超高压处理改善羊乳及其酪蛋白胶束的理化和流变特性
发布时间：2021-04-26 22:20
羊乳的凝乳能力相对较差,加工酸奶后会导致酸奶乳清析出,奶酪得率降低,给加工企业带来不小的经济损失。目前,已采用多种方法改善羊乳的凝乳特性,但有关于超高压处理改善凝乳的研究报道较少。在不同贮藏温度条件下（25℃、4℃）,研究了不同超高压（200-500 MPa）对原料羊乳理化性质的影响。在25℃条件下贮藏的原料羊奶,与未处理的样品相比,经过超高压处理后蛋白质构象发生了变化,蛋白质沉降系数发生改变、pH值、可溶性钙和磷含量逐渐降低,粘度显著降低（P>0.05）,以及在储存结束时酪蛋白的水合度降低。相反,在4℃条件下贮藏的原料羊奶与25℃下储存的样品相比,超高压处理与未处理的样品表现出不同的特性。这可能是由于钙和磷酸盐与酪蛋白的结合,从而导致电荷的屏蔽和胶束排斥力的减少。因此,为了改善羊奶的凝乳特性,本研究通过Box-Behnken设计,在不同压力（300、400和500 MPa）、保持时间（20、40和60min）和温度（20、40和60℃）下评估通过超高压处理对凝乳酶诱导凝胶品质的影响。随着压力水平的升高、时间的延长或温度的降低,凝乳时间呈下降趋势,而凝胶强度和凝乳速率却得到了改善...
【文章来源】：中国农业科学院北京市
【文章页数】：107 页
【学位级别】：博士
【文章目录】：
摘要
abstract
Chapter 1 Introduction
1.1 Goat's milk composition and coagulation properties
1.1.1 Goat's milk production in the world
1.1.2 Goat's milk composition and nutritional benefits
1.1.3 Coagulation properties of caprine milk
1.2 High hydrostatic pressure（HHP）
1.2.1 High pressure equipment
1.2.2 Effects of HPP on milk constituents and some properties of milk
1.2.2.1 Casein micelles
1.2.2.2 Whey proteins
1.2.2.3 Mineral balance in milk
1.2.2.4 Appearance and p H of milk
1.2.2.5 Rennet coagulation properties of milk
1.3 The main problems of the study
1.4 General objectives of the study
1.5 The specific objectives
Chapter 2 Combined effects of high pressure treatment and storage temperature on the physicochemical properties of caprine milk
2.1 Introduction
2.2 Materials and methods
2.2.1 Caprine milk samples
2.2.2 High hydrostatic pressure treatment
2.2.3 Determination of p H
2.2.4 Determination of soluble calcium and phosphorus
2.2.5 Determination of the hydration of ultracentrifuged pellet
2.2.6 Nitrogen analysis
2.2.7 Turbidity
2.2.8 Determination of color parameters
2.2.9 Viscosity
2.2.10 Particle size distribution
2.2.11 Statistical analysis
2.3 Results and discussion
2.3.1 pH
2.3.2 Hydration
2.3.3 Nitrogen compounds
2.3.4 Calcium and phosphorus in the serum phase
2.3.5 Viscosity
2.3.6.Turbidity and Size distribution
2.3.7 Color
2.4 Conclusion
Chapter 3 Rheological and microstructural properties of rennet gel made from caprine milk treated by HHP
3.1 Introduction
3.2 Materials and methods
3.2.1 Milk supply and treatment
3.2.2 Experimental design
3.2.3 p H measurement
3.2.4 Calcium（Ca）and phosphorus（P）in the serum phase
3.2.5 Gel Electrophoresis
3.2.6 Rheological measurements
3.2.7 Texture measurements
3.2.8 Water holding capacity（WHC）
3.2.9 Microstructure
3.2.10 Statistical analysis
3.3 Results and discussion
3.3.1 HP-induced changes in the p H and soluble Ca and P concentrations of caprine milk
3.3.2 Rheological properties of rennet-induced gels from caprine and bovine milk
3.3.3 Surface plots for rheological properties of rennet-induced gels from HP-treated caprine milk
3.3.4 WHC and GF of rennet-induced gels from caprine and bovine milk samples
3.3.5 Microstructure of rennet-induced gels from caprine milk
3.4 Conclusion
Chapter 4 Microfiltration retentates of caprine milk treated by high hydrostatic pressure:physicochemical,protein structure and rheological properties changes
4.1 Introduction
4.2 Materials and methods
4.2.1 Materials
4.2.2 Microfiltration retentate（MFR）preparation
4.2.3 High hydrostatic pressure treatment
4.2.4 Milk and MFR composition analysis
4.2.5 pH measurement
4.2.6 Mineral analyses
4.2.7 Particle size and zeta potential
4.2.8 Turbidity
4.2.9 Fluorescence spectroscopy Measurements
4.2.10 Determination of Fourier transform infrared（FTIR）spectroscopy
4.2.11 Sodium dodecyl sulphate-Polyacrylamide gel electrophoresis（SDS-PAGE）
4.2.12 Rheological measurements
4.2.13 Statistical analysis
4.3 Results and discussion
4.3.1 Physicochemical changes in MFR samples treated with HP
4.3.2 Changes in the secondary and tertiary structure of proteins
4.3.3 Rheological properties of MFR caprine milk samples treated by HP
4.4 Conclusion
Chapter 5 The functionality of micellar casein powders produced from microfiltration retentate caprine milk treated by high hydrostatic pressure prior to spray drying
5.1 Introduction
5.2 Materials and methods
5.2.1 Materials
5.2.2 Microfiltration retentate（MFR）preparation
5.2.3 High hydrostatic pressure treatment
5.2.4 MCC powder preparing by spray drying of HP-treated MFR
5.2.5 MCC powder composition analysis
5.2.6 Solubility
5.2.7 Foaming capacity and stability
5.2.8 Emulsion Stability
5.2.9 Microstructure
5.2.10 Statistical analysis
5.3 Results and discussion
