Cleaning in the food processing plants are an important obligation. Fouling from products after processing can create substantial problems for production. In this study two new cleaning procedures were developed. A chemical procedure and water procedure. To remove soiled product from two food processing vats in a chutney food manufacturer. They were developed to be used in live trials, to assess the effectiveness on cleaning. The experiments parameters were temperature (80 °C), agitation (20rpm) with the water clean. Sodium hydroxide concentration (detergent 5-10% concentration) for chemical procedure. Both used ambient water spray and mechanical parameters. Established contact times, were made for both the chemical and water cleans. To monitor the effectiveness of both cleans, hygiene ATP swab tests performed on the surfaces. Titration sample were collected to measure chemical residue. The both procedures managed to comply with the factory standards for ATP swabbing. There was no significant difference (P>0.05) found between ATP samples collected before and after cleaning. Although there was a visible difference after using both cleaning methods. No titration samples retained sodium hydroxide residue (detergent). The new cleaning methods were both effective for cooking vats. Health and safety concerns were highlighted when working with chemicals. The water procedure may raise cost of the budget set for cleaning. Despite this, both procedures can successfully be implemented for cleaning the cookers.

Keywords: Good manufacturing practice (GMP), Colony forming units (CFU), relative light unit (RLU), sodium hydroxide (detergent) & soiled product (fouling)

1. Introduction

In the United Kingdom, food manufacturing is an enormous industry that produces large quantities of food. This is executed by the use of effective cleaning. Cleaning is an essential business requirement to achieve protection from physical, chemical and microbiological hazard within food. Therefore, a consistently high standard of product quality can be maintained (Goode et al, 2013). Manufacturers must consider the financial implications of cleaning. There is lost production capacity, because of the time needed to clean, and utility costs (water, electricity and wastage disposal) (Atwell et al 2017).

Poor hygiene conformance can result in fouling layers building up and causing other problems (Liu et al. 2006). In food processing plants cleaning of the processing line are essential for eliminate fouling. Residual product remaining on the surface causes fouling and potential microbial growth. Microbes that will remain in the processing line during production. Microbes then have the possibility to transfer into any other products being made (Goode et al, 2013).

Good manufacturing practice (GMP) ensures hygiene is kept to a high standard. An ideal processing line will be completely sanitized under GMP. Complying with requirements of the Regulation (EC) N0. 852/2004 (McLauchlin et al, 2007;2012). GMP is maintained by good hygiene practices like the Adenosine triphosphate (ATP) bioluminescent swab testing. ATP swab testing is a rapid hygiene monitoring tool, used to estimate how effective cleaning is in real time. It uses bioluminescence to count relative light units (RLU). One RLU is estimated to be equivalent to 102-103 Colony Forming Units/mL, these results are given immediately. ATP swabs are not used to distinguish between microbial and non-microbial ATP, but either at high level indicates poor hygiene (Aycicek et al, 2006).

Chutney production has high soiling ability of during processing. The ingredients that make up the chutney contains numerous small pieces of fruit, veg and sugars that stick to surfaces. Adhesion of ingredient is caused by heat processing and ambient cooling. The sugar and acidic based products forces a caramelised effect during cooking, binding the product to contact surfaces. Temperatures of 75^oC have increased the possibility of caramelisation in acid based foods (chutneys) (Chen et al, 2009 & Quintas et al. 2007).

Equally important, are the variations in cleaning procedures used because of a changeover of products made. This could be down to the fouling ability of each product. The cleaning requirements for one batch of product might not be sufficient to another batch of product (Atwell et al, 2017). An example of a cleaning procedure would be to use a chemical to aid the removal of a soiled product.

When using chemicals for cleaning, staff are required to use personal protective equipment under the European council (EC) 89/656/EEC legislation and COSHH (PPE, 2014). Equipment worn by staff to minimize the exposure to hazards like chemicals in the workplace and to prevent injury. Titrations minimise the risk of cross contamination from any chemicals that remain after cleaning. A sample of wash water is collected and tested for concentration. High concentration result in further washing and low results in passing.

Chutneys produced by manufacturers are condiments served along with food. They are made with a wide variety of ingredients such as fruits, veg, sugars. These ingredients generate sour, spicy, sweet or mild tastes (chutneys and sauces, 2011). The water activity (a_w) is available water in the sample (Beuchat et al, 2013). Measured by ratio between vapour pressure of water in food and pure water at the same temperature (water activity, 2009). Chutneys usually contain between 0.80-0.87aw, which indicates a low risk product from spoilage. The water activity is lowered in chutneys due to processing (heating). Water activity identifies foods stability and potential for microbiological growth (Beuchat et al, 2013). The combination of all of these ingredients and cooking result in a product with a 9 month to a year shelf life, once opened and stored correctly.

The hazard analysis critical control point (HACCP) system is put in place to prevent spoilage of the product. Food manufacturers use HACCP to limit contamination in production during processing. Although, chutneys are still at risk of spoilage from yeasts, Clostridium botulinum, moulds (mycotoxin), osmophilia yeast (grow in high sugar concentrations) and halophilic bacteria (more than 1% salt) (Hobbs et al, 2012).

