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

AIAD, A.S.

doi:10.21608/avmj.2008.176254

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

Assiut Veterinary Medical Journal

Article 16, Volume 54, Issue 119 - Serial Number 4, October 2008, Page 1-8 PDF (405.54 K)

DOI: 10.21608/avmj.2008.176254

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Author

A.S. AIAD

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

Key words: HACCP - pasteurized milk; UHT milk

Full Text

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)

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

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 × 10²	100	7.3×10 ± 0.5×10	100	3.8×10² ± 1.5×10²	100	3.4×10⁵ ± 1.7×10⁵	100	Total aerobic bacteria
100	00	00	97.16	9.1× 10² ± 7.7× 10²	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× 10²	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× 10² ± 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
verification	Records	Corrective action	Who	Frequency	How	What	Critical limits for each preventive measure	Significant hazards		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

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

- fat

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
verification	Records	Corrective action	Who	Frequency	How	What	Critical limits for each preventive measure	Significant hazards		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 6^oC 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.

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