SPECTROPHOTOMETRIC DETERMINATION OF WPNI AND HMF IN UHT MILK THROUGH THE PRINCIPAL COMPONENTS ANALYSIS

Química Nova

Oliveira, Marcone A. L. de¹  Neves, Leandra N. O.¹  Silva, Paulo Henrique F. da¹  Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil¹ 

关键词:  Maillard reaction;    denaturation;    chemometric;    quality control;   

DOI  :  10.5935/0100-4042.20160082

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

During heat treatment milk suffers changes among which whey proteins insolubility and Maillard reaction can be monitored using spectrophotometric methods by determining the whey protein nitrogen (WPNI) and 5-hydroxymethylfurfural (HMF). The aim of this work was the evaluation of heat treatment in commercial UHT milk samples through HMF and WPNI determination by spectrophotometric methods in visible region, using chemometric tools in data analysis. The regression models were fitted and statistical assumptions were tested. The WPNI confidence interval (CI) was (0.91; 3.73) mg mL-1 showing the heat treatment severity and classifying the samples as "medium heat treatment" according to American Dairy Products Association. For free HMF index, the CI were: (2.39; 3.27) and (6.01; 6.89) µmol L-1 for regular and low lactose content samples, respectively; while these two samples group presented CI of (11.67; 12.39) and (132.28; 143.22) µmol L-1 for total HMF index, respectively; showing the influence of lactose content in total HMF index. Descriptive statistical analysis associated with principal component analysis demonstrated a lack of standardization in the current Brazilian UHT process. The spectrophotometric methods allowed obtaining further inferences about the product quality associated to its heat treatment.

【 授权许可】

Unknown