Navitron Renewable Energy and Sustainability Forum

BIOMASS => General => Topic started by: stannn on June 18, 2018, 11:38:52 AM



Title: One small step for Sainsburys.
Post by: stannn on June 18, 2018, 11:38:52 AM
Wifey this morning spotted that the vine tomatoes are in a cardboard tray instead of the usual black plastic tray. The latter cannot be recycled because of machine-reading difficulties. This must come as a result of the outcry on social media against single-use plastics generally. I hope that it is a cheaper material as well.
Stan


Title: Re: One small step for Sainsburys.
Post by: Nickel2 on June 18, 2018, 11:56:01 AM
I'll look out for those. Usually I get my toms from Chavda's in a clear plastic tray. The clear ones have a recycle triangle and the labelling "PET", (polyester) which means they should get recycled with the drinks/water bottle material. Rinse and recycle. I thought the black ones got turned into McDarnolds picnic tables and chairs.


Title: Re: One small step for Sainsburys.
Post by: Philip R on June 18, 2018, 12:01:37 PM
One small step indeed.
Aldi Engish grown vine tomotoes have been in a cardboard tray as long as we have been buying them. They are grown in Teeside and are nice and tasty. No Sharp metallic hints that I have experienced with some Spanish and Dutch Tommys.

I saw the piece on black plastic PET recycling too on the box a couple of weeks ago. I had been washing it and putting it in the grey recycling bin. Only to find out that it cannot be recycled in the UK. Why on earth do HMP allow its continued use.!!!

The technology does exist to deel with these plastics. other than fleeces and dralon sofa covers. It is a pyrolysis process first used in Australia, now being  developped for use by "Cynar". The product is middle distillate ( diesel fuel,).

Philip R


Title: Re: One small step for Sainsburys.
Post by: TheFairway on June 18, 2018, 12:23:38 PM
Everything can be recycled. It's just a matter of having the will or the incentive to do so.

Look at Costa as a high profile example. Coffee cups were 'non recyclable' if you listened to the mass press and most recycling companies. Then Costa said that they would pay iirc £75/tonne extra to the recycling companies and 'suddenly' the recycling companies found a way to recycle the coffee cups.


Title: Re: One small step for Sainsburys.
Post by: Nickel2 on June 18, 2018, 12:36:41 PM
Where there's a will, there's a way:

https://www.kedel.co.uk/technicalspecifications.html



Title: Re: One small step for Sainsburys.
Post by: smegal on June 18, 2018, 02:27:28 PM
Everything can be recycled. It's just a matter of having the will or the incentive to do so.

Look at Costa as a high profile example. Coffee cups were 'non recyclable' if you listened to the mass press and most recycling companies. Then Costa said that they would pay iirc £75/tonne extra to the recycling companies and 'suddenly' the recycling companies found a way to recycle the coffee cups.

Agreed, by recyclable. They mean "economic to recycle".

For example, (I understand that) black plastic packaging is recyclable, it just can't be sorted using automated sorting machines, so it is hand picked out and becomes RDF.


Title: Re: One small step for Sainsburys.
Post by: Warble on June 18, 2018, 10:35:44 PM
It's polypropylene packaging (pp) <5> that is the worst - yogurt, soup containers, etc. It doesn't seem to be recycled at the moment.


Title: Re: One small step for Sainsburys.
Post by: stannn on June 25, 2018, 11:18:24 AM
https://www.businessgreen.com/bg/news/3034713/morrisons-brings-back-paper-bags-in-grocery-aisle


Title: Re: One small step for Sainsburys.
Post by: AndrewE on June 25, 2018, 06:26:52 PM
I was warned off vine tomatoes by a botanist who explained that they are only all ripe at the same time (unlike the natural successive ripening) because of the amounts of hormones applied to them.  I suppose that they are OK if you just assume that "plant hormones can't possibly affect us mammals!"


