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  • Writer's pictureGary Moller

A Question about chemicals in NZ Blackcurrant

Updated: Mar 27

"Hi, Gary,

Thanks for your postings. I've been meaning to ask you, why don't you sell and recommend organic blackcurrant powder? Viberi is an organic NZ grower. I don't know what the pesticides are like in blackcurrants, but I know that frozen mixed berries from overseas came up high with pesticide residues in the last Total Diet Study in NZ.

Generally, berry fruit is very highly sprayed. In the US, frozen blueberries had 21 different pesticides in them, from domestic and imported varieties (see )".



Good question and good timing because I have been meaning to write about this topic. So, I wrote to Michelle Manson the CEO of Sujon Berries, asking her to respond and here is what she wrote:


Hi Gary Likewise, lovely to hear from you. Again, many thanks for the opportunity to share our views.

Probably the key points are: We are talking about the general organic world here not specifically Viberri or what their practices might be. We are certainly not anti-organic or trying to denigrate them, that said there is often a misunderstanding by consumers as to what organics are and like everything there is a wide spectrum.

Firstly organic does not mean no pesticides are used or that there are not pesticides residues on organic produce. It means the type of pesticide used in organics is natural, non-synthetic or from a limited permissible range of synthetic chemicals. In typical pesticide testing the test methodologies are targeted at synthetic chemicals. We typically use a multi residue test that covers some 230 chemicals.

So it is often argued that a low level of residues on organics may be down to the fact the chemicals used in organics are simply not tested for. That is, the test method used has to fit the pesticide type used. A pesticide be it natural or synthetic is designed to kill or control some pest and all are dangerous at the wrong levels.

Some organic/natural chemicals (e.g. copper sulphate) are more dangerous than their synthetic alternative. Using a natural chemical compound does not mean it cannot be toxic to humans, it can be. Some of the copper compounds used for pest control in organics are very toxic and being a heavy metal can build up year on year in the soil, so environmentally damaging. Copper sulphate is a very widely used organic fungicide, can be very toxic not only to humans, non-target species and a range of wildlife. So it really comes down to the farmers and the brands, both organic and conventional.

The good farmers/brands care about producing a safe crop for their consumers, the bad don't and as you will appreciate there are good and bad in both camps. All of our growers (whether organic/conventional, NZ/offshore) undergo a strict Sujon supplier approval programme. Most of our growers have supplied us for 22+ years and they are good farmers. Each bag of retail packaged fruit is traceable back to the growers field it was harvested from. We do routinely check each batch to ensure that what they supply us is safe for our consumers and their families.

Perhaps a bit more background on how we operate: We aim to have residue free products for our customers and consumers. So controlling the pests affecting the fruit we sell has to reflect this. Probably the most common pesticide usage (organic or conventional) for berries is for control of moulds such as botrytis, so a botryticide might be used. These are not GMO.

Berries can be prone to many diseases such as botrytis, as such they can be very difficult to grow in some (e.g. wet) seasons and so at times there is a need to use disease control options. Growers generally operate under an Integrated Pest Management Plan, and chemicals are applied only in circumstances when other control methods ( mechanical/biological etc) are not working well enough and elevated pest and disease levels (monitored and measured) are reached. That is, an integrated pest management plan takes a holistic view as to how the fruit is produced.

Pests are identified and monitored and when certain thresholds are reached, solutions involving either (or combinations of) biological , cultural, mechanical or chemical are utilised. For example for insect pests, a lot of growers use pheromone traps, small cardboard traps that give off a pest pheromone which attracts the insect into the trap. This is checked regularly to see how many and what type of insects are frequenting the fruit.

When the levels of insect reach the threshold at which they are having a significant detrimental impact, a suitable control is applied. If a chemical control is to be used it can only be a chemical authorised for that specific crop and how it is used is also regulated. In New Zealand the Ministry of Primary Industries is the overseeing authority. Once a chemical has been applied growers may not harvest fruit until after a specified time period has elapsed (again regulated). This is known as the withholding period or pre-harvest interval.

This time period is scientifically determined as the period during which the chemical applied decays to a safe or non-detectable level. That is, after application chemicals decay naturally due to environmental factors such sunlight, rain etc. Samples of fruit are taken at different times before and over harvested and test for residue and microbiological levels. After vetting grower spray diaries we would then select the test suites to be applied. A regular test for residues might be by using a multi residue test, (this covers 250 odd chemicals). We would check not only on anything that may have been applied by our grower, but also anything that may have resulted from spray drift from neighbouring growers (of different crops possibly).

We encourage our growers to use sprays as a last resort and to endeavour to be spray free at harvest. We are very aware of the trust our consumers place in us and do our best to ensure that we and our growers honour that trust with tasty, nutritious and safe food. I have an interesting article on organic foods which I'll send through to you separately also.

Organic Food Article
Download PDF • 2.64MB

Thanks, Michelle


Thank you, Michelle, for responding to this inquiry. It must have been about ten years ago that I attended a meeting at your Nelson offices where Professor Mark Willems of Exeter University presented his research findings to growers on the athletic performance gains from ingesting NZ blackcurrant. I had a good talk with your growers about this issue of chemical residues on the blackcurrant they supply to Sujon. They were aware of my concerns, including the problems of residues in imported berries. I recall Poland as being particularly problematic. The assurance I received from them is they use the absolute minimum of chemicals to ensure a high quality product is delivered. I returned to Wellington confident that NZ blackcurrant is the best in the world regarding its nutritional value and is low in chemical residues.

Living life to the full is about making calculated trade-offs: If we play things too safe, there is nothing we can eat or do - life will be bland and probably miserable. This especially applies to the food choices we make. Blackcurrant is an excellent example of this trade-off conundrum: like most food these days, it may contain traces of chemicals, but it also has health benefits.

Blackcurrant enhances athletic performance because it facilitates detoxification at cellular and bodily levels while protecting us from oxidative stress. Therefore, I think these nutritional properties cancel out the possible downsides of trace amounts of chemicals if they are present. One of the most important ways we protect ourselves from toxins is to consume nutrients that protect us from damage and ensure we excrete the toxin as fast or faster than it comes in. Yes, we are all exposed to toxins, and increasingly so, but the key is to minimise the intake and facilitate removal.

Just because something is organic does not mean it is safer to consume than non-organic, and organic does not guarantee there are no (organic) pesticide and fungicide residues, as Michelle outlined earlier. An example of potential toxicity is organic fish fertiliser. Fish fertiliser may be used in organic farming without realising that toxic levels of mercury may build in the soil and, thus, in the crops grown, ultimately making the animals and humans ill. I have hair tissue tests that show this. I must get permission to use these tests and write an article on this topic.

One valuable tool for ensuring food safety is the Interclinical Hair Tissue Mineral Analysis (HTMA), which will pick most inorganic toxins such as arsenic and cadmium and indicate any issues with detoxification.



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