Sorbate addition in Dulce de Leche: pH and thermal effect determinate by RP-HPLC

• Published in: European food research & technology 2024-03, Vol.250 (3), p.763-770
• Main Authors: dos Anjos Pinto, Caroline Barroso, Cunha, Carolina Neves, de Carvalho da Costa, Juliana, Wolfschoon-Pombo, Alan, Perrone, Ítalo Tuler, Stephani, Rodrigo
• Format: Article
• Language: English
• Subjects: Acceptance criteria; Acids; Agriculture; Analytical Chemistry; Biotechnology; Chemistry; Chemistry and Materials Science; Evaporation; Food; Food Science; Forestry; Heat treatment; Heat treatments; High-performance liquid chromatography; Investigations; Liquid chromatography; Milk; Original Paper; pH effects; Potassium; Sorbic acid; Stability analysis; Sucrose; Temperature effects; Thermal stability
• ISSN: 1438-2377; 1438-2385
• DOI: 10.1007/s00217-023-04418-3

The method (RP-HPLC ISO 9231| IDF 139) for sorbic acid (H-Sorb) determination in Dulce de Leche (DL) was investigated and fulfilled the acceptance criteria: selectivity (single peak), linearity (3.1–50.0 μg/mL; R 2  = 0.9977), precision (CV = 0.66–2.04%), accuracy (recoveries = 93.6–101.9%), detection limit (0.72 μg/mL) and quantification limit (2.17 μg/mL). In DL samples, the accuracy of H-Sorb determination from added K-Sorb before/after heat treatment varied from 88.8 to 96.5%. Addition of K-Sorb before/after evaporation (pH ~ 6.9, 100 min and 120 ºC) did not interfere with the final H-Sorb concentration. The evaluation of the thermal stability of K-Sorb in aqueous sucrose solutions at different pH values showed that H-Sorb losses were pH dependent. At pH ≤ p K a evaporation losses of H-Sorb occurred. H-Sorb analysis of commercial samples ( n  = 10) showed that their concentrations (265–572 mg/kg) were within Brazilian DL regulations, except for one sample that was mislabeled.