[Correlation analysis of color change and Maillard reaction during processing of Gardeniae Fructus Praeparatus].

The chromaticity space parameters of the samples during the processing of Gardeniae Fructus Praeparatus(Jiaozhizi in Chinese herbal name, JZZ) were measured by the visual analyzer to analyze the color variation rule during the processing of JZZ, and the content changes of total reducing sugar, total amino acid and 5-hydroxymethylfurfural(5-HMF) related to Maillard reaction were measured. Pearson correlation analysis and linear regression analysis of the data were carried out by SPSS 24.0 software. The experimental results showed that the objective coloration of the samples in the processing of JZZ was basically consistent with the traditional subjective color judgment; the contents of total reducing sugar and total amino acids showed a decreasing trend during the processing of JZZ, and the content of 5-HMF showed an increasing trend, which was in line with Maillard reaction law. Pearson correlation analysis results showed that there was a significant correlation between the chromaticity space parameters L~*(lightness value), a~*(red green value), b~*(yellow blue value), E~*ab(total color value) and the contents of total reducing sugar, total amino acid and 5-HMF(P<0.01), among which the values of L~*, a~*, b~*, E~*ab were positively correlated with the contents of total reducing sugar and total amino acid, and negatively correlated with the contents of 5-HMF. The results of linear regression analysis also showed that these two were highly correlated. In this study, by establishing the correspondence relationship between the color change of JZZ processing and Maillard reactants, wecan not only provide a basis for the objective digital expression of subjective color of JZZ, but also provide a reference for explaining the processing mechanism of JZZ from a new perspective.

Mechanisms of biohydrogen recovery enhancement from peanut shell by C. guangxiense: Temperature pretreatment ranges from -80 to 100 °C.

The potential of low-cost bioenergy recovery from peanut shell was limited for its complex cellulose structure. In order to enhance the total reducing sugar (TRS) yield for bio-H2 production, peanut shell with heat (HT, 50-100 °C) or freezing pretreatment (FT, -80 to 0 °C) under different duration (0.5-12 h) was investigated. For uncovering the enhancement mechanisms, morphological feature and crystalline structure were analyzed by scanning electron microscope (SEM) and X-ray powder diffraction (XRD). The optimal pretreatment of 50 °C for 12 h was obtained with TRS yield increased 73.6%, while the H2 yield of 1.25 ml/mg-TRS was peaked with pretreatment at -80 °C. The SEM and XRD further demonstrated that mechanisms of HT and FT were realized through different ways, which were cracking and collapsing in HT, and delamination and peeling in FT, respectively.

Correlation analysis of color change and Maillard reaction during processing of Gardeniae Fructus Praeparatus / 中国中药杂志

The chromaticity space parameters of the samples during the processing of Gardeniae Fructus Praeparatus(Jiaozhizi in Chinese herbal name, JZZ) were measured by the visual analyzer to analyze the color variation rule during the processing of JZZ, and the content changes of total reducing sugar, total amino acid and 5-hydroxymethylfurfural(5-HMF) related to Maillard reaction were measured. Pearson correlation analysis and linear regression analysis of the data were carried out by SPSS 24.0 software. The experimental results showed that the objective coloration of the samples in the processing of JZZ was basically consistent with the traditional subjective color judgment; the contents of total reducing sugar and total amino acids showed a decreasing trend during the processing of JZZ, and the content of 5-HMF showed an increasing trend, which was in line with Maillard reaction law. Pearson correlation analysis results showed that there was a significant correlation between the chromaticity space parameters L~*(lightness value), a~*(red green value), b~*(yellow blue value), E~*ab(total color value) and the contents of total reducing sugar, total amino acid and 5-HMF(P<0.01), among which the values of L~*, a~*, b~*, E~*ab were positively correlated with the contents of total reducing sugar and total amino acid, and negatively correlated with the contents of 5-HMF. The results of linear regression analysis also showed that these two were highly correlated. In this study, by establishing the correspondence relationship between the color change of JZZ processing and Maillard reactants, wecan not only provide a basis for the objective digital expression of subjective color of JZZ, but also provide a reference for explaining the processing mechanism of JZZ from a new perspective.

Preparation of the recycled and regenerated mesocarbon microbeads-based solid acid and its catalytic behaviors for hydrolysis of cellulose.

Mesocarbon microbeads (MCMB) from coal tar pitch have excellent mechanical strength, high density, and good thermal stability. Moreover, a great deal of aromatic constituents occur on its surface, favoring the substitution reaction of sulfonic group. Results showed that the total acid and -SO3H amount was 4.36 mmol/g and 2.18 mmol/g, respectively. Moreover, the yield of total reducing sugar (TRS) and conversion ratio (Cr) for pretreated cellulose (DP = 101.5) can reach 66.7% and 68.8% at 140 °C for 240 min in distilled water, respectively. After four recycles, the TRS and Cr decreased by 12.6% and 10.2%, respectively. Through the secondary and third regeneration for the catalyst, acid density still reached 88.1% and 87.2% of the initial R1-MCMB-SO3H, demonstrating excellent regeneration ability and recyclability of the solid acid. Therefore, MCMB-based solid acid exhibits an attractive potential in the conversion of cellulose into platform chemical compounds.

Subcritical carbon dioxide-water hydrolysis of sugarcane bagasse pith for reducing sugars production.

The aim of present study was to obtain total reducing sugars (TRS) by hydrolysis in subcritical CO2-water from sugarcane bagasse pith (SCBP), the fibrous residue remaining after papermaking from sugarcane bagasse. The optimum hydrolysis conditions were evaluated by L16(45) orthogonal experiments. The TRS yield achieved 45.8% at the optimal conditions: 200°C, 40min, 500rmin-1, CO2 initial pressure of 1MPa and liquid-to-solid ratio of 50:1. Fourier transform infrared spectrometry and two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance were used to characterize hydrolysis liquor, treated and untreated SCBP, resulting in the removal of hemicelluloses to mainly produce xylose, glucose and arabinose during hydrolysis. The severity factors had no correlation to TRS yield, indicating that the simple kinetic processes of biomass solubilisation cannot perfectly describe the SCBP hydrolysis. The first-order kinetic model based on consecutive reaction was used to obtain rate constants, activation energies and pre-exponential factors.