Potential of commodity chemicals to become bio-based according to maximum yields and petrochemical prices

Carbohydrates are the prevailing biomass components available for bio-based production. The most direct way to convert carbohydrates into commodity chemicals is by one-step conversion at maximum theoretical yield, such as by anaerobic fermentation without side product formation. Considering these hypothetical yields and petrochemical prices in Europe in 2010–2014, a ranking of 58 commodity chemicals was made using a simple model with ethanol as a base case. It was concluded that base chemicals such as lower olefins and benzene-toluene-xylene (BTX) are too cheap and require too much carbohydrate to be produced competitively compared to bioethanol. However, more oxidized products that require multiple conversion steps in petrochemical production, such as adipic acid, acrylic acid, acrylate esters, and 1,4-butanediol, can be produced competitively from carbohydrates if theoretical yields are approached and if processing is efficient. Instead of carbohydrate fermentation, hypothetical photochemical production from CO2 was also considered. Using again a simple model, the same commodity chemicals remained the most attractive ones.BT/Bioprocess EngineeringBT/Design and Engineering Educatio

Comparison of different extraction methods of Pistacia lentiscus var. chia leaves: Yield, antioxidant activity and essential oil chemical composition

In the present study, four different extraction methods were employed to recover extracts from Pistacia lentiscus var. chia (mastic tree) leaves. The methods include conventional Soxhlet extraction (SE), green extraction processes such as microwave assisted (MAE) and ultrasound assisted extraction (UAE), as well as the innovative supercritical fluid extraction (SFE). Extractions were carried out in both fresh and freeze-dried leaves. Traditional hydrodistillation process (HD) was also applied for the recovery of the essential oil from fresh and dried mastic tree leaves. The efficiency and selectivity of processes were determined in terms of extraction yield and antioxidant activity. Antioxidant activity of the extracts was measured using the DPPH assay. The essential oil from HD was analyzed by GC-MS. The initial moisture of the leaves was 49.6±1.31% on wet basis (w.b.), while final moisture after drying was 2.7±0.27% (w.b.). The results showed that the extraction techniques and the drying procedure significantly affected the extractive yield and antioxidant activity of the extracts. Specifically, fresh mastic tree leaves showed better performance in both yield and antioxidant potential. MAE of fresh leaves using water presented the greatest extraction yield (48.11±0.56% on dry basis (d.b.)) followed by UAE (39.39±1.13% d.b.) and SE both using water as solvent (31.99±1.55% d.b.). UAE water extracts exhibited the highest antioxidant activity (IC50=37.13±2.7μg/mL) followed by MAE water extracts (37.18±0.99μg/mL) and UAE ethanol extracts (38.46±1.91μg/mL). SFE had an extraction yield of 22.3%±0.25% (w.b.) for fresh leaves but no antioxidant activity was attributed to the extract. HD's performance was 0.06mL/100g dry plant matter for the fresh leaves and 0.03mL/100g dry plant matter for the dried ones. The presence of Myrcene, Limonene, δ-Germacrene, trans-Caryophyllene, δ-Cadinene and α-Amorphene was confirmed in the essential oils obtained by HD. © 2014 Elsevier GmbH

Evaluation of total antioxidant potential of Pistacia lentiscus var. chia leaves extracts using UHPLC-HRMS

In this study, Pistacia lentiscus var. chia leaves were dehydrated by freeze drying and the initial, final moisture content and the drying kinetics were examined. Soxhlet Extraction (SE), Microwave Assisted (MAE) and Ultrasound Assisted Extraction (UAE) were employed to recover extracts with high antioxidant activity, total phenolic and flavonoid content from fresh and dried leaves. Fresh leaves showed higher yield and antioxidant potential, with MAE extracts exhibiting the greatest extraction yield (48.11 ± 0.56% d.b.), followed by UAE (39.39 ± 1.13% d.b.) and SE (31.99 ± 1.55% d.b.). UAE extracts exhibited the highest antioxidant activity (IC50 = 37.13 ± 2.7 μg/mL), while SE extracts showed the highest total phenolic content (314.88 ± 0.01 mg GAE/g dry extract). UAE extracts of dried leaves exhibited total flavonoid content (106.5 ± 0.02 mg QE/g dry extract). Moreover, UHPLC-ESI-HMRS was performed to the extract with the highest antioxidant activity and confirmed the presence of isomers of galloyl quinic acid, quercetin and kaempferol glucosides, luteolin and neorehmannioside. © 2014 Elsevier Ltd