"My DH is a chemist - apples contain maelic acid
. Don't know which Course you were on or what the qualifications of the tutor was
………… "
I think that is an insulting thing to say CLKD it was NVQC level 3 equivalent to A level and I got Distinction.
Your DH must know that apples become alkaline when digested, if you check the links they are under the alkalising fruits! Lemons are another.
http://www.edgarcayce.org/are/holistic_health/data/thdiet3.html "ACID-FORMING & ALKALINE-FORMING FOODS
It must be noted that because a food is acid it is no indication that it REMAINS acid in the body. It can turn alkaline. Honey and raw sugars produce alkaline ash, but because of a high concentrate of sugar become acid-formers. Those fruits marked with an * should not be eaten with other foods. They are acid externally but alkaline internally"