Hip Seng Yim

Influence of extraction conditions on antioxidant properties of passion fruit (Passiflora edulis) peel

BACKGROUND As a by-product of tropical fruit juice industry, passion fruit peel is a valuable functional food. It is rich in antioxidants. To determine its potential antioxidant properties of passion fruit peel, this study aimed to evaluate the effect of extraction conditions on total phenolic content and antioxidant activity. METHODS The extraction conditions were selected from different percentages of ethanol (0-100%, v/v), extraction times (60-300 min), and extraction temperatures (25-60°C) that based on the optimal percentage of DPPH radical scavenging activity. The selected extraction condition was applied for further determination of total phenolic content (TPC) of the passion fruit peel extract using Folin-Ciocalteu reagent assay, while the antioxidant activities were evaluated using DPPH and ABTS radicals scavenging assays, ferric reducing antioxidant power (FRAP), and β-carotene bleaching (BCB) assay. The best extraction conditions were 40% ethanol, 60 min extraction time, and extraction temperature of 30°C. RESULTS The chosen extraction conditions have contributed to the high TPC and antioxidant activity of passion fruit peel. The levels of antioxidant activity obtained from the passion fruit peel were also lower compared to BHA and α-tocopherol. Positive correlations were observed between TPC and antioxidant activities as assessed by DPPH, ABTS, FRAP, and BCB assays. CONCLUSION As a waste of passion fruit consumption or by-product of fruit juice industry, its peel could be considered as a potential source of natural antioxidant for possible functional food and industrial applications.

Optimization of extraction parameters on the antioxidant properties of banana waste.

BACKGROUND Banana is grown worldwide and consumed as ripe fruit or used for culinary purposes. Peels form about 18-33% of the whole fruit and are discarded as a waste product. With a view to exploiting banana peel as a source of valuable compounds, this study was undertaken to evaluate the effect of different extraction parameters on the antioxidant activities of the industrial by-product of banana waste (peel). METHODS Influence of different extraction parameters such as types of solvent, percentages of solvent, and extraction times on total phenolic content (TPC) and antioxidant activity of mature and green peels of Pisang Abu (PA), Pisang Berangan (PB), and Pisang Mas (PM) were investigated. The best extraction parameters were initially selected based on different percentages of ethanol (0-100% v/v), extraction time (1-5 hr), and extraction temperature (25-60°C) for extraction of antioxidants in the banana peels. Total phenolic content (TPC) was evaluated using Folin-Ciocalteu reagent assay while antioxidant activities (AA) of banana peel were accessed by DPPH, ABTS, and β-carotene bleaching (BCB) assays at optimum extraction conditions. RESULTS Based on different extraction solvents and percentages of solvents used, 70% and 90% of acetone had yielded the highest TPC for the mature and green PA peels, respectively; 90% of ethanol and methanol has yielded the highest TPC for the mature and green PB peels, respectively; while 90% ethanol for the mature and green PM peels. Similar extraction conditions were found for the antioxidant activities for the banana peel assessed using DPPH assay except for green PB peel, which 70% methanol had contributed to the highest AA. Highest TPC and AA were obtained by applying 4, 1, and 2 hrs extraction for the peels of PA, PB and PM, respectively. The best extraction conditions were also used for determination of AAs using ABTS and β-carotene bleaching assays. Therefore, the best extraction conditions used have given the highest TPC and AAs. CONCLUSIONS By-products of banana (peel) can be considered as a potential source of antioxidants in food and pharmaceutical industry.

Influence of different extraction conditions on antioxidant properties of soursop peel

BACKGROUND Soursop is a healthy fruit. Peels form about 20% of the soursop fruit and are usually discarded as waste product. With a view to utilizing soursop peel as a source of valuable compounds, this study aimed to investigate the influence of different extraction conditions on total phenolic content (TPC) and antioxidant capacity (AC) of soursop (Annona muricata L.) peel. METHODS Different ethanol concentrations (20-100%, v/v), extraction temperatures (25- 60°C), and extraction time (1-5 h) were tested. Extracts were prepared on the basis of the best optimal extraction conditions (20% ethanol, 40°C the extraction temperature, and 4 h of extraction time), an optimal TPC and AC was determined for the soursop peel using DPPH, ABTS, FRAP and β-carotene bleaching (BCB) assays. The different extraction conditions tested at best optimum conditions have significantly affected the TPC and AC of the soursop peel. RESULTS Soursop peel extract extracted in the best optimal extraction conditions had moderate levels of TPC (52.2 μg GAE/ml), and FRAP value (58.9 μg TE/ml extract). The extract demonstrated high BCB inhibitory activity (80.08%). The EC50 values of the extract were high, 1179.96 and 145.12 μg/ml, as assessed using DPPH and ABTS assays, respectively. The TPC was positively and highly correlated with the AC of soursop peel assessed by ABTS, FRAP, and BCB assay, but it was moderately correlated with DPPH radical scavenging activity. A moderate correlation of TPC with DPPH suggested that polyphenols in the extracts were partially responsible for the AC. CONCLUSIONS By-products of soursop such as its peel could be an inexpensive source of good natural antioxidants with nutraceutical potential in the functional food industry.