5.3.1 Solubility
5.3.2 Foamability
5.3.3 Emulsifying property
5.3.4 Microstructure
5.4 Conclusion
Chapter 6 Overall conclusion and recommendation
6.1 Overall conclusion
6.2 Recommendations
6.3 Perspective
References
Acknowledgement
Resume
本文编号：3162222
【文章来源】：中国农业科学院北京市
【文章页数】：107 页
【学位级别】：博士
【文章目录】：
摘要
abstract
Chapter 1 Introduction
1.1 Goat's milk composition and coagulation properties
1.1.1 Goat's milk production in the world
1.1.2 Goat's milk composition and nutritional benefits
1.1.3 Coagulation properties of caprine milk
1.2 High hydrostatic pressure（HHP）
1.2.1 High pressure equipment
1.2.2 Effects of HPP on milk constituents and some properties of milk
1.2.2.1 Casein micelles
1.2.2.2 Whey proteins
1.2.2.3 Mineral balance in milk
1.2.2.4 Appearance and p H of milk
1.2.2.5 Rennet coagulation properties of milk
1.3 The main problems of the study
1.4 General objectives of the study
1.5 The specific objectives
Chapter 2 Combined effects of high pressure treatment and storage temperature on the physicochemical properties of caprine milk
2.1 Introduction
2.2 Materials and methods
2.2.1 Caprine milk samples
2.2.2 High hydrostatic pressure treatment
2.2.3 Determination of p H
2.2.4 Determination of soluble calcium and phosphorus
2.2.5 Determination of the hydration of ultracentrifuged pellet
2.2.6 Nitrogen analysis
2.2.7 Turbidity
2.2.8 Determination of color parameters
2.2.9 Viscosity
2.2.10 Particle size distribution
2.2.11 Statistical analysis
2.3 Results and discussion
2.3.1 pH
2.3.2 Hydration
2.3.3 Nitrogen compounds
2.3.4 Calcium and phosphorus in the serum phase
2.3.5 Viscosity
2.3.6.Turbidity and Size distribution
2.3.7 Color
2.4 Conclusion
Chapter 3 Rheological and microstructural properties of rennet gel made from caprine milk treated by HHP
3.1 Introduction
3.2 Materials and methods
3.2.1 Milk supply and treatment
3.2.2 Experimental design
3.2.3 p H measurement
3.2.4 Calcium（Ca）and phosphorus（P）in the serum phase
3.2.5 Gel Electrophoresis
3.2.6 Rheological measurements
3.2.7 Texture measurements
3.2.8 Water holding capacity（WHC）
3.2.9 Microstructure
3.2.10 Statistical analysis
3.3 Results and discussion
3.3.1 HP-induced changes in the p H and soluble Ca and P concentrations of caprine milk
3.3.2 Rheological properties of rennet-induced gels from caprine and bovine milk
3.3.3 Surface plots for rheological properties of rennet-induced gels from HP-treated caprine milk
3.3.4 WHC and GF of rennet-induced gels from caprine and bovine milk samples
3.3.5 Microstructure of rennet-induced gels from caprine milk
3.4 Conclusion
Chapter 4 Microfiltration retentates of caprine milk treated by high hydrostatic pressure:physicochemical,protein structure and rheological properties changes
4.1 Introduction
4.2 Materials and methods
4.2.1 Materials
4.2.2 Microfiltration retentate（MFR）preparation
4.2.3 High hydrostatic pressure treatment
4.2.4 Milk and MFR composition analysis
4.2.5 pH measurement
4.2.6 Mineral analyses
4.2.7 Particle size and zeta potential
4.2.8 Turbidity
4.2.9 Fluorescence spectroscopy Measurements
4.2.10 Determination of Fourier transform infrared（FTIR）spectroscopy
4.2.11 Sodium dodecyl sulphate-Polyacrylamide gel electrophoresis（SDS-PAGE）
4.2.12 Rheological measurements
4.2.13 Statistical analysis
4.3 Results and discussion
4.3.1 Physicochemical changes in MFR samples treated with HP
4.3.2 Changes in the secondary and tertiary structure of proteins
4.3.3 Rheological properties of MFR caprine milk samples treated by HP
4.4 Conclusion
Chapter 5 The functionality of micellar casein powders produced from microfiltration retentate caprine milk treated by high hydrostatic pressure prior to spray drying
5.1 Introduction
5.2 Materials and methods
5.2.1 Materials
5.2.2 Microfiltration retentate（MFR）preparation
5.2.3 High hydrostatic pressure treatment
5.2.4 MCC powder preparing by spray drying of HP-treated MFR
5.2.5 MCC powder composition analysis
5.2.6 Solubility
5.2.7 Foaming capacity and stability
5.2.8 Emulsion Stability
5.2.9 Microstructure
5.2.10 Statistical analysis
5.3 Results and discussion
5.3.1 Solubility
5.3.2 Foamability
5.3.3 Emulsifying property
5.3.4 Microstructure
5.4 Conclusion
Chapter 6 Overall conclusion and recommendation
6.1 Overall conclusion
6.2 Recommendations
6.3 Perspective
References
Acknowledgement
Resume
本文编号：3162222
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