Volatile and non-volatile chemical composition of the white guava fruit (Psidium guajava) at different stages of maturity

The effect of the maturation stages on the chemical composition and volatile compounds of the white Guava (Psidium guajava) Cv. Cortibel was investigated during three different stages. The stages were characterized by evolution of color, pH, titratable acidity, sugars, soluble solids, vitamin C and volatile components. The fruits were stored at 24 degrees C and air humidity of 74% for 13 days. The volatile extracts were obtained using headspace technique and analyzed using gas chromatograph/mass spectrometry (GC/MS) system. The titratable acidity and sugars decreased. The pH level and amount of vitamin C increased throughout progress of maturation. The behavior of volatile compounds of fruits in the three stages of maturation was: in immature fruits and those in their intermediate stage of maturation, were predominantly the aldehydes such as (E)-2-hexenal and (Z)-3-hexenal. In mature fruits, esters like Z-3-hexenyl acetate and E-3-hexenyl acetate and sesquiterpenes caryophyllene, alpha-humulene and beta-bisabollene are present. (c) 2005 Published by Elsevier Ltd.