Socioeconomic Status and Glycemic Index Among Punjabis in Kuala Lumpur, Malaysia: Possible Association with Metabolic Syndrome

There are only limited reports on Punjabi’s health status in Malaysia. This cross-sectional study assessed the prevalence of metabolic syndrome (Mets) and its risk factors among 277 subjects recruited from the Malaysian Punjabi community. Overall prevalence of Mets was 43%, but 61% among females. Subjects classified with Mets had significantly (p < 0.05) higher body mass index, visceral fat and percentage of body fat. Daily carbohydrate and glycemic index (GI) were also higher among Mets subjects (p < 0.05). Logistics regression analysis showed that primary level of education (OR 5.57, CI 1.29–23.97, p = 0.021) was a factor associated with Mets, followed by middle household income (OR 2.30, CI 1.01–5.20, p = 0.046), GI (OR 1.03, CI 1.00–1.06, p = 0.026), and age (OR 1.03, CI 1.00–1.05, p = 0.023). Mets shows high prevalence among the studied Punjabi population, prompting the consideration of adequate preventive measures, primarily among lower socioeconomic groups.

Psychological Factors and Cardiovascular Disease Risk Factors as Mediators of the Relationship between Overweight/Obesity and Cognitive Function among School Children in Kuala Lumpur, Malaysia

BACKGROUND Recent research suggests that a negative relationship exists between adiposity and cognitive function in children. However, limited information is known on how they are related. This study aimed to examine the mediators of the relationship between overweight/obesity and cognitive function among school children in Kuala Lumpur, Malaysia. METHODS This is a cross-sectional comparison study whereby 225 overweight/obese children matched for age, sex, and ethnicity with 225 normal weight children participated in this study. Body image dissatisfaction, disordered eating, and depressive symptoms were assessed through a self-administered questionnaire. Blood pressure was measured, whereas blood was drawn to determine insulin, high-sensitivity C-reactive protein (hs-CRP), glucose, and lipid profiles. Homeostasis model assessment-estimated insulin resistance (HOMA-IR) was calculated using glucose and insulin levels. Wechslers Intelligence Scale for Children-Fourth Edition (WISC-IV) was used to assess cognitive function in children. Ordinary least square regression analysis was conducted to determine the direct and indirect relationships between weight status and cognitive function. RESULTS A negative relationship was found between overweight/obesity with cognitive function. Overweight/obese children were on average 4.075 units lower in cognitive function scores compared to normal weight children. Such difference was found through mediators, such as body image dissatisfaction, disordered eating, depression, systolic blood pressure, triglycerides, HOMA-IR, and hs-CRP, contributing 22.2% of the variances in cognitive function in children. CONCLUSION Results highlight the important mediators of the relationship between overweight/obesity and cognitive function. Consequently, future interventions should target to improve psychological well-being and reduce cardiovascular disease risk for the prevention of poorer cognitive performance in overweight/obese children.

Rose, a Potential Nutraceutical: An Assessment of the Total Phenolic Content and Antioxidant Activity

Abstract : Rosa hybrida L. was reported to contain high total phenolic content and antioxidant activity. The scarce information on antioxidant properties of Malaysian cultivated R. hybrid L. had lead to the present study, which aimed to determine the effect of different solvent extraction on the total phenolic content and antioxidant activity of roses of different colours. All the 23 R. hybrida L. cultivars’ petals extracted with 70% ethanol had significantly higher 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity compared to the water extraction. The five cultivars (03, 203, 205, 402 and M203) that comprise the highest DPPH scavenging activity were subjected to various antioxidant assays. Cultivar M203 showed highest total phenolic content (TPC) at all concentration. Cultivar M203 and 402 gave higher DPPH radical scavenging ability (EC 50 =107.08 µg/ml) and 2,2-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS) radical cation scavenging ability (EC 50 =258.13 µg/ml). In ferric reducing antioxidant power assay, cultivar M203 has the highest trolox equivalent value at 200, 300 and 500 µg/ml concentrations while in b-carotene bleaching assay, cultivars 03, 205, and M203 (at the concentration of 500 µg/ml) showed higher antioxidant activity than synthetic antioxidant (BHA). Strong positive correlations were found between TPC and antioxidant activities, hence, suggesting that the high antioxidant activity of selected R. hybrida L. petals might be mainly contributed by the phenolic compounds. In general, cultivar M203 showed the best antioxidant activity with nutraceutical potential.