ArticlePDF Available

Oenological characterisation of white wines produced from some Georgian grape varieties using Kakhetian winemaking methods

March 2022
Ukrainian Food Journal 11(1):115-125

DOI:10.24263/2304-974X-2022-11-1-12

Authors:

Giorgi Kvartskhava

Georgian Technical University

Appearance of fresh (A) and dehydrated A. ursinum leaves at 40 °C (B), 50 °C (C), and 60 °C (D)

…

Sponge cakes made from composite flours containing wheat flour (WF) and barley malt flour (BMF)

…

Water absorption capacity,%

…

Effect of addition of algae Spirulina platensis and kelp on the oleic acid content in wheat bread Source: author's research

…

+16

Demographic and nutritional transition model

…

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ISSN 2313–5891 (Online)

ISSN 2304–974X (Print)

Ukrainian

Food Journal

Volume 11, Issue 1

2022

Kyiv

Kиїв

2022

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

Ukrainian Food Journal is an

international scientific journal that

publishes innovative papers of the experts

in the fields of food science, engineering

and technology, chemistry, economics and

management.

Ukrainian Food Journal is abstracted and

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Ukrainian Food Journal включено у перелік

наукових фахових видань України з технічних

наук, категорія А (Наказ Міністерства освіти і

науки України № 358 від 15.03.2019)

Editorial office address:

National University

of Food Technologies

68 Volodymyrska str.

Kyiv 01601, Ukraine

Адреса редакції:

Національний університет

харчових технологій

вул. Володимирська, 68

Київ 01601, Україна

e-mail: ufj_nuft@meta.ua

Scientific Council of the National

University of Food Technologies

approved this issue for publication.

Protocol № 10, 26.05.2022

Рекомендовано вченою радою

Національного університету

харчових технологій.

Протокол № 10 від 26.05.2022

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

Ukrainian Food Journal is open access journal published by the National University

of Food Technologies (Kyiv, Ukraine). The Journal publishes original research articles, short

communications, review papers, news and literature reviews dealing with all aspects of the

food science, technology, engeneering, nutrition, food chemistry, economics and

management.

Studies must be novel, have a clear connection to food science, and be of general interest

to the international scientific community.

Topic covered by the journal include:

 Food engineering

 Food chemistry

 Food microbiology

 Food quality and safety

 Food processes

 Automation of food processes

 Food packaging

 Economics

 Food nanotechnologies

 Economics and management

Please note that the Journal does not consider:

1. The articles with medical statements (this topic is not covered by the journal); the

subject of research on humans and animals.

2. The articles with statements, that do not contain scientific value (solving the typical

practical and engineering tasks).

Periodicity of the Journal

4 issues per year (March, June, September, December).

Reviewing a Manuscript for Publication

The editor in chief reviews the correspondence of the content of a newly submitted

article to the Journal Profile, approves the article design, style and illustrative material, can

provide suggestions how to improve them, and makes the decision whether to send it for

peer-review.

Articles submitted for publication in “Ukrainian Food Journal” are double-blind peer-

reviewed by at least two academics appointed by the Editors' Board: one from the Editorial

Board and one, not affiliated to the Board and/or the Publisher.

For a Complete Guide for Authors please visit our website:

http://ufj.nuft.edu.ua

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

International Editorial Board

Editor-in-Chief:

Olena Stabnikova, PhD, Prof., National University of Food Technologies, Ukraine

Members of Editorial Board:

Agota Giedrė Raišienė, PhD, Lithuanian Institute of Agrarian Economics, Lithuania

Bảo Thy Vương, PhD, Mekong University, Vietnam

Cristina Luisa Miranda Silva, Assoc. Prof., Portuguese Catholic University – College of

Biotechnology, Portugal

Cristina Popovici, PhD., Assoc. Prof., Technical University of Moldova

Dora Marinova, Prof., Curtin University Sustainability Policy (CUSP) Institute, Curtin

University, Australia

Egon Schnitzler, PhD, Prof., State University of Ponta Grossa, Ponta Grossa, Brazil

Eirin Marie Skjøndal Bar, Dr., Assoc. Prof., Norwegian University of Science and

Technology, Trondheim, Norway

Godwin D. Ndossi, Prof., Hubert Kairuki Memorial University, Dar es Salaam, Tanzania

