Indian traditional sweet dish i.e. halwa was developed from pearl millet grains. Pearl millet grains （Pennisetum typhoides var. PHB-2168） were steamed for 20 min at 1.05 kg cm^2 in order to minimize lipase activity,...Indian traditional sweet dish i.e. halwa was developed from pearl millet grains. Pearl millet grains （Pennisetum typhoides var. PHB-2168） were steamed for 20 min at 1.05 kg cm^2 in order to minimize lipase activity, total phenols, phytic acid and tannins content. Steamed grains were dried （12 ± 0.5% moisture content）, pearled, milled, sieved through sieve opening size of 0.234 mm and were used for study. Central composite rotatable design （CCRD） with three independent variables i.e. vanaspati, sugar and water for rehydration were used to design the experiments. Sensory responses and rehydration ratio were used to study the individual and interactive effects of variables. Sensory score for colour varied from taste 6.3-7.9, mouth feel 6.4-7.8, overall acceptability （OAA） 6.5-7.9 and rehydration ratio （RR） from 1.4 to 2.3. All the responses fitted into quadratic equation with R2 〉 0.80. Halwa dry mix was also evaluated for stability in polyethylene pouches at ambient conditions and the peroxide and free fatty acids value were 21.35 meqO2 kg^-1 fat, 0.55% （oleic acid）, respectively after 6 months of storage. Based on compromise optimization, optimum levels of the ingredients recommended with 86.4% desirability were： vanaspati 38.6 g 100 g^-1 pearl millet semolina （PMS）, sugar 88.7 g 100 g^-1 PMS and water for rehydration 151 mL 100 g^-1 dry mix.展开更多
Synthesizing epichlorohydrin(ECH) from dichloropropanol(DCP) is a complicated reaction due to the partial decomposition of ECH under harsh conditions. A microchemical system can provide a feasible platform for improvi...Synthesizing epichlorohydrin(ECH) from dichloropropanol(DCP) is a complicated reaction due to the partial decomposition of ECH under harsh conditions. A microchemical system can provide a feasible platform for improving this process by conducting a separation once full conversion has been achieved. In this work, referring to a common DCP feed used in industry, the reaction performance of mixed DCP isomers with Na OH in the microchemical system on various time scales was investigated. The operating window for achieving high conversion and selectivity was on a time scale of seconds, while the side reactions normally occurred on a time scale of minutes. Plenty of Cl-ions together with a high temperature were proved to be critical factors for ECH hydrolysis.A kinetic study of alkaline mediated ECH hydrolysis was performed and the requirements for an improved ECH synthesis were proposed by combining quantitative analysis using a simpli fied reaction model with experimental results on the time scale of minutes. Compared with the conventional distillation process, this new strategy for ECH synthesis exploited microchemical system and decoupled the reaction and separation with potentials of higher productivity and better reliability in scaling up.展开更多
文摘Indian traditional sweet dish i.e. halwa was developed from pearl millet grains. Pearl millet grains （Pennisetum typhoides var. PHB-2168） were steamed for 20 min at 1.05 kg cm^2 in order to minimize lipase activity, total phenols, phytic acid and tannins content. Steamed grains were dried （12 ± 0.5% moisture content）, pearled, milled, sieved through sieve opening size of 0.234 mm and were used for study. Central composite rotatable design （CCRD） with three independent variables i.e. vanaspati, sugar and water for rehydration were used to design the experiments. Sensory responses and rehydration ratio were used to study the individual and interactive effects of variables. Sensory score for colour varied from taste 6.3-7.9, mouth feel 6.4-7.8, overall acceptability （OAA） 6.5-7.9 and rehydration ratio （RR） from 1.4 to 2.3. All the responses fitted into quadratic equation with R2 〉 0.80. Halwa dry mix was also evaluated for stability in polyethylene pouches at ambient conditions and the peroxide and free fatty acids value were 21.35 meqO2 kg^-1 fat, 0.55% （oleic acid）, respectively after 6 months of storage. Based on compromise optimization, optimum levels of the ingredients recommended with 86.4% desirability were： vanaspati 38.6 g 100 g^-1 pearl millet semolina （PMS）, sugar 88.7 g 100 g^-1 PMS and water for rehydration 151 mL 100 g^-1 dry mix.
基金Supported by the National Natural Science Foundation of China(21036002,21176136)the National Science and Technology Support Program of China(2011BAC06B01)
文摘Synthesizing epichlorohydrin(ECH) from dichloropropanol(DCP) is a complicated reaction due to the partial decomposition of ECH under harsh conditions. A microchemical system can provide a feasible platform for improving this process by conducting a separation once full conversion has been achieved. In this work, referring to a common DCP feed used in industry, the reaction performance of mixed DCP isomers with Na OH in the microchemical system on various time scales was investigated. The operating window for achieving high conversion and selectivity was on a time scale of seconds, while the side reactions normally occurred on a time scale of minutes. Plenty of Cl-ions together with a high temperature were proved to be critical factors for ECH hydrolysis.A kinetic study of alkaline mediated ECH hydrolysis was performed and the requirements for an improved ECH synthesis were proposed by combining quantitative analysis using a simpli fied reaction model with experimental results on the time scale of minutes. Compared with the conventional distillation process, this new strategy for ECH synthesis exploited microchemical system and decoupled the reaction and separation with potentials of higher productivity and better reliability in scaling up.
