Pistachio nut cream is a new product that was produced by mixing powdered sugar, roasted pistachio nut, defatted powdered milk, lecithin, vanilla and margarine. Pistachio nut cream was stored at 4 and 20 °C in se...Pistachio nut cream is a new product that was produced by mixing powdered sugar, roasted pistachio nut, defatted powdered milk, lecithin, vanilla and margarine. Pistachio nut cream was stored at 4 and 20 °C in sealed jars. Nut creams were analyzed by chemical analysis such as peroxide values （meq kgt）, total and free fatty acidity （%）, moisture content （%）, pH, 2-tiobarbutric acid and browning indices. Sensory evaluations of the cream were examined according to the color, odour, texture, taste, aroma and feelings by the panelists. Samples containing 10% and 15% pistachio nut that were stored at 4 °C were better and more acceptable with respect to the chemical properties of pistachio nut cream compared to the nut cream samples that were stored at 20 °C.展开更多
Objectives:Colour is amongst the parameter which is used for process control during roasting.Materials and Methods:In this study,the effects of hot air roasting temperature(120,130,145,160,and 170°C)and hot air v...Objectives:Colour is amongst the parameter which is used for process control during roasting.Materials and Methods:In this study,the effects of hot air roasting temperature(120,130,145,160,and 170°C)and hot air velocity(0.6,1.3,and 2 m/s)on colour change kinetics of pistachio nuts were investigated by employing image analysis and simultaneously chlorophylls and xanthophylls(lutein andβ-carotenoid)concentration were determined by spectrophotometric measurement method.Results:We found that roasting temperature and hot air velocity had significant effect on colour changes.There is a correlation between a-and b-value with chlorophylls and xanthophylls concentration,respectively.The roasting temperature was found to be the main factor affecting colour development.The variations in the pigments concentration and colour parameters of pistachio nuts were adequately simulated by quadratic and cubic polynomials.The changes in L-,b-values,and xanthophylls degradation were well-fitted to the first-order kinetic model while a-value and chlorophylls degradation followed the zero-order kinetic.The activation energy was determined at 113.9,116.7,and 117.2 kJ/mol with R2≥99.9 and 191,195,and 163.2 kJ/mol with R2≥99.5 and 73.7,71.3,and 81.6 kJ/mol with R2≥99.9 for L-,b-,and a-value in hot air velocity of 0.6,1.3,and 2 m/s,respectively.Conclusions:Activation energy of chlorophylls and xanthophylls degradation were in the range of the activation energy for the yellowness(b-value)and redness(a-value)reactions.展开更多
文摘Pistachio nut cream is a new product that was produced by mixing powdered sugar, roasted pistachio nut, defatted powdered milk, lecithin, vanilla and margarine. Pistachio nut cream was stored at 4 and 20 °C in sealed jars. Nut creams were analyzed by chemical analysis such as peroxide values （meq kgt）, total and free fatty acidity （%）, moisture content （%）, pH, 2-tiobarbutric acid and browning indices. Sensory evaluations of the cream were examined according to the color, odour, texture, taste, aroma and feelings by the panelists. Samples containing 10% and 15% pistachio nut that were stored at 4 °C were better and more acceptable with respect to the chemical properties of pistachio nut cream compared to the nut cream samples that were stored at 20 °C.
基金Rafsanjan University of Medical Sciences,Rafsanjan,Iran,under the ethical code of IR.RUMS.REC.1397.150 at Rafsanjan University of Medical Sciences.
文摘Objectives:Colour is amongst the parameter which is used for process control during roasting.Materials and Methods:In this study,the effects of hot air roasting temperature(120,130,145,160,and 170°C)and hot air velocity(0.6,1.3,and 2 m/s)on colour change kinetics of pistachio nuts were investigated by employing image analysis and simultaneously chlorophylls and xanthophylls(lutein andβ-carotenoid)concentration were determined by spectrophotometric measurement method.Results:We found that roasting temperature and hot air velocity had significant effect on colour changes.There is a correlation between a-and b-value with chlorophylls and xanthophylls concentration,respectively.The roasting temperature was found to be the main factor affecting colour development.The variations in the pigments concentration and colour parameters of pistachio nuts were adequately simulated by quadratic and cubic polynomials.The changes in L-,b-values,and xanthophylls degradation were well-fitted to the first-order kinetic model while a-value and chlorophylls degradation followed the zero-order kinetic.The activation energy was determined at 113.9,116.7,and 117.2 kJ/mol with R2≥99.9 and 191,195,and 163.2 kJ/mol with R2≥99.5 and 73.7,71.3,and 81.6 kJ/mol with R2≥99.9 for L-,b-,and a-value in hot air velocity of 0.6,1.3,and 2 m/s,respectively.Conclusions:Activation energy of chlorophylls and xanthophylls degradation were in the range of the activation energy for the yellowness(b-value)and redness(a-value)reactions.