Jasmina Lukinac, PhD, Assoc. Prof., University of Osijek, Croatia

Kirsten Brandt, Dr., Newcastle University, United Kingdom

Lelieveld Huub, PhD, Global Harmonization Initiative Association, The Netherlands

Mark Shamtsian, PhD, Assoc. Prof., Black Sea Association of Food Science and

Technology, Romania

María S. Tapia, Prof., Central University of Venezuela, Caracas, Venezuela; Corresponding

Member of the Academy of Physical, Mathematical and Natural Sciences of Venezuela

Moisés Burachik, PhD, Institute of Agricultural Biotechnology of Rosario (INDEAR),

Bioceres Group, Rosario, Argentina

Noor Zafira Noor Hasnan, PhD, Universiti Putra Malaysia, Selangor, Malaysia

Octavio Paredes-López, PhD, The Center for Research and Advanced Studies of the

National Polytechnic Institute, Mexico.

Rana Mustafa, PhD, Global Institute for Food security, University of Saskatchewan,

Canada

Semih Otles, PhD, Prof., Ege University, Turkey

Sheila Kilonzi, Karatina University, Kenya

Sonia Amariei, PhD, Prof., University "Ştefan cel Mare" of Suceava, Romania

Stanka Damianova, PhD, Prof., Ruse University “Angel Kanchev”, branch Razgrad,

Bulgaria

Stefan Stefanov, PhD, Prof., University of Food Technologies, Bulgaria

Tetiana Pyrog, PhD, Prof., National University of Food Technologies, Ukraine

Oleksandr Shevchenko, PhD, Prof., National University for Food Technologies, Ukraine

Viktor Stabnikov, PhD, Prof., National University for Food Technologies, Ukraine

Umezuruike Linus Opara, Prof., Stellenbosch University, Cape Town, South Africa

Yordanka Stefanova, PhD, Assist. Prof., University of Plovdiv "Paisii Hilendarski",

Bulgaria

Yuliya Dzyazko, PhD, Prof., Institute of general and inorganic chemistry of the National

Academy of Sciences of Ukraine

Yun-Hwa Peggy Hsieh, PhD, Prof. Emerita, Florida State University, USA

Yurii Bilan, PhD, Prof., Tomas Bata University in Zlin, Czech Republic

Managing Editor:

Oleksii Gubenia, PhD., Assoc. Prof., National University of Food Technologies, Ukraine

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

Contents

Editorial……………………………………………………………………

Food Technology..........................................................................................

Jasmina Lukinac, Marko Jukić

Influence of drying temperature on the organoleptic properties, antioxidant

activity and polyphenol content in dried leaves of Allium ursinum L.

subsp. ucrainicum………………………………………………………………….

Dimitar Dimitrov, Dushko Nedelkovski

Aromatic profile of Macedonian and Bulgarian red wines from local

variety Vranec and hybrid variety Kaylashki Rubin………………………..

Galyna Simakhina, Nataliia Naumenko

Biological value of proteins of cultivated mushrooms…………………......

Eteri Tkesheliadze, Nino Gagelidze,

Tinatin Sadunishvili, Christian Herzig

Fermentation of apple juice using selected autochthonous lactic acid

bacteria……………………………………………………………………...

Marko Jukić, Gjore Nakov, Daliborka Koceva Komlenić,

Franjo Šumanovac, Antonio Koljđeraj, Jasmina Lukinac

Quality assessment of sponge cake with reduced sucrose addition made

from composite wheat and barley malt flour……………………………….

Maria-Camelia Golea, Marius Dan Şandru,

Georgiana-Gabriela Codină

Mineral composition of flours produced from modern and ancient wheat

varieties cultivated in Romania……………………………………………..

Anastasiia Shevchenko, Vira Drobot, Oleg Galenko

Use of pumpkin seed flour in preparation of bakery products……………...

Denka Zlateva, Rosen Chochkov, Dana Stefanova

Effect of Spirulina platensis and kelp biomass addition on the fatty acid

composition of wheat bread………………………………………………...

102

Tamari Makhviladze, George Kvartskhava

Oenological characterisation of white wines produced from some

Georgian grape varieties using Kakhetian winemaking methods…………..

