22 replies to this topic

[Nyame]

Hello. Please, we sell pineapple and papaya natural Juice, extraction the shell is just 2 days, how can we extend the shell life to 90 days, we have tried pasteurising to no avail, I will appreciate any inputs thanks.

[pHruit]

How are you pasteurising, and how are you then filling and storing the product?

These juices will readily grow lots of yeast, moulds, and various spoilage bacteria if given the opportunity. If you're pasteurising but not able to fill aseptically then any recontamination after pasteurising, or anything that survives pasteurisation if it isn't sufficiently robust, will start growing again quite happily, even if chilled.

Assuming you don't have access to an aseptic filler, I'd pasteurised and freeze. You could freeze without pasteurising, but that will make thawing much more risky!

 

 

Edit: I'd assumed this was bulk industrial product - is this e.g. drums to be sold to other manufacturers, or is this finished retail product in bottled/cartons?

Edited by pHruit, 08 August 2021 - 08:31 AM.

[Nyame]

Thanks Sir for the reply

We package in small bottle and retail.

We pasteuris but we just feel direct. So we need more tips on how to preserve it

Thanks

[pHruit]

You can potentially add preservatives, but whether that is a possibility will depend on exactly what's permitted for the product type in the country/ies in which you sell it.
Nonetheless, given that you are getting such a short shelf life I think that preservatives alone may be insufficient to deal with what is presumably quite considerable spoilage counts.

A shelf life of 90 days may be optimistic, but perhaps you can provide a quick overview of your current process - for example:

 

How do you wash the fruit?

What is your pasteurisation profile (time and temperature)?
What are your typical micro levels before and after pasteurisation?

How are you washing your bottles?

How do you fill the bottles? (e.g. hot fill, cold fill, any nitrogen used in headspace etc)

How quickly is the product cooled to final storage temperature?

[Nyame]

Thanks Sir for you contribution

The fruits where washed with tap Water using a pressure pump and was pasturised at 70 degree for 20min and we did cold feeling given we bottle in plastic container and the filling is done manually by employees who use gloove and 70% alcohol to disinfect their hands regularly... We also suffer a slow cooling that causes to take almost an hour to cold our products to 25°c

[Nyame]

The fruits where washed with tap Water using a pressure pump and was pasturised at 70 degree for 20min and we did cold feeling given we bottle in plastic container and the filling is done manually by employees who use gloove and 70% alcohol to disinfect their hands regularly... We also suffer a slow cooling that causes to take almost an hour to cold our products to 25°c...
Also due to our lack of complete laboratory we couldn't do a microbial count at the different level of the production and also the bottles where disinfect using alcohol 70%

[pHruit]

Ok, so there are potentially a few areas where your process can be improved to help with the shelf life.

 

The fruits where washed with tap Water using a pressure pump

I'd definitely look at adding something to your water, to improve the efficacy of your wash step - have a look at e.g. sodium hypochlorite, hydrogen peroxide, potentially peracetic acid. You want to get the microbiological loading down as low as possible, before the juice gets to the pasteurisation.

 

 

pasturised at 70 degree for 20min

What type/method of pasteurisation are you using?

Personally I'd look at increasing your temperature quite significantly if possible, and perhaps bringing the time down. Temperature is generally more effective (in a loose sense) than time, so for example increasing to 80°C or 90°C will make far more of a difference than increasing the time to 30/40 minutes.

 

we did cold feeling given we bottle in plastic container and the filling is done manually

 

Are the bottles washed before use? Or does the supplier send them to you prepared and ready for use?
If not, a bottle wash step (e.g. rinse with peroxyacetic acid, followed by inversion) might be worth investigating.

 

 

We also suffer a slow cooling that causes to take almost an hour to cold our products to 25°c...

 

Is 25°C (ambient?) the final storage temperature?
Based on the process discussed so far, this sounds to me like the sort of product that would need to be stored and distributed chilled. If it's a chilled product, do you know how long it takes to get down to 4°C or whatever the final storage/distribution temperature is?

