Effects of Pretreatment and Drying on the Volatile Compounds of Sliced Solar-Dried Ginger (Zingiber officinale Roscoe) Rhizome

Ginger (Zingiber officinale Roscoe) rhizomes are mostly used as spice and medicine due to their high aroma intensity and medicinal bioactive compounds. However, the volatile compounds of ginger, partly responsible for its aroma and medicinal properties, can be affected by the pretreatment, drying method, and extraction processes employed. The objective of this study was to assess the effects of pretreatment and drying on the volatile compounds of yellow ginger variety at nine months of maturation. The effect of potassium metabisulfite (KMBS) and blanching pretreatment and drying on the volatile compounds of ginger using head space solid-phase microextraction with GCMS/MS identification (HS-SPME/GCMS/MS) was investigated. KMBS of concentrations 0.0 (control), 0.1, 0.15, 0.2, and 1.0% and blanching at 50°C and 100°C were used for pretreatment and dried in a tent-like concrete solar (CSD) dryer and open-sun drying (OSD). The different concentrations of KMBS-treated fresh ginger rhizomes did not result in any particular pattern for volatile compound composition identification. However, the top five compounds were mostly sesquiterpenes. The 0.15% KMBS-treated CSD emerged as the best pretreatment for retaining α-zingiberene, β-cubebene, α-farnesene, and geranial. The presence of β-cedrene, β-carene, and dihydro-α-curcumene makes this study unique. The 0.15% KMBS pretreatment and CSD drying can be adopted as an affordable alternative to preserve ginger.

Plant Biomass Used for Green Concrete: A Review of Treatment Methods

Human activities require a growing need for raw materials. In order to contribute to sustainable development, many business sectors are focusing on biomass valorization. Whether from dedicated crops or first industrial processing, it generates materials with high potential that can be used in many fields. Non-food uses mainly concern the energy, chemical, and construction sectors. Whatever the intended application, a pre-treatment stage is essential to clean the material and/or to access a specific fraction. An additional modification may occur in order to endow the material with a new function thanks to a process known as functionalization. Uses of plant fractions (aggregates) in combination with cement offer advantages like low-density materials with attractive thermophysical properties for building. However, their development is limited by the compatibility of crop by-products with hydraulic binders such as Ordinary Portland Cement (OPC). This includes delays in setting time and hydrophilic character of vegetal components and their interaction with an alkaline environment. The aggregate/cement interfaces can therefore be strongly affected. In addition, the diversity of crop by-products and mineral binders increases the level of complexity. In order to overcome these drawbacks, the treatment of plant fractions before their use with mineral binders may result in significant benefits. In this way, various treatments have been tested, but the methods used at an industrial scale remain relatively under-researched. The purpose of this review is therefore to highlight the mechanisms involved in each specific process, thus justifying the operating conditions specific to each. This bibliography study aims to highlight potential treatments that could apply to biomass before their mixing with cementitious binders. According to the objective, a distinction can be made between extraction processes as hydrothermal or solvent treatments, assisted or not, and structural modification processes as surface treatments, impregnation, or grafting.

Pomelo (Citrus grandis L.) Essential Oil Extraction: A Comparison between Hydrodistillation and Microwave Assisted Hydrodistillation

Hydrodistillation (HD) is a traditional technique used in most extraction processes. On the other hand, microwave-assisted hydrogen distillation (MAHD), an advanced method using microwaves in the extraction process, has recently emerged. The chemical ingredients of essential oils obtained from pomelo (Citrus grandis L.) peels obtained by MAHD and by hydrodistillation (HD) were analyzed and compared gas chromatography-mass spectrometry (GC/MS). The results show that there is no significant difference between the two methods in terms of extraction efficiency, at around 4.45 to 4.7%. The main components of essential oils were Limonene, α-pinene, β-Myrcene and Sabinene. The content of those compounds showed no clear quantitative and qualitative difference between HD and MAHD. Experimental results show that the MAHD method provides a good alternative to extracting essential oils from grapefruit, saving time, operating costs and achieving more optimal levels. Keywords: Comparison, Pomelo (Citrus grandis L.), Essential oil, Hydrodistillation, Microwave assist hydrodistillation,

Polyphenol, Flavonoid Content and Antioxidant Activity of the Garlic (Allium sativum L.) Extract Obtained by Two Different Extraction Processes

Garlic is a globally used spice due to its pungent taste and a fishy deodorant and digestive stimulator. Owing to the widespread use of garlic in both Oriental and Western medicine, further investigations on garlic extracts might carry important implications in the industry. In this study, we conducted extraction of garlic extraction by two conventional methods and an ultrasonic assisted method. The processes were optimized with respect to various quality parameters including polyphenol, flavonoid content, and antioxidant activity. The results showed that extracting garlic under the ultrasonic support will show higher efficiency than the non-ultrasonic extraction. The optimal extraction parameters are: 70% ethanol solvent, 10/1 solvent / material ratio, 40 °C temperature and 40 minutes time. Keywords: Allium Sativum L., Garic, Polyphenol, Flavonoid, Antioxidant

The possibility of using DES based on polypropylene glycol 425 and tetrabuthylammonium bromide in the extraction processes of transition metals

Traditionally, the method of liquid extraction is used to extract metals from aqueous. This work is devoted to the combination of perspective alternative for hazardous solvents (aqueous two-phase systems based on water-soluble polymers) and the novel deep eutectic solvents in the non-ferrous metals extraction processes. In this work, the synthesis of deep eutectic solvent based on a water-soluble polymer (PPG-425) and tetrabutylammonium bromide (TBAB) by stirring for 10 minutes at 80° C has been shown. The obtained results showed not only the possibility of using DES in the metal extraction process, but the selectivity to the Fe(III) and Zn(III), the distribution coefficients were 71.64 and 25.17 respectively. The metal concentrations were determined spectrophotometrically using 4-(2-pyridylazo)resorcinol. This work shows the perspectives of using DESs in the metal extraction processes.

Implementation of the extraction method for the separation of Fe3+ and Ni2+ ions on cascade of mixing-settling extractors

Extraction processes are one of the most efficient methods of purification and separation of compounds. However, laboratory-developed methods commonly are not a complete technique that can be applied to the real manufacturing process with its extraction equipment. The extraction method for the separation of Fe3+ and Ni2+ ions using hydrochloric acid solution on a cascade of mixing-settling extractors has been determined. The extraction scheme chosen provides high efficiency of a cascade by using liquid pseudomembranes (LPM). Besides its extraction scheme simplicity, the LPM method is more economically beneficial compared to classical extraction methods. The process includes stages of Fe3+ ions extraction into the feed, followed by reextraction into the water and the feed purification for reusing it later on. The consumption of solvents and the stirring speed for the stable and efficient cascade work have been optimized. The described process is a complete technological solution for recycling processed battery waste.