APPLICATION OF HAZARD ANALYSIS CRITICAL CONTROL POINT (HACCP SYSTEM) IN THE PRODUCTION OF UHT MILK TO PRODUCE SAFE AND HIGH QUALITY PRODUCT

Author

Animal Health Research Institute, Alexandria

Abstract

The application of hazard analysis critical control point (HACCP) system principles and required tasks were carried out in a Dairy products processing plant in Alexandria-Egypt. Objective of this study is to evaluate the chemical and microbiological specification of sterilized milk through the application of HACCP system to produce high quality and safe product. Random samples were taken during monitoring of processing line for verification purpose 30 samples from each of raw milk, skim milk powder, milk fat, pasteurized and sterilized milk for chemical and microbiological examination. Samples were taken and transferred directly to the laboratory under aseptic condition with a minimum of delay. The samples were then subjected to chemical and microbiological examination. The obtained results revealed that the mean values of total aerobic bacterial count (cfu/ml), coliform count, staphylococcus aureus count, spore forming count and mold count in raw milk samples were 3.4´ 105 ± 1.7 ´ 105, 3.2 ´ 104 ± 1.9 ´ 104, 6.5 ´ 102 ± 1.8 ´ 102, 3.9 ´ 102 ± 2 ´ 10, and 1.9 ´ 102 ± 5.6 ´ 10, respectively. The reduction rate in microbial counts in pasteurized and sterilized milk were 99.18,100,97.16,100,92.15,100,81.28,91.28,100,100 respectively. UHT treatment of milk killed all pathogenic microorganisms which were present in raw milk and the UHT milk nearly sterile except small incidence (5%) with low spore forming count. The chemical and microbiological results were within acceptable limits according to Egyptian standards. (ES 2005). The results of monitoring the processing line revealed that the line was well controlled and within the limits of prescribed HACCP plan. Conclusion, AHACCP based risk assessment and good manufacturing practice should be employed for all stages of production and handling of sterilized milk from the farm to the consumer. The production of sterilized milk under the application of HACCP system can assume both quality and safety of the final product. Pasteurization can be used as critical control point to control microbial hazards. It is recommended that the HACCP system be implemented in all dairy industry to improve quality and safety of sterilized milk.

Keywords


Animal Health Research Institute, Alexandria.

 

Application of Hazard Analysis Critical Control Point (HACCP System) in the Production of UHT Milk to Produce
Safe and High Quality Product

(With 3 Tables)

 

By

A.S. Aiad

(Received at 20/9/2008)

 

تطبيق نظام تحليل المخاطر بطريقة  نقاط المراقبة الحرجة على إنتاج اللبن   ال UHT لتقديم منتج آمن وعالى الجودة

 

أحمد صلاح الدين عياد

 

يعتبر اللبن غذاء يقارب الکمال لأنه يحتوى على أهم العناصر التى يحتاجها الإنسان فى کافة الأعمار والتى قلما تتوافر فى طعام واحد. واللبن سريع التلوث بالجراثيم والتى تعتبر عاملا لنقل العديد من الأمراض. ولذلک أصبحت معاملة الألبان بالحرارة العالية تطبق بصورة واضحة کوسيلة لحفظ الألبان لمدد أطول خصوصاً تحت ظروف الأجواء الحارة حيث تهدف عملية تعقيم اللبن بواسطة الحرارة إلى تثبيط النشاط الميکروبى وتحطيم الإنزيمات الموجودة بغرض زيادة قوة حفظ اللبن وبالتالى إمکانية تخزينه لمدة طويلة. ونظراً لأن تقديم غذاء آمن وذو جودة عالية هو المطلب الأساسى للمستهلکين لذلک رؤى تطبيق نظام تحليل المخاطر بنظام مراقبة النقاط الحرجة (الهاسب) لإنتاج لبنUHT  آمن وعالى الجودة. وقد تم سحب عدد (30) عينة من کل من (اللبن الخام ولبن البودرة منزوع الدسم ودهن اللبن واللبن المبستر واللبنUHT) وتم نقل العينات إلى المعمل تحت ظروف صحية مناسبة لمنع التلوث وأجريت الاختبارات الکيمائية والميکروبيولوجية لهذه العينات. وکذلک مراقبة وتسجيل درجات الحرارة للبن عن الاستقبال والتخزين والبسترة والتعقيم والتخزين النهائى للمنتج. وقد وجد أن عملية تعقيم اللبن تقضى على معظم الميکروبات الممرضة والمسببة للفساد والتى کانت موجودة فى اللبن الخام.وکانت النتائج الکيميائية والميکروبيولوجية لجميع العينات فى الحدود المسموح بها طبقاً للمواصفات القياسية المصرية وخطة الهاسب للبن المعقم. وکان المنتج النهائى فى حدود متطلبات الجودة والأمان. وقد تم مناقشة النقاط اللازمة لإنتاج لبن معقم آمن وذو جودة عالية.

