The assesement of bioactive potential and sensory acceptability of coffee and its byproducts- cascara and silverskin

Abstract

Through the decades, coffee has been representing one of the most consumed beverages worldwide and consequently, during the coffee cherry processing, significant amount of coffee byproducts is generating, thus ending as an agro- industrial waste. Besides macro and micronutrient content, coffee cascara and coffee silverskin are coffee by-products which can have valuable bioactive potential. For that purpose, ethanol extracts and water infusions (beverages) of green coffee, roasted coffee, coffee cascara and coffee silverskin were analysed for total phenolic content, antioxidant capacity and individual identification of polyphenolic compounds by High Performance Liquid Chromatography Analysis paired with Photo-Diode Array detector (HPLC- PDA), with further sensory analysis of beverages. Results showed that beverages were generally evaluated with the higher bioactive potential than ethanol extracts, while roasted coffee beverages exhibited the highest content of TPC and antioxidant capacity in comparison to the ethanol extract. Among all samples, green coffee beverage was evaluated as the most valuable source of 5-caffeoylquinic acid (36.7 mg/g dw), while coffee cascara (9.2 mg/g dw) contained the highest content of caffeine. Although roasted beverage expectedly scored as the highest acceptable (6.2), silverskin and cascara were evaluated with relatively satisfactory results of the overall acceptability (4.6- 5.2), thus showing the potential for the improvement in terms of preparation and, furthermore, greater consumer acceptance.

Quality Attributes and Sensory Acceptance of Different Botanical Coffee Co-Products

“…Furthermore, we observed the absence of 3,5-dicaffeoylquinic acid in samples 1S, 2S, and 1C and the absence of 4,5-dicaffeoylquinic acid in samples 1S and 2C. Mandura et al (2021) [6] also reported similar phenomena. Moreover, the same authors found that the caffeine content of cascara reached 9.20 ± 0.50 mg•g −1 and silverskin 5.30 ± 0.2 mg•g −1 .…”

“…The main factors affecting the caffeine content of cascara include the fermentation process, botanical origin, variety, post-harvest processing, time, and method of extract preparation [6,46,62]. Comparable results of caffeine content in silverskin reaching 6.50 ± 0.60 mg•g −1 were published by Cantele et al [58].…”

“…Therefore, the coffee processing industry focuses on valorizing co-products created during post-harvest operations that are usually considered food waste [5]. There are two main methods of coffee processing: dry and wet [6]. Wet processing means that after harvesting coffee cherries, the skin and pulp are fermented or enzymatically split to yield the seeds.…”