Influence of thermal processing on the quality of hawthorn: Quality markers of heat‐processed hawthorn

Hawthorn and its derived products are used worldwide as foods as well as complementary medicine. During the preparation of hawthorn, heating and thermal processing are frequently reported. The thermal processing will change the medicinal purposes and modify the efficacy of hawthorn. However, details including the chemical profile shifting and quality markers of heat-processed hawthorn have not been well understood. In this study, we analyzed the hawthorn samples processed at different temperatures and different times by ultraviolet visible absorption spectrum and liquid-mass spectrometry technologies combined with multivariate statistical analysis. It was revealed for the first time that thermal processing could greatly change the ultraviolet-visible absorption spectra and chemical profiles of hawthorn even with heat treatment at 130°C for 10 min. And the ultraviolet visible absorption spectrum, especially the ratio value (R_{A500 nm/400 nm} ), was a descriptive and qualitative indicator of heating degree for the thermal processing at the macroscopic level. Several components, such as hyperoside, chlorogenic acid, quercetin, and apigenin, decreased or increased in content during the processing, and they could be utilized as the chemical quality markers. The proposed quality markers for heat-processed hawthorn will be helpful for further optimizing the processing conditions of hawthorn.