115

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

Economics and Management……………………………………………..

126

Dora Marinova, Diana Bogueva, Yanrui Wu, Xiumei Guo

China and changing food trends: A sustainability transition perspective…..

126

Processes and Equipment…………………………………………………

148

Mykhailo Hrama, Viktor Sidletskyi, Ihor Elperin

Intelligent automatic control of sugar factory evaporator operation using

behavior prediction subsystem……………………………………………...

148

Biotechnology, Microbiology……………………………………………...

164

Tetiana Pirog, Viktor Stabnikov, Svitlana Antoniuk

Application of surface-active substances produced by Rhodococcus

erythropolis IMB Aс-5017 for post-harvest treatment of sweet cherry…….

164

Tetiana Pirog, Igor Kliuchka, Liliia Kliuchka

Antimicrobial activity of a mixture of surfactants produced by

Acinetobacter calcoaceticus IMV B-7241 with antifungal drugs and

essential oils………………………………………………………………...

176

Abstracts……………………………………………………………..…….

187

Instructions for authors…………………………………………………...

199

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

Editorial

Ukrainian Food Journal is still a very young journal:

in the spring of 2012 its first issue was published.

However, the scientific and publishing traditions of the

publisher, the National University of Food Technologies,

date back to the middle of the 19th century. At the

beginning, our Journal was aimed at creative youth, and

until 2017, its description contained the sentence “The

advantage in publication is given to PhD students and

young scientists.” Gradually, the Journal gained

importance as a periodical publishing scientific research

by leading scientists in the field of food and related

branches of science, expanding the geography of authors

and the editorial board. Some time later, the Ukrainian

Food Journal began to be indexed by international scientometric databases, since 2018 – by

Web of Science, and in 2022 a decision was made to include the Journal in the Scopus

database. This indicates the proper rating and scientific significance of the materials

published in it.

We are grateful to the international organization the Association of the Global

Harmonization Initiative (GHI), which in 2022 helped us invite leading scientists in the field

of food technology, chemistry, processes and equipment, economics and management from

different countries to participate in the work of the editorial board of our journal. At this time,

new members entered the editorial board:

 Bảo Thy Vương (Mekong University, Vietnam)

− Cristina Luisa Miranda Silva (Portuguese Catholic University – College of

Biotechnology, Portugal)

− Dora Marinova (Curtin University Sustainability Policy (CUSP) Institute, Curtin

University, Australia)

− Eirin Marie Skjøndal Bar (Norwegian University of Science and Technology,

Trondheim, Norway)

− Godwin D. Ndossi (Hubert Kairuki Memorial University, Dar es Salaam,

Tanzania)

− Kirsten Brandt (Newcastle University, United Kingdom)

− María S. Tapia (Central University of Venezuela, Caracas, Venezuela; Academy of

Physical, Mathematical and Natural Sciences of Venezuela)

− Moisés Burachik (Institute of Agricultural Biotechnology of Rosario (INDEAR),

Bioceres Group, Rosario, Argentina)

− Noor Zafira Noor Hasnan (Universiti Putra Malaysia, Selangor, Malaysia)

− Rana Mustafa (Global Institute for Food security, University of Saskatchewan,

Canada)

− Sheila Kilonzi (Karatina University, Kenya)

− Umezuruike Linus Opara (Stellenbosch University, Cape Town, South Africa)

− Yun-Hwa Peggy Hsieh (Florida State University, USA)

We welcome new members of our editorial team and sincerely thank the editorial board,

which has been working fruitfully since 2012, as well as the authors who support the journal

and publish their articles in it.

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

On February 24, the civilized world shuddered at the news of the russian invasion of

Ukraine. Rockets flew from the territory of russia and belarus to Ukraine, the bombing of our

cities began, the occupying troops entered. Mass killings of civilians, robbery and looting,

destruction of transport and energy infrastructure, food industry enterprises and food

warehouses, farms, medical institutions, schools and universities, and research institutions

began.

Ukrainian science is working in times of war now. Some scientists were forced to

evacuate, the rest remained to work under rocket fire. We are grateful to colleagues from all

over the world for their moral support. This gave us the strength to hold on and continue

publishing our Journal.

