Effect of Sodium Carbonate on Extraction by Aqueous Decoction of Total Polyphenols from Crushed and Whole Leaves of Combretum micranthum

Sodium bicarbonate is sometimes used to aid in the extraction of total polyphenols. Its main effect is to increase the pH of the extraction solution. Raising the pH can cause changes in the chemical structure of polyphenols. This can lead to variations in their biological properties, solubility and stability. This work studied the effect of sodium carbonate on the extraction by aqueous decoction of total polyphenols from the leaves of Combretum micranthum. The content of total phenolic compounds in the extracts was estimated by the Folin-Ciocalteu method. The color of the samples was measured using a colorimeter (type: KONICA MINOLTA. Japan) based on the CIELAB color system. The results obtained were subjected to a one-way ANOVA analysis of variance with R software version 3.2.4 Revised (2018) and Minitab-18 software. The results reveal a drop in the concentration of extracted polyphenols proportional to the addition of sodium carbonate, i.e. a drop from 3.30 to 1.04 mg·AG·100 g-1 of extract on whole leaves and 3.921 to 2.551 mg·AG·100 g-1 extract on crushed leaves. On the other hand, the intensity of the coloring of the extracts increases significantly with the addition of sodium carbonate from 0.0 g·L -1 to 0.666 g·L-1.

A new household ultrasonic cleaning method for pyrethroids in cabbage

Pyrethroid is widely used in developing countries and is a potential threat to human health.So putting forward an effective pyrethroid cleaning method is of vital importance.Clearance of fenpropathrin,cypermethrin and deltamethrin in cabbage by using ultrasonic treatment accompanied with different baking soda concentrations were investigated in this study.The results of response surface methodology showed that the maximum clearance rate was 70.61% for fenpropathrin under the optimal power,treated time,treated temperature and baking soda concentration,which were 260.02 W,10 min,20.15◦C and 0.014 g/mL,respectively.Similarly,the maximum removal efficiency was 73.72% for cypermethrin under 240 W,13.84 min,19.53℃ and 0.014 g/mL,and 92.15%for deltamethrin under 238.99 W,12.42 min,25℃ and 0.013 g/mL.The clearance rate of pyrethroid by this method was significant higher(P<0.05)than traditional cleaning methods(bathing and running water washing).The contents of the compositions such as vitamin C,total soluble sugar,protein and dietary fiber,texture and sensory evaluation of cabbage were not found obvious changes after the ultrasonic treatment combined with baking soda(P>0.05).Results showed that ultrasonic treatment combined with baking soda was an effective way to eliminate the fenpropathrin,cypermethrin and deltamethrin in cabbage without influencing cabbage quality.