In this study, cow skim milk was chosen as raw materials, and micellar casein was obtained by ultrafiltration and spray-dried under the temperature of 130 ℃ and 150 ℃ with a spray pressure of 0.05 MPa and 0.1 MPa, respectively. The following parameters, including moisture content, particle size, bulk density, topography, solubility, intrinsic fluorescence and antioxidant properties of micellar casein, were measured. Freeze-drying samples were used as the control group. The results showed that as spray-drying temperature and pressure increased, the moisture content decreased and bulk density increased significantly with the maximum particle size of (2.16±0.29) μm under the conditions of 150 ℃-0.1 MPa. The solubility of freeze-drying samples was (87.63±0.35)% at pH7,which was similar to the solubility of spray drying samples. The freeze-drying samples had a minimum particle size of (1.31±0.02) μm, and maximum bulk density of (416.47±3.94) mg/mL. And the moisture content was similar to those of samples under 130 ℃-0.1 MPa and 150 ℃-0.05 MPa spray-drying conditions. Moreover, the solubility and intrinsic fluorescence reduced when temperature and pressure increased. However, the maximum emission wavelength and micellar topography did not alter. The best reduce power was obtained with the spray-drying samples at 130 ℃ had and ABTS free radical scavenging activities were also good, while samples obtained at 150 ℃ had the best DPPH free radical scavenging activities. Furthermore, the spray-drying micellar casein at 150 ℃ and 0.05 MPa had the best Fe2+ chelating capacity. This study could provide references for the industrial development of micellar casein and the optimization of spray-drying parameters.
[1] MCMAHON D J, OOMMEN B S. Supramolecular structure of the casein micelle[J]. Journal of Dairy Science, 2008, 91(5): 1 709-1 721.
[2] DE KRUIF C G, ZHULINA E B. κ-casein as a polyelectrolyte brush on the surface of casein micelles[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 1996, 117(1): 151-159.
[3] DALGLEISH D G, CORREDIG M. The structure of the casein micelle of milk and its changes during processing[J]. Annual Review of Food Science and Technology, 2012, 3(1): 449-467.
[4] HOLT C, DE KRUIF C G, TUINIER R, et al. Substructure of bovine casein micelles by small-angle X-ray and neutron scattering[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2003, 213(2-3): 275-284.
[5] YE A. Functional properties of milk protein concentrates: Emulsifying properties, adsorption and stability of emulsions[J]. International Dairy Journal, 2010, 21(1): 14-20.
[6] SALVATORE E, PIRISI A, CORREDIG M. Gelation properties of casein micelles during combined renneting and bacterial fermentation: Effect of concentration by ultrafiltration[J]. International Dairy Journal, 2011, 21(11): 848-856.
[7] 陈建行,刘鹭,孙颜君,等.酪蛋白胶束粉的陶瓷膜分离生产工艺[J].农业工程学报, 2013, 29(9):256-266.
[8] BELICIU C M, SAUER A, MORARU C I. The effect of commercial sterilization regimens on micellar casein concentrates[J]. Journal of Dairy Science, 2012, 95(10): 5 510-5 526.
[9] HURT E, ZULEWSKA J, NEWBOLD M, et al. Micellar casein concentrate production with a 3X, 3-stage, uniform transmembrane pressure ceramic membrane process at 50℃ 1[J]. Journal of Dairy Science, 2010, 93(12): 5 588-5 600.
[10] 陈建行,刘鹭,张书文,等. 乳蛋白浓缩物(MPC)的中试生产工艺研究[J]. 中国乳品工业, 2013, 41(10):11-14.
[11] 韩娜,杨敏,杨继涛,等.酪蛋白酶解物的分离及其抗氧化活性[J].食品工业科技, 2019, 40(9):166-170;229.
[12] TAVAF Z, TABATABAEI M, KHALAFI-NEZHAD A, et al. Evaluation of antibacterial, antibofilm and antioxidant activities of synthesized silver nanoparticles (AgNPs) and casein peptide fragments against Streptococcus mutans[J]. European Journal of Integrative Medicine, 2017, 12: 163-171.
[13] GU F L, KIM J M, HAYAT K, et al. Characteristics and antioxidant activity of ultrafiltrated Maillard reaction products from a casein-glucose model system[J]. Food Chemistry, 2009, 117(1): 48-54.