Ukraine has always made a significant contribution to food supplies around the world.

At present, when the rashists have blocked the supply of food raw materials from Ukraine,

the world has understood the true global significance of our country in world food security.

Wheat, sunflower, vegetables, fruits turned out to be more in demand than oil and gas.

Ukraine needs global support to unlock supply chains, and the world is in danger of starvation

without Ukrainian food.

There is no doubt that the truth will win this hateful war. Peace will reign again on

Earth, research, innovation, and the work of educational institutions will resume. But we

cannot just wait for victory. All ways to improve the Journal are now open. We have an

excellent professional team, the world's leading scientists publish their results in our Journal.

Let's join our efforts for the success of Ukrainian Food Journal!

Editor-in-Chief

Olena Stabnikova

DOI: 10.24263/2304-974X-2022-11-1-3

─── Food Technology ───

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

Influence of drying temperature on the organoleptic

properties, antioxidant activity and polyphenol content

in dried leaves of

Allium ursinum

L. subsp.

ucrainicum

Jasmina Lukinac, Marko Jukić

J. J. Strossmayer University of Osijek, Faculty of Food Technology, Osijek,

Croatia

Keywords:

Allium ursinum

L. subsp.

ucrainicum

Drying

Image analysis

Phenolic

Antioxidant

Abstract

Introduction. The short vegetative occurrence of Allium

ursinum limits its availability. Therefore, drying seems to be an

excellent method for year-round preservation. The aim of the present

study was to determine the influence of drying temperature on

antioxidant activity and polyphenol content in dried leaves of Allium

ursinum L. subsp. ucrainicum and their organoleptic properties.

Materials and methods. The effect of three drying temperatures

(40, 50 and 60 °C) on the organoleptic properties (colour, dehydration

and rehydration ability), antioxidant activity and polyphenol content

in the dried leaves of A. ursinum was evaluated. The colour of the

samples was measured using the computer vision system. The total

phenolic content was determined spectrophotometrically and the

antioxidant activity was determined using the 2,2-diphenyl-1-

picrylhydrazyl method.

Results and discussion. Significant differences were found

between the fresh, dehydrated and rehydrated A. ursinum samples for

all the colour parameters analysed (dried leaves showed a much lower

intensity of green colour than fresh). Drying at higher temperature

results in greater colour change, which is more pronounced at higher

drying temperatures (60 °C) due to chlorophyll degradation. The

drying temperatures had a statistically significant effect on the

dehydration and rehydration capacity of the dried samples. The higher

drying temperature resulted in the higher degree of dehydration and

rehydration (the pores of the dried food allowed water to re-enter the

cells). Convection air-drying resulted in considerable moisture

removal from the fresh leaves of A. ursinum (more than 91%), but the

organoleptic quality of the A. ursinum leaves was maintained. The

drying conditions tested had a significant effect on the total phenolic

content and antioxidant activity of A. ursinum leaves. An increase of

temperature drying decreased the total polyphenol content in the dried

A. ursinum leaves. Across the range of measurements, the samples

dried at lower temperatures had the higher antioxidant capacity, while

the higher drying temperatures resulted in a greater decrease in the

antioxidant activity of the dried plant material. A. ursinum is

considered one of the functional foods for human consumption due to

its high nutritional value and prophylactic or therapeutic effects in

various diseases. To obtain a high quality dried product, the drying

process should ensure a quality comparable to fresh vegetables.

Conclusions. Air drying showed a significant effect on the

colour, drying properties, total polyphenol content and antioxidant

activity of the leaves of A. ursinum. The losses were significantly

dependent on the drying temperature and were more pronounced at

higher process temperatures.