 

 

 

SUMMARY

 

The application of hazard analysis critical control point (HACCP) system principles and required tasks were carried out in a Dairy products processing plant in Alexandria-Egypt. Objective of this study is to evaluate the chemical and microbiological specification of sterilized milk through the application of HACCP system to produce high quality and safe product. Random samples were taken during monitoring of processing line for verification purpose 30 samples from each of raw milk, skim milk powder, milk fat, pasteurized and sterilized milk for chemical and microbiological examination. Samples were taken and transferred directly to the laboratory under aseptic condition with a minimum of delay. The samples were then subjected to chemical and microbiological examination. The obtained results revealed that the mean values of total aerobic bacterial count (cfu/ml), coliform count, staphylococcus aureus count, spore forming count and mold count in raw milk samples were 3.4´ 105 ± 1.7 ´ 105, 3.2 ´ 104 ± 1.9 ´ 104, 6.5 ´ 102 ± 1.8 ´ 102, 3.9 ´ 102 ± 2 ´ 10, and 1.9 ´ 102 ± 5.6 ´ 10, respectively. The reduction rate in microbial counts in pasteurized and sterilized milk were 99.18,100,97.16,100,92.15,100,81.28,91.28,100,100 respectively. UHT treatment of milk killed all pathogenic microorganisms which were present in raw milk and the UHT milk nearly sterile except small incidence (5%) with low spore forming count. The chemical and microbiological results were within acceptable limits according to Egyptian standards. (ES 2005). The results of monitoring the processing line revealed that the line was well controlled and within the limits of prescribed HACCP plan. Conclusion, AHACCP based risk assessment and good manufacturing practice should be employed for all stages of production and handling of sterilized milk from the farm to the consumer. The production of sterilized milk under the application of HACCP system can assume both quality and safety of the final product. Pasteurization can be used as critical control point to control microbial hazards. It is recommended that the HACCP system be implemented in all dairy industry to improve quality and safety of sterilized milk.

 

Key words: HACCP - pasteurized milk – UHT milk

 

 

 

INTRODUCTION

 

The hazard analysis critical control point system is a science based and systematically identifies specific hazards and measures for their control to ensure the safety of food. HACCP is a tool to assess hazards and establish a control system that focus on prevention rather than relying mainly on end product testing (Codex 2000). The HACCP method of food safety control is accepted as the best way to assure consumer safety in the production of foods, it is a preventive approach to food safety management (Early, 1997). Pasteurization and sterilization are the most common used heat treatment they are performed on a large industrial scale due to the need for qualified, experienced staff and strict controlled hygienic processing condition. Milk pasteurized by a special method involving ultra high temperature is called UHT milk. This process extends the shelf life of the milk without changing the nutrient value. The term sterilization refers to the complete elimination of all microorganisms. Ultra heat treatment is partial sterilization of milk by heating it for a short time at temperature exceeding 135ºC/4seconds which is the temperature required to kill spores in milk. UHT milk has atypical shelf-life of six to nine months, Pasteurized milk has a relatively short life and should be used immediately or stored in the refrigerator while sterilized milk keep unopened for several months and once opened the milk must be kept refrigerated.

The main potential hazards in most dairy products are microbiological hazards and the dairy industry has increased its efforts for quality and safety assurance through the development and implementation of protective programmes as HACCP (Kassem et al., 2002). Although UHT milk is processed in a manner makes its validity time longer than other heat treated milks (pasteurized and boiled), yet its shelf-life may be shortened due to same undesirable chemical or microbiological changes induced by certain microorganisms or their related heat resistant lipolytic or proteolytic enzymes that render such product of inferior quality or even un marketable (Abo-Donia et al., 1985). UHT milk may be contaminated with relatively high counts of viable aerobic bacteria, aerobic spore-formers and fungi. This may be due to inefficient heat treatment of processed milk, faults in packaging, neglected hygienic measures adapted during processing. Presence and multiplication of such microorganisms especially aerobic spore-formers bacteria in UHT milk during storage is not only of concern as a public health hazard, but also as a main cause of economic losses through spoilage of such products, rendering them unsuitable for human consumption (Khan and Natarajan, 1986). The presence of coliform organisms in UHT is considered as a bad index for the lower hygienic quality and leads to deterioration of the product and causing public health hazards (Saudi et al., 1990). Fungal contamination of UHT milk is indicative for errors in storage and defects in packaging processes, moreover, multiplication of these fungi in UHT milk during storage may induce undesirable flavours, poor appearance and discolouration (Bullerman, 1981).

The HACCP plan is the written document which is based up on the principal activity of HACCP and which delineates the procedures to be followed to assure the control of specific process or procedure and holds details of all that is critical to food safety management (Moy et al., 1994). The HACCP plan is drown up by the HACCP team and consists of two essential components, the process flow diagram and HACCP control chart (Mortimore and Wallace 1995). The aim of this work is the application of HACCP system in the production of sterilized milk to produce safe and high quality product.

 

MATERIALS and METHODS

 

The application of HACCP system principles and required tasks were carried out according to ICMSF (1988), Codex (2000) and ISO 22000: (2005) in the processing line of UHT milk on dairy products processing plant in Egypt. Prerequisite programs were established before application of HACCP system. The HACCP system consists of the following seven principles: Principle (1): Conduct a hazard analysis. Principle (2): Determine the critical control points (CCPS). Principles (3): Establish critical limit(s). Principle (4): Establish a system to monitor control of the (CCPs). Principle (5): Establish the corrective action to be taken when monitoring indicates that a particular (CCP) is not under control. Principle (6): Establish procedures for verification to confirm that the HACCP system is working effectively Principle        (7): Establish documentation concerning all procedures and records appropriate to these principles and their application. The process flow diagram for U HT milk was constructed and verified by the HACCP team as the following:

 

 

Receiving raw materials (skim milk powder, milk fat) →weight and preparing of raw materials

Receiving raw milk (5-10ºC) → cooling and storage of raw milk (less than 10°C) → filtration → Standardization→ (fat not less than 3%)→   Pasteurization ( 85°C /15 second) → storage of pasteurized milk → UHT treatment (137ºC/4 sec.) → Storage (aseptic tank less than 10°C) → filling → storage (sterilized milk) (Room temp. 25-30ºC) → Distribution → Consumer.

