Extraction Of Value-added Compounds Research Articles

Grape Pomace as a Renewable Natural Biosource of Value-Added Compounds with Potential Food Industrial Applications

Growing consumer demand for environmentally conscious, sustainable, and helpful products has prompted scientists and industry experts worldwide to look for inventive approaches to mitigate the environmental impact, particularly concerning agricultural and industrial waste. Among the by-products of winemaking, grape pomace (skins, seeds, stems) has the potential to be economically valuable as it is rich in value-added compounds (e.g., phenolic compounds, fibers, flavonoids, anthocyanins, terpenoids) related to health (e.g., antioxidant, antimicrobial, anti-inflammatory, cardioprotective effects) and technological issues (e.g., extraction of value-added compounds). These value-added compounds can be extracted using emerging green extraction techniques and then used in the food industry as preservatives, colorants, and for the formulation of functional foods, as well as in the development of smart food packaging. This review provides an overview of the value-added compounds identified in grape pomace, the emerging green extraction, and integrated approaches to extract value-added compounds based on the literature published in the last five years. The potential applications of these value-added compounds have been extensively researched for the food industry.

Valorization of Date Fruit (Phoenix dactylifera L.) Processing Waste and By-Products: A Review

The date is a well-established and important crop that holds economic significance. However, a substantial amount of waste in the form of low-grade dates and date pits is generated and accounts for 10 to 15% of the total production. Given the substantial amount of nutrients in these by-products and the large volume of waste generated, there is a promising opportunity to utilize them to create valuable commodities like fiber and phenolic compounds, which hold a high market value. This review presents a summary of the chemical and nutritional composition of dates and their by-products and aims to investigate the possibility of utilizing date processing by-products and waste as an eco-friendly resource for various chemical and biological processes like composting and extraction of value-added compounds, as well as providing insight into the date processing industry and typical methods employed for the beneficial use of date waste. In addition, this review also addresses the current challenges and future perspectives in date waste valorization expectations.

Anaerobic Biodegradation of Biodiesel Industry Wastewater in Mesophilic and Thermophilic Fluidized Bed Reactors: Enhancing Treatment and Methane Recovery.

In the past few years, the extraction of value-added compounds from the anaerobic digestion of glycerol has been an option to add value to this waste because biodiesel production is increasing worldwide. The evolution of research on glycerol valorization by anaerobic digestion has reached the use of high-rate reactors. However, no study has evaluated glycerol digestion in an anaerobic fluidized bed reactor (AFBR), a configuration with potential advantages in methane production. Still, the best operating temperature for high-rate glycerol digestion remains unclear. To clarify these gaps, the present study aimed to compare glycerol digestion in mesophilic AFBR (30 °C) and thermophilic AFBR (55 °C). In both reactors, glycerol concentration was increased from 1.0 to 7.0 g L-1 at a fixed hydraulic retention time of 24 h, resulting in an increase at the organic loading rate from 1.2 to 7.6 kg COD m-3 day-1. Thermophilic digestion of glycerol achieved superior removals of organic matter (67.7-94.2%) and methane yield (330.8 mL CH4 g-1 COD) than the mesophilic digestion (48.6-93.0% and 266.6 mL CH4 g-1 COD). Additionally, the application of the kinetic model of substrate utilization (modified Stover-Kincannon model) indicated a higher substrate utilization coefficient in the thermophilic AFBR (23.09 g L-1 day-1) than the mesophilic AFBR (7.14 g L-1 day-1). Therefore, the application of glycerol concentrations higher than 7.0 g L-1 in thermophilic AFBR should be further investigated. Also, given only operational results, the application of the AFBR in the two-stage anaerobic digestion of glycerol is recommended.

Hydrothermal carbonization of centrifuged sewage sludge: Determination of resource recovery from liquid fraction and thermal behaviour of hydrochar

Safe disposal of the sludge generated from sewage treatment plant is a major challenge worldwide. Hydrothermal carbonization (HTC) is considered a potential pretreatment alternative for sewage sludge to facilitate the improved resource recovery. In the present study, the mixed centrifuged sewage sludge (CSS) was subjected to the HTC pretreatment to determine characteristics of the solid hydrochar (HC) and liquid fraction (LF) with a purpose of energy recovery and extraction of value-added compounds, respectively. HTC was performed in a high pressure batch reactor at 200 °C temperature for 1–8 h duration. The HC produced after HTC resembled with the low quality peat coal whereas the LF contained value-added chemicals such as humic acid (HA) and phosphate phosphorous (PO43—P). Using ammonium sulphate as ‘salting out’ agent, ~70% of the total HA (~15–16 g/L) could be recovered from the LF. Using the recovered HA, an improvement in the root and shoot lengths of the seeds could be observed. In the subsequent step, the total PO43−-P recovery of ~80% was obtained as struvite from the residual wastewater.

Extraction of Value-Added Compounds from Wastewater Sludge

Extraction of Value-Added Compounds from Wastewater Sludge