Article history:

Received

01.09.2021

Received in

revised form

9.11.2021

Accepted

31.03.2022

Corresponding

author:

Jasmina Lukinac

E-mail:

ptfosptfos2@

gmail.com

DOI:

10.24263/2304-

974X-2022-11-1-

───Food Technology ───

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

Introduction

Allium ursinum L. is known by many different names: wild garlic, leek, wood garlic,

bear's garlic, ramsons, buckrams, broad-leaved garlic, gypsy onion and pig's garlic. It belongs

to the large family Amaryllidaceae, which is represented all over the world with 59 genera

and over 850 species. As a member of the genus Allium, wild garlic is closely related to herbs

such as onion (Allium cepa), garlic (Allium sativum), leek (Allium ampeloprasum), and chives

(Allium schoenoprasum) (Hanen et al., 2012). Allium species are considered a source of

phytonutrients with diverse biological activities (Lachowicz et al., 2017; Gitin et al., 2012),

such as antibacterial, antifungal (Parvu et al., 2011), antioxidant (Bozin et al., 2008), and

therapeutic activities, which are associated with the presence of sulfur components (Gođevac

et al., 2008). Due to the presence of sulfur compounds, which are otherwise rather

characteristic components of Allium plants, A. ursinum has a distinctive garlic-like odour.

A. ursinum is a plant with a high potential for the prevention and treatment of

cardiovascular, respiratory and digestive problems, as well as for the sterilisation of wounds

(Sobolewska et al., 2013) and the prevention of carcinogenic diseases (Sengupta et al., 2004).

These properties are due to many substances, including cysteine sulfoxides and

thiosulfinates, ajoenes and dithiines, phenolic compounds, saponins and vitamins C, E and A

(Lu et al., 2011; Roldan- Marin et al., 2009).

It grows mainly in moist deciduous forests throughout Europe and in parts of Asia and

North Africa (Oborny et al., 2011; Rola 2012). Allium ursinum L. comprises two subspecies

Allium ursinum subsp. ursinum and Allium ursinum subsp. ucrainicum. In Eastern and South

Eastern Europe, and Croatia as well, Allium ursinum subsp. ucrainicum grows in continental

and mountainous areas (Rola, 2012; Tutin 1957). Although all parts of this plant are edible

(bulbs, leaves, buds, flower stalks, flowers and immature green cobs), leaves and bulbs are

generally preferred for consumption. The fresh leaves or dried herb of A. ursinum is used in

local cuisines of Europe. There are many products derived from garlic as a raw material:

garlic powder, paste, extract, oil, macerated garlic, pickled garlic, dried garlic. The medicinal

parts of the plant are the young spring leaves, harvested in April and May, and the

underground bulbs, collected in the summer and autumn months. However, the short

vegetative presence of A. ursinum limits its availability, so drying can be a solution for

preserving it throughout the year.

Since agricultural products are highly seasonal and therefore abundant at certain times

of the year, preserving fruits and vegetables through drying can both avoid major waste and

ensure availability in the off-season. Drying is one of the thermal processes that agricultural

products undergo in the post-harvest phase. The aim is to reduce the moisture content of the

product in order to delay adverse biological (prevents the growth of microorganisms),

chemical and enzymatic processes. Although drying is an alternative to extend the shelf life

of food, it is a fact that the quality of dehydrated food is usually lower than that of the original

food. Therefore, it is of interest to minimise chemical changes such as enzymatic and non-

enzymatic browning and to maximise the retention of nutrients such as macronutrients

(proteins, sugars, fibres), micronutrients (vitamins, minerals) or bioactive compounds

(phenolic compounds, carotenoids, isoflavones) during drying. The drying process is

considered to affect the content, activity and bioavailability of bioactive compounds (mainly

polyphenols) in A. ursinum leaves. Therefore, the evaluation of the effects of drying on the

naturally occurring antioxidants is a key issue in the choice of technological conditions that

allow the preservation of their original activity and bioavailability. A lot of recent work has

focused on studying the effects of drying on the phenolic compound content and antioxidant

activities of dried vegetables (Kim et al., 2013; Ozgur et al., 2011; Sahoo et al., 2015; Telfser

─── Food Technology ───

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

et al., 2019). To achieve better results in terms of dried product quality, researchers have

worked on optimising drying methods and different drying conditions (Arslan et at., 2010;

Lim et al., 2007; Roshanak et al., 2015). The major quality problems associated with drying

are loss of flavour (Ozkan-Karabaca et al., 2018), discolouration (Guine et al., 2012) and

poor rehydration properties of the dried product (Aravindakshan et al., 2021; Lewicki, 1998).

The aim of the present study was to determine the influence of drying temperature on

antioxidant activity and polyphenol content in dried leaves of Allium ursinum L. subsp.

ucrainicum and their organoleptic properties.