When chutney factories have unsuccessful cleaning of processing lines there are unfavourable consequences for the quality of the products. This may breach the health and safety legislation. The legislation requires for safe wholesome food to be produced, failure can result in fines and prosecution by the local authority (Sprenger, 2012). According to the FSA, (2013), extreme cases can result in withdrawal or recall of unsafe foods placed on the market.

A Chutney manufacturer in this project is required to keep up-to-date with new cleaning methods. The manufacture in this research project has a long history of producing chutneys. Founded in 1889, they sold relishes, jams and pickles. They produce 9 chutneys, 2 relishes and 2 sauces (seen in appendix 1). These products are stocked in many food retailers within Yorkshire. Their biggest stockists are Co- operative, Sainsbury’s and Iceland. These retailers have audit teams that access their facilities to make sure they are producing safe food. 26 members of staff, helps produce around 10 tonnes of chutney a day, which makes about 20,000 jars.

When processing is finished for the day, the chutney leaves the cooking vats soiled. Chutney deposits on to the surface of the cooker, product chutes, floors, walls and equipment. Operatives that cooked the chutney, clean this by using the; light (water), daily(water), weekly (chemical) and monthly (chemical) cleaning procedures.

The adhesion between the fouling deposit (chutney) and surface begins. Fouling is a result of reduced sugars such as fructose and glucose. They undergo caramelization and maillard reaction. During heat processing chutneys sugar is recrystallized and water is removed (Khalid et al. 2016). This causes a crispy brown fouling texture on the surface (fouled chutney). The forces holding the fouling to surface include; van der waals forces; (2) electrostatic forces; (3) hydrogen bonding; and (4) hydrophobic binding together with contact area (Khalid et al. 2016).

A high powered pressure washer (HDS 7/10-4 M seen appendix 4). Is used for all the procedures. It is powered by diesel fuel, that uses up to 100 bar of pressure at 90 °C. To remove soils from the surfaces of the cooking vats. Moreover, it increases the risk of tainting the product from the diesel fumes produced. The high powered washer also develops large amount of aerosols, above the packing floor (ground floor).

As a result, the aims of this project were to develop two new end of day cleaning procedures for the cooking vats, by evaluating the current factory end of day procedure. The effectiveness of the new cleaning procedures will be tested on; time, ATP swabbing, titration tests and cost.

2. Materials and methods

2.1 Procedure

Two students from The University of Huddersfield were introduced to the technical manager and quality assurance manager. The objectives of the project were discussed on the 20/10/2017. The factory and University of Huddersfield confidentiality forms were also signed on the 20/10/2017. The confidentiality form was under the data protection act 1998, whereby data (information) obtained is stored and not disclosed. The factories induction and Health forms were signed on the 31/10/2017. The Level 1 Staff chemical training was passed on the 10/11/2017 (appendix 4). Level 2 food safety was acquired. The documents ensured the students had the basic requires to work in the factory.

Recommendations were given to the students by the technical and quality assurance managers. The; light, end of day, weekly and monthly cleans were observed. Observations took place between the months of November and December. The students made notes on faults observed in the cleaning processes. The students finally targeted the end of day procedure, on both cooking vats seen in figure 1.

Two new cleaning procedures were developed by the students in January 2018. The students regarded the cooking process in the HACCP system (table 1) to be the most important area to clean. Factory cleaning procedures can be seen in table 2, alongside the two new procedures. A new chemical clean and, water clean. They were tested by the students on each of the cooking vats seen in figure 1, between February and March

Table 1. HACCP system for production of chutney

Step

Hazard

Control procedure

Monitoring procedure

Raw material

storage

Microbiological load develops on storage- product taints or microbial toxins.

Pathogens and spore formers

-Dry storage

Ambient conditions

-Temperature checks

-Specification

-Stock rotation- FIFO

Each delivery by suppliers

Monitor storage weekly

Each delivery check

Preparation

Physical and microbial contamination

Operatives wear the correct equipment

Record batches prepared

Operative working

Cooking

CCP

-Bacterial and fungal growth will survive (C. Botulinum).

-Soiling of product.

-Ensure temperature is above 75°C for at least 3 minutes.

-Clean after cooking.

-ATP swabbing

-Microbial analysis

-Record the cooking time and temperature of batch.

-Record batch operative cooking.

-Ensure the cleaning has removed soiled product.

-Record of operative cleaning.

-Time taken to clean.

Holding tank

Soiling

Temperature control

Cleaning soils

Check corners

ATP swab tests

Swab tests for microbial infestation

Metal detector

CCP

Ferrous and nonferrous metals in batches

metal gets into a batch,

Physical contamination.

Detects metals before the batch reaches filling station.

Excretes product with metals into waste bin

Keep a record of any batch with metal contamination.

