This study was aimed at assessing the antioxidant capacity and phenolic (free, bound, and total) contents in selected commercial beverages. Three different types of beverages commonly available in Malaysian supermarkets namely, cocoa, coffee and tea were selected. Phenolic contents were determined using a Folin-Ciocalteu assay. Antioxidant capacity (ferric reducing power and scavenging activity) was determined using FRAP and TEAC assays. Based on analysis of variance, coffee showed the highest amount of free phenolic compounds and antioxidant capacity compared to cocoa and tea (p < 0.05). The major phenolic compound detected in coffee was chlorogenic acid. Cocoa showed higher phenolic content than tea. However, cocoa and tea have similar catechin content and possessed comparable antioxidant capacity. The free phenolic content in the three beverages was found to be highly correlated with antioxidant capacity. In addition, moderate correlation was observed between total phenolic content and antioxidant capacity. On the other hand, there was no significant contribution of bound phenolic compounds towards antioxidant capacity. The contribution of antioxidant capacity in these beverages could be due to phenolic compounds in the free form. The study indicated that the beverages studied possessed varying degrees of antioxidant capacity and phenolic contents.
Cocoa and cocoa products have received much attention due to their significant polyphenol contents. Cocoa and cocoa products, namely cocoa liquor, cocoa powder and chocolates (milk and dark chocolates) may present varied polyphenol contents and possess different levels of antioxidant potentials. For the past ten years, at least 28 human studies have been conducted utilizing one of these cocoa products. However, questions arise on which of these products would deliver the best polyphenol contents and antioxidant effects. Moreover, the presence of methylxanthines, peptides, and minerals could synergistically enhance or reduce antioxidant properties of cocoa and cocoa products. To a greater extent, cocoa beans from different countries of origins and the methods of preparation (primary and secondary) could also partially influence the antioxidant polyphenols of cocoa products. Hence, comprehensive studies on the aforementioned factors could provide the understanding of health-promoting activities of cocoa or cocoa products components.
Antioxidant activity, free radical scavenging activity and phenolic content of red cabbage (Brassica oleracea var. capitata rubra), Chinese cabbage (Brassica rapa pekinensis var cylindrica), green cabbage (Brassica oleracea var capitata), mustard cabbage (Brassica juncea var rugosa) and Chinese white cabbage (Brassica rapa var chinensis), grown in Malaysia, were evaluated. Red cabbage had the highest antioxidant activity and phenolic content compared to the other cruciferous vegetables studied (p < 0.05). The contributions of all cruciferous vegetables to the antioxidant activity was >79%. The radical scavenging activity was in the order of Chinese white cabbage > red cabbage > mustard cabbage > Chinese cabbage > green cabbage. There was a significant difference (p < 0.05) in the means of scavenging activity observed between cabbage, Chinese cabbage and Chinese mustard. Phenolic content was significantly different (p < 0.05) among all the cruciferous vegetables studied, and was in the order of red cabbage > Chinese white cabbage > green cabbage > Chinese cabbage >mustard cabbage. The study indicated that red cabbage possessed the highest antioxidant capacity and phenolic compounds concentration among all the cruciferous vegetables studied.
Chocolate contains a wide range of antioxidants that includes soluble phenolic compounds (phenolic acids, catechin, epicatechin, and proanthocyanidins), insoluble polymeric phenolics and methylxanthines. The objective of this study was to determine phenolic and theobromine contents in dark (DC), milk (MC), and white (WC) chocolates commonly found in the Malaysian marketplace. Total phenolic and flavonoids were determined by means of a spectrometric assay, while catechin, epicatechin and theobromine were quantified using a reverse-phase HPLC method. Dark chocolates exhibited the highest phenolics and flavonoids contents, followed by milk and white chocolates. Catechin and epicatechin were major flavonoids detected in dark chocolates. Theobromine was detected in dark and milk chocolates, but not in white chocolates. A high correlation (r= 0.93) between total phenolic and flavonoid contents, indicating that the major phenolic compounds in dark chocolates belong to the flavonoid class. When nutrition and health promotion are of concern, dark chocolates would be recommended over milk and white chocolates owing to their higher contents of antioxidant phenolic compounds.
Durian (Durio zibethinus Murr.) is an energy-dense seasonal tropical fruit grown in Southeast Asia. It is one of the most expensive fruits in the region. It has a creamy texture and a sweet-bitter taste. The unique durian flavour is attributable to the presence of fat, sugar, and volatile compounds such as esters and sulphur-containing compounds such as thioacetals, thioesters, and thiolanes, as well as alcohols. This review shows that durian is also rich in flavonoids (i.e., flavanols, anthocyanins), ascorbic acid, and carotenoids. However, limited studies exist regarding the variation in bioactive and volatile components of different durian varieties from Malaysia, Thailand, and Indonesia. Experimental animal models have shown that durian beneficially reduces blood glucose and cholesterol levels. Durian extract possesses anti-proliferative and probiotics effects in in vitro models. These effects warrant further investigation in human interventional studies for the development of functional food.
