To make low carb fried green tomatoes, first slice your green tomatoes into half-inch thick rounds. Next, follow a standard breading procedure: Dredge the slices in the protein powder/oat fiber combination. Remove excess. Dip each round into the egg mixture to coat, then into the keto breadcrumb mixture.
Green tomatoes are more acidic than ripened fruit and can be canned safely with any of the following recommendations.”[1] For canning green tomatoes in a jar on their own, however, the University of Wisconsin adds this advisory note: Do not ripen green tomatoes indoors for canning, the proper acidity may not develop.
So when a recipe calls for green tomatoes, use them and not ripe tomatoes. The only safe substitution that may be made for green tomatoes is swapping in tomatillos, as they also are very acidic, if not moreso. The USDA’s table of “Approximate pH of Foods and Food Products” assigns a pH value of 3.83 to tomatillos. [3]