ANSWER – Being a vegan involves a good deal of self discipline so I applaud you for having the determination to achieve it. I have to say that at the WPF headquarters veganism is something we look upon with admiration but is not something we have ever managed to achieve ourselves!
In answering this question we’ll assume a belief in deity but with the quantifier that many witches do not actually believe in any form of the Gods.
My view would be that the items in question are not a problem and would not be taken with offence by the Gods. But what I would question is whether items that no longer have any use for you can actually be considered to be a sacrifice. The nature of a sacrifice is giving something up and offering it to the Gods instead of taking it for yourself. With this in mind I could see that making a donation of food and drink you would like to consume yourself is a sacrifice but I’m not so sure that I’d consider food or drink you intend to discard has the same value. I feel the sacrifice should be actually giving something up rather than seeing the Gods as an alternative to the dustbin!
My suggestion would be to do something constructive with any usable food you have. Are there are sealed packets or tins you could donate to a local food bank for example? Or do you have any food that would be suitable to dig into the earth to nourish it as fertiliser for your plants? Could you compost any of the food down?
If there are no practical ways to dispose of the unwanted food I do agree that putting it in the bin can be disrespectful to the animal who died to produce the food. I’d suggest if this is the case you offer the food to the Gods but not so much as a sacrifice but as a statement of intent, a ritual to mark your passing from a meat eater to a vegan.