QUALITY ASSESSMENT OF SOME READY-TO-EAT AND LOCALLY PRODUCED CHICKEN MEAT PRODUCTS

Document Type : Research article

Author

Animal Research Institute, Damanhour Branch.

Abstract

50 random chicken meat products (25 of each nuggets and luncheon), which were ready-to-eat and locally produced in Egypt, were collected from supermarkets and minimarkets in DamanhourCity to assess their quality. The results of organoleptic and sensory evalution were accepted and all the examined samples were in good condition. The means ± S.E.M. of total aerobic, total psychrotrophic, total coliforms and total Staphylococcus aureus in chicken nuggets were: 8.2X104± 1.2X104, 8.6X104 ± 1.5X104, 2.4X102 ± 8.0X10 and 6.0X103 ± 1.5X103 cfu/g, respectively,while in luncheon were : 1.2X104 ± 5.9X103,1.5 X104 ± 1.2X104, 5.08 ± 1.61, 2.3X 10± 8.5X102 cfu/g,respectively. This study mentioned that all nuggets samples and 20% of luncheon samples slightly exceeded the maximum permissible limit for total aerobic counts         (104 cfu/g) according to Egyptian standard specifications Nos. 3493/2000 and its amendments in 2003 and 1114/2005 of Egyptian Organization for Standardization and Quality Control "EOSQC". Also, samples of both products were not be completely free from Staphylococcus aureus but were completely free from Escherichia coli and Salmonellae as a pathogenic microorganism. The chemical examination revealed that the means ± S.E.M. of hydrogen ion concentrations (pH) were 6.08 ± 0.046 and 6.15 ± 0.06 in nuggets and luncheon, respectively, while total volatile basic nitrogen (TVB-N) ranged from7.53 to 19.35, with a mean±S.E.M. of 13.36±0.76 mg/100g in nuggets and ranged from 1.08 to 13.98, with a mean ± S.E.M. of 5.54 ± 0.66 mg/100g in luncheon. These values of TVB-N were not exceeded the maximum permissible limit, (25&30 mg/100g of half partially cooked and completely cooked poultry meat products, respectively) according to ESS No.3493/2000. The fat   oxidation criteria determined by thiobarbituric value in both products were very low to be reflected on the flavour and did not exceeded the permissible limit (0.9 mg malonaldhyde/kg).

Animal Research Institute,

Damanhour Branch.

 

Quality assessment of some ready-to-eat and locally produced chicken

meat products

(With 7 Tables)

 

By

I.A. El-KEWAIEY

(Received at 15/12/2011)

 

تقييم جودة بعض منتجات لحوم الدواجن المعدة للأستهلاک والمنتجة محليا

 

إبراهيم على القويعى

 

أجريت هذة الدراسة لتقييم جودة بعض منتجات لحوم الدواجن المعدة للأستهلاک والمصنعة محليا. فقد تم جمع عدد 25 عينة عشوائية من کل من ناجتس ولانشون الدجاج من أسواق مدينة دمنهور. أظهرت نتيجة الفحص الظاهرى أن العينات المفحوصة ذات صفات ظاهرية وحسية جيدة. کما أظهرت نتائج الفحص البکتريولوجى أن متوسطات العد الکلى للبکتريا الهوائية والمحبة للبرودة وبکتريا القولون العصوية والميکروب العنقودى الذهبى فى منتج ناجتس الدجاج کانت کالأتى 8.2×410±1.2×410،8.6× 410±1.5× 410 ، 2.4×210 ± 8 ×10 ، 6.0 ×310 ± 1.5 ×310 بينما کانت مثيلاتها فى عينات اللانشون کالأتى 1.2×410 ±5.9×310،1.5×410 ± 1.2×410، 5.08± 1.61 ،2.3 × 310± 8.5 ×210 على التوالى. وقد بينت الدراسة أن کل عينات الناجتس و 20٪ من عينات اللانشون قد جاوزت بشکل طفيف الحد المسموح به (410 ميکروب/جرام) للبکتريا الهوائية ولم يثبت خلوها من الميکروب العنقودى الذهبى طبقا للمواصفة القياسية المصرية رقم 3493 لسنة 2000 والتعديلات المدخلة عليها فى 16/12/2003 . بينما لم يتم عزل أى عترات للميکروب القولونى کما لم يتم أکتشاف ميکروب السالمونيلا فى أى منهما. کما بينت نتائج الاختبارات الکيميائية المبينة للجودة أن متوسط ترکيز أيون الهيدروجين فى الناجتس 6.08 ± 0.046 ، وفى اللانشون 6.15±0.06 ، وکانت قيم المرکبات النيتروجينية القاعدية المتصاعدة تتراوح بين 7.53 و 19.35 بمتوسط 13.36± 0.76مجم/100جم فى عينات الناجتس بينما کانت تتراوح بين 1.08 و 13.98 بمتوسط 5.54 ± 0.66 مجم/100 جم فى عينات اللانشون. وبذلک لم تتعدى قيم المرکبات النيتروجينية المتصاعدة الحد المسموح به فى منتجات الدواجن (يساوى 25 و 30 مجم/100جم فى منتجات لحوم الدواجن نصف المطهية وکاملة الطهى على التوالى). هذا وقد سجلت قيم منخفضة جدا لم تتجاوز الحد المسموح به (0.9 مجم مالونالدهيد/کجم) لعدد حامض الثيوبربتيورک الدال على أکسدة الدهون ولم ينعکس ذلک على الصفات الحسية لتلک المنتجات.