[14] GOULA A M, ADAMOPOULOS K G. Spray drying of tomato pulp in dehumidified air: II. The effect on powder properties[J].Journal of Food Engineering, 2004, 66(1): 35-42.
[15] CANO-CHAUCA M, STRINGHETA P C, RAMOS A M, et al. Effect of the carriers on the microstructure of mango powder obtained by spray drying and its functional characterization[J]. Innovative Food Science and Emerging Technologies, 2005, 6(4): 420-428.
[16] YANG M, CUI N, FANG Y, et al. Influence of succinylation on the conformation of yak casein micelles[J]. Food Chemistry, 2015, 179: 246-252.
[17] WANG H X, YANG J T, YANG M, et al. Antioxidant activity of Maillard reaction products from a Yak casein-glucose model system[J]. International Dairy Journal, 2018, 91: 55-63.
[18] XIE Z J, HUANG J, XU X M, et al. Antioxidant activity of peptides isolated from alfalfa leaf protein hydrolysate[J]. Food Chemistry, 2008, 111(2): 370-376.
[19] KONG B H, XIONG Y L L. Antioxidant activity of zein hydrolysates in a liposome system and the possible mode of action[J].Journal of Agricultural and Food Chemistry, 2006, 54(16): 6 059-6 068.
[20] RE R, PELLEGRINI N, PROTEGGENTE A, et al. Antioxidant activity applying an improved ABTS radical cation decolorization assay[J].Free Radical Biology and Medicine, 1999, 26(9): 1 231-1 237.
[21] 王鹏杰,简澍瑜,王辰元,等.不同前处理条件对动态光散射检测酪蛋白胶束粒径的影响[J].农业工程学报, 2015, 31(14): 298-302.
[22] 苏东晓,廖森泰,张名位,等.喷雾干燥工艺条件对速溶龙眼粉理化特性的影响[J].中国农业科学, 2011, 44(18): 3 830-3 839.
[23] TAN S, EBRAHIMI A, LANGRISH T. Controlled release of caffeine from tablets of spray-dried casein gels[J]. Food Hydrocolloids, 2019, 88:13-20.
[24] ZHANG Ruihua, PANG Xiaoyang, LU Jing, et al. Effect of high intensity ultrasound pretreatment on functional and structural properties of micellar casein concentrates[J]. Ultrasonics Sonochemistry, 2018, 47:10-16.
[25] 闫忠心,靳义超.喷雾干燥温度对牦牛乳粉溶解特性的影响[J].食品科学, 2016, 37(7):23-26.
[26] LIU D S, ZHANG J, YANG T Y, et al. Effects of skim milk pre-acidification and retentate pH-restoration on spray-drying performance, physico-chemical and functional properties of milk protein concentrates[J]. Food Chemistry, 2019, 272: 539-548.
[27] KERENSA B, ALPHONS G J V, ROB J H, et al. Glycoforms of beta-lactoglobulin with improved thermostability and preserved structural packing[J]. Biotechnology and Bioengineering, 2004, 86(1): 78-87.
[28] MANEEPHAN K, MATTEO M, STEFANIA I, et al. Structural changes of soy proteins at the oil–water interface studied by fluorescence spectroscopy[J].Colloids and Surfaces B: Biointerfaces, 2012, 93: 41-48.
[29] JOSHI R, SOOD S, DOGRA P, et al. In vitro cytotoxicity, antimicrobial, and metal-chelating activity of triterpene saponins from tea seed grown in Kangra valley[J].Indian Journal of Medical Research, 2015, 22: 4 030-4 038.
[30] GARCíA-MORENO P J, BATISTA I, PIRES C, et al. Antioxidant activity of protein hydrolysates obtained from discarded Mediterranean fish species[J]. Food Research International, 2014, 65: 469-476.
[31] KUMARAN A, JOEL K R. Antioxidant and free radical scavenging activity of an aqueous extract of Coleus aromaticus[J]. Food Chemistry, 2006, 97(1): 109-114.
[32] FAN L L, WANG Y, XIE P J, et al. Copigmentation effects of phenolics on color enhancement and stability of blackberry wine residue anthocyanins: Chromaticity, kinetics and structural simulation[J]. Food Chemistry, 2018, 275: 299-308.
