Effects of the ratio of cow milk to soymilk on the physicochemical, rheological, microstructural and sensory properties of yogurt were investigated. Different ratios of cow milk to soymilk (100∶0, 75∶25, 50∶50, 25∶75, 0∶100) were mixed and fermented with 1 g/L direct vat set starter culture at 43 ℃ until pH dropped to 4.8, and then stored at 4 °C for analysis. With an increasing ratio of soymilk, the protein content in yogurt increased and the fat content decreased. The combination of cow milk and soymilk shortened the fermentation time. The water holding capacity were lower, the storage modulus and loss modulus were higher in yogurts produced from mixtures than that fermented from cow milk only, and these values in yogurt produced from soymilk were intermediate among them. Yogurts produced with solely cow milk or soymilk had a smooth microstructure, whereas the structure of yogurts produced with mixtures of cow milk and soymilk was coarse with numerous micropores throughout. Yogurt prepared from 50% cow milk and 50% soymilk had a suitable beany flavor, and high sensory score and stability during 28 d of storage.
[1] SHAHABBASPOUR Z, MORTAZAVIAN A M, POURAHMAD R, et al.The effects of ratio of cow's milk to soymilk, probiotic strain and fruit concentrate on qualitative aspects of probiotic flavoured fermented drinks[J].International Journal of Dairy Technology, 2013, 66(1):135-144.
[2] SCALABRINI P, ROSSI M, SPETTOLI P, et al.Characterization of Bifidobacterium strains for use in soymilk fermentation[J].International Journal of Food Microbiology, 1998, 39(3):213-219.
[3] TSANGALIS D, SHAH N P.Metabolism of oligosaccharides and aldehydes and production of organic acids in soymilk by probiotic Bifidobacteria[J].International Journal of Food Science and Technology, 2004, 39(5):541-554.
[4] GRANATA L A, MORR C V.Improved acid, flavor and volatile compound production in a high protein and fiber soymilk yogurt-like product[J].Journal of Food Science, 1996, 61(2):331-336.
[5] PHAM T T, SHAH N P.Biotransformation of isoflavone glycosides by Bifidobacterium animalis in soymilk supplemented with skim milk powder[J].Journal of Food Science, 2007, 72(8):M316-M324.
[6] RUI X, ZHANG Q Q, HUANG J, et al.Does lactic fermentation influence soy yogurt protein digestibility-A comparative study between soymilk and soy yogurt at different pH[J].Journal of the Science of Food and Agriculture, 2019, 99(2):861-867.
[7] DRAKE M A, CHEN X Q, TAMARAPU S, et al.Soy protein fortification affects sensory, chemical, and microbiological properties of dairy yogurts[J].Journal of Food Science, 2000, 65(7):1 244-1 247.
[8] KAZEMI A, MAZLOOMI S M, HASSANZADEH-ROSTAMI Z, et al.Effect of adding soymilk on physicochemical, microbial, and sensory characteristics of probiotic fermented milk containing Lactobacillus acidophilus[J].Iranian Journal of Veterinary Research, 2014, 15(3):206-210.
[9] MULLIN W J, FREGEAU-REID J A, BUTLER M, et al.An interlaboratory test of a procedure to assess soybean quality for soymilk and tofu production[J].Food Research International, 2001, 34(8):669-677.
[10] WANG F, TONG Q G, LUO J, et al.Effect of carrageenan on physicochemical and functional properties of low-fat Colby cheese[J].Journal of Food Science, 2016, 81(8):E1 949-E1 955.
[11] FERRAGUT V, CRUZ N S, TRUJILLO A, et al.Physical characteristics during storage of soy yogurt made from ultra-high pressure homogenized soymilk[J].Journal of Food Engineering, 2009, 92(1):63-69.
[12] LI H L, YANG C, CHEN C, et al.The use of trisodium citrate to improve the textural properties of acid-induced, transglutaminase-treated micellar casein gels[J].Molecules, 2018, 23(7):1 632.
[13] LI C K, SONG J H, KWOK L Y, et al.Influence of Lactobacillus plantarum on yogurt fermentation properties and subsequent changes during postfermentation storage[J].Journal of Dairy Science, 2017, 100(4):2 512-2 525.
[14] ZHAO L L, WANG X L, TIAN Q, et al.Effect of casein to whey protein ratios on the protein interactions and coagulation properties of low-fat yogurt[J].Journal of Dairy Science, 2016, 99(10):7 768-7 775.
[15] MARAFON A P, SUMI A, GRANATO D, et al.Effects of partially replacing skimmed milk powder with dairy ingredients on rheology, sensory profiling, and microstructure of probiotic stirred-type yogurt during cold storage[J].Journal of Dairy Science, 2011, 94(11):5 330-5 340.
[16] RAIKOS V, GRANT S B, HAYES H, et al.Use of β-glucan from spent brewer's yeast as a thickener in skimmed yogurt:Physicochemical, textural, and structural properties related to sensory perception[J].Journal of Dairy Science, 2018, 101(7):5 821-5 831.
[17] BONG D D, MORARU C I.Use of micellar casein concentrate for Greek-style yogurt manufacturing:Effects on processing and product properties[J].Journal of Dairy Science, 2014, 97(3):1 259-1 269.
[18] LEE S Y, MORR C V, SEO A.Comparison of milk-based and soymilk-based yogurt[J].Journal of Food Science, 1990, 55(2):532-536.
[19] MALAKI NIK A, ALEXANDER M, POYSA V, et al.Effect of soy protein subunit composition on the rheological properties of soymilk during acidification[J].Food Biophysics, 2011, 6(1):26-36.
[20] AKALIN A S, UNAL G, DINKCI N, et al.Microstructural, textural, and sensory characteristics of probiotic yogurts fortified with sodium calcium caseinate or whey protein concentrate[J].Journal of Dairy Science, 2012, 95(7):3 617-3 628.
[21] PARK D J, OH S, KU K H, et al.Characteristics of yogurt-like products prepared from the combination of skim milk and soymilk containing saccharified-rice solution[J].International Journal of Food Sciences and Nutrition, 2005, 56(1):23-34.
[22] CHENG Y J, THOMPSON I D, BRITTIN H C.Sogurt, a yogurt-like soybean product:Development and properties[J].Journal of Food Science, 1990, 55(4):1 178-1 179.
[23] GRYGORCZYK A, ALEXANDER M, CORREDIG M.Combined acid- and rennet-induced gelation of a mixed soya milk-cow's milk system[J].International Journal of Food Science & Technology, 2013, 48(11):2 306-2 314.
