I thought I'd asked every question possible about tomatoes but I've got another one. The San Marzanos I'm growing have a tendency to have something black around the end of the core where there should be seeds. In other words, in some of these tomatoes there are no seeds or few seeds but there's a black plaque surrounding the core where one would expect seeds and gel. I haven't actually worried about it just cut it out and use the tomato. My guess is that this black plaque, which is lumpy and hard, is composed of undeveloped or underdeveloped seed. Is this a trait of some varieties, a disease of some sort or what? Liz who's having so much fun with the new dehydrator that she wants another one with tons of trays