Healthy cookies from exhausted coffee

The coffee industry in the last two years alone has produced more than 10 million tons of roasted coffee, much of which is transformed into a by-product that with its approximately 6 million tons creates a lot of environmental pressure generally directed to the production of livestock feed, processing into bio-absorbents, use as biofuel or composting material.

In a study recently published in Foods, the many potentially health-promoting ingredients still present in spent coffee were identified and quantified by high-resolution tandem mass spectrometry.

 

The work is the result of the international working network consisting of Professor Michela Grosso of the Department of Molecular Medicine and Medical Biotechnology, Professor Alberto Ritieni of the Department of Pharmacy, Dr. Mario Rubino and is part of the international doctoral program in Nutraceuticals, Functional Foods and Human Health involving Drs. Castaldo, Izzo, Lombardi, Gaspari and Narvaèz, the latter from the University of Valencia.

 

The ingredients identified include molecules of great interest such as the family of chlorogenic and phenolic acids, in addition to melanoidins found up to 7.8 g per kilogram. Among the chlorogenic acids, it is 5-caffeylquinic acid, present up to 1.2 g per kilo, that accounts for 84 percent of the total chlorogenic acids; in addition, 1.2 grams per kilo of a pharmacologically interesting molecule such as caffeine is still found in the spent coffee.

 

The project planned to use this by-product of the coffee industry as an ingredient in the formulation of innovative fortified cookies, where 5 g of flour present in the dough is replaced with spent coffee, to which butter, sugar and water are added and then baked in an oven at 205°C for 10 minutes.

The fortified cookies thus obtained were then subjected to a simulated in vitro digestion process to evaluate the bioaccessibility of phenolic acids and various chlorogenic acids released during the various digestive steps. In parallel,antioxidant activity was investigated through three different biochemical methodologies. The results obtained from the fortified cookies were compared with samples of control cookies. The data show that especially at the level of the colon, the bioaccessibility of the various molecules identified in the spent coffee and the antioxidant activity are much more interesting than the control cookies not fortified with spent coffee.

Even very recent studies continue to support a proactive role of chlorogenic acids in the modulation of lipid and glucose metabolism; moreover, they are included in therapeutic protocols for the control of diabetes, cardiovascular disease, or hepatic steatosis as cotherapeutics. Toxicological evaluation of this ingredient has shown the absence of acrylamide, ochratoxin A, and hydroxymethylfurfural, making it absolutely candidate and usable as a food ingredient.

This study as a whole fits into the logic of the circular economy, which aims to reduce waste and environmental impact, reuse by-products from agribusiness supply chains, and provide functional ingredients for the nutraceutical, pharmaceutical, and food industries.