Keep record of maintenance checks on metal detector

Hot filling

CCP

Spoilage from

Pathogenic growth, if product is in danger zone (8-63^oC) during packing

Fill above 63°C or higher

Record filling temperature

Ensure aseptic filling

Maintenance checks

Final product

Breakages,

potential growth of pathogens

Dry storage, kept away from light

Monitor temperature in storage area.

Checks to ensure no jars have cracks.

Ensure no broken or cracks

CCP = critical control point, FIFO= first in first out (Mortimore, & Warren, 2014)

2.2 Data collection

A total of 5 tests were achieved, 3 chemical and 2 water. The Data were collected by; recording the time (taken to clean), ATP swabbing and chemical titrations tests. Equipment used to clean, and collect data can be seen in table 4. The tests were conducted in the cooking area, the floor plan can be seen in figure 1. Cooker 1 (right side) had water procedure, cooker 2 (left side) had chemical procedure (figure 1).

Figure 1. The floor plan of the cooking area (labelled)

Figure 2. Cooking vats 1 (left side) and 2 (right side)

Testing surface

The surfaces were type 316 stainless steel, standard for food production. Surfaces were soiled with product from previous cook (last of the day). Pre-rinsed for 2 minutes with tap water (blue hose) by the operatives before procedures were used.

2.3 Cleaning chemicals and treatments

ATP swabbing

A hand-held illuminometer device (Hygiena) and ATP swabs (UltraSnap) were used. The swabs were cotton wool tipped and pre-moistened with mild extract (it maximises sample collection via biofilm breakage). Two samples were taken. From the cooking deck and lower deck. A 20x20cm³ area inside the cooker, then a 20x20cm³ sample for outside the cooker. Sufficient pressure and rotation were applied to gain maximum Rotation of the swabs (figure 3). The swab is replaced in the tube. To activate UltraSnap the device is held in the fist, the snap valve must be broken and squeeze twice. The lyophilisation liquid enters the swab and should be shaken for 5 seconds. The swab was inserted in the read chamber illuminometer to measure the bioluminescence in RLU. The appropriate RLU limits table for the chutney manufacturer (table 2) were used as a guide.

Figure 3. Ultrasnap Surface ATP test

Table 2. ATP swabbing Reletive light units for facroy conformation

Reading conformations	Reading limits RLU
Pass	0-40
Caution	41-69
Fail	70+

Figure 4. Swabbed areas inside and outside of both cooking vats

Cleaning chemical

The detergent used in this study is currently used in the food factory. The detergent was Renew AS. It is a liquid alkaline (NaOH) blend of detergent and grease cutting agents. Diluted to 5-10% with cold water, causing powerful action on grease, fat and protein soils. It is safe to use on type 316 stainless steel. During foaming there were long contact times on vertical objects. The contact times used were 20 minutes.

Titration collection

Two 40ml samples of solution from inside the cooking vat were collected. Initial solution samples were collected straight after 2 minutes of rinsing inside the vat. The water was then released. The second samples were collected after rinsing the inside of the cooking vat for 10mins.

Pressure washing

The blue hose attached to the factory’s main water supply. The hose had limited supply of boiled water. Initial heated to 50°C but after 2 minutes, reduced to ambient temperature 8-15°C. The distance of the nozzle from the surface was routinely estimated to be 20cm away, to give control. Surfaces were sprayed for 10 minutes for each new procedure. At variation of angles that best suited the removal of the debris and foaming agent. Water at varying temperature was used for all the experiments.

Thermodynamic heating of water

Cooking vat 1 was filled with 450 litres of water. Turned on and heated to 80°C while stirring. This lasted for 10 minutes. At 20 rates per minute. An additional 375 litres of water were added, the cooker overflowed. After 5 min, water was expelled via a waste pipe.

Mechanical action

A banister brush, bottle scrubber and scrapper were used for both procedures. Visible Surfaces with debris were targeted. There were 1 min dedicated scrubs to under the ribbons (crevice above the cooking vat), using the bottle brush. Rotating the brushes in many directions across the surfaces. The scraper was used in back and forth motion across hardened debris for up to a minute.

Statistical analysis

Paired sample T –test was used for statistical analysis of the ATP swabbing results. The efficiency of the different cleaning techniques against the soiled product on the cooking vats. There were Four paired sample tests. The difference in the number of RLU remaining on surface after each treatment, were statistically analysed, to the variance (SPSS statistical software) at the 95% confidence level.

The exact step by step process can be seen in the results section of this report.

