â¢ Lychee average yields range from 600 pounds per acre in an âoffâ year to 10,000 pounds per acre in a heavy-bearing year (economic average is 5,000 pounds per acre). With a pack-out of 70 percent and a price of $3 per pound, income from an acre of lychee averages approximately $10,000 (3).
Generally foods contain complex mixtures of polyphenols. According to a 2005 review on polyphenols: The most important food sources are commodities widely consumed in large quantities such as fruit and vegetables, green tea, black tea, red wine, coffee, chocolate, olives, and extra virgin olive oil.
Some polyphenols are specific to particular food (flavanones in citrus fruit, isoflavones in soya, phloridzin in apples); whereas others, such as quercetin, are found in all plant products such as fruit, vegetables, cereals, leguminous plants, tea, and wine. This article is about larger phenolic substances.olyphenol oxidase (PPO) is an enzyme that catalyses the oxidation of o-diphenols to produce o-quinones. It is the rapid polymerisation of o-quinones to produce black, brown or red polyphenolic pigments that is the cause of fruit browning.