Estimation of dietary intake of melanoidins from coffee and bread

Abstract

Melanoidins are defined as polymeric high molecular weight, brown-coloured Maillard reaction end-products, containing nitrogen. They escape digestion and pass through the upper gastrointestinal tract and can interact with the different microbial species present in the colon. Major dietary sources of melanoidins are coffee and bread crust. Both coffee and bread crust melanoidins can be fermented by the human hindgut microflora thus sharing some of the properties attributed to dietary fibre. Despite the emerging positive physiological properties of such dietary constituents their intake has not been estimated yet. To this aim melanoidin content in different type of coffee brews, bread and dry biscuits was determined by sequential ultrafiltration and enzymatic digestion. Despite some drawbacks and limiting steps in the calculation, such as the lack of a reference material, an educated guess on the dietary intake of melanoidins has been put forward. Data indicated that the intake of coffee melanoidins ranged between 0.5 to 2.0 g per day for moderate and heavy consumers, respectively. For bread and dry biscuits an intake in the ranges of 1.8-15.0 and 3.2-8.5 g per day has been calculated. These figures suggest that a realistic estimation of melanoidins dietary intake for general population would be close to 10 g per day considering all the possible alimentary sources.

Reactivity of acrylamide with coffee melanoidins in model systems

“…Literature describes that 100 g of classical roasted coffee contains about 7.2 g of melanoidins, being close to 1.8 mg/mL in filtered coffee (Fogliano & Morales, 2011). According to EFSA (2010), average content of acrylamide in roasted coffee is 200 mg/kg Alves, Soares, Casal, Fernandes, and Oliveira (2010) estimated that acrylamide content in serving coffee is 42.3 mg/L.…”

Coffee reduces KRAS expression in Caco-2 human colon carcinoma cells via regulation of miRNAs

“…These compounds have been reported to possess various types of antioxidant and pro-oxidant activity (21,22) and often modulate antioxidant transcription factors, including nuclear factor-κB (NF-κB) and nuclear factor-E 2 -related factor 2. Furthermore, these compounds escape digestion and pass through the upper gastrointestinal tract into the colon (23). Thus, these compounds may be able to interact with colon epithelial cells.…”

The gastro-intestinal tract as the major site of biological action of dietary melanoidins

“…molecular weight, charge) and structural (depending on the nature of reactants) properties can be present in food (Table 1). Very recent review papers and research articles focused on this topic (Fogliano and Morales 2011;Wang et al 2011;Moreira et al 2012;Tagliazucchi and Verzelloni 2014;Pastoriza and Rufián-Henares 2014). In some foods such as coffee, cocoa, traditional balsamic vinegar, sweet wine and barley-derived beverages, most of the melanoidins are carbohydrate-based structures whereas in other foods (bakery foods) they are protein-based structures (melanoproteins).…”

“…Food melanoidins have also shown in vitro anti-caries and prebiotic activities. We conclude by underlining the possible role of food melanoidins in the prevention of gastro-intestinal vinegar (Summa et al 2008;Tagliazucchi et al 2008Tagliazucchi et al , 2010Fogliano and Morales 2011;Moreira et al 2012).…”

“…Considering the high intake of melanoidins (Fogliano and Morales 2011), their biological activity and potential impact on human health are topics of great interest. Different in vitro biological activities have been attributed to melanoidins, namely, antioxidant, antimicrobial, prebiotic, anti-cancer, antihypertensive and anti-glycative activities (Rufián-Henares and Morales 2007Morales , 2008aVerzelloni et al 2011;Borrelli and Fogliano 2005;Vitaglione et al 2012).…”