Flow diagram was used to indicate the major steps in UHT milk production; Random samples were taken during monitoring of raw materials.

Random 30 samples from each of (raw milk, skim milk powder, milk fat, pasteurized and UHT milk). Were taken during monitoring the processing line. The samples were directly transferred to the laboratory with minimum of delay under complete aseptic condition. The samples were taken according to (Marshal 1992).

The samples were subjected to the following examination:

 

- Chemical examination:

Determination of pH, titratabile acidity, fat, protein, casein, moisture and activity test for detection of antibiotic residue according to (AOAC 1990).

 

- Microbiological examination:

The samples were prepared according to the technique recommended by ICMSF (1978) and the following microbiological examination was then applied. Total aerobic bacterial count, total coliform count, staphylococcus aureus count, aerobic spore-forming count and mold count and determination of salmonellae according to Marshal (1992) and ISO (1993).  

 

 

RESULTS

 

The obtained results were recorded in Tables 1-3 

 

Table 1: Statistical analytical results of chemical examination of raw milk, skim milk powder, milk fat, Standardized Pasteurized milk and UHT milk   n = 30.

 

UHT  milk

Standardized         Pasteurized milk

Milk fat

Skim milk powder

Raw milk

 

mean± S.E

mean± S.E

mean± S.E

mean± S.E

mean± S.E

 

----

---

---

Good

Good

Activity test

6.46±0.025

6.31±0.044

5.35±0.06

6.08±0.02

6.33±0.028

PH

0.16±.003

0.16±0.001

0.14±0.03

0.15±0.003

0.15±0.001

Acidity

3.4±0.031

3.38±0.036

83.04±0.15

0

3.45±0.028

Fat

2.91±0.018

2.89±0.015

---

38.75±0.4

2.9±0.019

Protein

2.32±0.013

2.33±0.014

------

25.23±0.26

2.32±0.013

Casein

----

-----

15.22±0.13

3.05±0.06

---

Moisture

 

Table 2: Statistical analytical results during monitoring the UHT milk processing line.

 

UHT milk

Pasteurized milk

Raw milk

 

Storage temp. °C

 Sterilization temp °C/           4 seconds

Cooling temp. °C

Pasteurization temp °C/ 15 seconds

Storage temp. °C

Receiving temp. °C

5

137

6

85

3

5

Min

10

139

8

85

5

9

Max

7.15 ±0.28

137 ±0.24

7.25 ± 0.18

85

3.96 ± 0.16

7.4 ±0.25

Mean± S.E.

 Less than 10

Not less than 135

Less than 8

Not less than 85

2-5

 Less than 10

Normal value

 

 

          Table 3: Of raw milk, skim milk powder, milk fat, Pasteurized milk and UHT milk n = 30

 

UHT milk

Pasteurized milk

Milk fat

Skim milk powder

Raw milk

Type of samples

R%

Mean±

S.E.(a)

Positive samples %

R%

Mean

±

S.E.(a)

Positive samples %

Mean±

S.E.(a)

Positive samples %

Mean±

S.E.(a

Positive

Samples

 %

Mean±

S.E.(a)

Positive

 Samples

%

counts

100

00

00

99.18

2.8×103

±

8.5 × 10 2

100

7.3×10

±
0.5×10

100

3.8×102

±
1.5×102

100

3.4×105

±

1.7×10­ 5

100

Total

aerobic

bacteria

 

100

00

00

97.16

9.1× 10 2

±

7.7× 10 2

20

3.2×103

±
5.4×102

40

1.8×10

±
0.15

20

3.2×104

±

1.9× 104

100

Total

coliform

 

100

00

00

92.15

5.1× 10

±

2.1×10

26

3.2×102

±
2.6×102

30

00

00

6.5×102

±

1.8× 10 2

100

 Staphaureus

 

91.28

3.4×10

±
0.6×10

5

81.28

7.3×10
±

0.7×10

60

2.3×10

±
0.8×10

40

1.4×10

±
0.6×10

40

3.9× 10 2

±

2 × 10

100

Spore

forming

 

100

0

0

100

00

00

4.1×103
±

6.5×102

90

4.8×10

±

0.6×10

33.33

1.9×102

±
5.6×10

36

Mold

 

           a: standard error of mean

              R: reduction rate

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Form (1) : HACCP plan for Sterilized Milk

verification

Records

Corrective action

monitoring

Critical limits for each preventive measure

Significant hazards

CCP

CP

 

Critical point

Control point

Who

Frequency

How

What

 

Process steps

-record review

 

Calibration of thermometer

Receiving inspection record

 

Rejection of milk

 

 

Receiving engineer

 

Every batch

 

 

Recording

Temperature

Temperature

 

 

Temperature less than 10°c

 

Toxins from pathogenic microorganism

 

CCP

 

 

Receiving raw milk

 

 

 

 

-

-chemical and bacteriological examination of milk

 

 

 

laboratory record

 

 

 

 

 

 

Not used

 

 

 

 

 

 

 

Lab .engineer

 

 

 

 

 

 

 

Every batch

 

 

 

 

 

 

Every batch

 

 

 

 

Activity test

 

 

 

 

 

 

Chemical and bacteriological tests

 

