Free radicals cause degenerative human diseases such as cancer, heart disease, and cerebrovascular disease through multiple mechanisms. Recently, natural foods and food-derived antioxidants such as vitamins and phenolic phytochemicals have received growing attention, because they are known to function as chemo-preventive agents against oxidative damage. Vitamin C is one of the most popular and least toxic antioxidant components in food and has been most popularly used as a dietary supplement to prevent oxidative stress-mediated diseases. However, the contribution of vitamin C to the total antioxidant activity of fruits is generally lower than 15% (Wang et al 1996). In particular, theaflavin (TF), epifallocatechin gallate (EGCG), resveratrol, and procyanidin in cocoa have been considered as major chemo-preventive agents mainly due to their strong antioxidative activities.
Fruits, including berries, are one of the most important sources of phenolic compounds in our diets. Especially hydroxybenzoic and hydroxycinnamic acid derivatives, anthocyanins, flavonols, catechins, and tannins, hydrolyzable or condensed, are frequently present (Macheix et al 1990). In an earlier study, phenolic extracts of berries (blackberries, red raspberries, sweet cherries, blueberries, and strawberries) inhibited human low-density lipoprotein (LDL) and liposome oxidation (Heinonen et al 1998). Berries have also shown a remarkably high scavenging activity toward chemically generated active oxygen species (Wang et al 1997& 2000; Prior et al 1998). However, the antioxidant properties and activities are influence by the cultivar, growing environment, growing season, and growing climate as well.
Total phenolics ( mg galic acid eq/100 g sample)
Figure 6.1 shows the total phenolics present in common fruits and vegetables. Total phenolics content of cranberry is the highest followed by apple, red grape and strawberry at 550mg GAEs/100g, 300mg GAEs/100g, 200mg GAEs/100g, and 180mg GAEs/100g, respectively.
|Total Phenolic Content
Table 1.0 shows Total Phenolic Content of Cacao Nibs from different country origins.
Cacao nibs consist of similar phytochemical bioactive compounds as compared to berries. Benns has carried out antioxidant testing for cacao nibs of three different origins (Malaysia, Vietnam, and Venezuela). Malaysia cacao nib has the highest total phenolic content followed by Venezuela cacao nibs and Vietnam cacao nibs ( 1602.89, 1540.89, 937.11 mg GAEs/100g, respectively). As compared to berries, total phenolics content of cacao is considered as about 4 times higher which totally unveil the goodness of eating chocolates than berries.
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