Bioactivity of selected materials for coffee substitute

Abstract

Epidemiological studies have suggested that coffee consumption is negatively correlated with the incidence of Parkinson’s disease. Coffee contains relatively high levels of β-carbolines, which have been ascribed neuroactive effects in humans however the positive or negative effect has not been confirmed yet. Two ingredients with applications as coffee substitutes—chicory, which is traditionally used in this way, and artichoke—were considered in this study both from the neuroactive point of view but also in relation to the other bioactive compounds that result from their thermal processing. These thermal products are of concern because of their possible toxic properties. The estimated concentration of β-carbolines was high in both materials (1.8 μg/g and 2.5 μg/g harman and 2.9 μg/g and 3.1 μg/g norharman in chicory and artichoke, respectively). Artichoke had more β-carbolines than chicory, and also more all the toxic compounds examined here–acrylamide, carboxymethyllysine, and furans, which were detected in significantly higher concentrations in artichoke, particularly acrylamide. Chicory and artichoke also contain phenolic compounds that possess high antioxidant activity, on a similar level. Artichoke, a new proposed ingredient in coffee substitutes, appears to be a richer source of β-carbolines than the traditionally chicory. Both materials contained high level of undesirable components, such as furan and its derivatives, carboxymethyllysine and particularly acrylamide, much higher in artichoke.

β-Carbolines in Experiments on Laboratory Animals

“…The amount of carbolines in the diet was very low, at 0.13 µg/g H and 0.04 µg/g NH. This is much less than in a coffee substitute such as chicory, which has 1.76 µg/g H and 2.90 µg/g NH [ 21 ]. Thus, the addition of coffee substitute to the animal diet may increase the concentration of carbolines in the diet.…”

“…In our previous studies [ 16 ], we noted that roasted artichoke contained very significant levels of carbolines, and we proposed a mixture of chicory and artichoke to give the highest possible concentration of β-carbolines in coffee substitute. However, we ultimately omitted the artichoke as we found it contains relatively high levels of some toxic compounds, particularly of acrylamide [ 21 ]. During the experiment, the body weight of the rats and the amount of diet they consumed were monitored; they proved to be similar in both groups.…”

Bioactive β-Carbolines in Food: A Review

“…Many works have indicated the presence of NH and H in processed and stored food [1,11,13]. They can be found both in plant tissues [12,14,15] and in products of plant origin, such as bread [13], cookies [13], maize, barley, soy, coffee [2,8,16,17], coffee substitutes (such as chicory coffee) [10,18], and in fermented alcoholic beverages [13,19,20]. The presence of H and NH has also been determined in meat [11,13], fish [13], vegetables [21], fruits [21], and juices [13,21].…”

“…The addition of artichoke increased the levels of carbolines in the product. However, in another paper [18], the same authors found that roasted artichoke could also introduce high levels of other bioactive substances, including some that are undesirable for health, such as acrylamide.…”

“…In the studies of Alves et al (2007, 2010), fluorescence detection was carried out in both cases under the same conditions; the excitation and the emission wavelengths were 300 nm and 440 nm for NH and H [8,17]. The method of Alves et al (2007) and Alves et al (2010) was also used to determine β-carboline levels in the raw materials used to produce coffee substitute (Wojtowicz et al 2015 and Zawirska-Wojtasiak et al 2018) [10,18]. In those studies, a modification of the Alves method was used: sample sizes in the 1–4 g range were selected depending on the raw material.…”