A few more thoughts on grapefruit, squeezing baked or cooked Apple.
What Type of Actions Are Not Allowed as a דרבנן (Rabbinical Decree) of Zoreh;
Understanding the Difference Between the Melacha of Kotzair-קוֹצֵר (Reaping) and Gozez-גּוֹזֵז (Shearing);