Please use this identifier to cite or link to this item:
https://ptsldigital.ukm.my/jspui/handle/123456789/499550Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.advisor | Aminah Abdullah, Prof. Dr. | - |
| dc.contributor.author | Zuhair Radhi Addai (P51324) | - |
| dc.date.accessioned | 2023-10-13T09:32:44Z | - |
| dc.date.available | 2023-10-13T09:32:44Z | - |
| dc.date.issued | 2015-05-15 | - |
| dc.identifier.other | ukmvital:80059 | - |
| dc.identifier.uri | https://ptsldigital.ukm.my/jspui/handle/123456789/499550 | - |
| dc.description | Studies were conducted to assess the antioxidant activity of total phenolics content (TPC), total flavonoids content (TFC), ferric reducing antioxidant power (FRAP), free radical scavenging (DPPH), free radical scavenging (ABTS) and oxygen radical absorbance capacity (ORAC) of two papaya cultivars namely Hongkong and Eksotika. The effects of extraction solvent on the antioxidant activity of papaya fruits were examined. The most effectively extraction solvent was 50% methanol. Results of the study indicated that solvents with different polarity had significant effects on antioxidant activities. Papaya fruits harvested at five different ripening stages corresponding to 12, 14, 16, 18, and 20 weeks after anthesis. Significant differences (P<0.05) were found at different ripening stages. Between the two papaya fruit cultivars studied, Eksotika showed a higher antioxidant activity assays than cultivar Hongkong. The TPC, TFC, FRAP, DPPH, ABTS and ORAC values increased significantly (P<0.05) with ripening. The physicochemical changes were measured in terms of the pH, titratable acidity (TA), moisture, total soluble solids (TSS) and pulp color of the papaya fruits at the five RS. Significant differences (P<0.05) were found at different stages of ripening. Sensory evaluation based on the color, sweetness, sourness, flavor and overall acceptance for the last three ripening stages was also performed. It showed that the RS had significant effects on phenolic acids (gallic acid, hydroxybenzoic acid, ferulic acid, caffic acid and p-coumric acid), flavonoids (quercetin, myricetin and kaemferol) and carotenoids values increased significantly (P<0.05) with the ripening stages. Coating of papaya fruit (Hongkong) with gum arabic (GA) enhanced their shelf-life and postharvest quality. Gum Arabic in aqueous solutions of 5% and 10% was applied as edible coating to green-mature papaya and stored at 13°C±1 for 15 days. The result of the study showed that papaya fruits coated with 10% GA and stored for 7 days had significantly (P<0.05) higher antioxidant activity, sensory quality and reduced microbial load than the control sample or other treated fruits. The result showed 10% gum Arabic could delay the ripening process by inhibiting the respiration rate in the papaya fruit and improves the postharvest quality during cold storage. Papaya fruits pureed were formulated to papaya fruit leather using honey, pectin and citric acid then dried in an oven at 60°C for 12 hours. Processing the papaya cultivars led to a increasing in antioxidant activity for both cultivars. Between the cultivars, Eksotika had the highest antioxidant and phenolics contents in both the fresh and dried fruit leathers. The pH, moisture, and TSS of the fruit leather decreased significantly (P<0.05), whereas TA and colour increased significantly during the processing. Sensory evaluation using 30 panelists from the Faculty of Science and Technology of the University Kebangsaan Malaysia (UKM) showed that the fruit leathers were well accepted.,Ph.D. | - |
| dc.language.iso | eng | - |
| dc.publisher | UKM, Bangi | - |
| dc.relation | Faculty of Science and Technology / Fakulti Sains dan Teknologi | - |
| dc.rights | UKM | - |
| dc.subject | Antioxidant | - |
| dc.subject | Papaya fruits | - |
| dc.subject | Maturity | - |
| dc.title | Antioxidant activity of papaya fruits at different maturity stages during storage and processing | - |
| dc.type | Theses | - |
| dc.format.pages | 205 | - |
| dc.identifier.barcode | 002006(2016) | - |
| Appears in Collections: | Faculty of Science and Technology / Fakulti Sains dan Teknologi | |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| ukmvital_80059+SOURCE1+SOURCE1.0.PDF Restricted Access | 436.77 kB | Adobe PDF |  View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.