 

SUMMARY

 

50 random chicken meat products (25 of each nuggets and luncheon), which were ready-to-eat and locally produced in Egypt, were collected from supermarkets and minimarkets in DamanhourCity to assess their quality. The results of organoleptic and sensory evalution were accepted and all the examined samples were in good condition. The means ± S.E.M. of total aerobic, total psychrotrophic, total coliforms and total Staphylococcus aureus in chicken nuggets were: 8.2X104± 1.2X104, 8.6X104 ± 1.5X104, 2.4X102 ± 8.0X10 and 6.0X103 ± 1.5X103 cfu/g, respectively,while in luncheon were : 1.2X104 ± 5.9X103,1.5 X104 ± 1.2X104, 5.08 ± 1.61, 2.3X 10± 8.5X102 cfu/g,respectively. This study mentioned that all nuggets samples and 20% of luncheon samples slightly exceeded the maximum permissible limit for total aerobic counts         (104 cfu/g) according to Egyptian standard specifications Nos. 3493/2000 and its amendments in 2003 and 1114/2005 of Egyptian Organization for Standardization and Quality Control "EOSQC". Also, samples of both products were not be completely free from Staphylococcus aureus but were completely free from Escherichia coli and Salmonellae as a pathogenic microorganism. The chemical examination revealed that the means ± S.E.M. of hydrogen ion concentrations (pH) were 6.08 ± 0.046 and 6.15 ± 0.06 in nuggets and luncheon, respectively, while total volatile basic nitrogen (TVB-N) ranged from7.53 to 19.35, with a mean±S.E.M. of 13.36±0.76 mg/100g in nuggets and ranged from 1.08 to 13.98, with a mean ± S.E.M. of 5.54 ± 0.66 mg/100g in luncheon. These values of TVB-N were not exceeded the maximum permissible limit, (25&30 mg/100g of half partially cooked and completely cooked poultry meat products, respectively) according to ESS No.3493/2000. The fat   oxidation criteria determined by thiobarbituric value in both products were very low to be reflected on the flavour and did not exceeded the permissible limit (0.9 mg malonaldhyde/kg).

Key

 

INTRODUCTION

 

Poultry meat has become the second most popular eaten meat due to it is a good source of protein and many nutrients and is relatively low in fat.

The increasing price of meat has encouraged the food processors to produce new meat products available as either fresh or precooked (i.e.fried), in different shapes, easily handled, stored and rapidly used with low costs as luncheon and nuggets. Deep fat frying is a popular cooking method because it generates flavourful products having crispy exteriors with moist and juicy interiors.

Poultry and poultry products ranked the first or the second in foods associated with diseases in most of the countries all over the world, in the USA ranked the third of the reported food-borne disease outbreaks (Bean and Griffin, 1990). 

Chicken products are highly perishable foods, depending on the degree of processing following slaughter, their spoilage varies between 4 and 10 days under refrigeration (Marenzi, 1986). Susceptibility of chicken meat and chicken-based meat products to microbial spoilage presents a potential health hazard due to poultry meat may harbor pathogenic microorganisms(Geornaras et al., 1998). Spoilage is commonly detected by sensory and/or microbiological analysis, in addition to an alternative method involves the measurement of chemical changes associated with the growth of specific spoilage organisms in meat and meat products (Dainty, 1996). In the washing process, poultry haeme removing is important because white meat is more valuable than dark meat(Yang and Froning, 1994). The edible coatings and films applied to food substrates before frying aid to limiting moisture and oil transfer during frying (Albert and Mittal, 2002) and also act as barriers in controlling the transfer of moisture and oxygen, thereby preventing quality deterioration of food products (Mate and Krochta, 1996).

Lipid oxidation is one of the main factors used to estimate meat quality due to the susceptibility of meat and meat products to oxidative degeneration (Morrissey et al., 1998). Fresh and in particular, processed poultry meat products are very susceptible to oxidative deterioration (Higgins et al., 1998b) because they contain a high proportion of polyunsaturated fatty acids (PUFA) (Higgins et al., 1998a). The control of lipid oxidation in fresh and further processed meat products is a goal of food scientists and food processors (Sheldon et al., 1997). The changes in quality incurred by lipid oxidation are manifested by adverse changes in colour, flavour, and nutritive value, and also by the possible production of toxic compounds (Jensen et al., 1998). Adverse changes in colour are not very easily detected in chicken meat. Changes in flavour occur especially in cooked-stored chicken products. Warmed-over flavour, and overall off flavour intensities increased in chicken patties as a result of storage for one or more days after cooking (Ang and Lyon, 1990). In addition, clour deterioration of ground chicken meat has  been observed as storage time progressed(Yang and Chen, 1993), in particular, colour attributes associated with lightness / darkness and redness.

Hence, this study was conducted to assess the quality of some ready-to-eat chicken meat products favoured by most of the consumers in Egypt.

 

MATERIALS and METHODS

 

A total of 50 random packaged samples of about 500g of locally processed chicken meat products (25 each of nuggets and luncheon) were collected from different super and mini markets of Damanhour city in summer of 2011. Each sample was wrapped separately in sterile polyethylene bag and transferred directly to the laboratory without delay in an ice box. In the laboratory, the whole surface of each sample was aseptically exposed and a part about 150g for each examination from each sample was put on a sterile plate and the following examinations were performed.

I- Organoleptic and Sensory evaluation:

The samples of chicken nuggets were frozen and luncheon samples were kept refrigerated until sensory evaluation. Each nugget unit was reheated for 4 minutes including time of defrosting and a panel of seven judges familiarized with flavor attributes (off-odor and off-taste) was used for sensory evalution. Acceptability as a composite of odor and taste was estimated using a descriptive scale ranging from 1-9, where1=extreme foreign flavor or dislike intensely and 9=no foreign flavor or like extremely. A score of 6 was taken as the lower limit of acceptability (Penney et al., 1993). Other defects in colour and consistency were noted and recorded. 

II-Bacteriological examination:

1. Preparation of samples according to ICMSF (1978):

Ten grams of the prepared sample were transferred to a sterilized homogenizer flask containing 90 ml of 0.1% sterile peptone water. The contents were homogenized at 14000 r.p.m. for 2.5 minutes to provide a dilution of 10‾¹. The homogenate was allowed to stand for 5 minutes at room temperature, then 1 ml of homogenate was transferred with a sterile pipette into a sterile test tube containing 9 ml of 0.1% sterile peptone water to obtain a dilution of 10‾². Then further decimal ten fold serial dilutions up to 10‾6 were prepared.

 

2. Total aerobic bacterial count (APC) according to APHA (1992):

One ml from each dilution was transferred into duplicate sterile Petri dishes and mixed with about 10 ml of sterile plate count agar medium “melted and kept at 45ºC”. After solidification, cultivated plates as well as control one were incubated at 37ºC for 48 hours in an inverted position. Average count was calculated as a total aerobic count per gram of sample.  

 

3. Total Psychrotrophic bacterial count according to APHA (1992):

The same steps, as in total aerobic bacterial count, were carried out but the incubation was done at 7ºC for 10 days. 

