Impact of cold atmospheric plasma pretreatment on the recovery of phenolic antioxidants from spent coffee grounds

In the present study, cold atmospheric plasma (CAP) was employed as a pretreatment method for the extraction of phenolic compounds from spent coffee grounds (SCGs). The impact of CAP treatment conditions, i.e., thickness of the SCGs layer (mm), distance between the plasma source and the SCGs layer (mm) and duration of CAP treatment (min), on the total phenol content, in vitro antioxidant activity, as well as caffeine and chlorogenic acid content of SCGs, was investigated. The process parameters were optimized with the aid of response surface methodology (RSM). After optimizing the CAP pretreatment conditions, the CAP-treated SCGs were subjected to ultrasound-assisted extraction using ethanol as the extraction solvent. The optimum conditions for CAP treatment identified, i.e., thickness, 1 mm; distance, 16 mm; and duration, 15 min, led to a significant enhancement in the recovery of bioactive compounds from SCGs compared to those obtained from untreated SCGs. Total phenolic content and antioxidant activity significantly increased (i.e., TPC from 19.0 ± 0.7 to 24.9 ± 1.4 mg GAE/100 g dry SCGs, ADPPH from 106.7 ± 5.01 to 112.3 ± 4.3 μmol Trolox/100 g dry SCGs, AABTS from 106.7 ± 5.01 to 197.6 ± 5.8 μmol Trolox/100 g dry SCGs, ACUPRAC from 17938 ± 157 to 18299 ± 615 μmol Trolox/100 g dry SCGs). A significant increase in caffeine content from 799.1 ± 65.1 mg to 1064 ± 25 mg/100 g dry SCGs and chlorogenic acid content from 79.7 ± 15.3 mg to 111.3 ± 3.3 mg/100 g dry SCGs, was also observed. Overall, CAP pre-treatment can be used to enhance the recovery of bioactive compounds from SCGs

Coupling of cold atmospheric plasma treatment with ultrasound-assisted extraction for enhanced recovery of bioactive compounds from cornelian cherry pomace

Cornelian cherry pomace is produced during the production of juice from this traditional superfood. Due to its high nutritive value, the by-product can be utilized as a source of bioactive compounds. The present study aimed to develop a sustainable methodology for the recovery of bioactive compounds based on the combination of atmospheric cold plasma (CAP) with ultrasound assisted extraction. The pomace was treated with cold plasma under different conditions. Cyclodextrin was used as green extraction enhancer due to its capacity to develop inclusion complexes with bioactive compounds. CAP pretreatment before extraction appeared to enhance the recovery of the target compounds. GC–MS analysis and in vitro digestion analysis conducted in order to evaluate the composition and the protentional bioavailability of the bioactive compounds

Preparation and characterization of chitosan-citric acid edible films loaded with Cornelian cherry pomace extract as active packaging materials

The development of environmentally-friendly, intelligent and active packaging materials is crucial for the protection of food products and the prevention of environmental pollution. This work aimed to study the development of chitosan films containing an extract form Cornelian cherry pomace extract, a by-product of juice production. Citirc acid was utilized as an alternative acidifier and the effect of β-cyclodextrin incorporation on film properties was evaluated. Compared to chitosan-acetic acid films, the films produced in the present study were found to be more elastic, with a lower moisture content and higher water solubility as well as water vapor permeability. Moreover, the obtained results showed that the increase of β-cyclodextrin concentration from 0.45 to 1.85 % w/v improved the mechanical and water vapor barrier properties of the film. Addition of the Cornelian cherry pomace extracts resulted in alteration of the color of the prepared films as well as improvement of the light barrier properties. Also, the presence of the phenolic compounds in the film matrix enhanced the antioxidant activity of the prepared films

Green extraction of caffeine from coffee pulp using a deep eutectic solvent (DES)

The objective of this work was the development of a green extraction method based on the use of a deep eutectic solvent (DES) to extract caffeine from coffee pulp (CP). Choline chloride and glycerol were used as hydrogen bond acceptor and hydrogen bond donor, respectively. ATR-FTIR and viscosity measurements were conducted for the characterization of DES mixtures. The effects of DES mixtures concentration (CDES), liquid-to-solid ratio (L/S), extraction temperature (T) on caffeine extraction yield (CCaf) and extract antiradical activity (AAR) were studied, and the extraction process was optimized. The optimum of extraction was achieved at a temperature of 55 °C, a solvent/pulp ratio of 47 mL/g, and a DES concentration of 70% w/v in aqueous solution. In addition, a mathematical model to describe the kinetic mechanisms of the extraction was developed, whereas the dependence of the best descriptive model constants on extraction variables was expressed by an appropriate model. These results would offer scientific reference for promoting the valorization of coffee pulp

Green Extracts from Coffee Pulp and Their Application in the Development of Innovative Brews

Coffee pulp, a by-product of coffee production, contains valuable compounds such as caffeine and chlorogenic acid with high antiradical activity. In this study, aqueous solutions of β-cyclodextrin (β-CD) were used as a non-conventional solvent for the extraction of targeted compounds from coffee pulp. The parameters of β-CD concentration (Cβcd), liquid-to-solid ratio (L/S), and temperature (T) were evaluated based on the antiradical activity (AAR) and the caffeine content (CCaf). The optimum operational conditions were found to be Cβcd: 9.25 mg/mL, L/S: 30 mL/g and T: 80 °C. The sensory profiles of brews prepared with coffee and coffee pulp with or without cyclodextrin were studied with quantitative descriptive analysis. The brew from the by-product had fruity, botanic, sweet and sourness sensory properties, and cyclodextrin was found to be able to affect the overall taste of the brew