Sandrine Périno-Issartier

A comparison of essential oils obtained from lavandin via different extraction processes: Ultrasound, microwave, turbohydrodistillation, steam and hydrodistillation

A total of eight extraction techniques ranging from conventional methods (hydrodistillation (HD), steam distillation (SD), turbohydrodistillation (THD)), through innovative techniques (ultrasound assisted extraction (US-SD) and finishing with microwave assisted extraction techniques such as In situ microwave-generated hydrodistillation (ISMH), microwave steam distillation (MSD), microwave hydrodiffusion and gravity (MHG), and microwave steam diffusion (MSDf)) were used to extract essential oil from lavandin flowers and their results were compared. Extraction time, yield, essential oil composition and sensorial analysis were considered as the principal terms of comparison. The essential oils extracted using the more innovative processes were quantitatively (yield) and qualitatively (aromatic profile) similar to those obtained from the conventional techniques. The method which gave the best results was the microwave hydrodiffusion and gravity (MHG) method which gave reduced extraction time (30min against 220min for SD) and gave no differences in essential oil yield and sensorial perception.

Batch and Continuous Ultrasound Assisted Extraction of Boldo Leaves (Peumus boldus Mol.)

Vegetal extracts are widely used as primary ingredients for various products from creams to perfumes in the pharmaceutical, nutraceutic and cosmetic industries. Having concentrated and active extract is essential, as the process must extract as much soluble material as possible in a minimum time, using the least possible volume of solvent. The boldo leaves extract is of great interest for the industry as it holds a great anti-oxidant activity due to high levels of flavonoids and alkaloids such as boldine. Ultrasound Assisted Extraction (UAE) has been used to improve the efficiency of the plant extraction, reducing extraction time, increasing the concentration of the extract with the same amount of solvent and plant material. After a preliminary study, a response surface method has been used to optimize the extraction of soluble material from the plant. The results provided by the statistical analysis revealed that the optimized conditions were: sonication power 23 W/cm2 for 40 min and a temperature of 36 °C. The optimized parameters of the UAE provide a better extraction compared to a conventional maceration in terms of process time (30 min instead of 120 min), higher yield, more energy saving, cleanliness, safety and product quality.

An innovative grape juice enriched in polyphenols by microwave-assisted extraction

The grape juice by-product obtained from grape traditional press was extracted by Microwave Hydrodiffusion and Gravity (MHG); a green extraction technique preliminarily optimized at 1 W/g. The MHG extract (MHGE) was analyzed by HPLC for identification and quantification of anthocyanins and other phenolic compounds. Then, MHGE was added to the natural juice (NJ) to produce an innovative grape juice (IJ). These three juices were evaluated for their total polyphenol content (TPC), total anthocyanin content (TAC) in addition to their sensorial characteristics. MHGE showed the highest values of TPC (21.41±0.04 mg GAE/g DW), TAC (4.49±0.01 μg MVGE/g DW). Moreover, IJ (grape juice enriched with MHGE) was richer in TPC (6.70±0.0 1mg GAE/g DW) and TAC (3.96±0.01 μg MVGE/g DW) than NJ (2.90±0.02 mg GAE/g DW and 3.63±0.06 μg MVGE/g DW, respectively).

Extraction by steam distillation of Artemisia herba-alba essential oil from Algeria: kinetic study and optimization of the operating conditions.

Abstract In order to study the extraction process of essential oil from Artemisia herba-alba, kinetic studies as well as an optimization of the operating conditions were achieved. The optimization was carried out by a parametric study and experiments planning method. Three operational parameters were chosen: Artemisia mass to be treated, steam flow rate and extraction time. The optimal extraction conditions obtained by the parametric study correspond to: a mass of 30 g, a steam flow rate of 1.65 mL.min−1 and the extraction time of 60 min. The results reveal that the combined effects of two parameters, the steam water flow rate and the extraction time, are the most significant. The yield is also affected by the interaction of the three parameters. The essential oil obtained with optimal conditions was analyzed by GC-MS and a kinetic study was realised.

Chapter 11:Microwave Food Processing

Consumers prefer food products with enlarged shelf life, which are quick to prepare, healthy and fresh like. Traditional food processing methods are based on intensive heating and as a result cause quality loss. Minimal processing techniques such as microwaves approach consumers demands to create fresh like products with enlarged shelf life. Microwave technology can be very useful for food processing, because products are heated directly instead of conventional heating by convection and conduction. This means a reduction of the total processing time, no overheating on the outside of the product, and preservation of the fresh product quality. This chapter presents a complete picture of current knowledge on application of microwave in food processing which has been used for different processes like blanching, sterilisation, thawing, drying and extraction of various products. In many cases combinations with microwaves gave the best results.