I sometimes smell of vinegar. How can I overcome this?

This is not the first time it happens to me, but I hope it will be the last, hope I can find the reason and the solution.

I realize that I start smelling of vinegar sometimes, even if I take at least a thorough shower a day.

My backpack, which I often wear for most of the day going around (I have a very active day life at the moment) starts smelling of vinegar from the straps.

As for the backpack, I washed it at 40 degrees celsius in the machine. Could there be any bacteria there or something that still resists the machine wash and could the smell come from there?

I have recently stopped eating meals high on spice and salsa as I suspect that it might contribute. I had been eating much of that stuff for the last few weeks, I mean kebabs and stuff, with everything, meaning, with all the sauces and so on.

So yes on one hand I am trying to change my nutrition.

As for deodorant, I wear one that keeps me from smelling like armpit (a Rexona 48h) but the vinegar smell still occurs.

I am not 100% sure if it is from me or the backpack and that’s why I mentioned it.

But it could very well be me because in the past I think I had the same type of smell coming from my feet during a travel.

And because I washed the backpack in the machine.

Anyway, your thoughts?

Many thanks.