Drinking coffee has become part of our everyday culture. Coffee cultivation is devoted to over 50 countries in the world, located between latitudes 25 degrees North and 30 degrees South. Almost all of the world's coffee production is provided by two varieties, called ‘Arabica’ and ‘Robusta’ whereas the share of Arabica is 70% of the world's coffee harvest. Green (raw) coffee can not be used to prepare coffee beverages, coffee beans must first be roasted. Roasting coffee and reaching a certain degree of coffee roasting determine its flavor and aroma characteristics. In the present study the fate of sucrose, chlorogenic acid, acetic acid, formic acid, lactic acid, caffeic acid, total phenolic compounds and 5-hydroxymethylfurfural was studied in coffee (Brazil Cerrado Dulce, 100% Arabica) roasted in two ways (Medium roast and Full city roast). It has been found that almost all sucrose has been degraded (96 – 98%) in both roasting ways. During Medium roast 65% of chlorogenic acid contained in green coffee was degraded while during Full city roast it was 85%. During both Medium and Full city roasting, the formation of acetic acid but especially formic and lactic acid was recorded. The highest concentration of organic acids was recorded at Full City roasting at medium roasting times (3.3 mg.g-1 d.w. acetic acid, 1.79 mg.g-1 d.w. formic acid, 0.65 mg.g-1d.w. lactic acid). The amount of phenolic substances also increased during roasting up to 16.7 mg.g-1 d.w. of gallic acid equivalent. Highest concentrations of 5-hydroxymethylfurfural were measured at medium roasting times at both Medium (0.357 mg.g-1 d.w.) and French city (0.597 mg.g-1 d.w.) roasting temperatures. At the end of roasting, the 5-hydroxymethylfurfural concentration in coffee were 0.237 mg.g-1 d.w. (Medium roast) and 0.095 mg.g-1 d.w. (Full city roast).
1 November 2019 in Biochemical Engineering Journal
This study investigated the effect of fortifying baked goods with wheat bran (WBPI) and whey protein isolates (WPI) on their physicochemical and sensory properties. The aim was to enhance the nutritional value by incorporating high-protein ingredients. WBPI and WPI, which are rich in essential amino acids, were chosen to create high-protein flour blends. The main advantage of WBPI is that it is derived from readily available and inexpensive wheat bran. High-protein flour blends fortified with substitutions of 5%, 10%, and 15% flour with WBPI and WPI were subjected to chemical and rheological analysis. WBPI substitution slightly increased water binding and softening, but it resulted in a decrease in dough quality. In contrast, WPI substitution prolonged dough development time, improved dough stability, and enhanced farinographic quality. WBPI-substituted dough exhibited comparable extensographic properties to the reference flour, with 5% WBPI substitution leading to improved energy and dough resistance. However, as the level of WBPI flour substitution increased, extensographic parameters gradually declined without further enhancing the dough’s mechanical properties. Samples with 5% WPI substitution demonstrated superior mechanical properties compared to the reference sample. Baguette with high WBPI substitution was associated with reduced overall acceptance due to a bitter taste caused by the presence of small peptides, ferulic acid, and tannins, as confirmed by correlation analysis.
The ascorbic acid, total polyphenols, total anthocyanins and mineral content, together with antioxidant activity, was determined in five Czech, two Ukrainian and two Austrian cultivars of cornelian cherry (Cornus mas L.) widely grown in the Czech Republic. Ascorbic acid content varied between 199–433 mg kg−1, total polyphenols between 2174–6143 mg kg−1, and total anthocyanins between 61–253 mg kg−1. All fruits were good sources of major metals (K, Ca, Mg, Fe, and Mn) and trace elements (Cu, Zn, and Cr). The antioxidant activity was determined by EPR and DPPH radical scavenging assay and ranged from 29.5% to 67.2%. There was a linear relationship between antioxidant activity and total polyphenol content. Based on the obtained results, Ekotišnovský, Fruchtal, and Ruzyňský cultivars were recommended for further investigation and breeding programme of cornelian cherry fruit in the Czech Republic