 

For some types of pasteuriser you can add a heat-exchanger after the holding stage, which will allow the finished juice to come out at a much cooler temperature. If there is potential investment for this type of thing then it's worth looking into

 

 

Also due to our lack of complete laboratory we couldn't do a microbial count at the different level of the production and also the bottles where disinfect using alcohol 70%

This is quite common in small to medium-size factories; lots of places I've worked/been don't have a microbiological lab on site. It's worth looking for an external contract lab who can do some testing for you.

[Nyame]

Thanks for your contribution, pls I want to point out something, our reason for cooling is because we dont want to damage our bottles because they are plastics, secondly we wish to store the juice at room temperature, we dont want to store them in a cooler. So if you could give us some tips we will grateful, be I forget, this product is made up of 70% natural juice and 30% flavor, thanks for you input once more

[pHruit]

Ah, ok, for an ambient-stable product you need to be a bit more thorough in the approach, as any presence of viable yeasts, moulds, and certain types of bacteria will very happily grow in a warm environment with plenty of nutrients available. My experience has been that pineapple is exceptionally good at fermenting and at growing mould, so it does need to be approached with caution.

 

As a first stage I think it's critical to get some microbiological data to understand what the current situation actually is. Appreciate that this will take a little while to organise and test, so please feel free to post back here in a week or two once results are available :)

 

As this isn't a pure juice product, if you're permitted to use any preservatives in this type of drink then I'd look into this too. I wouldn't assume these will stop everything, as they definitely won't, but they can help provide an extra defence against things that might otherwise cause a problem.

 

To get to ambient stability with a cold-filled product, you need to ensure that your product is clean, your bottles are clean, and the environment in the process area is clean - if there is any microbiological contamination of the bottle, or the environment is such that there are lots of yeasts and moulds floating around in the air, then these will multiply rapidly if they get into your juice.

 

I'd suggest working through your process one stage at a time, looking at what you can do to optimise each stage. As I'd noted above, I'd have a look at fruit washing, at your pasteurisation process, and at bottle washing. Also go back one step before fruit washing and make sure that your sorting process is working reasonably well, as having lots of e.g. mouldy fruit around is going to intro another source of potential issues into your process and factory.

 

Given that you're aiming for ambient stable end product, the filling process is also worth scrutinising, as at this point there are no further processes that will address contamination. Preservatives can help, but I wouldn't rely on them too much. When you say the filling is done manually, how is this physically done?

There are some plastic bottles available that can be used for hot filling, so this could also be worth investigating.

[Nyame]

Thanks for your contribution,

For the filling we have made a simple tap flow were the juice leaves the coole by the tap to the plastic bottles.

[Nyame]

As for the pasteurisation we use batch pasteuriser.

[Nyame]

Sir

Since we are faceing this challenges and we need deep analysis to over come this.

Please can you help us with the step to follow, as we will like to do unpasteurized first to with preserveties that are not harmful.

To give a shelf life of at least 30 days.

Thanks for your Contribution.

[pHruit]

I think that unpasteurised product with a day ambient life is perhaps rather optimistic!
The current observations suggest that your raw unpasteurised product has a fairly high microbiological loading (not uncommon for raw fruit) so you'll definitely need to improve your washing process if possible. I wouldn't expect to see unpasteurised juice product with a chilled shelf life of 30 days, let alone ambient.

Preservatives can help stop growth, but I wouldn't treat them as a way to achieve a 5+ log kill.

 

With the greatest respect, it sounds like there are a few areas of your process that could benefit from being refined, and this is perhaps more than can reasonably be accomplished through forum posts. If there is no in-house expertise in processing and bottling juices, I'd perhaps recommend looking at bringing a consultant in for a while, to fully review your site/processes and oversee some improvements with you, as well as potentially teaching you and your colleagues about what they're doing and why.

[Nyame]

Sir
Thanks for your contribution.

[Nyame]

Please which chemicals can we apply to clean the Pasteuriser, Cooler and pipe lines ?

Pls can you further recomend us some machines that can test bacterias ?

Thanks for your
Contributions

[pHruit]

Please which chemicals can we apply to clean the Pasteuriser, Cooler and pipe lines ?

You're probably going to want some sort of caustic wash, followed by a sanitiser (e.g. PAA). I'd recommend getting in touch with a local cleaning chemical supplier, as they'll generally be able to recommend specific products for your application, and the better ones will also help you set up your cleaning process and potentially even assist with validating it. Unfortunately I've got very little experience in West/Central Africa so I'm not able to provide specific suggestions.

