Effect of the modified high methoxyl pectin on the stability of the fermented milk beverage

Yanhua Li,Xinwei Wang,Yuecheng Meng,Fan Zhang,Zhipeng Shao,Ling Hu

doi:10.1080/10942912.2018.1485029

Yanhua Li, Xinwei Wang + Show 4 more

Open Access

https://doi.org/10.1080/10942912.2018.1485029

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Abstract

ABSTRACTStability of milk drinks could be improved by adding high methoxyl pectin. In this work, effect of the modified high methoxyl pectin (MHMP) on the fermented milk beverage (FMB) was investigated by the characteristics of adsorption, viscosity, rheological properties, particle size, zeta-potential (ζ-potential), microstructure, and phase behavior. The low concentration of MHMP (<0.2%, w/v) and final pH (<4.0) might easily cause the instability among the particles inducing from the bridging flocculation. The FMB system obviously had a good stability as the adding of 0.4% MHMP. Meanwhile, the particle size had a slight downward trend with decreasing the value of pH. The increase of MHMP concentration could increase the properties of viscosity and ζ-potential. However, the ζ-potential of the system had a decreasing trend by reducing the pH of the FMB with the same concentration of MHMP. The microstructure of the FMB was thick and dense compared with the sample without MHMP. As the concentration of MHMP was above 0.4%, the FMB system presented the uniform dispersion and only slight stratification water occurred for the phase behavior. Besides, it was also indicated that most part of MHMP was not adsorbed onto the casein micelles but was involved in a network with MHMP/casein complexes in the FMB.

Highlights

During the acidified process of milk drinks, a firm space-filling network of the aggregated casein micelles was created
As the concentration of modified high methoxyl pectin (MHMP) was above 0.4%, the fermented milk beverage (FMB) system presented the uniform dispersion and only slight stratification water occurred for the phase behavior
It could be found that as the concentration of MHMP was inferior to 0.2%, non-adsorbed MHMP in the supernatant was low and the adsorption rate was more than 80%

Summary

Introduction

During the acidified process of milk drinks, a firm space-filling network of the aggregated casein micelles was created. The formation of this network was induced by the weakening electrostatic interactions and steric forces between the casein micelles.[1,2] To prevent the gel/network formation, the stabilizers were required that could avoid casein micelles from aggregation. Some of the carboxyl groups are methyl esterified, and pectin with more than 50% of esterified carboxyl groups is defined as HMP.[3,5,6] The stability of the fermented milk beverage (FMB) was substantially the problem of how to prevent the extensive aggregation of the casein micelles, which could lead to a macroscopic gel. The separation of calcium phosphate from casein micelles could appear as adjusting the

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