The alkaline diet states that you should balance out your basic and acidic foods. That means that, whether Jake is basic or acidic, it either way depends on the other foods you eat whether Jake fits into your diet.
For the purpose of the alkaline diet, whether food is either basic or acidic isn't a matter of the acidity of the food itself, but of the acidity of the products and byproducts of its metabolic pathways within our body. That's how it's possible that e.g. vinegar, which is acidic, is actually considered basic for the purpose of the alkaline diet.
So knowing the pH level of Jake (6.68 ± 0.4) doesn't help. We'd need to know the sum of the acidity of all the products and byproducts of Jake in the body. And that's practically impossible. Please note that there's no scientific evidence for the working mechanisms or beneficial health effects of the alkaline diet.
That being said, the foods that are generally recommended in the alkaline food lists are quite healthy overall. So as long as you eat a varied diet, picking your ingredients from these lists, you should be good.