Investigation on the Physical and Phytochemical Variation of Different Parts of Sour Orange Fruit (Citrus aurantium L.) During Maturity Stages

In order to evaluate the effects of fruit maturation stages on physical and phytochemical characteristics in sour orange, a factorial experiment was performed based on complete randomized block design (RCBD) with two factors and four replications. Four maturation stages of the fruit including green immature, half-ripened, ripened and over ripened stages constituted the first factor and different parts of the sour orange fruit containing flavedo, albedo, fruit juice, dross and seed built up the second factor. The results demonstrated a significant effect of maturation stage on most of the measured traits (essential oil percentage and yield, fresh and dry weight of fruit parts, flavon and flavenol content, total flavonoid, phenolic compounds and antioxidant activity). Essential oil content in sour orange peel varied between minimum 3.13 % (v/w) to maximum 10.30 % at over ripened stage and green immature stage, respectively. This factor significantly decreased during fruit maturation. The maximum antioxidant activity (75.79%) related to albedo tissue at half-ripened stage. Phenolic compounds decreased during fruit maturation (from 12.38 to 6.39 mg gallic acid/g dry matter). Generally, flavedo tissue at the green immature stage contained the maximum bioactive compounds rate concerning most of the traits.