 

 

 

 

Presence of antibiotic residues

 

 

 

 

- chemical and bacteriological specification

 

 

 

Free from antibiotic residues

 

 

 

 

6.6- 6.8

0.14-0.18

Not less than3%

-3%

 

Less than5x104

Antibiotic residues

 

 

 

Chemical and bacteriological specification

pH –

titratable acidity

Fat

 

- protein  

                -

Total bacterial count

 

 

 

 

 

 

 

 

 

 

 

 

 

Raw milk analysis

 

 

 

 

 

 

 

Record review

-calibration of thermometer

 

 

 

 

                calibration of pH

Process control records

Recooling

Receiving engineer

 

At receiving and every

2 hours

Recording

Temperature

 

Recording

Cleaning program

 

 

Recording

pH

Temperature

time record

 

CIP

 

 

 

 

Record pH

Temperature less than 10°c

Time3-hours

Cleaning &hygienic instruction

 

 

6.6-6.8

temperature/time

 

 

change filter and

cleaning

receiving and storage tank cleaning

PH

 

CP

 

Filtration,

Cooling and storage of raw milk

 

 

 


 

 

verification

Records

Corrective action

Monitoring

Critical limits for each preventive measure

Significant hazards

CCP

CP

 

Critical point

Control point

 

 

Who

Frequency

How

What

 

Process steps

Certificate of analysis for chemical and microbiological examination

Incoming inspection record

Refused

Receiving

 Eng

At receiving

Chemical and bacteriological methods

Chemical and bacteriological

tests

According to specification of each substance

Chemical and bacteriological specification

pH –

titratable acidity

fat

-                                                                                                                                      - protein- casein

moisture

 

Receiving raw materials(skim milk powder, milk fat)

 

Record review

 

 

 

 

 

 

Process control records

readjustment

Lab .engineer

 

Every batch

Chemical tests

 

 

 

 

 

 

 

 

Chemical specification

 

 

 

 

 

 

Not less than

3%

 

- fat

 

CP

 

 

 

 

 

 

 

standardization

 

 

 

 

 

                           

 

Form (1) : HACCP plan for Sterilized Milk

verification

Records

Corrective action

monitoring

Critical limits for each preventive measure

Significant hazards

 

 

CCP

CP

 

Critical point

Control point

 

Who

Frequency

How

What

 

Process steps

-record review

-calibration of thermometer                                                

 

Process control records

Adjust temperature and re-pasteurization

 

 

                                                                                                                                      Stop work use other unite

production engineer

Each hour

 

 

 

At work beginning and finish

Measuring and recording temperature

 

 

Check its work

Temperature

 

 

 

Diversion valve

PasteurizatinTemperature  85°c/15 seconds

 

cooling

Temperature less than 8°c

 

Survival of vegetative pathogenic microorganisms

CCP

 

 

 

 

 

 

pasteurization

 

 

Record review

Process control records

Re-sterilization

Repeat cleaning

production engineer

 

During work

 

Before and after work

 

Every half hour

Temperature/

time recording

Cleaning follow up

CIP

monitoring sterilization apparatus

Temperature/

time

Cleaning of sterilized milk tank

sterilization apparatus

 

137°c   /4 seconds

 

Cleaning program

 

Temperature/ time

 

 

 

&cleaning

CCP

 

 

 

 

CP

 

sterilization

 

 

 

Record review

Process control records

Repeat cleaning process

Avoid damaged packages

Adjust filling machine

quality control engineer

Before work

 

During work

 

Cleaning follow up

Filling machine follow up

Cleaning

Filling machine

Cleaning and hygienic requirement

Filling machine instruction

Cleaning

Filling machine

Product handling

CP

 

Filling

 

 

 

 

Record review

 

 

 

Calibration of thermometer

Process control records

Re-Adjust temperature

Repeat cleaning training

production engineer

 

 

 

 

Continues

 

 

Every 6 hours

Measuring and recording temperature

Cleaning follow up

Chemical and

Temperature

cleaning

 

 

 

 

Storage procedure

Cleaning program

 

Storage temperature

Cleaning

Product handling

CP

 

Storage of final product and distribution

Visual examination

Container data

Not drink it

consumer

At buying and before handling

Visual inspection

Expire date

Storage temperature

Firmly closed

Used within expire date

Room temperature

Used after expire date

Contaminated opened container

CP

 

consumer

 

 

DISCUSSION

 

Hazard analysis:

(Receiving-cooling – storage, preparation and standardization):

The results in Table 1 showed that the mean values of pH, acidity, fat, protein, and casein in raw milk were 6.33 ± 0.028, 0.15±0.001, 3.45±0.028, 2.9±0.019 and 2.32±0.013 respectively. All results were within acceptable limits according to E S (2005). From the data present in Table 1 it is evident that all samples were with good results for the activity test for detection of antibiotic residues in milk. Test for antibiotic residues were carried out to prevent problems with allergic reaction to antibiotic (Varnam and Sutherland 1994). While data present in Table 2 showed that the mean values of receiving and storage temperature oC of raw milk were 7.4±0.25 and 3.96±0.16 respectively. Raw milk was often implicated in outbreaks of staphylococcal intoxication before rapid cooling of milk and pasteurization become accepted practices (Bryan, 1983). Raw milk transported to the plant in tankers and may be subjected to long transport times and variety of temperatures that may lead to microbial growth and production of microbial toxins that will not be destroyed by subsequent pasteurization process hence control of raw milk delivery is a critical control point (CCP) (ICMSF 1988). The mean values of pH, acidity, fat, protein, casein and moisture in skim milk powder were 6.08 ±0.02, 0.15±0.003, 0, 31.75±0.4, 25.23 ±0.26 and 3.05 ±0.06, respectively. this comply with ES (2005) which stated that fat should be not more than 1.5%, moisture not more than 5%, acidity not more than 1.5% and protein not less than 34%. While the mean value of pH, acidity, fat and moisture in milk fat were 5.35 ±0.06, 0.14±0.03, 83.04 ± 0.15 and 15.22 ±0.13 respectively. This comply with ES (2005) which stated that fat should be not less than 80%, moisture not more than 16% and acidity not more than 0.1%. The chemical composition of raw milk affects the nature of the final sterilized milk so it is general practice to standardized milk composition to ensure consistency and maximum yield. Standardization was by addition of skim milk powder or milk fat.