 

4. Total coliform count (MPN/g):

The multiple tube method recommended by ICMSF (1978) was applied. Most probable numbers (MPN) of coliforms per gram of the examined samples were calculated by using MPN table.

Isolation of Enteropathogenic Escherichia coli (ICMSF, 1978):

One ml from each positive MacConkey broth tube was inoculated to E.coli broth. The inoculated tubes were incubated at 44 ± 0.5ºC for 48 hours in thermostatically controlled water bath (Eijkmann test). A loopful from each positive tubes showing gas production was streaked onto plate of Eosine methyline blue agar and incubated at 37ºC for 24 hr.Two typical colonies (greenish metallic with dark purple center with or without sheen) were picked up and inoculated into sterile semisolid nutrient agar tubes for further biochemical identification.

 

5. Detection and isolation of Salmonellae was carried out according to the methods outlined by (AOAC, 1984).

 

6. Total Staphylococcus aureus count (ICMSF, 1978):

0.1 ml from each decimal dilution was spread over the surfaces of duplicate dried Baired Parker agar plates. The inoculated plates were incubated at 37ºC for 48 hours in an inverted position. The black shiny colonies with narrow white margines and surrounded by a clear zone were counted. Suspected colonies were stabbed in semi-solid agar for further morphological and biochemical identification (catalase, mannitol, coagulase, thermostable nuclease production and oxidation-fermentation of glucose).

 

 III- Chemical examination:

 

 1- pH (Hydrogen ion concentration):according to Pearson(1973).

 2-Determination of total volatile basic nitrogen "TVB-N" (FAO, 1980): by Conway microdiffusion method.

 3- Determination of thiobarbituric acid value (TBA): according to Vyncke (1970).

 

RESULTS

 

Table 1: Frequency distribution of the examined chicken products samples according to Organoleptic and Sensory evalution.

 

 

Appearence

Colour

Flavour

 

Consistency

Normal

Abnormal

Normal

Abnormal

Normal

Abnormal

Normal

Abnormal

No.

%

No.

%

No.

%

No.

%

No.

%

No.

%

No.

%

No.

%

Nuggets

25

100

0

0

25

100

0

0

25

100

0

0

25

100

0

0

  Luncheon

25

100

0

0

25

100

0

0

25

100

0

0

25

100

0

0

 

Luncheon

Nuggets

Paramter

S.E.M.

Mean

Positive Samples

S.E.M.

Mean

Positive Samples

%

 No.

%

  No.  

5.9 X 103

1.2 X 104**

84

21

1.2 X 104

8.2 X 104*

100

25

APC(cfu/g)

1.2 X 104

1.5 X104**

76

19

1.5 X104

8.6 X 104*

100

25

T. psych. count(cfu/g)

1.61

5.08

100

25

8.0 X10

2.4 X 102

100

25

T. coliform count(MPN/g)

8.5 X 102

2.3 X103**

72

18

1.5 X103

6.0 X 103*

100

25

 Staph. aureus count(cfu/g)

Table 2: Statistical analytical results of the examined chicken products samples (n=25 of each).                                                              

 

 -No.= Number      S.E.M.= Standard error of mean   

-Values with the same symbols were significantly correlated at 0.01 level.                                                   

                                     

Luncheon

 

Nuggets

 

Index

 

SEM

Mean

Positive Samples

SEM

Mean

 

Positive Samples

 

%

NO.

 

%

NO.

 

0.06

6.15

-

-

0.046

6.08

-

-

pH

 

0.66

5.54

100

25

0.76

13.36

100

25

TVB-N(mg/100g)

 

0.002

0.028

100

25

0.005

0.038

100

25

TBA-RS(mg/kg)

 

Table 3: Statistical analytical results of chemical quality indexes values in examined chicken meat products (n=25 of each).                                                                                               

 

Total Staph.aureus count

Total Coliforms(MPN)

Total aerobic count

Range

P.L.*

%

No. of samples

E.coli

P.L.*

%

No. of samples

P.L.*

%

No. of samples

Free

0

0

Free

10

28

7

104

0

0

≤10

0

0

44

11

0

0

≤102

36

9

12

3

0

0

≤103

52

13

16

4

0

0

≤104

12

3

0

0

64

16

≤105

0

0

0

0

36

9

>105

Table 4: Frequency distributions of the examined chicken nuggets samples based on their bacterial contamination values.                                                                                                   

 *P.L.= maximum acceptable limit according to Egyptian Standard Specification"E.S.S.",No. 3493/2000 for poultry meat products.           

 

Table 5: Frequency distributions of the examined chicken luncheon samples based on their bacterial contamination values.                                     

Total Staph.aureus count

Total Coliforms(MPN/g)

Total aerobic count

Range

P.L.*

%

No. of samples

E.coli

P.L.*

%

No. of samples

P.L.*

%

No.of samples

Free

28

7

Free

102

96

24

104

16

4

≤10

12

3

4

1

0

0

≤102

28

7

0

0

4

1

≤103

24

6

0

0

60

15

≤104

8

2

0

0

16

4

≤105

0

0

0

0

4

1

>105

 

**P.L=maximum acceptable limit according toE.S.S.,No.1114/2005 for luncheon.

 

Table 6: Frequency distributions of the examined chicken meat products based on their chemical quality indexes values.                                 

Luncheon

Nuggets

TVB-N

pH

TVB-N

pH

%

No.

Range

%

No.

Range

%

No.

Range

%

No.

Range

44

11

≤5

0

0

≤5.0

0

0

≤5

0

0

≤5.0

44

11

≤10

0

0

≤5.5

28

7

≤10

0

0

≤5.5

12

3

≤15

44

11

≤6.0

28

7

≤15

44

11

≤6.0

0

0

≤20

44

11

≤6.5

44

11

≤20

52

13

≤6.5

0

0

≤25

12

3

≤7.0

0

0

≤25

4

1

≤7.0

0

0

≤30

0

0

≤7.5

0

0

≤30

0

0

≤7.5

 

Table 7: Incidence of coagulase positive Staph. aureusstrains in examined chicken meat products samples (n=25 of each)                                        

Chicken luncheon

Chicken nuggets

%

No. of +ve strains

%

No.of +ve strains

48

12

16

4

DISCUSSION

 

Organoleptic and Sensory evalution:

 

From the summarized results in Table 1, it was shown that all the examined chicken nuggets and luncheon samples were organoleptically accepted.

