Processed grains and baked goods that are made with them are high in acidity. Examples of these include white bread, white rice, pasta, biscuits, bagels, doughnuts, pastries and crackers. These are also low in fiber and nutrients. White bread has a pH of 5, while white rice has a pH of 6.rocessed grains and baked goods that are made with them are high in acidity. Examples of these include white bread, white rice, pasta, biscuits, bagels, doughnuts, pastries and crackers. These are also low in fiber and nutrients. White bread has a pH of 5, while white rice has a pH of 6.