No abstract

An optimal condition for extraction of soluble sugars from green coffee using water and a validated chromatographic method for its separation and quantification were proposed in this research. An orbital incubator shaker (OIS) and microwave-assisted extraction (MAE) were the 2 techniques used to extract soluble sugars. In such experiments, the variables: sample amount (300, 400, and 500 mg), time (30, 60, and 90 min), and temperature (30, 45, and 60 °C) were tested. The separation of sugars was performed in a chromatographic system (high-performance liquid chromatography refractive index detector [HPLC-RID]), which presented the selectivity for the analytes, a limit of detection of 0.020 g/L, a limit of quantification of 0.0625 g/L, and recovery rates greater than 95%. The repeatability and inter-day precision had low dispersion, RSD < 2.0% and < 3.0%, respectively. Sucrose content ranged from 0.65 to 2.39 g/L using an OIS and from 1.19 to 2.72 g/L by MAE, while glucose and fructose concentration varied from 0.08 to 0.12 g/L using both methods. The OIS technique is preferably indicated for extraction of soluble sugars at the following conditions: 500 mg of grounded green coffee, 90 min, and 60 °C. The proposed method for soluble sugar extraction and quantification may be applied in research laboratories and food industries since it is a low-cost and environment-friendly technique.

Background and Aims Crop rotation systems and rhizobial inoculation are strategies to increase yield through organic matter addition and modulation of microbial diversity, yet the extent to which these agricultural practices change soil Bradyrhizobium populations, soybean grain yield and economic benefits to farmers are unclear. Thus, this study aimed to evaluate the interaction between crop rotation and inoculation of soybean (Glycine max) cultivated in two contrasting soils (clayey and sandy soil) on biological nitrogen fixation (BNF) components, grain yields and profits. Methods Field experiments with a three-year crop rotation system were carried out to compare effects of inoculation soil chemical attributes, the of bradyrhizobia most probable number (MPN) and diversity, soybean nodulation, grain yield and economic value. Results The crop management system did not affect the soil MPN of bradyrhizobia, which was altered by the soil sampling time, with higher values during the postharvest period for the summer crops. In clayey soil, soybean nodulation was influenced by crop rotation. The grain yield of inoculated soybean in clayey soil was higher than that in sandy soil. Conclusion The soybean response to inoculation is influenced by cropping history. Crop rotation and inoculation of soybean is a strategy for improving BNF components, grain yields and profits. Over time, diversified production systems with crop rotation and inoculation with nitrogen-fixing bacteria will make great contributions to environmental and economic sustainability.

No abstract