Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above...Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above 42°C. Protein solubility was also studied. The addition of dissociating reagents allowed concluding that solubility was decreased during oven drying due to thermo denaturation including hydrogen bonds. The volatile compounds of the different powders were extracted by solid phase micro-extraction and identified by mass spectrometry. Volatile compounds were related to lipid oxidation and Maillard reactions occurring during the preparation of the powders. High drying temperatures led to more volatile compounds resulting from Maillard reactions. In the protein powder preparation process, a fractionation step led to a “pulp fraction” and a “juice fraction” of earthworms. The “pulp fraction” contained less odorant volatile compounds resulting from Maillard reactions than the “juice fraction” did.展开更多
In recent years, there has been an increase in demand of gluten free products that are suitable for people with celiac disease. The present study was carried out to produce gluten free flat bread and biscuits with goo...In recent years, there has been an increase in demand of gluten free products that are suitable for people with celiac disease. The present study was carried out to produce gluten free flat bread and biscuits with good quality. The ingredients under this study were cassava flour, rice flour, extruded soy protein (ESP) and pumpkin powder. Four levels of ESP were used for production of flat bread and biscuits: 2.5%, 5%, 7.5% and 10% for flat bread and 5%, 10%, 15% and 20% levels for biscuits. Results of flat bread samples showed that protein, fat, ash and fiber contents increased in all samples as increasing the level of ESP. Flat bread at level 10% ESP had the highest value of β-carotene. Alkaline water retention capacity (AWRC) at zero time and 24 h of flat bread storage had high values for levels 2.5% and 5% ESP. Water holding capacity (WHC) increased insignificantly by increasing the level of ESP. Color measurements revealed that the lightness decreased and the redness increased with increasing the level of ESP. Sensory evaluation of flat bread revealed that 2.5% followed by 5% ESP level had high score of overall acceptability. Physical properties of biscuits indicated that as the level of ESP increased the diameter, thickness, volume and specific volume decreased. Biscuits sample with 20% ESP had the highest values of protein, fat, ash and fiber but the lowest in total carbohydrates. Also β-carotene and vitamin A content increased in biscuit samples. Caloric values of biscuits in all treated samples were lower than control. Lightness decreased while redness increased with increasing the level of ESP. Data of texture profile analysis (TPA) showed that hardness and adhesiveness (g) increased as ESP level increased. Sensory evaluation of biscuits showed that addition of ESP at 20% level decreased significantly texture score from 9.51 to 6.61 (P < 0.05) but insignificantly affected the other sensory scores.展开更多
Cow's milk allergy is mainly observed in infants and young children. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems. Conventional diagnosis is based on positive a...Cow's milk allergy is mainly observed in infants and young children. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems. Conventional diagnosis is based on positive allergy studies and evaluation of parameters including IgE and IgG1 levels, acute allergic skin response and anaphylactic shock reactions. We developed a cell membrane chromatographic(CMC)method based on human mast cells(HMC-1) for screening potential allergens in infant formula milk powders(IFMP). HMC-1 cell membranes were extracted and mixed with silica to prepare cell membrane chromatography columns(10 mm ? 2 mm i.d., 5 mm). Under the conditions of 0.2 mL/min flow rate and214 nm detection wavelength, human breast milk showed no retention. However, IFMP showed clear retention. The retained fractions were collected and analyzed through matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS). Four major milk proteins, i.e., α-casein, β-casein, α-lactalbumin, and β-lactoglobulin A, were identified. Furthermore, these proteins and β-lactoglobulin B showed clear retention on HMC-1/CMC columns. To test the degranulation effects of the five proteins, histamine and β-hexosaminidase release assays were carried out. All five proteins induced HMC-1 cells to release histamine and β-hexosaminidase. Also, we established a reversed phase liquid chromatographic(RPLC) method for the determination of the five proteins in IFMP and the results showed that 90% proteins in IFMP were α-casein and β-casein. We concluded that cow's milk proteins may be potential allergens and caseins cause more β-casein allergic risk than other proteins. This conclusion was consistent with other studies.展开更多
Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were...Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were investigated. The results showed that the optimum separation parameters were a centrifugal speed at 6 000 r/min, centrifugal time of 20 min, a mass fraction of dry matter of 20%, an inlet air temperature at 180 ℃ and a feed rate at 400 ml/h, under which the plasma protein was a pale yellow powdery solid, indicating a good separation effect.展开更多
本研究旨在评估复合蛋白粉(Complex Protein Powder,CPP)的安全性和免疫功能。急性经口毒性实验、遗传毒性实验和亚急性口服毒性实验(28 d)结果显示,CPP安全性较高,不会对小鼠的生长发育产生负面影响。CPP对小鼠免疫功能的影响试验显示...本研究旨在评估复合蛋白粉(Complex Protein Powder,CPP)的安全性和免疫功能。急性经口毒性实验、遗传毒性实验和亚急性口服毒性实验(28 d)结果显示,CPP安全性较高,不会对小鼠的生长发育产生负面影响。CPP对小鼠免疫功能的影响试验显示,中剂量组(1667 mg·kg^(-1)bw·d^(-1))CPP可以显著提升小鼠的NK细胞活性、巨噬细胞吞噬率等指标,有效增强小鼠的免疫功能。展开更多
文摘Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above 42°C. Protein solubility was also studied. The addition of dissociating reagents allowed concluding that solubility was decreased during oven drying due to thermo denaturation including hydrogen bonds. The volatile compounds of the different powders were extracted by solid phase micro-extraction and identified by mass spectrometry. Volatile compounds were related to lipid oxidation and Maillard reactions occurring during the preparation of the powders. High drying temperatures led to more volatile compounds resulting from Maillard reactions. In the protein powder preparation process, a fractionation step led to a “pulp fraction” and a “juice fraction” of earthworms. The “pulp fraction” contained less odorant volatile compounds resulting from Maillard reactions than the “juice fraction” did.
