If your goal is optimal nutrition, would you choose grapes or raisins? To most, the obvious answer would be grapes, because they’re less calorie dense than raisins. Grapes contain 20 calories per ounce, whereas raisins contain 85 calories/ounce. But, what if I asked the same question, and you had 100 calories to spend on either grapes or raisins? Although they’re the same fruit-raisins are dehydrated grapes-is there a difference in nutrition, when normalized to calories?
Before delving into the nutritional comparison it is important to briefly discuss what happens during the dehydration process. The grape obtains energy through photosynthesis occurring in the green stem. Once the grape is removed from its stem, it still has an energy requirement that needs to be met. Since the stem is no longer providing this energy, the grape begins to use its own chemical processes to maintain energy demand. At the core of the difference between the raisin and the grape is that once the grape leaves the stem, it starts to break down its own energy stores (ATP) to maintain the cellular energy demand, a process that consumes water.
Are there nutritional differences between the grapes and raisins?
In the table we see that when normalized to 100 calories, there isn’t a difference in protein, fat or carbohydrate, when comparing grapes and raisins.
Among the minerals, Copper content is reduced by more than 40% in raisins when compared with grapes. Copper is a cofactor for the antioxidant enzyme, Copper-Zinc Superoxide Dismutase. That its content reduced in raisins indicates a diminished antioxidant response.
Antioxidant depletion in raisins is also evident when looking at the vitamin list. Vitamin C (95% reduced), β-Carotene (100%), Vitamin A (100%), Leutein + Zeaxanthin (100%), Vitamin E: α-Tocopherol (86%), and Vitamin E: γ-Tocopherol (90%) are all dramatically reduced in raisins, when compared with grapes. That raisins are depleted in antioxidants, when compared with grapes is confirmed by looking at their respective ORAC (Oxygen Radical Absorbance Capacity) values: 261 for grapes vs. 113 for raisins.
The B-vitamins riboflavin (59%), pantothenate (56%), and Vitamin B6 (54%), each of which are required for efficient energy metabolism are reduced in raisins.
Finally, both Vitamin K (94%) and choline (neurotransmitter, 54%) are also reduced in raisins, when compared with grapes.
So, if your interest is optimal nutrition, eat grapes, not raisins!
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Reference values for raisins and grapes obtained from http://www.nal.usda.gov/fnic/foodcomp/search/
ORAC values for raisins and grapes obtained from w ww.ars.usda.gov/SP2UserFiles/Place/…/Data/ORAC/ORAC_R2.pdf