Right. Homogenization should not impact fatty acid chain length. Dairy systems are complicated though, and there are protein interactions that help the emulsion by supporting the formation of micelles[1]. It's the same stuff after pasteurization, just distributed differently.

Pasteurization is an entirely different matter though. Heat treatment will convert some fraction of lactose into smaller sugars, including its constituent galactose and glucose[2]. This is why ultra-pasteurized can taste a bit sweeter than untreated milk. Pasteurization also inactivates lipases which would otherwise cleave the fat molecules, reducing the likelihood of rancidity[3].

1. https://books.google.com/books?id=1OhFPZ7tFz8C&pg=PA864&lpg=...

2. https://books.google.com/books?hl=en&lr=&id=6Q8mX8DsDe4C&oi=...

3. https://books.google.com/books?id=gJ6jA7LG-bsC&pg=PA276&lpg=...

How did you learn?

I learned about lipase when I was a kid and followed my dad around at the farm. According to him it was the lipase in the homogenized whole milk that made the difference in taste that I recognized between milk from the storage tank on the farm and bought milk.

Reading up on it now it seems to be a bit more complicated but still.

From a quick reading it looks like homogenization may make fatty acids more accessible to lipase (greater accessible surface area, maybe also charge interactions?). Of course enzyme activity is also a function of pH and temperature. If it was a chilled storage tank, perhaps the taste was different because lipase had not yet had a chance to work--if homogenization happens before pastuerization, it could cause some breakdown after storage but before heat-moderated lipase inactivation.

I have some formal training in biology, but I'm certainly no expert and may be incorrect. What I do know is that dairy systems are complicated.

Maybe that's taking it too far? Clump size may indeed affect absorption, change the time it takes to travel down the intestine, or even change the speed of chemical reaction with increased surface area.

I have examined enough human intestines, macroscopically, microscopically, and biochemically, to feel fairly confident this is not in fact something to worry about.

Not worry about which? Homogenized milk, or shaking it up? Either?

either