Tag Archives: phenolic compounds

1367–1379 I. Laukaleja and Z. Kruma
Phenolic and volatile compound composition influence to specialty coffee cup quality
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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.

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xxx A. Roumani, A. Biabani, A.R. Karizaki, E.G. Alamdari and A. Gholizadeh
Effects of salicylic acid and spermine foliar application on some morphological and physiological characteristics of isabgol (Plantago ovata Forsk) under water stress
Abstract |
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Effects of salicylic acid and spermine foliar application on some morphological and physiological characteristics of isabgol (Plantago ovata Forsk) under water stress

A. Roumani*, A. Biabani*, A.R. Karizaki, E.G. Alamdari and A. Gholizadeh

University of Gonbad Kavous, Faculty of Agricultural and Natural Resources, Department of Crop Production, Crop Physiology, IR4971799151 Golestan, Iran
*Correspondence: azamroumani2012@gmail.com; abs346@yahoo.com

Abstract:

Yield as well as concentration of relevant component in many medical plants are influenced by growing condition water stress. Field experiment was done based on a randomized complete block design with 18 treatments and three replications, at Gonbad Kavous University, Golestan, Iran in winter 2016. Irrigation treatment with three levels (normal irrigation, water stress imposed at flowering stage or at seed filling stage) was placed in main plot. Salicylic acid (SA) with three levels (control, 0.4 and 0.8 mM) and spermine (Spm) with two levels (control and 0.02 mM) were assigned in sub-plots. Result showed the foliar application SA and Spm treatments under normal irrigation and cutoff irrigation at seed filling stage have significantly affected relative water content, electrolyte leakage and membrane stability index, but under cutoff irrigation at flowering stage did not significantly affected measured traits. Exogenous applications of SA and Spm applied increased the plant height, 1,000 grain weight and biological yield in compared to the non-use product at normal irrigation regime. Foliar spraying SA and Spm under cutoff irrigation at flowering stage did not significantly affected measured traits. Application product especially SA0.8 mM and Spm0.02 mM under cutoff irrigation at seed filling stage increased the most characteristics in compared to control. Foliar application of phenolic compounds such as salicylic acid and polyamines like spermine can be considered as an effective measure to reduce the adverse effects of water stress and ultimately increase the yield and yield components of isabgol.

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1546-1554 R. Zarins, Z. Kruma, L. Tomsone, S. Kampuse, I. Skrabule and I.H. Konosonoka
Comparison of phenolic compounds and antioxidant activity of fresh and freeze-dried potatoes
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Comparison of phenolic compounds and antioxidant activity of fresh and freeze-dried potatoes

R. Zarins¹, Z. Kruma¹*, L. Tomsone¹, S. Kampuse¹, I. Skrabule² and I.H. Konosonoka²

¹Latvia University of Agriculture, Faculty of Food Technology, Department of Food Technology, Rigas iela 22, LV-3004 Jelgava, Latvia
²Institute of Agricultural Resources and Economics, Zinātne iela 2, Priekuli, Priekuli municipality, LV-4126 Latvia
*Correspondence: zanda.kruma@llu.lv

Abstract:

Potatoes (Solanum tuberosum L.) contain a wide range of compounds with health benefits, and different techniques have been developed for the determination of these compounds. Freeze-drying is a common method for the preservation and preparation of samples for the analyses of bioactive compounds, but it is well known that drying influences the composition of food products. The aim of the current study was to compare phenolic compounds and antioxidant activity of fresh and freeze-dried potatoes. In the experiment 11 cultivar potatoes grown in experimental fields of the Institute of Agricultural Resources and Economics in 2016 were analysed. Potatoes were freeze-dried. Homogenized fresh and freeze-dried samples were extracted with an ethanol/water (80/20 w/w) solution. Total phenolic content (TPC) was determined using the Folin-Ciocalteu method, and the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH˙) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. The highest TPC and radical scavenging activity were determined in cultivars ‘Peru Purple’ and ‘Blue Congo’ potatoes. Freeze-drying influenced all the tested parameters but more significantly the TPC, and for certain cultivars a reduction of more than 30% was observed. A strong correlation between TPC, DPPH and ABTS in fresh and freeze-dried samples was observed, r = 0.81, r=0.93, r = 0.92, respectively. It could be concluded that the effect of freeze-drying on TPC and antioxidant activity is cultivar dependent.

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1316–1329 L. Klavins, J. Kviesis, M. Klavins
Comparison of methods of extraction of phenolic compounds from American cranberry (Vaccinium macrocarpon L.) press residues
Abstract |
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Comparison of methods of extraction of phenolic compounds from American cranberry (Vaccinium macrocarpon L.) press residues

L. Klavins, J. Kviesis, M. Klavins*

University of Latvia, 19 Raina Blvd., LV–1586, Riga, Latvia
*Correspondence: maris.klavins@lu.lv

Abstract:

American cranberries (Vaccinium macrocarpon L.) contain significant quantities of
various phenolic compounds. Most of these compounds are recovered when berry juice is
produced. However, a considerable part of polyphenols remain in berry press residues and are
discarded as food industry waste. The aim of the study was to compare the methods of extraction
of polyphenols (ultrasound, microwave-assisted, Soxhlet) from press residues of American
cranberry. The impact of main extraction parameters (e.g., extraction time, solid/solvent ratio,
solvent type) on the yield of extracted polyphenols. Ultrasound-assisted extraction showed the
highest potential from all studied methods, given its fast, convenient use and low cost. Aqueous
ethanol and methanol in the presence of acid (anthocyanin extractions should be assisted with
trifluoroacetic acid, polyphenol extractions – with HCl) were assessed as the best solvents for
extraction. The obtained extracts were characterised using the Folin-Ciocaulteu method for
determination of total phenolics and the pH-differential method for determination of total
anthocyanins, and UPLC–PDA was used to determine the content of individual anthocyanins.
Cyanidin-3-O-arabinoside, peonidin-3-O-galactoside, peonidin-3-O-glucoside and peonidin-3-
O-arabinoside were identified as the main anthocyanins in cranberry press residue extracts.

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