This study was undertaken to evaluate the potential of fruit waste materials as source of natural antioxidant. The fruit peels including mango, guava and papaya peel were used in this study. The total phenolic content (TPC) was determined by Folin-Ciocalteu assay while antioxidant activities were determined by using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, ferric thiocynate (FTC) and thiobarbituric acid (TBA) assays. These antioxidant activities were compared to synthetic antioxidants, BHA/BHT combination and ascorbic acid. The results demonstrated that TPC ranged from 3.23 to 15.84 g GAE/100 g extract. Mango peels extract exhibited highest TPC compared to guava peel and papaya peel extract. In the FRAP assay, mango peel extract at 200 ppm, guava peel extract at 400 ppm and papaya peel extract at 1200 ppm, exhibited reducing power comparable to the permissible amount of BHA/BHT at 200 ppm. At concentration of 250 μg/ml, the DPPH radical scavenging activity of extracts and standards decreased significantly in the order of mango peel extract > guava peel extract > BHA/BHT > ascorbic acid > papaya peel extract. For the FTC assay, the antioxidant activity of mango peel extract was significantly higher than ascorbic acid, guava peel and papaya peel extract but lower than BHA/BHT while in the TBA assay, percentage inhibition of BHA/BHT and ascorbic acid were found to be higher than fruit peel extracts. The quantitative analysis for flavonoids showed the presence of catechin, epicatechin and kaempferol in the peel extracts.
The bioaccessibility property of apigenin from Mangifera indica (Water Lily var.) was
investigated using in vitro gastrointestinal digestion model. Two digestion stages were
simulated namely the gastric and small intestinal digestion by using different enzymes and
physiological conditions that mimicked the digestion process. Following digestion, the
bioaccessible apigenin was analysed using HPLD-DAD-MS. Results showed that the apigenin
fraction in intestinal phase was higher than in gastric phase with amounts 1.03 ± 0.35 mg/100
g DW and 0.50 ± 0.08 mg/100 g DW, respectively. After 1 h exposure to gastric juice, the
bioaccessibility of apigenin was 20.26 ± 3.06% with 79.74 ± 3.06% losses during the digestion,
whereas in intestinal phase, the percentage of bioaccessibility significantly increased to 41.53
± 13.99% and 58.47 ± 13.99% losses after 2 h treatment with pancreatin. It was concluded that
the apigenin in Water Lily mango became bioaccessible, suggesting the absorption possibility
of the compound in the upper part of intestine, which can lead to the health-related outcomes.
Nasopharyngeal diphtheria is an acute infectious upper respiratory tract disease caused by toxigenic strains of Corynebacterium diphtheriae. We report a case of a young adult who presented to us with a short history of fever, sore throat, hoarseness of voice and neck swelling. He claimed to have received all his childhood vaccinations and had no known medical illnesses. During laryngoscopy, a white slough (or membrane) was seen at the base of his tongue. The epiglottis was also bulky and the arytenoids were swollen bilaterally. The membrane was sent to the microbiology laboratory for culture. A diagnosis of nasopharyngeal diphtheria was made clinically and the patient was treated with an antitoxin together with erythromycin, while awaiting the culture result. Nevertheless, the patient's condition deteriorated swiftly and although the laboratory eventually confirmed an infection by toxin-producing C. diphtheriae, the patient had already succumbed to the infection.