Black Grapes Vs. Red Grapes

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Black Grapes vs. Red Grapes

Black Grapes vs. Red Grapes


In order to look beyond the superficial layers of Vitis vinifera and into the chemical reaction process, enzyme, and carbohydrate composition, a series of tests had to be conducted. The question investigated was: what are the differences and similarities between the carbohydrates, enzymes, and the photosynthetic process in red and green grapes (Vitis vinefera)? We hypothesized that both grapes would be the same in enzyme activity and carbohydrate concentration, but the photosynthetic process is higher in red grapes than in green. The carbohydrate analysis included Benedict's test, which determined whether or not carbohydrates contain a free ketone or aldehyde reducing group, and Selivanoff's test, which is based on whether ketoses or aldoses are present within solution. The results showed both grapes contain monosaccharide ketoses because an orangish/red precipitate formed. Iodine test was conducted to see if starch is present within the compounds, the results showed no starch was present. The Pigment Identification test was used to determine the presence of certain pigments and their rates of low. Absorbance Spectrum tested how much light was absorbed, while the Action spectrum tested for efficiency of each color as a fuel source for photosynthesis. Our results neither supported nor opposed our hypothesis. The Environmental Effects of Enzyme Activity tested for the presence of PPO, the affect of heat inhibitors on the enzyme, and the affect of pH on enzymes. The results showed a PPO presence in both of the grapes and similar enzyme activity. Overall green and red grapes had similar results when testing for carbohydrates, phtotosynthesis, and enzymes.

Purpose of Study

Purpose of the study is to involve designing by conducting, analyzing results from my own experiment to test the sensory discrimination of one of my friends.


Green and Red Grapes Have Similar Carbohydrate & Enzyme Activity, Supported by Benedict's Test, and the Presence of PPO Test.

Resveratrol, the Prize of Darker Grape Skin

All grapes are beneficial for your health, but what makes darker skinned grapes significantly more valuable is their content of resveratrol. Resveratrol is a natural anti-pathogenic compound found on the skin of dark skinned grapes and other fruits and vegetables with a reddish pigment. In grapes, those that are deeply purple or black in color contain the highest concentration of resveratrol and thus, darker colored grapes are your top choices for health preservation.

Resveratrol has been proven to have several health promoting benefits.

Anti-aging: studies have shown that resveratrol has certain life extension properties and has been incorporated into anti-aging cosmetic formulas.

Anti-inflammation: resveratrol is a powerful bactericide and fungicide. Oral intake or topical application of resveratrol can lower your risk of pathogenic infections and inflammations.

Cancer prevention: resveratrol has shown the greatest effectiveness in treatment of skin and gastrointestinal cancers. It has also shown tumor suppressive effects in lung, breast, prostate and pancreatic cancers as well as leukemia.

Blood sugar control: resveratrol activates the SIRT 1 gene which increases your insulin secretion and sensitivity.

Blood pressure reduction: resveratrol inhibits the activity of the blood ...
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