The data present in Table 3 showed that the mean values of total aerobic bacterial count (cfu/ml), coliform count, staphylococcus aureus count, spore forming count and  mold count in raw milk samples were    3.4´ 105 ± 1.7 ´ 105, 3.2 ´ 104 ± 1.9 ´ 104, 6.5 ´ 102 ± 1.8 ´ 102, 3.9 ´ 102 ± 1.7 ´ 102, and 1.9 ´ 102 ± 5.6 ´ 10, respectively. Salmonella could not be detected. Nearly similar results obtained by Abdel-Hafiez (2006), while higher results were obtained by El-Shishnagui et al. (2001). Presence of large numbers of coliform bacteria in raw milk provides an index of the poor hygienic condition under which milk is produced (Richer et al., 1992). Raw milk should be purchased from inspected and approved suppliers and should be stored and distributed under conditions that prevent microbial growth and/or contamination (Hayes 1992). The data present in Table (3) showed that the mean values of total aerobic bacterial count (cfu/ml), total coliform count,staphyloccus aureus count, spore forming count and mold count were 3.8´102 ± 1.5´102, 7.3´10 ± 0.5´10, 1.8´10 ± 0.15, 3.2´ 103 ± 5.4´102,00, 3.2´102 ± 2.6´102, 1.4×10 ± 0.6×10, 2.3×10 ± 0.8×10, 8´10 ± 0.6´10 and 4.1´103 ± 6.5´102 in skim milk powder and milk fat receptively, Salmonella could not be detected in milk powder and milk fat. this comply with ES(2005) which stated that milk powder must be free from pathogenic microorganisms, Salmonella and E. coli, total bacterial count not more than 10cfu/gm and mold count not more than 10 cfu/gm. while milk fat must be free from pathogenic microorganisms, E. coli, spoilage bacteria and mold, coliform not more than10cfu/gm

Pasteurization:

The data present in Table 2 showed that he pasteurization temperatures were 85с°for exactly 15 seconds. Almost all potential microbiological hazards can be eliminated with a heat treatment (pasteurization). Pasteurization has proved to be successful as CCP to control zoonoses as well as food borne pathogens such as Campylobacter and Salmonella (IDF 1994).

Table 1 reported that the mean values of pH, acidity, fat, protein and casein in standardized pasteurized milk were 6.31±0.044, 0.16±0.001, 3.38±0.036, 2.89±0.015 and 2.33±0.014 respectively. All results comply with (ES 2005) which stated that fat not less than 3% in full cream pasteurized cow milk

The data in Table 3 showed that the mean values of  total aerobic bacterial count (cfu/ml), coliform count, staph aureus count, spore forming count, and mold count in standardized pasteurized milk were 2.8 ´ 103 ±8.5´ 102 ,9.1´ 102 ±7.7´ 102 ,5.1´ 10 ±2.1´10 and 7.3´ 10±0.7´10, respectively. Salmonella and mold could not be detected. The present count may be due to the presence of spore forming bacteria as well as thermoduric count which can resist the pasteurization temperature. Lower results were obtained by Abdel- Hafiez and Ragab (2004), Abdel Hafiez (2006). All results were within control limits according to HACCP plan form (1) and comply with (ES 2005). Which stated that pasteurized milk should be free from pathogenic microorganisms. The reduction rate in pasteurized milk samples were 99.18, 97.16, 92.15, 81.28 and 100 in total aerobic bacterial, coliform, staphyloccus aureus, Spore forming and mold counts respectively. In most developed countries; fresh milk is rapidly chilled and stored at refrigeration temperatures in an attempt to limit microbial growth. Prolonged refrigeration storage of milk has been resulted in problems of quality for dairy industry (Swart et al., 1989).

Heat resistant spore formers are most important microorganisms as these spores are able to survive the pasteurization process, germinate at temperature as low as 7ºC followed by auto growth and subsequent spoilage of milk faster than mesophilic types (Sutherland and Murdach, 1995).

Cooling:

Illustrated data present in Table 2 showed that the cooling temperature of pasteurized milk ranged from 6oC to 8ºC with a mean value of 7.25 ± 0.18. Pasteurized milk has a relatively short life (7-10 days) and should be used immediately, or stored in the refrigerator. Pasteurization does not destroy all of the microorganisms; therefore the milk has to be cooled rapidly to prevent the growth of surviving bacteria.