Table 3. Equipment used during trialling of new cleaning procedures

Equipment name	Image of equipment
(1) The Hygiena ATP device and ATP swab (2) Detectable retractable gel pen (3) Paper with stainless steel clip board	(1) (2) (3) (2) (3)
(1) Titration flask Indicator ALK 1 ALK 3 neutralizer (2) Foamer (detergent) (3) Measuring cylinder	(1)
(1) Hygiene plastic specular (2) Bannister Brushes (3) Bottle brush (4) stainless steel sample dipper	(1) (3) (4) (2)
Chemical protective equipment (1) Face guard (2) Chemical protective apron (3) Long chemical protective gloves (4) Steel toe boots chemical resistant	(2) (1) (3) (3)

3. Results

Table 4. The end of day cleaning procedures for the current clean (used by operatives), new chemical clean and new water cleaning procedures (see figure 1 for all locations)

Current cleaning for the cooking areas daily clean used currently

New water cleaning procedure

Vat 1

New chemical cleaning procedures (Renew AS) Vat 2

Stage 1

1. The cooker stirrers should be turned off before working on the cooker.

2. Check that the cooker stream is turned off at the panel, empty cookers as normal into the holding tank.

3. While the cookers are emptying the product, remove the cooker lids and clean.

4. Clean the lids away from the cooker to ensure no spray enters the cookers.

5. Ensure all cookers are fully empty before closing the valve.

6. Turn the cooker stirrer power off and make sure bottom valves are closed before cleaning inside.

7. Use the blue hose to remove the bulk of the product from the internal cooker surface.

8. Make sure the underside to the bridge, underside ribbons, paddles and the stirrer arms are clear.

9. Move the stirrer as you clean, any stubborn marks can be removed later in the process.

10. Move to the cooker deck depress the front cooker stirrer, remove and clean the chute, keeping the food contact surface off the floor.

11. Take the hose to the cooker valve.

12. Hose the inside and outside of the valve until the water runs clear.

13. Use a blue scraper to clear the product chute.

Stage 2

17. Move to the pressure washer (HDS 7/10-4 M) and set to the high temperature (90°C).

19. Ensure extraction fan is on and at a reasonable level before commencing the clean.

20. Move to the cooking deck, pressure wash all remaining deposits from shoot, external and internal cooking surfaces.

21. Again spray the underside bridge, ribbon and paddles and stirring arm.

22. Key target is the connection point between the stirrer and the ribbon (known for debris to get trapped in the point).

23. Take pressure washer cooking platform and route away any debris from the front of the cookers

24. Take pressure washer to lower deck, remove waste pipe, and hose the outside and the inside of the valve until is clear.

Stage 3

25. Put pressure washer on eco mode and rinse until cool to touch, then put it away.

26. Reconnect all the appropriate chutes after the production line operatives have cleaned the production tank.

27. When Cleaning is complete; any questions should be directed to the senior management team before cooking starts again.

28. Remove all cleaning equipment used, put in their correct storage areas, hang hose back up.

29. complete check sheet to ensure the cooking vats are cleaned.

30. operative cleaning should sign off on clean (time & date).

Stage 1

1.Once cooking is finished, cookers should be switched off.

2. make record the time of the clean.

4. Check the cookers stream is switched off at the panel, empty product from cookers using valve.

5. While the cookers are emptying the product, remove the cooker lids and clean.

6. lids should be cleaned away from cookers, to ensure no spray enters cooer.

7. Ensure cookers are fully empty before closing valve.

8. Turn the cooker stirrer power off and make sure bottom valves are closed before cleaning inside.

9. Move to the cooking deck

10. Use the blue hose to remove the bulk of the product from the internal cooker surface.

11. Make sure the underside to the bridge, the underside ribbon, paddles and the underside to the stirrer arms are sprayed.

12. Move the stirrer while spraying, any stubborn marks can be removed later in the process.

13. Move to the lower deck to hose the cooker valve, until it runs clear.

14. spray chute, keeping the food contact surface off the floor.

15. Attach the waste pipe to the cooker.

16. Use blue scraper to clear chute.

17. move to the cooking platform to hose the front of the cooker.

Stage 2

9. Move upstairs to the veg room and fill vinegar tanks with approximately 450 litres of water.

10. Move back to the cooking platform, and Ensure extraction fan is on and at a reasonable level before commencing the clean.

11.Drop water into cooking vats.

12. Switch the cookers back on via the control panel.

13.heat water in cookers to 80°C and let paddles circulate for 10minutes.

14. Move to veg room again, add 345 litres of water to veg tanks, and drop water into vats to overflow.

16. Ensure the waste pipe is attached by, moving to lower deck

15.Release the water via the waste pipe

16. Use a mirror to check if there is any debris on the underside of the ribbon.

17. Brush the underside of both, With bottle brusher and spray with blue hose.

18. Key target is the connection point between the stirrer and the ribbon, check for debris.

Stage 3

19. Use the scraper and spray to remove any visible debris from the top edges of the cookers

20. Re-rinse the cookers with blue hose. Hang the hose back up after rinse.

21. When the cleaning process is complete, a staff member from a different station should check if the cleaning is up to standard.

22. Reconnect all the appropriate chutes after the production line operatives have cleaned the production tank.

22. Documentation should be signed and dated

23. the cleaner and checker should, sign off on the clean sheet.

Stage 1

1.Once cooking is finished, cookers should be switched off.

2. make record the time of the clean.

4. Check the cookers stream is switched off at the panel, empty product from cookers using valve.

5. While the cookers are emptying the product, remove the cooker lids and clean.

6. lids should be cleaned away from cookers, to ensure no spray enters cooer.

