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Li Y.,Zhejiang GongShang University | Xu X.,Zhejiang GongShang University | Meng Y.,Zhejiang GongShang University | Chen J.,Zhejiang GongShang University | And 2 more authors.
Advance Journal of Food Science and Technology | Year: 2015

Interactions between stabilizer and casein were believed to influence the texture and stabilizing behavior of fermented milk. In this study, interactions between Soybean Soluble Polysaccharide (SSPS) and casein were studied by investigated the properties of potentiometric titration, turbidity, ζ-potential and particle size. Attractive interaction of SSPS with caseins was initiated at pH 5.3. By adding SSPS, the values of turbidity and ζ-potential were much lower than casein alone at the same pH during acidification. It was confirmed that the process of desorption during neutralization was irreversible which resulted from the decrease of ζ-potential and the changes of particle diameter. The study of interactions between negatively charged SSPS and casein could have important theoretical and practical implications in the stabilizing behavior in acid milk drinks. © Maxwell Scientific Organization, 2015. Source

Zhang J.,Zhejiang University | Zhang J.,U.S. Center for Disease Control and Prevention | Lai S.,Zhejiang Beingmate Scientific Industrial Trade Share Co. | Zhang Y.,Zhejiang University | And 3 more authors.
Analytica Chimica Acta | Year: 2012

The determination of α-lactalbumin in various dairy products attracts wide attention in multidiscipline fields because of its nutritional and biological functions. In the present study, we quantified the bovine α-lactalbumin in various infant formulas and whey protein concentrates using ultra-high performance liquid chromatography coupled to tandem mass spectrometer in multiple reaction monitoring mode. Bovine α-lactalbumin was quantified by employing the synthetic internal standard based on the molar equivalent relationship among the internal standard, bovine α-lactalbumin and their signature peptides. This study especially focused on the recovery rates of the sample preparation procedure and robust quantification of total bovine α-lactalbumin in its native and thermally denatured form with a synthetic internal standard KILDKVGINNYWLAHKALCSE. The observed recovery rates of bovine α-lactalbumin ranged from 95.8 to 100.6% and the reproducibility was excellent (RSD. <. 6%) at different spiking levels. The limit of quantitation is 10. mg/100. g for infant formulas and whey protein concentrates. In order to validate the applicability of the method, 21 brands of infant formulas were analyzed. The acquired contents of bovine α-lactalbumin were 0.67-1.84. g/100. g in these infant formulas in agreement with their label claimed values. The experiment of heat treatment time showed that the loss of native α-lactalbumin enhanced with an increasing intensity of heat treatment. Comparing with Ren's previous method by analysis of only native bovine α-lactalbumin, the present method at the peptide level proved to be highly suitable for measuring bovine α-lactalbumin in infant formulas and whey protein concentrates, avoiding forgoing the thermally induced denatured α-lactalbumin caused by the technological processing. © 2012 Elsevier B.V. Source

Zhang J.,Zhejiang University | Ren Y.,U.S. Center for Disease Control and Prevention | Huang B.,U.S. Center for Disease Control and Prevention | Tao B.,Zhejiang Beingmate Scientific Industrial Trade Share Co. | And 2 more authors.
Journal of Separation Science | Year: 2012

A method of ultra-performance liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry (UPLC-ESI-MS/MS) has been established for simultaneous determination of major disialoganglioside 3 (GD3) and monosialoganglioside 3 (GM3) in infant formulas and whey protein concentrates. Gangliosides were extracted by using the technique of Svennerholm and Fredman and then cleaned up with OASIS HLB solid-phase extraction (SPE) cartridges. The various molecular species of gangliosides were separated on an Acquity UPLC BEH C8 column and analyzed under the negative ion mode. GD3 and GM3 were rapidly quantified using internal standard (IS) method. The developed method was further validated by determining the linearity, average recovery, sensitivity (limit of quantification), and precision. The results presented high correlation coefficients (R2 > 0.993) of the selected 16 gangliosides molecular species and provided the respective linear ranges. The limit of quantification was 0.325-0.734 mg/100 g for eight molecular species of GD3 and 0.008-0.312 mg/100 g for eight molecular species of GM3, respectively. The reasonable average recoveries (81-95%) and precision (relative standard deviation [RSD] ≥15%) were also demonstrated in three different spiked levels. This new method would be very useful in the quantitative determination of gangliosides in infant formulas and whey protein concentrates. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Chu X.,Zhejiang University | Chu X.,Zhejiang Beingmate Scientific Industrial Trade Share Co. | Du W.,Zhejiang Beingmate Scientific Industrial Trade Share Co. | Xiao G.,Zhejiang University of Science and Technology | And 2 more authors.
Journal of Chinese Institute of Food Science and Technology | Year: 2013

Some infants can be caused allergy by milk protein, so how to find another anti-protein agents was very important, through control the enzymatic conditions of whey protein can eliminate allergies. The small whey peptides by enzymatic control and animal tests through 180~220 g SD rats, Using the passive cutaneous anaphylaxis test(PCA) as the index of anti-protein allergy, the small peptides and formula milk powder was studied in this paper. The results showed that considering the main indicators of the degree of hydrolysis and bitterness value of auxiliary indicators, the control of hydrolysis time of 5.0 h, the hydrolysis temperature 55°C, initial pH of 7.0, the E/S of 0.05, which can obtain better effect. The animal tests showed that when giving 0.2 g/kg, 0.4 g/kg small whey peptide and 4.0 g/kg with 10% of the whey, a small peptide infant nutrition formula milk powder can significantly reduce the rats locus coeruleus OD value and area(P<0.01), giving 4.0 g/kg of infant nutrition formula milk powder can be slightly elevated rat locus coeruleus OD value and area(P>0.01), and showed that the small whey peptide can inhibite rat passive cutaneous anaphylaxis. Source

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