Phenolic and volatile compound composition influence to specialty coffee cup quality

I. Laukaleja* and Z. Kruma

Latvia University of Life Sciences and Technologies, Faculty of Food Technology, Department of Food Technology, Rigasiela 22, LV–3004 Jelgava, Latvia
*Correspondence: ilze.laukaleja@gmail.com

Abstract:

With increasing specialty coffee consumption, more attention is focused not only on the cup quality (sensory quality) of the coffee beverage but also about the impact of coffee on health. The beneficial effects of coffee on human health are mainly based on a wide range of biologically active components, including phenolic compounds. The aim of the study was to evaluate the influence of phenolic and volatile compound composition to specialty coffee cup quality. Seven specialty coffees from two Latvian roasteries were selected and analysed. Total phenolic and flavanoid content and radical scavenging activity by DPPH and ABTS assay were determined spectrophotometrically. Sensory evaluation (cup quality) was performed by trained panellist team using the SCAA protocols cupping specialty coffee. Volatile compounds were extracted by SPME and analysed by Gas Chromatography-Mass Spectrometry (GC–MS). Coffee final cup quality score ranged in amplitude of 83–90.25 points. HON_2 with dry fruits and melon characteristics has shown the highest final cup quality score. Almost detected volatile compounds in KEN_1 is associated with positive specialty coffee characteristics. In ETH_1 coffee with the final cup quality score 88.25 was detected highest floral, fruity compounds and highest coffee–like roasted notes. The highest total phenolic content and DPPH, ABTS^•+˙ value showed Roastery_1 coffee samples (HON_1; KEN_1; COL_1) and the lowest values Roastery_2 coffee samples (HON_2; ETH_1; HON_3; SAL_1).The results indicate that the roastery specific roasting process parameters could influence not only volatile compounds profile and cup quality but also the total and individual phenolic compound content.

Key words:

Production and investigations of antioxidant rich beverage: utilizing Monascus purpureus IHEM LY2014-0696 and various malts

P. Adadi¹*, E.G. Kovaleva², T.V. Glukhareva² and N.V. Barakova¹

¹Department of Food Biotechnology for Plant Origin Products, Faculty of Food Biotechnologies and Engineering, ITMO University, Lomonosova street 9, RU191002, St. Petersburg, Russia Federation
²Department of Technology for Organic Synthesis, Institute of Chemical Engineering, Ural Federal University, Mira street 19, RU620002 Yekaterinburg, Russia Federation
*Correspondence: pariseadadi@gmail.com

Abstract:

Antioxidant evokes numerous health benefits to the consumer as well as stabilisation of the beverages flavours. Therefore, this paper provides detailed information on the application of Monascus purpureus IHEM LY2014-0696 in combination with various malts in brewing antioxidant rich beverage (ARB). Starter culture Angkak was prepared by solid state bioprocessing (SSB). Single infusion method of mashing was used. Physicochemical parameters, volatile compounds, DPPH (2, 2-diphenyl-1-picrylhydrazyl) radical scavenging activity and fermentability of the wort were evaluated. Distillation procedure based on pycnometry technique was use to quantify the alcohol content (%ABV). Fermentability of the wort was found to be 97.6 ± 0.46% whilst %ABV was equal to 5.42 ± 0.03. It was observed that ARB showed a strong DPPH radical scavenging activity of 1.00 × 10^–4 mol × equ (R² = 0.91) whereas 3.43 × 10^–5 mol × equ (R² = 0.81) for wort. The strong antioxidant activity (AOA) is thought to be caused by pigments produced by M. purpureus IHEM LY2014-0696 and other compounds originated from the malts and hops utilised in brewing ARB. A total of 4 volatile compounds were identified in the present study. Incidence of microbial load ranged from 2.14 ± 0.04 × 10⁷ and 0.8 ± 0.1 × 10⁵ for M. purpureus IHEM LY2014-0696 and bacterial respectively was observed in the ARB. This study contradicts some previous ones, as the ARB brewed did not take the red pigment produced by the M. purpureus. Panellists generally expressed their acceptance for the ARB as they assessed it as a new product, moreover, taking account its health benefits.

Key words:

Angkak, Fermentability, Pigments, Solid state bioprocessing, Volatile compounds