  The level of acceptance of coated products, as nuggets, depended on the coating characteristics such as the general appearance, colour, batter texture and crispness (Parinyasiri and Chen, 1991). The increase in frying temperature directly influenced the colour of the coated fried food to a darker golden brown colour. The colour of the cooked food is influenced by the ingredients composition, cooking method, coating medium and the oil used (Suderman, 1983). The reduction of moisture loss could increase the juiciness of the product, so, with the addition of water-binding agents, much of the added water in low-fat meat products can be retained after cooking. Also, the coated nuggets breaded units contained more pressed juice than the detached ones and the increased juiceness caused the interior substrate to be less tough. To restore juiciness, flavours and mouthfeel that are lost when fat is removed, various functional additives in conjunction with the addition of water are added. Among such additives are starch, dietary fibers, soy, milk proteins and egg solids(Chang and Carpenter, 1997).Fletcher et al. (2000) stated that cooked nuggets were lighter and less red than the raw ones, similar to what occurred during breast poultry meat cooking. Marked off-odour was not noticed just at opening of the luncheon packages during sensory evalution, and also, neither greening discolourtion either surface or internal greening (green core) nor browning due to charring of carbohydrate (starch and/or sugar) incorporated in the emulsion by long period of cooking or high temperature or the lack of antioxidant and the further development of denatured metmyoglobin in this cured product(Meat Board, 1983) could not marked. Fading discolourtion may be attributed to use of chicken meat with oxidized fat or addition of fat having high peroxide number resulting in instability of the cured meat colour (Price and Schweigert, 1971), the use of bad grade nitrite or under estimation of it, using meat poor in myoglobin content and/or thawing of frozen chicken meat too long before comminution leading to dripping of myoglobin radical of meat proteins which is readly soluble in water (Meat Board, 1983).

 

Bacteriological examination:

The results recorded in Table 2 showed that the means ± S.E.values of total aerobic count , total psychrotrophic count, total coliforms count (MPN) and total Staph.aureus count in the examined chicken  nuggets  samples were 8.2X 104 ±1.2X 104 ,8.6X 104 ±1.5 X104, 2.4X 102±8.0 X10 and 6.0X 103 ±1.5X 103 cfu/g , respectively. While in chicken luncheon samples were 1.2 X 104 ±5.9 X 103 ,1.5 X104 ±1.2 X 104 , 5.08 ± 1.61 and 2.3 X 103 ± 8.5 X 10cfu/g, respectively.

Nearly the same results for APC and total Staph.aureus counts were recorded as 14.0 X104 and 13.7 X103 by Essa et al. (2004). Bkheet et al. (2007) studied the microbiological content of the local manufactured poultry meat products in El-Bohira Governorte. They recorded that the means of total mesophilic, total psychrotrophic, total Staphylococcus auraus and total coliform counts were 2.5x105; 6.9x104; 41.4±12.2 and 2.1x104 cfu/g in chicken nuggets and were 4.3x104; 6.2x103; 154.4±39.8 and 2.3x104 cfu/g, respectively in chicken luncheon.

Higher APC counts were recorded by El-Khateib et al. (1988) "1X106 cfu/g in chicken luncheon" and by El-Tahan et al. (2006) who stated that total bacterial count in chicken nuggets collected from Shubra, Down Town and Nasr city were ranged from 14X105 to 47X106 cfu/g, and in chicken luncheon ranged from 91X105 to 8 X107cfu/g; while total coliforms counts ranged from 0 to 9X104 in nuggets and from 0 to17 X10cfu/g in luncheon and also, the incidences of S.aureus isolations ranged from 0 to 33.5% in nuggets, while in luncheon ranged from 0 to100 %.

Tables 4 and 5illustrated that100% and20% of samples of nuggets and luncheon exceeded the maximum permissible limit (104) for toal aerobic bacterial count (APC) according to Egyptian Standard Specifications "E.S.S.", No.3493/2000 and No.1114/2005. The incidence of total coliform counts (MPN/g), as a bacterial indicator of fecal pollution, were high in nuggets, where only 28% of the examined samples exhibited satisfactory results (≤10 cfu/g), on the otherside, 100% of the examined luncheon samples not exceeded the permissible limit (102 microorganisms/g) according to E.S.S., No.1114/2005.   

The high aerobic plate count often indicates contamination of raw material or unsanitary measures during processing (Icmsf, 1978). Also it may be due to unsuitable environmental storage. Most of psychrotrophic bacteria are non pathogenic but their presence in high numbers may be decrease the keeping quality of the products and makes it unfit for human consumption (Elliott and Michener, 1965). Internal microbial levels in cooked meats depend on the initial microbial levels and types before heating, the thermal process and the subsequent holding-time temperatures. Freshly prepared cooked uncured meats normally have counts of 102 or less per gram. During handling, packaging or serving of cooked products, some low level of contamination invariably occurs on the products surfaces from equipments and food handlers. Cooked non fermented cured meats products have counts of 103 or less/g; higher levels in products from retail outlets reflect the time-temperture history of the storage. Under proper refrigeration, such meats do not support the growth of mesophilic pathogens, so that high aerobic plate counts are unrelated to health hazard. Coliforms present as unavoidable contaminants at low levels    (± 10cfu/g), can grow in refrigerated products if they are psychrotropgic (Johnston and Tompkin, 1992). Jurgeen (1994) estimated that the killing temperature of psychrotrophic bacteria ranged from 60-70°C.

Ranken and Kill (1993) described microbiological quality in terms of microbial count/g, 102-excellent quality, 104-good commercial quality, 106-rejection limit in many commercial conditions, 108-meat and meat product smell and 109-meat become slimy. 

In this study, E.coli failed to be isolated from neither nuggets nor luncheon samples. El-Tahan et al. (2006) isolated E.coli only from both nugget and luncheon samples collected from Down Town retail markets but the samples collected form Shubra and Nasr city were free. Salmonellae were not detected in both nuggets and luncheon examined samples and this result agreed with that of El-Tahan et al. (2006) and Al-Dughaym and Altabari (2010).This was due to that the heating process destroys Salmonellae and other non sporeforming pathogens (Johnston and Tompkin, 1992). 

