I thought I solved the problem of mother's food complaints but now I think there is no solution.

I had a good laugh reading all of these comments & answers. I have been a drop in cooking & care giver for a lady of 94 who has diminished sight, memory lapses, and fears due to lack of abilities and fear of being moved from her home to a nursing home. I have heard many of those similar complaints from her. One of the best moves I have done with her, is to involve her in some way with what ever we are doing. She likes to sit on the stool near the kitchen counter while I am prepping things, so instead of her being in the way I usually try to have her do something useful, while she sits there. Sometimes it works, and she feels LESS helpless, and more HELP FULL when she is some how involved. It is usually moving what I have already cut into a pan or another dish, or washing & drying something that will be needed real soon. When she just sits at the table and waits for food to come to her, she feels useless, and unworthy instead of useful & valuable.

My mom has dementia too & im preparing all her meals. The kitchen was her domain, good solid home cooking. She had 7 kids & once everyone was over 20 & she had time she would prepare the same dish 3/4 different ways: 2 no onions, 1 no onions & no herbs, 1 less spicy, 3 would eat anything. Each of us had a favorite food & she'd prepare it a certain way. She was the main cook even with 3 daughters, we just showed up. The boys didn't even try. No potlocks-she did it all & then I did it all but she still pretended to do it all. Now that she doesn't even light a burner, it doesn't matter what I'm cooking I get "what did you burn now?" , "what's that ugly smell?". Happens 4 out of 7 days easily. My answer, "don't eat it if you don't want to". She likes it, she eats it never says wow that was good but also no more complaints after that one necessary first one. She just needs to let herself know that I couldn't possibly cook well enough for her. I'm 50 I've been cooking for myself, my spouse & our friends a long time. I know I can cook.

Oh, I see from your profile that she has alzheimer's / dementia. In that case ignore everything that I wrote and go with what Barb wrote.

Dam, stop, just stop.

Stop trying to fix, ameliorate, and make things better for your mom.

You mother has dementia. She is stuck in a loop of negativity. Nothing you can do or say is going to change her attitude. If you want to continue to help her, do so, but without expectation of love or gratitude. I hope the antidepressants kick in soon!

I remember your earlier post, probably because I had a bit of the same problem with my mom. I tried to make you laugh by telling you the story about how the hospital dietician said that even though she didn’t like anything she was offered to eat that clearly my mom was not malnourished.
Sadly she was malnourished in the end. Of course her food was not nourishing her because she refused to eat anything green because she took blood thinners. No matter what her doctor said....
Anyway, I will take a different tack tonight.
Tonight I would like to suggest to you that you withdraw your energy from this problem. That you consider that you are so focused on your mom that you are neglecting yourself.
And in a way you are malnourished from not receiving that validation you are so hungry for.
I know I’m not your mama but let me tell you what’s good demstress.
You are good.
You are very good.

Sounds like a passive aggressive way of taking out her frustration about no longer being able to cook on you by not being grateful. That is not fair. I wonder if you could say to her calmly, 'you must really miss being able to cook now with your mobility problems and this must be really hard to accept as your new normal?' and see if such an empathetic statement might get past her passive aggressive ungratefulness.

I really don't like it when people are passive aggressive instead of just being honest about what is really bothering them.

Otherwise, if empathy does not win her over I'd be tempted to calmly say, "mom I know you must miss cooking, but this is your new normal now what can we do together to deal with this new reality?

Then, I think I'd loose my patience and say "look I'm not your wipping girl to take your frustrations out on because you can't cook anymore. So stop it.

Thank you cmagnum. She has been grateful in the past but not when it comes to food preparation. That was her domain. Maybe she feels that no one can match her culinary skills. But I told her that I would be grateful if someone would make me a nice meal once in a while. I cook three meals a day, seven days a week for my mother and father. My father has dementia and I puree his meals. I don't look for a pat on the back for everything, but honestly it would be nice to hear "this tastes good" just once.

Has she ever been grateful in the past?

From your description, you can't change her. It is her problem. It is not your monkey, not your circus. It's up to her to build a bridge and get over it.