego 31, 60-624 Poznań, Poland
ph (+48 61) 846 72 61
fax (+48 61) 846 72 54
email: janpyrcz@up.poznan.pl

Ryszard Kowalski
Institute of Meat Technology,
University of Life Sciences in Poznań, Poland
Wojska Polskiego 31, 60-624 Poznań, Poland
ph (+48 61) 846 72 61
fax (+48 61) 846 72 54
email: kowalski@au.poznan.pl

Bożena Danyluk
Institute of Meat Technology,
University of Life Sciences in Poznań, Poland
Wojska Polskiego 31, 60-624 Poznań, Poland
ph (+48 61) 846 72 61
fax (+48 61) 846 72 54

Agnieszka Bilska
Institute of Meat Technology,
University of Life Sciences in Poznań, Poland
Wojska Polskiego 31, 60-624, Poznań, Poland
phone: (+48 61) 846 72 61
email: abilska@au.poznan.pl

Waldemar Uchman
Institute of Meat Technology,
University of Life Sciences in Poznań, Poland
Wojska Polskiego 31, 60-624, Poznań, Poland
ph: (+48 61) 846 72 61
fax: (+48 61) 846 72 54
email: waluchm@au.poznan.pl

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Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.

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