Simultaneous determination of four sesame lignans and conversion in Monascus aged vinegar using HPLC method.
A simple, accurate and specific high-performance liquid chromatography (HPLC) method has been developed and validated for simultaneous determination of sesamol, sesamin, asarinin and sesamolin in Monascus aged vinegar. The effects of acid hydrolysis and four heating treatments on the components content in Monascus aged vinegar were discussed. The results showed that the isomerisation of sesamin to asarinin, and decomposition of sesamolin to sesamol significantly increased, regardless of heating or acid hydrolysis. Thermal processes and acid hydrolysis increased the content of sesamol and asarinin, respectively, but severe thermal processes resulted in the loss of total sesame lignans. Sesamol and asarinin reached the highest (2.720 ± 0.202 μg/mL and 2.064 ± 0.075 μg/mL) for autoclaving (125 °C, 15 min) and acid hydrolysis (25 °C, 15 min, nature pH), respectively. Therefore, autoclaving and acid hydrolysis were considered as the optimal way to obtain higher content of sesamol and asarinin.
Effect of milling, soaking, malting, heat-treatment and fermentation on phytate level of four Sudanese sorghum cultivars
Abstract Four cultivars of Sudanese sorghum ( Sorghum bicolor ) were analysed for their phytate content, with respect to effects of processing operations, namely milling extraction, water soaking, malting, heat-treatment and fermentation. The conditions of processing used were: decortication to give an 80% extraction meal; 12 and 24 h soaking in tap water; 96 h germination; fermentation for 3,6,9 and 12 h; and cooking at 95°C until starch gelatinized. Total phosphorus, phytate phosphorus and phytic acid were determined. Results showed that phytic acid phosphorus formed >85% of total phosphorus of the sorghum cultivars studied. All treatments investigated caused phytic acid reduction to various extents. Enzymic methods of phytic acid removal (fermentation and malting) were found to be more effective than physical extraction methods, i.e. milling, soaking and heating.
Investigations on the rôle of organic matter in plant nutrition
1. As the result of decomposition of green manure in a swamp soil, the coarse fractions (including coarse and fine sand) of the surface layer (first 3 inches) decreased by 11·2 per cent. while the fine ones (silt+clay) increased by 9·8 per cent. in the course of 43 days. The effect was less pronounced in the manured soil maintained at 60 per cent. saturation, while no alteration was to be noticed in the case of the unmanured specimens. 2. Treatment with dilute hydrochloric acid prior to dispersion had no appreciable effect on the estimates of mechanical composition obtained in the different cases. Loss in solution was also comparatively small. 3. The silica-sesquioxide ratio increased slightly as the result of decomposition of green manure in swamp soil. The composition of the fine fractions was also altered, the total percentages of the oxides of iron, aluminium and silicon increasing from 90·5 to 99·3 in the course of 71 days. 4. The practical significance of the above and related observations has been discussed.