文摘In recent years, there has been an increase in demand of gluten free products that are suitable for people with celiac disease. The present study was carried out to produce gluten free flat bread and biscuits with good quality. The ingredients under this study were cassava flour, rice flour, extruded soy protein (ESP) and pumpkin powder. Four levels of ESP were used for production of flat bread and biscuits: 2.5%, 5%, 7.5% and 10% for flat bread and 5%, 10%, 15% and 20% levels for biscuits. Results of flat bread samples showed that protein, fat, ash and fiber contents increased in all samples as increasing the level of ESP. Flat bread at level 10% ESP had the highest value of β-carotene. Alkaline water retention capacity (AWRC) at zero time and 24 h of flat bread storage had high values for levels 2.5% and 5% ESP. Water holding capacity (WHC) increased insignificantly by increasing the level of ESP. Color measurements revealed that the lightness decreased and the redness increased with increasing the level of ESP. Sensory evaluation of flat bread revealed that 2.5% followed by 5% ESP level had high score of overall acceptability. Physical properties of biscuits indicated that as the level of ESP increased the diameter, thickness, volume and specific volume decreased. Biscuits sample with 20% ESP had the highest values of protein, fat, ash and fiber but the lowest in total carbohydrates. Also β-carotene and vitamin A content increased in biscuit samples. Caloric values of biscuits in all treated samples were lower than control. Lightness decreased while redness increased with increasing the level of ESP. Data of texture profile analysis (TPA) showed that hardness and adhesiveness (g) increased as ESP level increased. Sensory evaluation of biscuits showed that addition of ESP at 20% level decreased significantly texture score from 9.51 to 6.61 (P < 0.05) but insignificantly affected the other sensory scores.
基金supported by the National Natural Science Foundation of China (No: 81230079, 81102414, 81227802)the Natural Science Basic Research Plan in Shaanxi Province of China (Program No. 2017JQ8024)
文摘Cow's milk allergy is mainly observed in infants and young children. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems. Conventional diagnosis is based on positive allergy studies and evaluation of parameters including IgE and IgG1 levels, acute allergic skin response and anaphylactic shock reactions. We developed a cell membrane chromatographic(CMC)method based on human mast cells(HMC-1) for screening potential allergens in infant formula milk powders(IFMP). HMC-1 cell membranes were extracted and mixed with silica to prepare cell membrane chromatography columns(10 mm ? 2 mm i.d., 5 mm). Under the conditions of 0.2 mL/min flow rate and214 nm detection wavelength, human breast milk showed no retention. However, IFMP showed clear retention. The retained fractions were collected and analyzed through matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS). Four major milk proteins, i.e., α-casein, β-casein, α-lactalbumin, and β-lactoglobulin A, were identified. Furthermore, these proteins and β-lactoglobulin B showed clear retention on HMC-1/CMC columns. To test the degranulation effects of the five proteins, histamine and β-hexosaminidase release assays were carried out. All five proteins induced HMC-1 cells to release histamine and β-hexosaminidase. Also, we established a reversed phase liquid chromatographic(RPLC) method for the determination of the five proteins in IFMP and the results showed that 90% proteins in IFMP were α-casein and β-casein. We concluded that cow's milk proteins may be potential allergens and caseins cause more β-casein allergic risk than other proteins. This conclusion was consistent with other studies.
基金Supported by"123"Science and Technology Support Program from Science and Technology Department of Qinghai Province(2014-GX-136A)~~
文摘Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were investigated. The results showed that the optimum separation parameters were a centrifugal speed at 6 000 r/min, centrifugal time of 20 min, a mass fraction of dry matter of 20%, an inlet air temperature at 180 ℃ and a feed rate at 400 ml/h, under which the plasma protein was a pale yellow powdery solid, indicating a good separation effect.
文摘本研究旨在评估复合蛋白粉(Complex Protein Powder,CPP)的安全性和免疫功能。急性经口毒性实验、遗传毒性实验和亚急性口服毒性实验(28 d)结果显示,CPP安全性较高,不会对小鼠的生长发育产生负面影响。CPP对小鼠免疫功能的影响试验显示,中剂量组(1667 mg·kg^(-1)bw·d^(-1))CPP可以显著提升小鼠的NK细胞活性、巨噬细胞吞噬率等指标,有效增强小鼠的免疫功能。
