METHODS: This cross-sectional study conducted in 2016 involving 388 late adolescents from six government colleges in Kelantan, Malaysia, aged 18 to 19 years. They were requested to answer self-directed questionnaires with items on sociodemographic information and types of ATNP used. Other variables obtained include the environmental influence and reasons for using the products. Regression analyses between the dependent and independent variables were conducted using IBM SPSS ver. 20.0 (IBM Corp., Armonk, NY, USA).
RESULTS: The prevalence of ATNP use among late adolescents was 14.4%. The male sex, cigarette smoking status, and peer use were significantly associated with ATNP use. Several reasons for use were not significantly associated with ATNP use: perception of ATNP being less harmful and less addictive compared with cigarettes, curiosity, less expensive than cigarettes, to aid smoking cessation, and pleasurable flavors and taste.
CONCLUSION: The prevalence of ATNP use among late adolescents studying in government colleges in Kelantan is significant. There is higher perception on ATNP being less harmful and addictive than the conventional cigarette among the users compared with non-users. Significant associations are seen for the male sex, peer use, and concurrent cigarette smoking.
RESULTS: The key volatile compounds and aroma profile of six pineapple varieties grown in Malaysia were investigated by gas chromatography-olfactometry (GC-O), gas-chromatography-mass spectrometry and qualitative descriptive sensory analysis. A total of 59 compounds were determined by GC-O and aroma extract dilution analysis. Among these compounds, methyl-2-methylbutanoate, methyl hexanoate, methyl-3-(methylthiol)-propanoate, methyl octanoate, 2,5-dimethyl-4-methoxy-3(2H)-furanone, δ-octalactone, 2-methoxy-4-vinyl phenol, and δ-undecalactone contributed greatly to the aroma quality of the pineapple varieties, due to their high flavour dilution factor. The aroma of the pineapples was described by seven sensory terms as sweet, floral, fruity, fresh, green, woody and apple-like.
CONCLUSION: Inter-relationship between the aroma-active compounds and the pineapples revealed that 'Moris' and 'MD2' covaried majorly with the fruity esters, and the other varieties correlated with lesser numbers of the fruity esters. Hierarchical cluster analysis (HCA) was used to establish similarities among the pineapples and the results revealed three main groups of pineapples.
Results: The aroma compounds in roasted white yam (Dioscorea rotundata) were isolated and identified using static headspace-gas chromatography-mass spectrometry (SH-GC-MS) and gas chromatography-olfactometry (GC-O). In addition, the anti-oxidative activities of the most abundant volatile heterocyclic compounds (2 pyrroles, 4 furans and 3 pyrazines) were evaluated on their inhibitory effect towards the oxidation of hexanal for a period of 30 days. Twenty-nine aroma-active compounds with a flavour dilution (FD) factor range of 2-256 and an array of odour notes were obtained. Among them, the highest odour activities (FD ≥ 128) factors were determined for 2-acetyl furan and 2-acetylpyrrole. Other compounds with significant FD factors ≥ 32 were; 2-methylpyrazine, ethyl furfural, and 5-hydroxy methyl furfural.
Conclusion: Results of the anti-oxidative activity showed that the pyrroles exhibited the greatest antioxidant activity among all the tested heterocyclic compounds. This was followed by the furans and the pyrazines which had the least antioxidant activity.