lentils are a staple in my diet and i have never perceived a benefit, they are more likely to interfere with ldopa absorption since they are about 20% protein.

ldopa is actually considered a toxin, something plants developed as a defense to keep animals from eating the plant. if they ever had ldopa, i imagine over the hundreds of years they have been grown it has been selected/bred out.

lentils/pulses are a staple in south asia, i assume billions of people consume them, i can't believe they have ldopa.

as far as electrophoresis in the home, i imagine anything is possible, when i did it in college i think the gel had to be handled/prepared very carefully since it was slightly toxic, a highly regulated power source was used to give consistant results. i used it just to compare banding on different samples of oats to compare/contrast their genetics, not to make specific measurements. you still need to quantify the bands which i imagine needs another instrument to optically measure the density of the band and compare it against a control of pure l-dopa. so measuring very small amounts - if too much won't get bands, just huge smudges, need more than a kitchen scale, filters, centrifuge

have fun.