UHT treatment:

While pasteurization conditions effectively eliminate potential pathogenic microorganisms, it is not sufficient to inactivate the thermoresistant spores in milk. The term sterilization refers to the complete elimination of all microorganisms. The chemical and microbiological tests were carried out for verification of that the final product (UHT milk) achieved required quality and safety. The data present in Table (1) showed that the mean values of pH, acidity, fat, protein and casein in examined sterilized milk samples were 6.46 ± 0.025, 0. 16±0.003, 3.4 ± 0.031, 2.91 ± 0.018 and 2.32 ± 0.013, respectively. All results comply with (ES 2005). Which stated that fat not less than 3% in full cream sterilized milk and acidity not more than 0.17%.

Table 2 showed that the UHT temperature ranged from 137°C to 139°C with a mean value of 137±0.024 for exactly 4 seconds. The basis of UHT milk is the sterilization of milk before packaging, then filling into pre-sterilized containers in a sterile atmosphere.

Data in Table 3 showed that  the mean values of total bacterial count (cfu/ml) and total spore forming count in examined sterilized milk samples were: 00, 3.4 ´ 10 ± 2.4 respectively. Coliform, staphyloccus aureus, mold and salmonella could not be detected. The reduction rate in sterilized milk samples were 100, 100, 100, 91.28 and 100 in total aerobic bacterial, coliform, staphylococcus aureus, spore forming and mold counts respectively. All results were within control limits according to HACCP plan form (1) and comply with (ES 2005). This stated that UHT milk should be free from pathogenic microorganisms, total bacterial count not more than 10 cfu/ml and free from E coli. Higher results were obtained by (El-Asuoty 2006).

For production of high quality UHT milk high quality raw milk should be used in its manufacture and strict attention to sterilization procedure and packaging materials should be applied (Farahnik, 1982). Presence and multiplication of aerobic spore formers bacteria in UHT milk during storage is not only of concern as a public health hazard but also cause economic losses through spoilage of such product rendering them unsuitable for human consumption (Khan and NataraJan, 1986 and Abo-Donia et al., 1985). The presence of coliform organisms in UHT milk is considered as a bad index for hygienic quality and lead to deterioration of the product and causing public health hazards (Saudi    et al., 1990). UHT milk may be contaminated with such organisms due to inefficient heat treatment of processed milk, faults in packaging, neglected hygienic measures during processing or using improperly cleaned and sterilized equipment or due to leakage of package during transportation and storage (Farahnik, 1982). Food handling personnel play an important role in ensuring food safety through out the chain of production, processing, storage and preparation. Mishandling and disregard of hygienic measures on their part may enable pathogens to come in contact with food and in some cases to survive and multiply in sufficient numbers to cause illness in the consumer (WHO, 1980). Staphylococcus aureus is a good indicator of the personal hygiene of workers with respiratory infections and suppuration (Kamat et al., 1991). Contamination of UHT milk with moulds is indicative of the neglected hygienic measures applied during processing, packaging and storage and constitutes a public health hazard (Lee, 1984).

Filling:           

A septic filling of UHT milk is the most important factor of contamination (langefeld, and Bolle, 1979). The sterilized milk was filled on laminated paper tetrapak. Sterilization and aseptic packaging is the goal for most milk products, the most common packaging  material for both pasteurized and UHT milk is glass bottles sealed with either foil or metal caps, although plastic bottles, plastic bags, card board cartons and laminated paper tetrapak are all used.

Storage:

The results of Table1 showed that the storage temperature of UHTmilk ranged from 5to 10 oC with a mean value of 7.15± 0.28. Sterilized milk will keep unopened for several months (6 months), but once opened the milk must be kept refrigerated and used within 4-5 days.

Distribution-Consumers

Control during distribution to prevent post contamination and control hazard at customer by increase his awareness to follow instruction printed in the package especially expiry date and method of preservation.

It can be concluded that the raw milk should be collected and maintained in a good hygienic condition. If the raw milk is not be used immediately, it should be refrigerated to minimize multiplication of bacteria. The raw milk should under go a full pasteurization or equivalent process, good conditions of hygiene should be maintained through out UHT production, distribution and storage until consumption to prevent contamination. A HACCP based risk assessment and good manufacturing practice should be employed for all stages of production and handling from the farm to the consumer.

 

REFERENCES

 

AbdEl-Hafiez, E.M.E. and Ragab, Mervat, K.I. (2004): Application of Hazard Analysis Critical Control Point (HACCP) system to produce high quality and safe plain yoghurt. Alex. J. Vet, Vol 21 No.1, 168-185.

AbdEl-Hafiez, E.M.E. (2006): Evaluation of quality and safety of feta cheese produced by application of quality assurance program. Benha Vet. Med. J, Vol. 17, No. I,

Abo-Donia, S.A.; El-Dosa, M.; Sirry, I. and Harfaush, S. (1985): Milk lipolytic bacteria IA. Quantitative and qualitative study on lipolytic activity of four bacterial cultures. Alex. J. Agric. Res., 29 (3): 257.

AOAC (1990): Official Methods of Analysis, 931,15Th Ed. Public AOAC, Box 540 Benjamin Franklin station, Washington, 4, DC.

Bryan, F.L. (1983): Epidemiology of milk borne diseases J. Food Prot. 46.637-649.

Bullerman, L.B. (1981): Public health significance of mold and mycotoxins in fermented dairy products. J. Dairy Sci., 69: 2439.

Codex ALimentarius (2000): Milk and Milk Products Joint FAO/WHO food standards programme, Codex Alimentarius Commission, 2nd Ed., Vol. 12 World Health Organization, Rome, p.42-45., Rome.