7. Ensure cookers are fully empty before closing valve.

8. Turn the cooker stirrer power off and make sure bottom valves are closed before cleaning inside.

9. Move to the cooking deck

10. Use the blue hose to remove the bulk of the product from the internal cooker surface.

11. Make sure the underside to the bridge, the underside ribbon, paddles and the underside to the stirrer arms are sprayed.

12. Move the stirrer while spraying, any stubborn marks can be removed later in the process.

13. Move to the lower deck to hose the cooker valve, until it runs clear.

14. spray chute, keeping the food contact surface off the floor.

15. Attach the waste pipe to the cooker.

16. Use blue scraper to clear chute.

17. move to the cooking platform to hose the front of the cooker.

Stage 2

14. Go to the Personal protective equipment stage and get all the equipment

15. Put the warning chain, across the door.

16. Put the equipment on.

17. Pump up Renew AS foamer until there is sufficient pressure.

18.Foam internal and external vat surfaces until it is fully covered.

19. Let the Renew AS soak for 20min

20. Use the blue spray and hose down the outside of the vat for 5mins

21. Hose down the inside of the vats for 8mins

22. Ensure the waste pipe is connected

22. Empty the cooking vat and rinse internal surface clear for 2mins

23. Key target is the connection point between the stirrer and the ribbon, check for debris.

Stage 3

22. Use scraper to remove hardened visible debris from inside the cooker.

23. use a brush to physically remove and detach any remaining debris. This should be done for 5 minutes.

24. Rinse down the internal surface of the cooker with blue hose for 3 minutes and 2 minutes for the outside, ensuring all debris and foam has been removed.

25. Reconnect all the appropriate chutes after the production line operatives have cleaned the production tank.

26. When the cleaning process is complete, a staff member from a different station should check if the cleaning is up to standard.

27. Documentation should be signed and dated.

27. The cleaner and checker should sign off on the clean sheet.

Figure 5. visible difference from cleaning the product. A) before. B) after cleaning

A.	B

3.1 Economic cost of using water for water clean and high pressure washer HDs 7/10-4 M

Equation 1. Energy required to heat water (Dutton. 2017).

Q=m∙cp∙∆T

Heating 450 litres for 10min and finishing at 80°C uses an estimated 219.77Kw (Dutton, 2017 & Heat processing service LDT, 2012)

219.77Kw both cooker can cost between 274.27- 314.36 per month (UK Power, 2018).

According to Yorkshire water (2018), the average cost of 1000 Litres in West Yorkshire costs £1.35.

Equation 2. The cost of water used for new water clean.

£1.35÷1000=£0.00135

1 litre=£0.00135

£0.00135×450L=£0.607

0.607×30=£18.20

£0.00135× 375L=£0.506

£0.506×30=£15.18

18.20+15.18=£33.38

One month of 825 litres of water per day costs £33.38

Equation 3. Cost of high pressure washer HDs 7/10M cleaners estimated water use per hour.

£1.35÷1000=£0.00135

1 litre=£0.00135

£0.00135×525L=£0.707

1 hour of uses=£0.71

Table 5. Time and cost, collected for cooking vat cleans

No. specific cleaning approach	Product	Type of clean	Time	Estimated monthly cost for both cookers
Chemical
	Red onion chutney	EOD	47min
	apricot and stem ginger chutney	EOD	54 min	N/a
	Chunky mango chutney	EOD	57min	N/a
Water
	Chunky mango chutney	EOD	1hr 4min
	Red onion chutney	EOD	55min	£355.32
Manufacturer
	Devilish chilli tomato relish	EOD	1hr 57min
	Red onion chutney	EOD	1hr 10min
	apricot and stem ginger chutney	EOD	1hr	£5.78
	mighty American relish	EOD	1hr 32min	£5.78
	Ham burger relish	EOD	1hr 4min

End of day (EOD), Minutes (Min), hour (hr)

3.2 ATP swab

The swab data collected from each experiment can be seen below.

Table 6. ATP swabs before for new EOD cleaning procedures (new chemical procedure and new water procedure).

Trial	Inside cooker 1 RLU	Outside cooker 1 RLU	Inside cooker 2 RLU	Outside cooker 2 RLU
chemical clean
1	22	21
2	193	0
3	25	27
Water clean
1			17	47
2			2	79

Relative light units (RLU)

Table 7. ATP swabs after the factory EOD clean (pressure washer), new chemical procedure and new water procedure.

Trial	Inside cooker 1 RLU	Outside cooker 1 RLU	Inside cooker 2 RLU	Outside cooker 2 RLU
Chemical clean
1			2	5
2			3	2
3			4	0
Water clean
1	4	0
2 Manufacturers procedures	1	2
1	2		0
2	0		2
3	0		0

RLU, Relative light units

Table 8. RLU paired sample T test differences for before and after cleaning.

