Can anyone notice a difference in taste between big brands and supermarket own brands?

Not in the least. I never buy 'brand name' food if there is a store brand available. I have actually tricked people who were absolutely positive they would choose Heinz ketchup as the best, only to find out they liked the 'no-name' brand better.

For the most part, I purchase the store brand. Tastes just as great. However, there are a few things that you just can't do that with. Kraft Macaroni and Cheese is one of those things. Another is SPAM. 

generally food items, no. generic sodas- absolutely!

Some but most are just as good and they are actually sold by the major brands under a private label..this has been going no for years.brand names cost more because of advertising costs, whereas private label is same with lower costs.

 some store make their own milk, ice cream and orange juice but not everything can be made so they turn to private label products.

I've noted a couple of exceptions. Target peanut butter (G&G) is better to me than the nationals, because it has less added hydrogenated oil. This also makes it more flavorful. Another difference is in canned stewed tomatoes. Aldi's house brand is inferior to hunt's and such, but Walmart's Great Value is superior to some national brands.

Many of the the big brands use the same as store brands, so they are basically the same, just marked up.

Shop Aldi, They are insane in quality, just German,,,, What? hahaha, Never had an issue with their food.

I've noted a couple of exceptions. Target peanut butter (G&G) is better to me than the nationals, because it has less added hydrogenated oil. This also makes it more flavorful. Another difference is in canned stewed tomatoes. Aldi's house brand is inferior to hunt's and such, but Walmart's Great Value is superior to some national brands.

Yes, like with sauce and bread

Depends on the product, but usually difference is minimal.

Not always and not always in a bad way. Walmart deli chickens can be little too crispy and salty for my tastes. They have the scope to do their own taste branding the way name brands do... you KNOW you're eating an Oreo vs a Hydrox even though Hydrox was first. Some like Aldi Sur/Trader Joes and Costco are moving towards in house labels which are outsourced to their own production facilities, many generic brands in stores are what you might call "second run." Or else piggy backing major labels.

King Kullen may ask Nabisco to make them a strawberry sandwich cookie which they sell under their own name. One very clear example is in Lill Joe's "filtered cigars." A small cigar company uses the trash cuttings and processes them into $0.75/pack cigarettes.

One way to know is if it has it's own name like Lucerne dairy, Safeway owns it and sells it exclusively. If it says Safeway chicken nuggets, it is likely a piggyback product, making the regional meat packer produce it under their specifications. The issue beyond the obvious is the specifications may be off-brand meaning if Tyson claims 'always 100% whole white meat' but Safeway knows there's a call for cheaper and thus, emulsified, Tyson can't put out that image for itself, so it becomes a store brand even though by all means it is a Tyson product and will taste similar.

p.s., these are speculative examples given typical trends. I'm sure you dad manages a Kroger and maybe an exact name or process was off. I don't want to hear it.

They are often the same thing. Supermarket brands are simply big brands with private labeling.

I typically shop in my smaller local markets, in my area we have a plethora of healthier market options, on the theme of Whole Foods but much smaller and less ... mainstream.

I tend toward organic and whole grain and free range and antibiotic free, avoid transfats and high fructose corn syrup and most processed foods.