The development of a combined enzymatic and microbial fermentation as a viable technology for the spent coffee ground full utilization

Coffee protein is reported to have high levels of branched-chain amino acids of value in sports nutrition and malnutrition recovery. However, data demonstrating this unusual amino acid composition are limited. We investigated the extraction and isolation of protein concentrates from coffee bean fractions, viz. green coffee, roasted coffee, spent coffee and silver skin, and determined their amino acid profile, caffeine content and protein nutritional quality, polyphenol content and antioxidant activity. Alkaline extraction/isoelectric precipitation gave lower concentrate yields and protein content than alkaline extraction/ultrafiltration. The protein concentrate from green coffee beans had a higher protein content than those from roasted coffee, spent coffee and silver skin, regardless of extraction method. The isoelectric precipitated green coffee protein concentrate had the highest in vitro protein digestibility and in vitro protein digestibility corrected amino acid score (PDCAAS). Silver skin protein concentrate had a very low digestibility and in vitro PDCAAS. In contrast to a previous finding, the amino acid levels in all coffee concentrates did not demonstrate high levels of branched-chain amino acids. All protein concentrates had very high levels of polyphenols and high antioxidant activity. The study suggested investigating coffee protein’s techno-functional and sensory attributes to demonstrate their potential applications in different food matrices.

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“…Caffeine content of the coffee protein concentrates were analysed in triplicate as per Milić et al and expressed as g/100 g db [ 10 ].…”

Section: Methodsmentioning

confidence: 99%

Extraction, Isolation and Nutritional Quality of Coffee Protein

Bhattarai

Al-Ali

Johnson

2022

Foods

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“…For P. granatum, immediately after harvesting, the peels (exocarp + mesocarp) were separated from the rest of the fruit (endocarp + seeds), frozen (at −80 • C) and lyophilized. Two types of extraction were conducted with the dry materials, namely fermentation and ultrasonic-assisted extraction (UAE), according to the literature protocols [18,36,40,41].…”

Section: Fruit Materials and Extraction Processesmentioning

confidence: 99%

“…In addition, this fermentation has been successfully applied to fruits containing anthocyanins [37,38]. Moreover, the combination of microbial fermentation with enzymatic treatment, in a simultaneous or sequentially way, has been recently applied to improve the content of polyphenols and the bioactivity of final products [39,40]. Due to its novelty and recently large application, the comparison between the efficiency of this extraction method with that of other techniques is of great importance, being barely found in the literature.…”

Section: Introductionmentioning

confidence: 99%

Comparison between Fermentation and Ultrasound-Assisted Extraction: Which Is the Most Efficient Method to Obtain Antioxidant Polyphenols from Sambucus nigra and Punica granatum Fruits?

et al. 2021

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Fruit extracts of Sambucus nigra L. (elderberry) and Punica granatum L. (pomegranate) have several applications in nutraceutical, cosmetics, and pharmaceutical industries thanks to their richness in antioxidant polyphenols, whose composition changes with the extraction method applied. We aimed to compare the efficiency of the fermentation extraction, recently applied by industries, with the ultrasound-assisted extraction–UAE, a well-known and efficient technique, on the yield of antioxidant polyphenols from elderberry fruits and pomegranate fruit-peels. Extracts were obtained by both methods, analyzed by high-performance liquid chromatography (HPLC) and the antioxidant capacities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Hydroxyl Radical Scavenging (HRS) assays. The main compounds detected in elderberry were caffeoyl and quercetin derivatives, present in higher amounts in UAE extracts. In pomegranate, punicalagin were the main constituents, also detected in higher contents in the UAE extracts compared to fermented ones. The UAE was more suitable for extracting anthocyanins from pomegranate. In addition, higher antioxidant capacities were observed in UAE extracts, possibly due to their richness in polyphenols. Therefore, despite the recent wide applicability and the good performance of the fermentation process, the UAE may be considered more efficient for the extraction of polyphenols from S. nigra and P. granatum fruits and may be used to obtain polyphenolic antioxidant extracts to be applied by several industries.

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