Changes of Antioxidant Capacity of Robusta Coffee during Roasting

Abstract

Abstract:The in vitro radical scavenging capacity of the roasted and ground coffee is generally known as well as the published results of lowering the incidence of various diseases by regular intake of coffee. The antioxidant capacity of coffee is based mainly on the phenols, but during the roasting phenols are degraded and new products with antioxidant capacity are formed. A major contributor to the antioxidant activity was identified as N-methylpyridinium, which is formed during the roasting by degradation of trigonelline, the degradation is about 50% of trigonelline content and the concentration of N-methylpyridinium in roasted coffee is up to 0.25% on a dry weight basis. These literature data were verified within the processing plant experiment, during the usual roasting procedure of Robusta coffee the following parameters were analysed: humidity, water activity, total antioxidant capacity, total phenols, chlorogenic acid and trigonelline content, and colour (L*, a*, b*). The changes of the evaluated parameters were correlated to each other. During the roasting the total antioxidant capacity (TAC) decreased to about one half of original level in the beginning stages of roasting, another decrease continued during the storage of roasted coffee at about 10% within the year. The degradation of trigonelline, neither the content of chlorogenic acid or total phenols did not correlate with TAC in samples during the roasting and storage.

Functional properties of coffee and coffee by-products

“…They result from the combination of sugars and amino acids through the Maillard reaction or caramelization of carbohydrates. Progressive reduction in the antioxidant activity of the coffee brew was observed with the degree of bean roasting, showing the medium roasted coffee the highest activity, due to the balance between the degradation of phenolic compounds and the generation of Maillard reaction products during this process (Bekedam et al, 2008;del Castillo, Ames, & Gordon, 2002;del Castillo, Gordon, & Ames, 2005;Sacchetti, Di Mattia, Pittia, & Mastrocola, 2009;Votavová et al, 2009). Budryn and Nebesny (2008) found that extracts of Robusta coffee had higher antioxidative efficacy than those from Arabica coffee beans and, also, that the most efficient method for extraction of antioxidants was boiling ground coffee beans in water under elevated pressure.…”

Effect of roasting degree on the antioxidant activity of different Arabica coffee quality classes

“…Since coff ee contains signifi cant amounts of antioxidants and other positive active components, researchers have indicated the potential benefi cial health eff ects of coff ee (Mišik et al, 2010;Nicoli et al, 1997;Trandafi r et al, 2013). Svilaas et al (2004) and Votavova et al (2009) confi rmed that coff ee beverages contribute 66% of the total antioxidant intake. Recent studies have shown that coff ee components such as tocopherols, carotenoids, caff eine, phenolic compounds such as chlorogenic acid, hydroxycinnamic acid and products of the Maillard reaction, such as melanoides, have antioxidant properties (Parras et al, 2007;Vignoli et al, 2011).…”

Impact of coffee components on inflammatory markers: A review

“…As trigonelline chemically changes to Nmethylpyridinium during the roasting process, it increases in AA, thus improving its TEAC (Votavova et al, 2009). Nicotinic acid produced by N-methylpyridinium shows promise as an anti-inflammatory agent, as it reduces MCP-1 and upregulates adiponectin in adipocytes infused with TNF-a (Digby et al, 2010).…”