Toxicological Assessment of Roasted Coffee Silver Skin (Testa of Coffea sp.) as Novel Food Ingredient

Abstract

Roasted coffee silver skin is a coffee by-product, the uses of which are currently limited, e.g., as fertilizer, for energy production, or animal feed. Due to a low content of fat and carbohydrates combined with a high content of fiber, polyphenols and proteins, roasted silver skin is a valuable possible food ingredient. Potential applications include partial flour replacement in bakery products, as antioxidant and providing protein or fiber sources in sports or functional foods. As no relevant consumption of isolated silver skin occurred before 1997 in the European Union (EU), it was classified as a novel food in need of premarketing approval. Novel food applications must meet legal requirements for compositional and toxicological information. This review presents information on silver skin composition and toxicological studies. Several in vitro studies and subchronic in vivo studies are available with negative results, not suggesting a need for further studies on carcinogenic effects, reproduction, or chronic toxicity. All available studies so far concluded that no toxic effects of silver skin were found or are to be expected. For a novel food application in the EU, further in vitro studies on mutagenic potential may be needed to close a formal data gap.

Sustainability Assessment of Coffee Silverskin Waste Management in the Metropolitan City of Naples (Italy): A Life Cycle Perspective

“…However, CS has been classified as a novel food (category: "Foodstuffs from plants or parts of plants") [48] according to Regulation (EU) 2015/2283 on novel foods [49], thus requiring pre-market authorization, released by the European Food Safety Authority (EFSA). Moreover, several contaminants can be found in CS [36], such as ochratoxin A, which was detected at concentrations of up to 34.4 µg/kg, well above the 5 µg/kg limit established by Regulation (EC) No. 1881/2006 [50] for coffee and cereals [36,[51][52][53].…”

“…Moreover, several contaminants can be found in CS [36], such as ochratoxin A, which was detected at concentrations of up to 34.4 µg/kg, well above the 5 µg/kg limit established by Regulation (EC) No. 1881/2006 [50] for coffee and cereals [36,[51][52][53]. In addition, aflatoxins concentrations were found safe only for food not intended for children or for medical purposes [36,54].…”

“…Furthermore, the food industry has shown increasing interest in CS due to its richness in valuable components and properties [3,[34][35][36]. For example, Nolasco et al [37,38] reported that CS is characterized by a low fat content (3.0%) and a high presence of dietary fiber (34.7%) and protein (18.9%), while other authors also highlighted its richness in antioxidants [39,40].…”

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

“…Another study determined the pH value of silverskin aqueous extract as an average value for both Coffea arabica and Coffea canephora at 5.00. A possible explanation for this might be the different origins of the analyzed samples in the given study [36].…”

“…Rodriguez et al [54] reported a similar fiber content in silverskin (56-62%). However, Loorbeer et al [36] reported a much wider range (34.70-68.50%).…”