Azotobacter is a type of bacterium nonpathogenic, Gram-negative with ability to synthesize simultaneously under aerobic conditions two biodegradable polymers extra and intracellular such as alginate and polyhydroxyalkanoates, respectively, whose physical, mechanical, and biodegradable properties have awoken the interest in the industry. Thus, this review compiles information on synthesis chemistry of these polymers and the genetic modification of this bacterium in order to produce a particular polymer and improve its yields. Additionally, we show that alginates obtained present a higher molecular weight, degree of acetylation and M/G ratio compared with other organic sources like seaweed; while polyhydroxyalkanoate polymers have better physical and mechanical characteristics (melting temperature, Young's modulus, elongation and glass transition temperature) compared with other synthetic ...

Grape pomace is an agroindustrial residue with significant concentrations of polyphenols and reducing sugars, which limit its use in developing nutraceuticals. Therefore, the objective was to evaluate the effect of solvent composition (ethanol: 20–60%) and temperature (100–160°C) on polyphenols and sugar content recovery from grape pomace using a subcritical extraction process. To this end, the sample was conditioned within a pressurized liquid extraction system. Optimal extraction conditions (temperature and ethanol) were then established using a central composite design to maximize polyphenol content with minimal reducing sugars (glucose). Increased ethanol concentration (20–60%) and high temperatures improve polyphenol recovery, while the presence of ethanol reduces the extraction of reducing sugars. Conversely, temperature increases increase the presence of undesirable compoun...

Olive leaves are residues from pruning and harvesting and are considered an environmental management problems. Interestingly, these residues contain high polyphenol concentrations, which can be used to treat chronic diseases. However, these compounds are a technological challenge due to their thermolability and reactivity during extraction. Thus, this study assessed the use of pressurized liquid extraction (PLE) with green solvents like water-ethanol and water-glycerol mixtures (0–15%) at 50 °C and 70 °C to yield polyphenol-rich antioxidant extracts with reduced glucose and fructose content. The use of 30% ethanol at 70°C presented the highest polyphenol content (15.29 mg gallic acid equivalent/g dry weight) and antioxidant capacity, which was expressed as IC50 (half maximal inhibitory concentration): 5.49 mg/mL and oxygen radical absorbance capacity (ORAC): 1259 μmol Trolox equiva...

Olive leaves are residues from pruning and harvesting and are considered an environmental management problems. Interestingly, these residues contain high polyphenol concentrations, which can be used to treat chronic diseases. However, these compounds are a technological challenge due to their thermolability and reactivity during extraction. Thus, this study assessed the use of pressurized liquid extraction (PLE) with green solvents like water-ethanol and water-glycerol mixtures (0–15%) at 50 °C and 70 °C to yield polyphenol-rich antioxidant extracts with reduced glucose and fructose content. The use of 30% ethanol at 70°C presented the highest polyphenol content (15.29 mg gallic acid equivalent/g dry weight) and antioxidant capacity, which was expressed as IC50 (half maximal inhibitory concentration): 5.49 mg/mL and oxygen radical absorbance capacity (ORAC): 1259 μmol Trolox equiva...