Table showed that 16% and 48% of chicken nuggets and luncheon samples, respectively, were contaminated with coagulase positive Staph. aureus. Human contact with cooked food, as in handling and in slicing, invariably adds S.aureus at levels of 10 to 102 to many of sample units (Surkiewicz et al., 1973). Such levels are harmless but offer  sufficient inoculum for growth to hazardous levels if subsequent conditions of time-temperture abouse occur (Johnston and Tompkin, 1992).

Studies indicated that large numbers (usually greater than 1 million cfu/g) of coagulase positive Staph. aureus must contaminate the food for producing sufficient enterotoxin to cause food poisoning (Liston et al., 1971; Gilbert et al., 1972). Cooked cured luncheon meats seldom cause staphylococcal food poisoning because S.aureus does not grow as well anaerobically in the presence of salt and nitrite (luncheon meats are usually vacuum packaged). Moreover, S.aureus competes poorly with the lactic acid bacteria that dominate in vacuum-packaged cured meats and will not grow below 6.7ºC "luncheon meats are usually well refrigerated" (Johnston and Tompkin, 1992).

The biofilm formation in food processing plants is mainly associated with damp surfaces, on which the microorganisms can easily aggregate (Chmielewski and Frank, 2003). Some bacteria (such as in genera Klebsiella, Pseudomonas and Staphylococcus) produce exopolymers that can fix additional microorganisms firmly attached to the surface, these can survive in form of mixed biofilms (Sasahara and Zottola, 1993).Both pathogenic and food spoilage microorganisms have been isolated from such bacterial communities. It was also found that Listeria monocytogenes and Enterobacter aerogenes or bacteria of the genera Bacillus, Streptococcus, Staphylococcus, Shigella, Escherichia, and Klebsiella survived cleaning and disinfection (Austin and Bergeron, 1995; Sharma and Anand, 2002; Gunduz and Tuncel, 2006). Bacteria which survive in the biofilms on surfaces are much more resistant to biocidal agents than planktonic cells of the same species (Carpentier and Cerf, 1993; Campanac et al., 2002). Due to this fact, the conventional sanitation and disinfectant agents may fail to kill bacteria under certain conditions (Hodd and Zottola, 1997).Moreover, it was found that the cell-to-cell DNA transmission occurs in a micro-community, and the biofilm development can be stimulated by their conjugation mechanism (Molin and Tolker–Nielsen, 2003). 

Chemical examination:

Table 3showed that the means ± S.E.values of pH, TVB-N (mg/100g) and TBA(mg/kg) in the examined nuggets samples were 6.08 ±0.046; 13.36± 0.76 and 0.038 ± 0.005, respectively, while in luncheon samples were 6.15± 0.06 ; 5.54 ±0.66 and 0.028± 0.002, respectively.

Nearly similar results were recorded by Daoud et al. (2001) who analysed chicken luncheon for keeping quality parameters. They found that the mean values of of pH, TBA and TVB-N were 6.07, 0.124 mg/kg and 13.0 mg/100g; respectively. Higher results were obtained by Fath El-Bab and Sayed-Eman (2005) who collected thirty chicken luncheon samples from different governorates (Cairo, Giza, Zagazig, Alexandria and Beni Suef) and they found that the thiobarbituric acid value ranged from 0.62 to 0.86 with a mean ± S.E. of 0.73±0.02mg malonaldehyde/kg which were within the permissible limit (0.9 mg malonaldehye/kg) as recommended by Egyptian Organization for Standardization and Quality Control "EOSQC" (1995).

Al-Dughaym and Altabari (2010) examined the further processed poultry meat products in Al-Ahsa markets-Kingdom of Saudi Arabia. Nuggets showed a high TBA values which varied from 0.53 to 2.09 mg malonaldhyde/kg, with a detectable unacceptable flavour and lower degree of acceptability. While pH and TVB-N values varied from 5.87 to 6.03 and from 13.5 to 15.4 mg TVB-N /100g, respectively, according to manufacture companies.

Hammad-Manal (2005) recorded similar results for the pH and TVB-N in chicken luncheon which were ranged from 6.0 to 6.99 and 12.37 to 15.71mg/100g, with means ± S.E of 6.23±0.03 and 14.15±0.14mg/100g but the TBA values were higher and were ranged from ranged from 0.19 to 0.63 mg malonaldehyde/kg, with a mean ± S.E. value of 0.42 ± 0.02 mg/kg, respectively.

Table 6 showed that the examined samples of nuggets and luncheon exhibited slightly increasedpH values (>6.5-<7) in about 4% and 12%, respectively. Also, the TVB-N values in all the examined samples of both products types were completely complied with the E.S.S.,No.3493/ 2000 for poultry meat productsand its amendments in 16/12/2003. The maximum permissible limits were 25 and 30 mg TVB-N /100g for partially and completely cooked poultry meat products.

The final pH of pasteurized cured meat products depends largely on the initial pH of the meat which ranges from 5.6 to 6.4. The inclusion of polyphosphates may increase the pH by 0.3, and the final pH after processing may vary between 6.1 and 6.5 (Ingram and Simonsen, 1980).

The increase inpH might be due to the addition of phosphates in the formulation,the addition of whole egg liquid (pH 7.83) in nuggets. Also, an increase inpH was observed after frying,this is in agreement with other studies on poultry restructured meat products (Polanne et al., 2001; Jimenez-Colmenero et al., 2003) and breast poultry meat (Allen   et al., 1998) and it could be attributed to the formulation and/or the protonation of some basic amino acids residue side chains which became exposed due to the protein denaturation during cooking (Xiong et al., 1999).

The formation of TVB-N is related mostly to the degradation of animal protein, i.e.deamination of protein during spoilage that begins as a result of the growth of proteolytes. So, it could be used as criterion for the detection of spoilage (Vyncke, 1980).

The results illustrated in Table 3 showed that the ranges of TBA values in both nuggets and luncheon obeyed the allowable permissible level (<0.90mg/kg as malonaldhyde) according to E.S.S., No.3493/ 2000 for poultry meat products and its amendments in 16/12/2003 for coated and non coated poultry meat products.