Pair	1 Chemicals Inside	2 Chemical Outside	3 Water Inside	4 Water Outside
Mean	77	13.6	7	62
Standard deviation	97.8	14.6	8.4	21.2
Standard error of the mean	55.5	8.4	6	15
P value	0.30	0.24	0.45	0.15

Sig. (2-tailed) 0.05

Equation 4. Titration equation for Renew AS concentration activate alkalinity.

Droplets of AKL3 ×0.004×100=active Alkalinity (as % w/v NaOH)

Example before rinse

3 ×0.278×100

= 0.83%

After 10min rinse

0×0.278×100

= 0%

Table 11. Titration for Renew AS chemical cleaning procedure

Trial	chemical before concentration %	After 10min rinse concentration %
1	3.8	0
2	3.8	0
3	0.8	0

4. Discussion

The aim of the project was to develop two new cleaning procedures for the end of day clean. The two new cleaning procedures were successful in the removal of soiled debris. Both procedures were effective at reducing the time taken to clean each cooking vat. The ATP swabs tests were at acceptable levels for both procedures. Although the cost of the new water procedure was considerably increased.

4.1 ATP swabs analysis

The ATP swabs took place before and after the new cleaning procedures on both vats. Results displayed a clear difference in the approximate removal of debris and possible microorganisms from the surfaces of the cooking vats. These cleaning procedures effectively qualified for being efficient. Both removed the majority of soiled product, upholding the factory standard. Passing the factory regulated ATP limit test. Therefore, both would fit into the HACCP system for maintaining cleanliness on the cookers. Although when statistical analysis was performed, there was no significant difference (P>0.05) found between swabbing samples. This could have been due to the areas swabbed. The irregular surface of the cookers made it slightly harder to swab. Aycicek et al, (2006) stated that higher RLU values indicates more organic soils. The water procedure could be exposed to greater resistance from soils.

4.2 Water clean

The highest RLU sample was after the water clean. Soiled material traces may have remained on the surfaces. Although this result was not a concern to the acceptability levels in the factory. Kinetic energy during the water procedure was an ideal form energy for removing debris. The combination of boiling and stirring was perfect for heat transfer, to lift soiled material from the internal surfaces. The heat from the water and flow velocity of (stirring at 20 rpm), potentially disrupted the structure of the soils. Disrupting intermolecular bonds resulting in cohesive failure (Khalid et al. 2016). Softening the top layer, cracks and detachment of fouling deposits. A constant agitation from stirrers. Equally, microorganism’s essential life processes can become damaged due to impaired structural components (denatured proteins) from heat processing at 80^oc. The blue hose had limited hot water supply. This did not enhanced removal. Ambient temperature during spraying (15-8 °C). Therefore, mechanical action was required for removal of any product soils. Visual inspection alone may not always be adequate in assessing surface cleanliness (Aiken et al, 2011).

According to Marriott & Gravani, (2006) hot water sanitation is not a sterilization method. Boiling the water to 80°C for 10mins, did considerably removed debris from the surfaces of the vat. However, hot sanitizing using water can only be done by raising the surface temperature to 85°C for 15mins (Marriott & Gravani, 2006). The water does not make the surface sterile (no microbes). However, it does reduce microbes to an acceptable level, but Heat resistant yeasts and spores may remain present. Traditionally, chutneys are low risk products. Nevertheless, some vegetable ingredients of chutneys are associated with spore forming bacteria (Durand et al. 2015). Heat processing of vegetables can present favourable conditions for sporulation (Sevenier et al. 2012). Consequently, spores remain on any contact surfaces along the processing line (Durand et al. 2015).

Nevertheless, as reported by Tebbutt et al, (2007;2006), relationships between ATP and microbiological results might not be expected to be bacteria. Bacteria may only contribute to a small fraction of the total ATP measure (Tebbutt et al. 2007;2006). Therefore, microbiological swabbing may give a definitive identification of any microorganisms.

4.3 Detergents

The formulation of detergents aid removal of soils; fatty, carbohydrate proteins. They do not remove microorganisms. The detergent in this study was beneficial to soil removal. Small amounts of the fouled chutney were able to adhere to the vat after cleaning. These soils were softened, and majority were removed by spray. The molecular bonds between the fouled surface and chutney deposits. Needed agitation from mechanical energy. It improved the overall removal. The detergents tests did have the lowest results for the ATP swabs. This could have been due to the sufficient contact time from the agent. In reality, the Renew AS’s inability to completely remove soil could have been because of the poor penetrating power. At lower concentrations (5-10%).

According to Gibson et al, (1999) & Burfoot & Middleton, (2009), the use of detergents can facilitate the breakdown of soils which may harbour microbes. Although, detergents are not made for the destruction or removal of microorganisms from the surface (Gibson et al, 1999). Similarly, with this study, Burfoot & Middleton, (2009), used cold water at high pressure and increased the microbial removal. Gibson et al, (1999) found no such contrast. Moreover, Peng et al, (2002) disagrees stating, wash time and temperature are major factors in the effective removal of fouled chutney from stainless steel surfaces.