Early, R. (1997): Putting HACCP into practice International Journal of Dairy Technology Vol. 50. No. I February.

Egyptian Standard specification (2005): Egyptian Standards Hazard analysis critical control point system and guide lines for its application. Codex: 1-1969 Rev. 4.2003 Es: 3778/ 2005.           

El-Asuoty, M.S. (2006): Quality assurance procedures of Ultra Heat Treated milk at local markets. A thesis M.V. Sci, dept. Food hyg, Fac. Vet. Med. Sci. Alex. Uni. (2006).

El-Shishnagui, Sawsan, M.L.; Saleh, S.K. and Fathalla, M.G. (2001): The microbiological quality of raw and pasteurized milk in Alexandria with special reference to the incidence of sane cold-Tolerant Pathogens. Bull H.I.P.H, Vol. 11(2): 217-232.

Farahnik, S. (1982): A quality control program for recommendation for UHT milk processing and aseptic packaging of milk and milk by-products Dairy Food Sanit., 2 (11): 454-456.

Hayes, P.R. (1992): Food Microbiology and Hygiene 2nd Ed. Elsevier science publisher LTD England.

ICMSF (International Commission on Microbiological Specification for Foods (1978): Microorganisms in foods Vol. I Univ. of Toronto press, Toronto and Buffalo, Canada.

ICMSF, International Commission of the Microbiological specification of Foods (1988): Microorganisms in food. Vol. 4: Application of the hazard analysis critical control point (HACCP) system to ensure microbiological safety and quality Black well scientific publications.

IDF (International dairy federation) (1994): Recommendation for the hygienic manufacture of milk and milk based products. Bull. Int. Dairy Fed. 292, 41.          

ISO (1993): General guidance on methods for the detection of salmonella. ISO 6579: 1993 (E).

ISO 22000 (2005): Food safety management systems requirements for any organization in the food chain (Iso 22000: 2005) National Standards Authority of Ireland glasnevin, Dublin 9 Ireland.

 

Kamat, M.Y.; Sulebele, G. and Nirupama, Sabnis (1991): Acomparative evaluation of media for enumeration of enterotoxigenic staphylococci by selective enrichment technique. J. Food Sci. Technol., India, 28(6): 381-383.  

Kassem, M.; Salem, E.; Ahwal, A.M.; Saddik, M. and Gomaa, N.F. (2002): Application of hazard analysis and critical control point system in the dairy Industry Eastern Mediterranean Health Journal Volume 8, No. I, January 2002.

Khan, I.M. and Natarajan, T. (1986): Incidence of aerobic spore formers in milk. Madras Agric J. 73 (10): 570-572.

Langefeld, l.P.M. and Bolle, A.C. (1979): Duration of the preincubation period in the sterility control of UHT sterilized milk. The Netherlands milk Dairy J.33:1172-180.

Lee, C.M. (1984): Spoilage microorganisms encountered in UHT processed milk-Chinese J. Microbiol. Immunol. 17(2): 86-91.

Marshall, R.T. (1992): Standard Methods for the examination of  dairy products, 16th Edition American Public Health Association, Washington DC, 2005, 1015 Fifteeth Street N.W.

Mortimore, S. and Wallace, C. (1995): HACCP A practical approach. Chapman and Hall. 2-6 Boundary Row London.

Moy, G.; Kaferstin, F. and Motar, J. (1994): Application of HACCP to food manufacturing some consideration on harmonization through training. Food Control vol. 5 number 3, p. 131-139.

Richer, R.L.; Ledford, R.A. and Murphy, S.C. (1992): Compendium Methods for the Mcrobiological Examination of Foods 3rd. 387-856, American Public Health Association D.C.

Saudi, A.M.; Salam, S.S.; El-Essawy, H.A. and Hafez, N.M. (1990): Bacterialogical quality of UHT milk at Giza. Alex J. Vet-Med., 6(1): 39-45.

Sutherland, A.D. and Murdach, R. (1995): Seasonal occurrence of psychrotrophic Bacillus species in raw milk, and studies on the interaction with mesophilic Bacillus species. International J.Food Microbiol., 21: 279-292.

Swart, G.J.; Jooste, P.J. and Mastert, J.F. (1989): The occurrence and seasonal distribution of psychrotrophic and certain mesophilic bacterial types in the bulk milk supply of the Pretoria Oreg. Suid-Afrikaans Tydskrif Virsiwelkunde, 21 (1): 1-8 Dairy Sci. Abstr., 51 (12), (1989).

Varnam, A.H. and Sutherland, J.P. (1994): Milk and Milk Products technology, chemistry and microbiology, Chapman & Hall. London-New York-Tokyo.

WH0 (World Health Organization) (1980): "Health examination of food handling personnel" Report of working group Copenhagen. WHO Regional office for Europe.