These lower values of TBA in the investigated chicken meat products may be attributed largely to the absence of oxygen which is the most critical factor influencing lipid oxidation, using  freshly  slaugltered chicken  broilers meats, increasing inhibition of meat enzymes by incorporation of sodium chloride and nitrite and the efficient removing of heme pigments during bleeding and washing techniques. Membrane-bound lipids consist largely from polyunsaturated phospholipids which are especially susceptible to lipid oxidation (Asghar et al., 1988). Polyunsaturated fatty acids (PUNA) such as linoleic and arachidonic acids, undergo the greatest oxidation in red meats and poultry during frozen storage (Lai et al., 1991). Studies dealing with nonenzymatic catalysts of lipid oxidation in meat and meat products have focused on iron compounds, including haeme pigments, free iron and ferritin (Monahan et al., 1993). The presence of antioxidants as vitamine E which act as free radical scavengers (Monahan et al., 1992). Washing techniques for mechanically deboned poultry meat have been investigated because of the advantages of removing fat, haeme pigments and other water soluble compounds (Yang and Fronging, 1992). Pearson et al. (1983) stated that the oxidation products of lipids are chronic toxicants in man and contribute to the aging process, cancer and cardiovascular diseases.

 

REFERENCES

 

Albert, S. and Mittal, G.S. (2002): Comparative evaluation of edible coatings to reduce fat uptake in a deep-fried cereal product. Food Res. Int. 35(5): 445-458.

Al-Dughaym, A.M. and Altabari, G.F. (2010): Safety and quality of some chicken meat products in Al-Ahsa markets-Saudi Arabia. Saudi J. of Biological Sciences 17: 37-42.

Allen, C.; Fletcher, D.; Northcutt, J. and Rusell, S. (1998): The relationship of broiler breast color to meat quality and shelf life. Poultry Sci. 77: 361-366.

Ang, C.Y.W. and Lyon, B.G. (1990): Evaluations of warmed-over flavour during chill storage of cooked broiler breast, thigh and skin by chemical, instrumental and sensory methods. J. Food Sci., 55: 644-648, 673.

AOAC. (1984): Official Methods of Analysis(14th ed.). Washington, DC, USA; Association of Official Analytical Chemists.

APHA (1992): Compendium of Methods for Microbiological Examination of Foods. American Public Health Association, WashingtonDC.          

Asghar, A.; Gray, J.I.; Buchley, D.J.; Pearson, A.M. and Booren, A.M. (1988): Perspectves on warmed-over flavor. Food Technol. 42(6): 102-108.

Austin, J.W. and Bergeron, G. (1995): Development of bacterial biofilms in dairy processing lines. Journal of Dairy Research, 62: 509–549.

Bean, N.N. and Griffin, P.M. (1990): Food borne disease outbreaks in the United States, 1973-1987; pathogens, vehicles and trends. J. Food Prot. 53: 804-817.

Bkheet, A.A.; Rezk, M.SH. and Mousa, M.M. (2007): Study on the microbiological content of local manufactured poultry meat products in El-Bohira Governorate. Assiut Vet. Med. J. 53, 112: 115-125.

Campanac, C.; Pineau, L.; Payard, A.; Baziard-Mouysset, G. and Roques, C. (2002): Interactions between biocide cationic agents and bacterial biofilms. Antimicrobial Agents and Chemotherapy, 46: 1469–1474.

Carpentier, B. and Cerf, O. (1993): Biofilms and their consequences, with particular reference to hygiene in the food industry. Journal of Applied Bacteriology, 75: 499–511.

Chang, H.C. and Carpenter, J.A. (1997): Optimizing quality of frankfurters containing oat bran and added water. J. Food Sci. 62: 194-197, 202.

Chmielewski, R. and Frank, J.F. (2003): Biofilm formation and control in food processing facilities. Comprehensive Reviews in Food Science and Food Safety, 2: 22–32.              

Dainty, R.H. (1996): Chemical/biochemical detection of spoilage. Int. J. Food Microbiol. 33: 19-34.     

Daoud, J.R.; Kamel, A.A. and Gab-Allah, H.M. (2001): Studies on chemical constituents of some poultry products. J. Egypt Vet. Med. Assoc., 61: 187-19.

Egyptian Organization for Standardization and Quality Control "EOSQC" (1995): Frozen chicken and turkey sausage. Ministry of Industry. Egyptian Standard Specifiction "E.S.S." No.1114/2005 for luncheon meat. Egyptian Organization for Standardization and Quality Control.

Egyptian Standard Specifiction "E.S.S." (No.3493/2000): Poultry meat products. Egyptian Organization for Standardization and Quality Control.

El-Khateib,T.;Abdel-Rahman,H.;Hamdy,M. and Lotfi,A.(1988):Poultry meat products in Egypt. "Proximal chemical composition and microbiological quality". Fleishwirtschaft, 68(6): 756-757.

Elliot, R.P. and Michener, H.D. (1965): Factors affecting the growth of psychrotrophic microorganisms in food: A review. Washington Dc.

El-Tahan, M.H.; EL-Tahan, F.H. and Abdel-Salam, A.F. (2006): Microbiological and chemical properties in chicken products collected from local markets.  J. Agric. Sci. Mansoura Univ., 31(2): 989-997.

Essa, H.H.; Makar, N.H. and Sohair, Z. Hussein (2004): Bacteriological evaluation of chicken luncheon in AssiutCity. Assiut Vet. Med.J., 50, 102: 64-71.

FAO (1980): Food and Agriculture Organization of the United Nations. Manual of Food Quality, 3-Commodities. United Nations, Rome.

Fath El-Bab, G.F.A. and Eman M. Sayed (2005): Some bacterial and chemical investigations on chicken luncheon and beef luncheon.  Vet. Med. J., Giza. Vol. 3: 855-862.

Fletcher, D.L.; Qiao, M. and Smith, D.P. (2000): The relationship of raw broiler breast meat color and pH to cooked meat color and pH. Poultry Sci., 79: 784-788.

Geornaras, I.; De Jeus, A.; Van Zyl, E. and Von Holy, A. (1998): Bacterial populations associated with the dirty area of the south African poultry abattoir. J. Food Prot. 61: 700-703.

Gilbert, R.T.; Wieneke, A.A.; Lanser, J. and Simkovicova, M. (1972): Serological detection of enterotoxin in foods implicated in staphylococcal food poisoning. J. Food Hyg., 70: 755-762.

Gunduz, G.T. and Tuncel, G. (2006): Biofilm formation in an ice cream plant. Antonie Van Leeuwenhoek, 89: 329–336

Hammad, Manal, I. Abdel-Fadeel (2005): Study on effect of non meat ingredients on the quality of poultry products. Ph.D. Thesis, Faculty of Vet. Med., Beni-SuefUniv.

