Enhancement of anaerobic biodegradability of flower stem wastes with vegetable wastes by co-hydrolysis

The vegetable wastes and flower stems were co-digested to evaluate the anaerobic hydrolysis performance of difficultly biodegradable organic wastes by introducing readily biodegradable organic wastes. The experiments were carried out in batches. When the vegetable wastes were mixed with the flower stems at the dry weight ratio of 1 to 13, the overall hydrolysis rate increased by 8%, 12%, and 2% according to the carbon, nitrogen, and total solid （TS） conversion rate, respectively. While the dry weight ratio was designed as 1 to 3, there was a respective rise of 5%, 15%, and 4% in the conversion rate of carbon, nitrogen, and TS. The enhancement of anaerobic hydrolysis from the mixed vegetable wastes and flower stems can be attributed to the formation of volatile fatty acids （VFA） and nutrient supplement like nitrogen content. The maximum VFA concentration can achieve 1.7 g/L owing to the rapid acidification of vegetable wastes, loosing the structure of lignocellulose materials. The statistic bivariate analysis revealed that the hydrolysis performance was significantly related to the physical and biochemical compositions of the feeding substrate. Especially, the soluble carbon concentration in the liquid was significantly positively correlated to the concentration of nitrogen and hemicellulose, and negatively correlated to the concentration of carbon and lignocellulose in the feeding substrate, suggesting that the regulation and control of feedstock can have an important influence on the anaerobic hydrolysis of organic wastes.

Correlation between 5-hydroxymethylfurfural content and color of Rehmanniae Radix and Rehmanniae Radix Praeparata

In the present study,we explored the correlation between 5-hydroxymethylfurfural(5-HMF)and color of Rehmanniae Radix(RR)and Rehmanniae Radix Praeparata(RRP).The color was observed by human eyes under sunlight.The chromatic value and color difference were detected by a colorimeter.The water content was determined by an oven-drying method.The 5-HMF content was determined by an HPLC method.The correlation between the 5-HMF content and the color was analyzed by bivariate correlation analysis.The results showed that the color was greyish-brown and dark brown for RR,and it was black for RRP.The deepening color of RRP was reflected in the decrease of L^*,a^*and b^*values.The water content was in accord with the requirement of Chinese Pharmacopoeia.The 5-HMF contents of RR and RRP were 0.9711–25.71μg/g and 213.4–4010μg/g,respectively.The average 5-HMF contents of RR and RRP were 8.059μg/g and 1433μg/g,respectively.The 5-HMF content in RRP was higher than that in RR.The correlations between 5-HMF content and L^*,a^*and b^*values were significant.The color of RRP was deeper than that of RR.The 5-HMF content of RRP was higher than 0.02%,while it was less than 0.02%of RR,which could be used as a marker component for judging RR and RRP.