A more acidic detergent could have assisted removal (Kowalska. 2014). Strong alkaline cleaners have greater dissolving power. They are used for heavy soils and have little effect on mineral properties. Consequently, these alkaline detergents may have a great chance at reducing microbial population. As a bi-product to reducing soils on contact surfaces. Introducing a high alkaline concentrations increase, the extent of damage on the stainless steel surfaces (Brasil et al. 2017). Thus, removal of soil for the surface may still depend on manual removal with scraper and high pressure water.

One of the most effective methods was scrubbing. Scrubbing or brushing can be a strenuous task and is not usually a part of cleaning practice. Scrubbing or brushing have been found to disrupt biofilm on surfaces (Jessen & Lammert, 2003). Ideally the it is only done on special occasions (Jessen & Lammert, 2003). As reported by Jessen, & Lammert, (2003) removal of bacteria cannot be achieved by one single treatment or detergent.

4.4 Hazard of chemical detergents

When using chemical cleans there is a risk of cross contamination. Titration samples collected were all negative for any remaining Renew AS on the surfaces. The rinsing of the vat was clearly sufficient. Therefore, no risk of chutney product being tainted during the next production. When chemical residues are not successfully removed from surfaces, there can be chemical contamination and tainting of food. Foods readily pick up compounds. Care needs to be taken during food production and processing, exposing to potential off flavours (Mottram et al 1998). Chemicals should be strictly controlled. The implication of off-flavours in food can have an enormous impact on customer goodwill, financial impacted ultimate cost. Sales are struck (Mottram et al 1998).

Working with Renew AS can be dangerous. The chemical procedure was hazardous to operatives working in the environment. Especially, on the production floor, below the vats. There is an increased risk of getting hit by the high pressure foamer unit. The foamer unit works at high pressure which can produce higher vapour, aerosols and dispersion. Roughly 5 operatives are at risk of getting hit by the detergent (alkaline) foams.

According to Vanhanen et al, (2000) the alkalinity of detergents can cause irritation to the skin. Furthermore, removal with the high pressure spray, can generate aerosols containing detergent, that travel through the environment. These aerosols are hazardous to operatives without PPE. Massin et al, (2006, 2007) states that cleaning in the food industry with chemicals create higher risk to eye, nasal, and throat irritation syndromes.

To avoid the possible risk from the detergent foamer, all staff working below should remain clear from the production area. Maintaining safety and prevents accidental injury. Under the safety at work act 1974 and European council (EC) 89/656/EEC legislation (Health and Safety Executive, 2018). These ensure safety at work is kept to a high standard, and reduce accidents at work.

4.5 High pressure washer (HDS 7/10-4 M)

The high pressure washers, ATP swab results complied with factory standards. It was effective at removing all soils. Although, it produced significant amounts of aerosols and amplified risk to possible tainting, microbial and debris dispersion. Aerosol generation significantly increased with higher pressure spraying in comparison to the blue factory hose. According to Holah et al (1990, 1993) higher pressure systems generate aerosols that could potentially disperse viable debris and microorganisms across an extensive area. Additionally, droplet size can be smaller and remain suspended for longer periods of time. Increasing risk to microbial and debris distribution to environmental surfaces (walls and floors) (Holah et al, 1990, 1993 & Gibson et al, 1999). Gibson et al, (1999) states that a lower pressure of 17.2 bar or below (blue factory hose) may limit potential for spread of physical contaminants through less aerosol generation, but not enhance removal of soils. The high pressure washer used up to 100 bar of pressure, it increased risk to aerosols.

Tainting could also occur due to the burned diesel fuel. Generates high temperature and pressure. Airborne aromatic diesel emissions above production area, posed a risk to food being packaged (Chesworth. 1999). Mottram, (1998) found that Taints and off flavours are usually from volatile compounds at concentrations of less than 1 μg per kg−1, Causing flavour problems. Consequently, the risk of using the HDS 7/10-4 M increases risk to chutney production.

4.6 The economic costs

As a result of reducing the cleaning time, the cost of the water clean increased. The water procedure had a major increase in electrical energy expended. When the kilowatts and Water expended per month calculated it was extremely more expensive to implement. It would clearly have a higher environmental impact. Though if the water was recirculated (sent to the holding tank), it would be more economically friendly and reduce cost (Khalid et al. 2016). The HDS 7/10-4 M and renew AS clean were more economically viable. The cost of Replacing the high pressure washer with the water cleaning, is less possible. Although the chemical clean may be a cheaper option as it is already purchased in bulk by the factory. Furthermore, the cleaning is considered to be relatively low cost of the total cost production (Khalid et al. 2016). Whenever implanting a new cleaning procedure cost should always be taken into account.

4.7 Limitations

This study has several limitations, firstly arranging the time for new cleaning procedures tests was difficult. As usual cleaning times vary with product being produced. The time for this project was limited. 5 months was a short time to achieve the cleaning method for this factory. Then incorporate it into the cleaning schedule. The chemical clean was only able to be done of one cooking vat as it was a hazard to operatives. The cost of the chemical was not disclosed by the wholesaler disclosed CCL Pentasol. The project ran over the time set, and give limited data. Microbiological swabs should have been considered. Giving more accurate information qualitative data. Finally, there was limited research available from other factories, documenting cleaning procedures are not disclosed for research.