Higgins, F.M.; Kerry, J.P.; Buckley, D.J. and Morrissey, P.A. (1998a): Assessment of "-tocopheryl acetate supplementation, addition of salt and packaging on the oxidative stability of raw turkey meat. Br. Poult. Sci., 39: 596-600.

Higgins, F.M.; Kerry, J.P.; Buckley, D.J. and Morrissey, P.A. (1998b): Effect of dietary "-tocopheryl acetate supplementation on "-tocopherol distribution in raw turkey muscles and its effect on the storage stability of cooked turkey meat. Meat Sci., 50:      373-383.

Hodd, S.K. and Zottola, E.A. (1997): Growth media and surface conditioning influence the adherence of Pseudomonas fragi, Salmonella typhimurium, and Listeria monocytogenes cells to stainless steel. J. Food Prot., 60: 1034–1037.

ICMSF (1978): International Commission on Microbiological Specifications for Foods. Microorganisms in Food, their Significance and Method of Enumeration. 2nd Ed. Univ. Toronto Press, Toronto and Buffalo, Canada.

Ingram, M. and Simonsen, B. (1980): Meat and meat products. In: Microbial Ecology of Foods, Vol. II, Food Commodities, pp. 333-409. ICMSF, Academic Press, New York.

Jensen, C.; Lauridson, C. and Bertelsen, G. (1998): Dietary vitamin E: quality and storage stability of pork and poultry. Trends in Food Sci. and Tec., 9: 62-72.

Jimenez-Colmenero, F.; Serrano, A.; Ayo, J.; Solas, M.T.; Cofrades, S. and Carballo, J. (2003): Physicochemical and sensory characteristics of restructured beef steak with added walnuts. Meat Sci., 65: 1391-1397.

Johnston, Ralph, W. and Tompkin, R.B. (1992): Meat and poultry products. In: Compendium of Methods for the Microbiological Examination of Foods. 3 rd Ed., Chapter, 44. American Public Health Assoc. "APHA" pp. 821-835.

Jurgeen, (1994): Facts to know about heating food staffs. Dieflescherei 9/1994.

Lai, S.; Gray, J.I.; Smith, D.M.; Crackel, R.L. and Buckley, D.J. (1991): Effects of oleoresin rosemary, tertiary butylhydroquinone and sodium tripolyphosphate on development of oxidative rancidity in restructured Chicken nuggets. J. Food Sci. 56: 616-620.

Liston, J.; Matches, J.R. and Baross, J. (1971): Survival and growth of pathogenic bacteria in food. In: Food Inspection and Quality Control. (ed.) Kreuzer, R.; Fishing News Lid., London, England, P. 246.

Marenzi, C. (1986): Proper meat storage prevents spoilage. Poultry Misset 6:12-15.

Mate, J.I. and Krochta, J.M. (1996): Comparison of oxygen and water vapor permeabilities of whey protein isolate and B-lactoglobulin edible films. J. Agric. Food Chem. 44(10): 3001-3004.

Meat Board (1983): Published by National Livestock and Meat Board, USA, No.6 -305/8835.

Molin, S. and Tolker-Nielsen, T. (2003): Gene transfer occurs with enhanced efficiency in biofilms and induces enhanced stabilisation of the biofilm structure. Current Opinion in Biotechnology, 14: 255–261.

Monahan, F.J.; Gray, J.I.; Brooren, A.M.; Miller, E.R.; Buckley, D.J.; Morrisey, P.A. and Gomaa, E.A. (1992): Influence of dietary treatment on lipid and cholesterol oxidation in pork.J.Agric.Food Chem., 40: 1310.

Monahan, F.J.; Crackel, R.L.; Gray, J.I.; Buckley, D.J. and Morrisey, P.A. (1993): Catalysis of lipid peroxidation in muscle model systems by haeme and inorganic iron. Meat Sci. 34: 95-106.

