[Establishment of near-infrared on-line monitoring model and determination of endpoint in frying process of Hordei Fructus Germinatus].

Hordei Fructus Germinatus has been always used by "stir-frying" as a traditional medicine and the endpoint judgment of "fragrant" and "yellow" has been the focus and difficulty in frying process research. In this study, a quantitative calibration model between index components and NIRS was established in order to rapidly detect the contents of reducing sugar, total amino acids, total flavonoids, A420 and moisture; besides, an endpoint judgment method of frying process was put forward based on the "component change rate". Near-infrared spectra of samples with different frying time were collected, and a quantitative analysis model based on near-infrared spectroscopy was established to optimize the parameters such as spectral pretreatment and modeling band. HCA and PLS-DA were used to study the relationship between component and "stir-frying", and the endpoint of frying process was determined. The established calibration model had a good performance that the correlation coefficients between the predicted results and the actual measured values were both more than 0.9, with predicted relative deviations less than 10%. Hordei Fructus Germinatus with different frying time was divided into 4 categories by HCA analysis. PLS-DA analysis showed that total reducing sugar had a significant contribution to distinguishing the Hordei Fructus Germinatus of different frying time. When the change rate of total reducing sugar was 80%, it could judge that the endpoint of frying had been obtained. Results showed that NIRS could not only quickly and accurately determine the contents of reducing sugar, total amino acid, total flavonoid, A420 and moisture in Hordei Fructus Germinatus samples of different frying time, but also judge the endpoint of frying in the process. This study provided a new method for the evaluation and endpoint judgment of "stir-frying" process in research of traditional Chinese medicine.

[Dynamic change rules of active ingredients and inactive ingredients from Fructus Hordei Germinatus with frying process].

It is not scientific to explain that fried Fructus Hordei Germinatus is more effective than row Fructus Hordei Germinatus in resolving food stagnation from the aspects of amylase, tricine and other "active ingredients". In the present experiment, the contents of active ingredients including quercetin, tricine, kaempferol, catechin, ferulic acid and inactive ingredients including 5-hydroxymethyl furfural, acrylamide in frying process were determined by HPLC. The dynamic change rules of active ingredient and inactive ingredients in the frying process were investigated by HCA, PCA and PLS-DA analysis. The results showed that the Fructus Hordei Germinatus samples with different frying temperatures were classified into 4 groups by HCA and PCA analysis. PLS-DA analysis showed that frying temperature mainly impacted the contents of inactive ingredients including 5-hydroxymethyl furfural and acrylamide, with less effects on the contents of active ingredients. Simultaneously, with the increase of time in frying process, the content of 5-hydroxymethyl furfural was significantly increased from 2 min and became stable at 16 min, while the content of acrylamide was increased continuously from 18 min. Based on the variation of the contents of various ingredients, samples at different frying time were classified into 5 groups. The results showed that the content changes of "inactive ingredients" were closely related to the duration and degree of frying process, and the dynamic change rules of "inactive ingredients" can provide scientific basis for evaluating the frying process and elucidating the efficacy mechanism of Fructus Hordei Germinatus.