 

 

Pls can you further recomend us some machines that can test bacterias ?

 

I'm a bit wary of the automated / rapid micro systems for spoilage organisms in juices. If used well and properly understood, then they can certainly provide useful data to augment classical micro, but as a business with no/limited historical microbiological data, its probably not something I'd recommend. I've seen some sites implement them very well and genuinely get real value out of them, but I've also seen them cause more confusion and problems than they've solved
If you've got the space and expertise to set up a properly segregated small microbiological laboratory to do basic analysis like yeasts/moulds/TVC on site then that could be worth looking at, as you can always support that with external analysis if needed. Otherwise I'd recommend using an external laboratory for this type of testing.

[Nyame]

Ok
Thanks for your Contribution

[Ted S]

Hello Nyame. One very important piece of information that is missing for me is pH. What is the highest allowable pH for this product? Since it is not 100% juice, what does the 30% flavor contribute and how does this affect the overall pH of the final, packaged product? 

 

As pHruit mentions, you need to better understand your microbiological situation in order to better understand processing/process change implications. Do you have microbiological specifications on the juice and flavor that you are using in order to support the type of shelf life you are looking for? Everything from start to finish must be microbiologically controlled/specified in order to best understand if what you are working towards (longer shelf life) is even realistic. 

 

Finally, many companies in the US and around the world use High Pressure Processing (HPP) instead of Pasteurization for juice products in order to achieve the desired shelf life you are looking for. The problem with Pasteurization is the negative effect that the cooking will have on both color, flavor and appearance. HPP achieves the same microbiological reduction as Pasteurization, but without the use of heat. 

 

Thank you. 

 

Ted

[Nyame]

Sir
Thanks for your contribution.

[Nyame]

Hello Sir,

We have been makeing some progress base on you people's contributions thanks very much.

We are also facing some challenges on the color. We face low valtage issue with electricity so the pasteurizer take a longer period to heat up that affects the color of the natural Juice, pls can anything be done to improve on the color?

Waiting for you kind contributions thanks

[pHruit]

Your challenge here is that any sort of elevated temperature will increase the rate of colour change, so the period where your juice is starting to warm, but isn't warm enough to actually pasteurise, will be damaging the colour. It will also affect the flavour/aroma, although that may be less noticeable initially - it might accelerate the decline further into the shelf life though.

Dissolved oxygen is going to make this effect more pronounced, so anything you can do to limit/reduce exposure could help - for example, purging the headspace of tanks with nitrogen if available. You might also find that adding some ascorbic acid will help with the colour. It's not something I recall seeing used for pineapple, as it's normally a relatively robust juice in terms of pasteurisation, but it might be worth a try. You won't need much - I'd start with about 300-400ppm.

 

Is the intermittent voltage drop in the electrical supply something that happens regularly? It might be worth looking at whether there is anything you can do to mitigate this - for example installing an uninterruptible power supply (if the drops of relatively short) or purchasing a backup generator to help provide a continuous supply, given that it is going to be critical to keeping your process running.

[Nyame]

Hello Sir
Thanks for the reply.

Another thing I think of doing to help heat up the juice fast is, I thought of getting a food grade stainless still coil pipe and put it inside a pot filled with water, apply a pressure burner to make the water hot, then connect both the inlet and outlet coiled pipe to the pasteurizer,

I don't know if this maybe Possible to help heat up the juice faster, since we are facing challenges on low voltage.

[pHruit]

There are potentially two ways you could do that:

1) A heat exchanger that uses the outgoing hot material from the pasteuriser as the heat source, and the incoming could material as the cool source - this can help cool the pasteurised product and pre-warm the incoming product, and therefore doesn't require an external heat/energy source. I'm not sure how feasible this will be with your pasteurisation setup though?
2) A water-fed heat exchanger prior to the pasteuriser, exactly as you'd envisaged. The potential challenge with this will be that you'll need a boiler to heat the juice, and that will need power, which takes you back to the same issue as you're having with the pasteuriser - if the electricity supply is unreliable then you'll have the same issue with this. You can potentially power a boiler with other energy sources, but I don't know how readily available a sufficient e.g. gas supply would be for you?