title: Variation in antioxidant attributes at three ripening stages of guava (Psidium guajava L.) fruit from different geographical regions of Pakistan.
abstract: The present investigation was carried out to appraise the levels of total phenols and vitamin C as well as antioxidant potential at three different ripening stages (un-ripe, semi-ripe and fully-ripe) of guava (Psidium guajava L.) fruit collected from three different geographical regions of Pakistan (Islamabad, Faisalabad and Bhakkar). The antioxidant potential of guava fruit extracts was assessed by means of different in-vitro antioxidant assays, namely inhibition of peroxidation in linoleic acid system, reducing power and radical scavenging capability. Overall, fruit at the un-ripe stage (G1) exhibited the highest levels of TPC, TFC, reducing power and DPPH radical scavenging activity, followed by the semi-ripe (G2) and fully-ripe (G3) stages. On the other hand, vitamin C content increased as the fruit maturity progressed, with highest value seen at the fully-ripe stage (G3) followed by the semi-ripe (G2) and un-ripe stage (G1). The concentration of vitamin C in fruits varied as: Faisalabad (136.4-247.9 mg 100 g⁻¹), Islamabad (89.7-149.7 mg 100 g⁻¹) and Bhakkar (73.1-129.5 mg 100 g⁻¹). The results showed that different stages of maturation and geographical locations had profound effects on the antioxidant activity and vitamin C contents of guava fruit.
authors.affiliation: Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad-38040, Pakistan.
authors.forename: Javaria
authors.initials: J
authors.lastname: Gull
authors.forename: Bushra
authors.initials: B
authors.lastname: Sultana
authors.forename: Farooq
authors.initials: F
authors.lastname: Anwar
authors.forename: Rehana
authors.initials: R
authors.lastname: Naseer
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ashraf
authors.forename: M
authors.initials: M
authors.lastname: Ashrafuzzaman
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry / Q000302:isolation & purification; D001713:Biphenyl Compounds / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification; D005638:Fruit / Q000737:chemistry*; D019787:Linoleic Acid / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects; D010154:Pakistan; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D031647:Psidium / Q000737:chemistry*; D019163:Reducing Agents / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D001713:Biphenyl Compounds; C518724:CML-1 plant extract; D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D019163:Reducing Agents; D019787:Linoleic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid