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: Pineapple juice vinegar, which had the highest total phenolic acid content, also exhibited the greatest in vitro antioxidant capacity compared to coconut juice and nipah juice vinegars. Following acute and sub-chronic in vivo toxicity evaluation, no toxicity and mortality were evident and there were no significant differences in the serum biochemical profiles between mice administered the vinegars versus the control group. In the sub-chronic toxicity evaluation, the highest liver antioxidant levels were found in mice fed with pineapple juice vinegar, followed by coconut juice and nipah juice vinegars. However, compared to the pineapple juice and nipah juice vinegars, the mice fed with coconut juice vinegar, exhibited a higher population of CD4+ and CD8+ T-lymphocytes in the spleen, which was associated with greater levels of serum interleukin-2 and interferon-γ cytokines.
CONCLUSIONS: Overall, the data suggested that not all vinegar samples cause acute and sub-chronic toxicity in vivo. Moreover, the in vivo immunity and organ antioxidant levels were enhanced, to varying extents, by the phenolic acids present in the vinegars. The results obtained in this study provide appropriate guidelines for further in vivo bioactivity studies and pre-clinical assessments of vinegar consumption. © 2017 Society of Chemical Industry.
MATERIALS AND METHODS: Seventy-five participants underwent MRE as an initial investigation or follow-up for inflammatory bowel disease. A systematic sampling method was used to divide the participants into three different groups: group 1 received 6.7% mannitol concentration, group 2 received 3.3% mannitol concentration and group 3 received pineapple juice as an oral contrast agent during their MRE examination. The degree of bowel distension on MRE images was assessed by a radiologist by measuring the bowel diameter from inner wall to inner wall at specified levels, while qualitative analysis was evaluated based on the presence of artefacts. All patients were asked to score their acceptance of the oral contrast and were asked about side effects such as diarrhoea, abdominal discomfort and vomiting.
RESULTS: All patients were able to completely ingest 1.5L of oral contrast. The mean diameter of bowel distension was 2.1cm in patients who received 6.7% mannitol concentration, 2.0cm in patients who received 3.3% mannitol concentration and 1.6 cm in patients who received pineapple juice. Twothirds of patients who received 6.7% mannitol and 3.3% mannitol solutions had good-quality MRE images, but 68% of patients who received pineapple juice had poor-quality MRE images. Twenty-four patients (96%) who received pineapple juice rated it as slightly acceptable and acceptable but only 12 patients (48%) who received 6.7% mannitol solution rated it as slightly acceptable and acceptable. Eighty-eight percent of patients who received 6.7% mannitol solution experienced at least one form of side effect as compared to 44% of patients who received 3.3% mannitol solution and 18% of patients who received pineapple juice.
CONCLUSION: Optimum small bowel distension and good image quality can be achieved using 3.3% mannitol concentration as an oral contrast agent. Increase in mannitol concentration does not result in significant improvement of small bowel distension or image quality but is instead related to poorer patient acceptance and increased side effects. Pineapple juice is more palatable than mannitol and produces satisfactory small bowel distension. However, the small bowel distension is less uniform when using pineapple juice with a considerable presence of artefacts. Mannitol, 3.3% concentration, is therefore recommended as an endoluminal contrast agent for bowel in MRE.