Nutrients are present in all the fruits but in different quantities. Hence, it is essential to be aware of the nutritional value of fruits before we add them to our health routine. Grape vs Blackberry Nutrition will help you choose the best fruit among the two. Carbs in Grape and Blackberry are 18.10 g and 9.60 g respectively. The protein content of Grape and Blackberry is 0.72 g and 1.40 g. Protein to carb ratio of any fruit must be approximately 1.34. Protein to carb ratio of Grape is 0.04 and in Blackberry, it is 0.15. Nutritional value of fruits is incomparable to other food items. They provide all the vital nutrients required for proper functioning of our body.