I think I might be getting what you're after. Are you washing the produce in a mixture containing this natureseal?
From personal experience, having performed washing in chlorine based washes and organic acid based washes, the organic acid had far better anti microbial effects. I was looking at food safety though and it appears your concerns are quality. (Where I say "organic acid", I mean this is a chemical context, i.e. an acid based upon a carbon based structure not a mineral acid like hydrochloric or sulphuric.) What was surprising to me was it seemed to be more effective than the pH would suggest so it wasn't just working by lowering the pH.
Ascorbic acid and citric acid are not particularly expensive chemicals I don't think and they're not exactly dangerous either. We were using acetic acid but this was for onion washing and so not likely to be an issue for taint so I wouldn't recommend washing your fruit in vinegar!
Why not get some ascorbic and citric acid in, make sure they are food grade of course, mix in similar quantities to the natureseal you were using and trial it? Also for convenience, why not ask different food chemical suppliers to pre make some mixes for you and price it up? Just because they don't have a product now, doesn't mean they won't make one for you.
Alternatively I know Ecolab do an organic acid based wash mix but I've no idea if they supply to Canada?
Thanks GMO you did capture my point. It is a quality issue. We are trying to improve the shelf life. According to Alibaba.com, some manufacturers sell citric acid (Preservative) for 0.9$/kg while ascorbic acid (Antioxydant) is sold $4-$6/kg. I need both because they have different properties. I was looking at:
1- If there is a cheaper alternative
2- If there is a known mixture of both that would be cheaper while keeping properties (Shelf life) intact.
I will try contacting Ecolab.
Thanks again