Title: Re: One small step for Sainsburys.
Post by: Nickel2 on June 25, 2018, 06:42:09 PM
There was a bit on one of the gardening programs a while back about 'on the vine tomatoes'. It seems that the primary reason is to stop the toms ripening all at the same time.
The explanation went something like this:  (Bob Flowerdew)
As long as the fruit is on the vine, it can carry on growing, so stays healthy and takes longer to mature.
As soon as the fruit is detached from the stalk, (i.e. at the 'navel'), the fruit is programmed by nature to start rotting  and put nutrition into the soil to give it a start.
I find they do last the week on the vine, and I pick them in growth order, so it works for me.
As for hormones, I don't seem to have died from eating them!  ;D


Title: Re: One small step for Sainsburys.
Post by: dan_b on June 25, 2018, 07:22:09 PM
I find the on the vine tomatoes actually have some flavour - , I guess a lot of “fresh” produce is picked relatively unripe in order to last longer?


Title: Re: One small step for Sainsburys.
Post by: AndrewE on June 26, 2018, 06:59:13 PM
I find they do last the week on the vine, and I pick them in growth order, so it works for me.
As for hormones, I don't seem to have died from eating them!  ;D
...yet!  That's very complacent, especially from somebody on here.  
Do you  remember the problems of male river fish turning female from the synthetic oestrogens getting through sewage works?   Or crops in polytunnels dying - eventually it was discovered that the phthalate plasticisers in PVC were seriously phytotoxic? Or the worries about Bisphenol-A in food-can lacquer? http://www.packagingdigest.com/food-packaging/most-food-cans-no-longer-use-bpa-in-their-linings-2018-02-20 says
Quote
  As with any packaging material, though, trace levels can migrate into the food contained within, which is why there were health concerns about BPA. Despite reassurances about the safety of BPA from the Food and Drug Administration, some research shows that even trace amounts of BPA might cause problems with reproductive, neurological and immune systems in humans and animals.
You don't often die from exposure to a toxin in your environment (unless NOx or SO2 kill you by causing an asthma attack.)  And cancers typically have a 30 - 40 year latent period...   I have lost friends to mesothelioma and what I think was beryllium oxide exposure.  Both died within a few months of retirement age with no previous symptoms at all.


Title: Re: One small step for Sainsburys.
Post by: Nickel2 on June 27, 2018, 08:50:17 AM
Ease up there Andrew! I have no problems with hormones and tomatoes. Just about every single living thing on the planet is controlled by hormones, 99.9999% of them naturally occurring, being produced by the plants themselves.
Singling out vine-grown tomatoes for being as dangerous as phthalate plasticisers or bisphenol-A is a bit panicky don't you think? Those two items are man-made chemicals added to other man-made chemicals.
Plant hormones that are made naturally by the plants themselves occur all over the world, without input from man.
I am a rational thinker, so I weigh up the pros and cons of all the food I eat, and wash/clean/prepare it accordingly.

Please don't slate me as complacent, I am fully aware of the enormously extensive panoply of unwanted chemical compounds that surround me; I know the damage that certain trace compounds can cause, but tend to focus more on the larger immediate killers, like the 100 tons per year of mercury in the atmosphere that comes from burning coal, the nitrogen oxides from IC engines, the dioxins from burning waste, the sulphur compounds from volcanic activity, weedkillers, organic tin compounds used on boats, pollution emissions caused by global shipping, etc, etc, etc.

Tomatoes are the least of my worries and concerns; If I thought for one minute that they were going to kill me, I'd be onto the supermarket chiefs quicker than you could say knife, believe me!

http://www.simplyhydro.com/Hormones.htm

http://www.tomatogrowing.co.uk/hormones-tomato-plants

N2


Title: Re: One small step for Sainsburys.
Post by: brackwell on June 27, 2018, 10:54:03 AM
Tomatoes in shops are picked green and stored so that supply can meet demand. When required they are taken out of store and blasted with gas which makes them all turn red - have you never wondered why they are all the same colour unlike nature.


