Food waste recovery for health sustainability. Coffee case

Abstract

Very recently, the term "sustainable health" was coined as "a healthy and active ageing avoiding the risk of diseases". The goal may be accomplished by delivering high quality care and improved public health without exhausting natural resources or causing severe ecological damage. Bioactive compounds with health promoting properties can be obtained by food waste recovery. The present research aimed to validate coffee by-products (husk, parchment and silverskin) as health-promoting food ingredients by recycling the complete by-product avoiding the generation of new wastes. Aqueous extracts from coffee by-products were obtained according to WO2013004873A1. Pesticides, mycotoxins, acrylamide, microorganisms and acute toxicity experiment following OECD Test Guidelines 425 were performed for assessing food safety of extracts, solid residues and raw materials. Chemical characterization of the novel ingredients was carried out by raman and infrared spectroscopy and analysis of total phenolic compounds, chlorogenic acid, caffeine and dietary fiber. Antioxidant properties of the novel ingredients were tested by ABTS and intracellular ROS formation in HepG2. Aqueous extracts from coffee by-products showed high phenolic content (15.58 - 68.21 mg chlorogenic acid (CGA) eq./g) and antioxidant capacity (80.6 - 202.16 mg CGA eq./g). Robusta silverskin extract presented the highest content of CGA (21.3 mg/g) and parchment extract the highest values for caffeine (58.18 mg/g). The extracts were not cytotoxic at the concentrations tested (0.1 - 1 mg/ml) and reduced physiological reactive oxygen species in HepG2 cells. Insoluble fractions contained high values of total dietary fiber (husk, 71.9 %; parchment, 91.56 %; Arabica and Robusta silverskin, 67.69 % and 69.33 %). No lesions were found on examination of selected isolated vital organs from testing animals. In conclusion, husk and silverskin are proposed as sources of two food ingredients: aqueous extracts enriched in phytochemicals and antioxidant dietary fiber; while parchment as a single source of antioxidant dietary fiber. Coffee by-products can be converted into health-promoting food ingredients for a sustainable health allowing a whole food waste recovery.