5. Conclusion

To conclude, the investigation for developing two new cleaning processes for the factory were successful. Although the implementing the water process is costly, therefore it unlikely the factory my use this process. The chemical procedure should be considered. Good manufacturing practice must always be considered when introducing a new cleaning procedure into the factory.

5.1 Further research

Further research should be done on the use of cleaning chemical method and, changing the HDS 7/10-4 M with qualified food grade washer. When searching for high pressure washers the HD 10/15-4 high pressure washer was found. It is designed specifically for cleaning in the food industry. Research into the types of product soils. The rheological properties of the products, to measure what type of materials. Soils are made from (viscous, elastic or viscoelastic) this would aid the understanding of shearing stress, and ability for removal.

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Appendices

Appendix 1. product produced names and ingredients

Chutney products from the everyday range and heritage collection

Flaming hot chutney,

Caramelised red onion chutney

Chunky mango chutney

Caramelised red onion chutney with balsamic

Spiced apricot and ginger chutney

Beetroot & horseradish chutney

Plum & rhubarb chutney

Fig & honey chutney

Relishes

Mighty American style relish

Devilishly tomato & chilli relish

Sauces

Cranberry

Piccalilli

Appendix. 2 the process of production in the factory

The factory is split up into many areas that are the used to produce chutneys.

Process	Information
Raw material	The Raw materials are stored in 3 different areas. Vinegar is stored in a 320 litre tank. Dried materials are stored in the dry storage area. Plastic and glass jars are stored in the warehouse. Veg are stored in the veg room.
Preparation area	The production area on the first floor is where all the sugar, xanthan gum, sodium sulphite, spices and dried veg is weighed out using a scale, these are then set and ready to be used for the cook each product.
Processing	Two stainless steel cooking vats (500 Litres), a moveable steel used for sensory analysis station. All the products are made here, by heating raw materials and mixing at a rate of 20 per minute, essentially cooking the product.
Filling	Holding tank retains the cooked product, slowly feeding the filler machine (machine name). The multifiller, fills glass or plastic jars depending on the product.
Final product	A Harland labeller applies the labelling to all the product. A staff member then put the final product onto a paper tray, the product is shrink wrapped with plastic by a YPS shrinkwrap. the product is removed from the machine and stored on a wooden pallet ready for distribution.
Storage	The storage area contains the final product, on wooden pallet in the final product storage warehouse.
Distribution	The product is picked up by ventures and distributed to retail

Appendix 3. Chemical training certificate

Appendix 4. High pressure washer HDs 7/10-4 M

Appendix 5. Chemicals technical data

There are 6 chemicals that are used to clean the factory; Renew AS, activate 04, Pentacip 140, brightlight and D-Grease. these chemicals are detergents, caustics, emulsifying agent. These chemicals all help the removal of soils from the surface of objects.

Activate 04 is a combination of powerful amphoteric biocide, surfactants and sequestrates, that provides a broad spectrum bactericidal activity and good detergency. Fast acting, effective in hard water and high soil tolerance, free of BAC and DDAC. It has been formulated primarily for the use as a terminal disinfectant in the food, dairy and beverage industries but can also be used as a detergent sanitiser for light duty cleaning applications. Independently assessed for biocidal efficacy and passes EN1276, EN1650 and EN13697 at 1%. Accredited by marks and spencer for use as a terminal disinfectant. Typical properties are it is a clear blue liquid with no insoluble components. Suitable for manual use, soak, fogging or spraying, its used at 0.5-1% v/v solution, on previously cleaned surfaces. Contact time should be 15-20 minutes. There is no need to rinse off when applied at recommended concentration. At 1-3% concertation activate 04 can be used as a detergent sanitiser. It is stored in the chemical storage area above 0°C, the original shipping container.

Additionally, Pentacip 140 is a caustic based detergent, formulated for use in recirculation and Cleaning in place system, for heavy duty cleaning of food processing plant in food, during the weekly clean. Blend of caustic and organic chelation and threshold agents in pentacip 140 ensures rapid and effective penetration and removal of heavy soils. Not for use on soft metals. Clear, colourless liquid, low foaming good detergency. Use at concentration of 1-5% v/v at temperatures up to 80°C, depending on the application and degree of soiling. Store in original shipping container, away from acid based products.

D-Greases is a combination of wetting agents, emulsifying agents and sequestrate, developed for food, Dairy and Beverage industries. Formulated for the removal of fats and Grease from equipment’s and floors. It dissolves all grease, oils and fats to prevent their redisposition. Safe on all surfaces, excellent emulsifying properties, soluble in all proportions in water, contains detergents to acid cleaning. Alkaline unaffected by hard water. Clear colourless to amber liquid, complete solubility, 1-2% in hot water for light daily applications, 10% to neat spray to remove stubborn grease deposit. Store above 0°C, store in shipping container, away from acids based products.