Title: Re: One small step for Sainsburys.
Post by: dan_b on June 27, 2018, 12:01:00 PM
What do you mean “blasted with gas”


Title: Re: One small step for Sainsburys.
Post by: brackwell on June 27, 2018, 12:50:35 PM
Ethylene actually.    https://www.frontlineservices.com.au/Frontline_Services/Fruit_ripening_gas_-_ethylene.html

I am not aware of any reason why tomatoes sold in the supermarket "on the vine" are any better than not


Title: Re: One small step for Sainsburys.
Post by: dan_b on June 27, 2018, 01:00:31 PM
Thanks, interesting link.  I had a vague memory that fruits like bananas emit ethylene whilst ripening which is why if you place a bunch of bananas near other fruits it makes them go off more quickly.  
I didn't realise that ethylene was used in commercial ripening though.

That article had the following paragraph about "vine ripened" tomatoes - ?

Vine-Ripe’

Some new varieties of tomatoes are marketed as ‘vine ripened’.  These ‘truss tomatoes‘ develop their colour and flavour while still attached to the plant.  They have been developed through cross-breeding with non-ripening tomato varieties and are usually grown hydroponically in greenhouses. They develop colour without softening like conventional tomatoes and remain firm for harvest, packing and distribution. These tomato varieties do not exhibit a climacteric like conventional tomato varieties but remain susceptible to external ethylene.


Title: Re: One small step for Sainsburys.
Post by: Nickel2 on June 27, 2018, 04:21:27 PM
Please read the link supplied above,  < http://www.simplyhydro.com/Hormones.htm > to find out a bit more about the ripening process of tomatoes.

Specifically the extract from the link about Ethylene:

'Ethylene is present as a gas produced by the plant. As levels of ethylene increase with plant development while other hormones are balancing in accordance, the effects of ethylene become more pronounced. Ethylene promotes fruit ripening, or "maturing". This signals the plant that it's life cycle is changing or ending. Tomatoes turn red and small flowers begin to wither. It will signal the plant to transfer it's nutrients back into the stem tissue from the leaves and other storage tissue.
Abcission (the process where leaves drop) is attributed to decreasing levels of auxin produced by the leaves, allowing further expression of abscic acid and ethylene. This response is brought on by shortening days and cooler nights.

Tomatoes can be grown with an ethylene inhibitor, shipped green for shelf life and resistance to handling damage, and then exposed to a sealed environment with controlled levels of ethylene to ripen the fruit at their point of destination. Burning fossil fuels, such as CO2 generators produce small amounts of ethylene. Inefficient and un-inspected burners may produce ethylene levels high enough to seriously harm plants. Ethylene is found in abundance in the skin of ripening fruit such as apples or green bananas. By placing unripened plant material in a paper bag with a green banana you can hasten ripening, bringing out flavour and aroma. If done at warmer temperatures fresher material will convert stored starches to sugars.'

Interesting reading to help prevent panic amongst the tomato-eating amongst us.  :)

N2



Title: Re: One small step for Sainsburys.
Post by: Warble on June 27, 2018, 06:45:25 PM
Is ethylene used on tomatoes anywhere other than in the US? The Dutch growers don't mention using it and I can't see the EU allowing it as it is a greenhouse gas. CO2 is used to stimulate growth in many places where it is available as a byproduct of heat and power.


Title: Re: One small step for Sainsburys.
Post by: AndrewE on June 27, 2018, 09:29:13 PM
I don't think of ethylene as a hormone - for one thing it is applied externally and hormones are usually considered to be internal chemical messengers, also it is a remarkably simple molecule compared with most hormones.  And who is to say that a biologically-active molecule won't have an undesirable effect if it's released inside another organism where it isn't designed to be?

Also a tray of picked tomatoes being brought to ripeness when needed by using the gas probably isn't a big deal either, although I can see the greenhouse gas problem.  There are some remarkable blind-spots in legislation and practice when it comes to greenhouse gases though.

The point made to me about "vine tomatoes" by the ex-Min of Ag lab botanist I worked with was that hormones (that she wouldn't accept in her diet) were used to either to stop the early ones ripening so that the whole bunch could be triggered to be ready together, or maybe to accelerate ripening so the whole bunch were ready, some prematurely.   I don't think Ethylene (at the end of the process) came into it.