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Download fileInfluence of pH, Temperature, and Water Activity on Covalent Adduct Formation between Selected Flavor Compounds and Model Protein β‑Lactoglobulin
journal contribution
posted on 2020-11-10, 21:30 authored by Vaidhyanathan Anantharamkrishnan, Gary A. ReinecciusThis study investigates the influence
of pH, temperature, and water activity on the occurrence of covalent
adduct formation between select flavor compounds and a model food
protein (β-lactoglobulin). These reactions potentially result
in the loss of flavor during processing and storage, reducing consumer
acceptability. Foods present a diverse reaction environment encompassing
a wide range of aw, pH, and storage temperature,
which potentially influence protein: flavor reaction rates. Liquid
chromatography/mass spectrometry (LC/MS) data showed that covalent
adducts were formed more slowly at low pHs (3) than basic pHs (8)
(for citral, allyl isothiocyanate, and dimethyl trisulfide). No reactivity
was observed for benzaldehyde at pH 3, but substantial reactivity
was found at pHs 7 and 8. The amount of adducts formed increased with
an increase in storage temperature. Higher temperatures (45 °C)
led to the formation of products that were not observed at lower temperatures
(4 and 20 °C). An increase in water activity (0.11–0.75)
led to an increase in formation of adducts for allyl isothiocyanate.
There were no observable differences in adduct formation as a function
of aw for benzaldehyde, citral, and dimethyl
disulfide. However, this lack of observed effect may be due to the
rate of reaction being too slow to be detected in the timeframe of
this study.