 
REFERENCES
 
AbdEl-Hafiez, E.M.E. and Ragab, Mervat, K.I. (2004): Application of Hazard Analysis Critical Control Point (HACCP) system to produce high quality and safe plain yoghurt. Alex. J. Vet, Vol 21 No.1, 168-185.
AbdEl-Hafiez, E.M.E. (2006): Evaluation of quality and safety of feta cheese produced by application of quality assurance program. Benha Vet. Med. J, Vol. 17, No. I,
Abo-Donia, S.A.; El-Dosa, M.; Sirry, I. and Harfaush, S. (1985): Milk lipolytic bacteria IA. Quantitative and qualitative study on lipolytic activity of four bacterial cultures. Alex. J. Agric. Res., 29 (3): 257.
AOAC (1990): Official Methods of Analysis, 931,15Th Ed. Public AOAC, Box 540 Benjamin Franklin station, Washington, 4, DC.
Bryan, F.L. (1983): Epidemiology of milk borne diseases J. Food Prot. 46.637-649.
Bullerman, L.B. (1981): Public health significance of mold and mycotoxins in fermented dairy products. J. Dairy Sci., 69: 2439.
Codex ALimentarius (2000): Milk and Milk Products Joint FAO/WHO food standards programme, Codex Alimentarius Commission, 2nd Ed., Vol. 12 World Health Organization, Rome, p.42-45., Rome.
Early, R. (1997): Putting HACCP into practice International Journal of Dairy Technology Vol. 50. No. I February.
Egyptian Standard specification (2005): Egyptian Standards Hazard analysis critical control point system and guide lines for its application. Codex: 1-1969 Rev. 4.2003 Es: 3778/ 2005.           
El-Asuoty, M.S. (2006): Quality assurance procedures of Ultra Heat Treated milk at local markets. A thesis M.V. Sci, dept. Food hyg, Fac. Vet. Med. Sci. Alex. Uni. (2006).
El-Shishnagui, Sawsan, M.L.; Saleh, S.K. and Fathalla, M.G. (2001): The microbiological quality of raw and pasteurized milk in Alexandria with special reference to the incidence of sane cold-Tolerant Pathogens. Bull H.I.P.H, Vol. 11(2): 217-232.
Farahnik, S. (1982): A quality control program for recommendation for UHT milk processing and aseptic packaging of milk and milk by-products Dairy Food Sanit., 2 (11): 454-456.
Hayes, P.R. (1992): Food Microbiology and Hygiene 2nd Ed. Elsevier science publisher LTD England.
ICMSF (International Commission on Microbiological Specification for Foods (1978): Microorganisms in foods Vol. I Univ. of Toronto press, Toronto and Buffalo, Canada.
ICMSF, International Commission of the Microbiological specification of Foods (1988): Microorganisms in food. Vol. 4: Application of the hazard analysis critical control point (HACCP) system to ensure microbiological safety and quality Black well scientific publications.
IDF (International dairy federation) (1994): Recommendation for the hygienic manufacture of milk and milk based products. Bull. Int. Dairy Fed. 292, 41.          
ISO (1993): General guidance on methods for the detection of salmonella. ISO 6579: 1993 (E).
ISO 22000 (2005): Food safety management systems requirements for any organization in the food chain (Iso 22000: 2005) National Standards Authority of Ireland glasnevin, Dublin 9 Ireland.
 
Kamat, M.Y.; Sulebele, G. and Nirupama, Sabnis (1991): Acomparative evaluation of media for enumeration of enterotoxigenic staphylococci by selective enrichment technique. J. Food Sci. Technol., India, 28(6): 381-383.  
Kassem, M.; Salem, E.; Ahwal, A.M.; Saddik, M. and Gomaa, N.F. (2002): Application of hazard analysis and critical control point system in the dairy Industry Eastern Mediterranean Health Journal Volume 8, No. I, January 2002.
Khan, I.M. and Natarajan, T. (1986): Incidence of aerobic spore formers in milk. Madras Agric J. 73 (10): 570-572.
Langefeld, l.P.M. and Bolle, A.C. (1979): Duration of the preincubation period in the sterility control of UHT sterilized milk. The Netherlands milk Dairy J.33:1172-180.
Lee, C.M. (1984): Spoilage microorganisms encountered in UHT processed milk-Chinese J. Microbiol. Immunol. 17(2): 86-91.
Marshall, R.T. (1992): Standard Methods for the examination of  dairy products, 16th Edition American Public Health Association, Washington DC, 2005, 1015 Fifteeth Street N.W.
Mortimore, S. and Wallace, C. (1995): HACCP A practical approach. Chapman and Hall. 2-6 Boundary Row London.
Moy, G.; Kaferstin, F. and Motar, J. (1994): Application of HACCP to food manufacturing some consideration on harmonization through training. Food Control vol. 5 number 3, p. 131-139.
Richer, R.L.; Ledford, R.A. and Murphy, S.C. (1992): Compendium Methods for the Mcrobiological Examination of Foods 3rd. 387-856, American Public Health Association D.C.
Saudi, A.M.; Salam, S.S.; El-Essawy, H.A. and Hafez, N.M. (1990): Bacterialogical quality of UHT milk at Giza. Alex J. Vet-Med., 6(1): 39-45.
Sutherland, A.D. and Murdach, R. (1995): Seasonal occurrence of psychrotrophic Bacillus species in raw milk, and studies on the interaction with mesophilic Bacillus species. International J.Food Microbiol., 21: 279-292.
Swart, G.J.; Jooste, P.J. and Mastert, J.F. (1989): The occurrence and seasonal distribution of psychrotrophic and certain mesophilic bacterial types in the bulk milk supply of the Pretoria Oreg. Suid-Afrikaans Tydskrif Virsiwelkunde, 21 (1): 1-8 Dairy Sci. Abstr., 51 (12), (1989).
Varnam, A.H. and Sutherland, J.P. (1994): Milk and Milk Products technology, chemistry and microbiology, Chapman & Hall. London-New York-Tokyo.
WH0 (World Health Organization) (1980): "Health examination of food handling personnel" Report of working group Copenhagen. WHO Regional office for Europe.