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REFERENCES
 
Albert, S. and Mittal, G.S. (2002): Comparative evaluation of edible coatings to reduce fat uptake in a deep-fried cereal product. Food Res. Int. 35(5): 445-458.
Al-Dughaym, A.M. and Altabari, G.F. (2010): Safety and quality of some chicken meat products in Al-Ahsa markets-Saudi Arabia. Saudi J. of Biological Sciences 17: 37-42.
Allen, C.; Fletcher, D.; Northcutt, J. and Rusell, S. (1998): The relationship of broiler breast color to meat quality and shelf life. Poultry Sci. 77: 361-366.
Ang, C.Y.W. and Lyon, B.G. (1990): Evaluations of warmed-over flavour during chill storage of cooked broiler breast, thigh and skin by chemical, instrumental and sensory methods. J. Food Sci., 55: 644-648, 673.
AOAC. (1984): Official Methods of Analysis(14th ed.). Washington, DC, USA; Association of Official Analytical Chemists.
APHA (1992): Compendium of Methods for Microbiological Examination of Foods. American Public Health Association, WashingtonDC.          
Asghar, A.; Gray, J.I.; Buchley, D.J.; Pearson, A.M. and Booren, A.M. (1988): Perspectves on warmed-over flavor. Food Technol. 42(6): 102-108.
Austin, J.W. and Bergeron, G. (1995): Development of bacterial biofilms in dairy processing lines. Journal of Dairy Research, 62: 509–549.
Bean, N.N. and Griffin, P.M. (1990): Food borne disease outbreaks in the United States, 1973-1987; pathogens, vehicles and trends. J. Food Prot. 53: 804-817.
Bkheet, A.A.; Rezk, M.SH. and Mousa, M.M. (2007): Study on the microbiological content of local manufactured poultry meat products in El-Bohira Governorate. Assiut Vet. Med. J. 53, 112: 115-125.
Campanac, C.; Pineau, L.; Payard, A.; Baziard-Mouysset, G. and Roques, C. (2002): Interactions between biocide cationic agents and bacterial biofilms. Antimicrobial Agents and Chemotherapy, 46: 1469–1474.
Carpentier, B. and Cerf, O. (1993): Biofilms and their consequences, with particular reference to hygiene in the food industry. Journal of Applied Bacteriology, 75: 499–511.
Chang, H.C. and Carpenter, J.A. (1997): Optimizing quality of frankfurters containing oat bran and added water. J. Food Sci. 62: 194-197, 202.
Chmielewski, R. and Frank, J.F. (2003): Biofilm formation and control in food processing facilities. Comprehensive Reviews in Food Science and Food Safety, 2: 22–32.              
Dainty, R.H. (1996): Chemical/biochemical detection of spoilage. Int. J. Food Microbiol. 33: 19-34.     
Daoud, J.R.; Kamel, A.A. and Gab-Allah, H.M. (2001): Studies on chemical constituents of some poultry products. J. Egypt Vet. Med. Assoc., 61: 187-19.
Egyptian Organization for Standardization and Quality Control "EOSQC" (1995): Frozen chicken and turkey sausage. Ministry of Industry. Egyptian Standard Specifiction "E.S.S." No.1114/2005 for luncheon meat. Egyptian Organization for Standardization and Quality Control.
Egyptian Standard Specifiction "E.S.S." (No.3493/2000): Poultry meat products. Egyptian Organization for Standardization and Quality Control.
El-Khateib,T.;Abdel-Rahman,H.;Hamdy,M. and Lotfi,A.(1988):Poultry meat products in Egypt. "Proximal chemical composition and microbiological quality". Fleishwirtschaft, 68(6): 756-757.
Elliot, R.P. and Michener, H.D. (1965): Factors affecting the growth of psychrotrophic microorganisms in food: A review. Washington Dc.
El-Tahan, M.H.; EL-Tahan, F.H. and Abdel-Salam, A.F. (2006): Microbiological and chemical properties in chicken products collected from local markets.  J. Agric. Sci. Mansoura Univ., 31(2): 989-997.
Essa, H.H.; Makar, N.H. and Sohair, Z. Hussein (2004): Bacteriological evaluation of chicken luncheon in AssiutCity. Assiut Vet. Med.J., 50, 102: 64-71.
FAO (1980): Food and Agriculture Organization of the United Nations. Manual of Food Quality, 3-Commodities. United Nations, Rome.
Fath El-Bab, G.F.A. and Eman M. Sayed (2005): Some bacterial and chemical investigations on chicken luncheon and beef luncheon.  Vet. Med. J., Giza. Vol. 3: 855-862.
Fletcher, D.L.; Qiao, M. and Smith, D.P. (2000): The relationship of raw broiler breast meat color and pH to cooked meat color and pH. Poultry Sci., 79: 784-788.
Geornaras, I.; De Jeus, A.; Van Zyl, E. and Von Holy, A. (1998): Bacterial populations associated with the dirty area of the south African poultry abattoir. J. Food Prot. 61: 700-703.
Gilbert, R.T.; Wieneke, A.A.; Lanser, J. and Simkovicova, M. (1972): Serological detection of enterotoxin in foods implicated in staphylococcal food poisoning. J. Food Hyg., 70: 755-762.
Gunduz, G.T. and Tuncel, G. (2006): Biofilm formation in an ice cream plant. Antonie Van Leeuwenhoek, 89: 329–336
Hammad, Manal, I. Abdel-Fadeel (2005): Study on effect of non meat ingredients on the quality of poultry products. Ph.D. Thesis, Faculty of Vet. Med., Beni-SuefUniv.
Higgins, F.M.; Kerry, J.P.; Buckley, D.J. and Morrissey, P.A. (1998a): Assessment of "-tocopheryl acetate supplementation, addition of salt and packaging on the oxidative stability of raw turkey meat. Br. Poult. Sci., 39: 596-600.
Higgins, F.M.; Kerry, J.P.; Buckley, D.J. and Morrissey, P.A. (1998b): Effect of dietary "-tocopheryl acetate supplementation on "-tocopherol distribution in raw turkey muscles and its effect on the storage stability of cooked turkey meat. Meat Sci., 50:      373-383.
Hodd, S.K. and Zottola, E.A. (1997): Growth media and surface conditioning influence the adherence of Pseudomonas fragi, Salmonella typhimurium, and Listeria monocytogenes cells to stainless steel. J. Food Prot., 60: 1034–1037.
ICMSF (1978): International Commission on Microbiological Specifications for Foods. Microorganisms in Food, their Significance and Method of Enumeration. 2nd Ed. Univ. Toronto Press, Toronto and Buffalo, Canada.
Ingram, M. and Simonsen, B. (1980): Meat and meat products. In: Microbial Ecology of Foods, Vol. II, Food Commodities, pp. 333-409. ICMSF, Academic Press, New York.
Jensen, C.; Lauridson, C. and Bertelsen, G. (1998): Dietary vitamin E: quality and storage stability of pork and poultry. Trends in Food Sci. and Tec., 9: 62-72.
Jimenez-Colmenero, F.; Serrano, A.; Ayo, J.; Solas, M.T.; Cofrades, S. and Carballo, J. (2003): Physicochemical and sensory characteristics of restructured beef steak with added walnuts. Meat Sci., 65: 1391-1397.
Johnston, Ralph, W. and Tompkin, R.B. (1992): Meat and poultry products. In: Compendium of Methods for the Microbiological Examination of Foods. 3 rd Ed., Chapter, 44. American Public Health Assoc. "APHA" pp. 821-835.
Jurgeen, (1994): Facts to know about heating food staffs. Dieflescherei 9/1994.
Lai, S.; Gray, J.I.; Smith, D.M.; Crackel, R.L. and Buckley, D.J. (1991): Effects of oleoresin rosemary, tertiary butylhydroquinone and sodium tripolyphosphate on development of oxidative rancidity in restructured Chicken nuggets. J. Food Sci. 56: 616-620.
Liston, J.; Matches, J.R. and Baross, J. (1971): Survival and growth of pathogenic bacteria in food. In: Food Inspection and Quality Control. (ed.) Kreuzer, R.; Fishing News Lid., London, England, P. 246.
Marenzi, C. (1986): Proper meat storage prevents spoilage. Poultry Misset 6:12-15.
Mate, J.I. and Krochta, J.M. (1996): Comparison of oxygen and water vapor permeabilities of whey protein isolate and B-lactoglobulin edible films. J. Agric. Food Chem. 44(10): 3001-3004.
Meat Board (1983): Published by National Livestock and Meat Board, USA, No.6 -305/8835.
Molin, S. and Tolker-Nielsen, T. (2003): Gene transfer occurs with enhanced efficiency in biofilms and induces enhanced stabilisation of the biofilm structure. Current Opinion in Biotechnology, 14: 255–261.
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