The objective of the study was to investigate the hypoglycaemic properties of Malaysian cocoa (Theobroma cacao) polyphenols extract in-vivo and insulin sensitivity in-vitro. Cocoa extract (CE) (containing 190 - 286 mg total polyphenol per gram extract) was prepared from fermented and roasted (140°C, 20 min) beans by extracting with 80% ethanol in the ratio of 1 to 10. For the in-vivo study, the CE was administered in three dosages (1%, 2%, and 3%) to groups of normal and diabetic rats for a period of 4 weeks by forcefeeding. Results showed that dosages of 1% and 3% CE significantly reduced (p < 0.05) plasma glucose levels in the diabetic rats. An in-vitro study (BRIN-BD11 cell lines) was used to evaluate the effect of CE on insulinsensitivity. The results demonstrated that CE at a concentration of 0.1 mg/ml significantly increased (p < 0.05) insulin level compared to the control. The results of this study showed that Malaysian cocoa polyphenol extract have the potential of being an insulin-mimetic agent. Further studies are on-going to elucidate the underlying mechanisms of polyphenols present in CE that contribute to the reduction of plasma glucose levels and insulin mimicking activity.
In this present study, we investigated the effects of cocoa extract containing polyphenols and methylxanthines prepared from cocoa powder on the biochemical parameters of obese-diabetic (Ob-db) rats. Obese-diabetic (Ob-db) rats were developed using a high-fat diet (49% fat, 32% carbohydrate, and 19% protein from total energy, kcal) for 3 months, followed by a low dose (35 mg/kg body weight) streptozotocin (STZ) injection. Cocoa extract (600 mg/kg body weight/day) was given to the rats for 4 weeks. The results indicated that there were no significant differences in fasting plasma glucose and insulin level after 4 weeks of cocoa extract administration. Oral glucose tolerance test revealed that cocoa supplementation in Ob-db rats significantly (p < 0.05) reduced plasma glucose at 60 and 90 min compared to unsupplemented Ob-db rats. Plasma free fatty acid and oxidative stress biomarker (8-isoprostane) were significantly (p < 0.05) reduced after cocoa supplementation. Superoxide dismutase activity was enhanced in Ob-db compared to that in nonsupplemented rats. However, no change was observed in catalase activity. The results showed that cocoa supplementation had an effect on postprandial glucose control but not for long term (4 weeks). Moreover, cocoa supplementation could reduce circulating plasma free fatty acid and 8-isoprostane and may enhance the antioxidant defense system.
Background and Objectives: Cognitive performance is essential for children, given this is a critical stage of brain growth and development. This systematic review and meta-analysis aimed to ascertain if physical activity or micronutrients impact cognitive performance in children. Materials and Methods: Electronic databases (PubMed and Scopus®) were searched for relevant articles published between 2012 and 2021. We emphasized randomized controlled trials (RCTs) that examined the effect of physical activity and micronutrients on cognitive performance. Data from eligible studies were gathered and evaluated using random-, fixed- or pooled-effects models with 95% confidence intervals (95% CI). Results: Physical activity appeared to improve both Mathematics (d = 1.12, 95% CI: 0.56, 1.67) and attention (d = 0.65, 95% CI: 0.15, 1.14) performances. The micronutrient vitamin B12 had a positive effect on Mathematics (d = 2.39, 95% CI: 0.79, 3.98), English (d = 5.29, 95% CI: 2.76, 7.83), Geography (d = 5.29, 95% CI: 2.76, 7.83), Science (d = 3.39, 95% CI: 2.62, 4.16) and Arts (d = 3.32, 95% CI: 1.84, 4.79). Zinc was found to positively affect English (d = 3.78, 95% CI: 0.44, 7.13), Geography (d = 4.77, 95% CI: 0.56, 8.98) and Arts (d = 2.39, CI: 0.33, 4.45). Iron positively affected Mathematics (d = 1.29, 95% CI: 0.54, 2.06), English (d = 1.29, 95% CI: 0.44, 7.13), Geography (d = 4.77, 95% CI: 0.56, 8.98) and Arts (d = 2.39, 95% CI: 0.33, 4.45). Conclusions: A more comprehensive intervention with a specific dose/level of physical activity, an increased range of cognitive performance, and a well-designed study design that accounts for dietary intake and other health outcomes are required for future studies.
Studies indicated that cocoa-based products effectively mitigate the risks associated with metabolic syndrome (MetS), however, the effect varies based on cocoa types, dosages, and study durations. This review aimed to determine the flavanol-rich cocoa consumption on MetS outcomes within the last decade (2013-2023), adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Seven randomized-controlled trials (RCTs) used cocoa-based products containing 0.3-1680 mg flavanol monomers and 3.5-1270 mg procyanidins. Cocoa-based products beneficially reduced glycemic response, blood pressure and lipid profiles. However, this review highlights little evidence pinpointing the best cocoa products type and required dosage for the observed effects. Further intervention aiming to improve MetS should justify the selection and concentration of flavanols (monomers and procyanidins). A robust study design should consider registering the trials before study commencement, consider multicenter RCT trials, and adjust for potential covariates that might "masked" the outcomes.