Materials and methods

Materials

The plant material (fresh leaves) used in this study was collected from a natural

population of wild garlic, Allium ursinum L. subsp. ucrainicum, before flowering (April

2021) in the Papuk Geopark (45°32'N 17°39'E) in the Slavonia region, Croatia. All plant

samples were free from external damage and hand-picked. The leaves of A. ursinum were

packed in linen bags and kept in the refrigerator for 24 hours until the start of the analysis of

the plant material.

Drying

Drying was carried out in a drying cabinet with hot air, in which the fresh leaves of A.

ursinum were placed in a thin layer on perforated stainless steel trays. The drying cabinet

were equipped with a fan, a speed controller, a temperature controller, heating elements, a

humidity, temperature, and air velocity meter. Fresh samples were dried at different drying

temperatures of 40 °C, 50 °C, and 60 °C with a constant air velocity of 1.5 m/s and relative

humidity of 35-45%. The drying process started when the drying conditions were reached.

Weight loss was performed at a fixed time interval, and drying continued until a moisture

content of approximately 12% (wet basis) was reached. Three independent dryings were

performed for each drying temperature. The effect of temperatures on the quality of dried

leaves of A. ursinum was determined by the colour characteristics, dehydratation and

rehydration capabilities phenolic compounds, and antioxidant properties.

Determination of physicochemical characteristics

Dry matter content, ash, crude fat, pH and total acidity were determined in fresh

A. urisnum samples. The analysis was performed in accordance with Association of

Officiating Analytical Chemists standards (AOAC, 2000). The dry matter content of the

leaves was determined by drying 5.0 g of the samples at 105 °C until constant weight. Ash

content was determined by burning 5.0 g of the fresh samples at 550-600 °C until a

homogeneous white ash without black spots was obtained. Crude fat was obtained by

exhaustive extraction of 10.0 g of each sample in a Soxhlet apparatus using petroleum ether

(boiling range 40-60 °C) as solvent (Dini et al., 2008). Tittratable acidity was determined by

potentiometric titration and pH by a digital pH meter (Mettler Toledo, FiveEasy FE20,

Switzerland).

───Food Technology ───

─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

Colour measurement

The colour of the fresh, dehydrated, and rehydrated leaves of A. ursinum samples was

measured using the computer vision system. Samples were ground in a grinder (Retsh,

Grindomix GM 200, Düsseldorf, Germany) to obtain a fine powder (Figure 1). For each

sample (fresh, dehydrated, and rehydrated), colour parameters were measured three times

directly on the product using a 2.2-megapixel digital SLR camera (EOS 1100D, Canon Ltd.,

Japan), calibrated with a calibration plate (Datacolor SpyderCheckr™, New Jersey, USA)

just before imaging. The 24-bit colour images were captured in TIFF format and in the 

colour model.Samples were photographed in a photochamber illuminated by four LED lamps

with a diffuser.

Figure 1. Appearance of fresh (A) and dehydrated A. ursinum leaves

at 40 °C (B), 50 °C (C), and 60 °C (D)

The colour parameters of the samples was determined using ImageJ™ image processing

software (Wayne Rasband, National Institute of Health, Maryland, USA). The results were

expressed as values for red (), green (), and blue () in the  colour system. The

obtained colour values were then converted (Viscarra Rossel et al., 2006) and presented in

the  and  colour system (Westland, 2016; Zhang et al., 2003), which is

commonly used to evaluate dried foods. The three parameters  (lightness, from black 

 to white ), (a negative value of represents green, while a positive value

represents red colour) and  (a positive  represents yellow and a negative represents blue

colour) were used for further calculation of hue angle, colour saturation, and total colour

difference.

Hue angle () is the attribute by which a colour is identified as green, yellow, red, etc.

An angle of 0° or 360° represents red hue, whilst angles of 90°, 180° and 270° represent

yellow, green and blue hues, respectively (Maskan, 2001). Hue angle is used to define the

difference of a certain colour with reference to grey colour with the same lightness:

  



Colour saturation or chroma (), considered the quantitative attribute of colourfulness.

The higher the chroma values, the higher is the colour intensity of samples perceived by

humans. Chroma were calculated from the values of  and  (Lopez Camelo et al., 2004):

 

Total colour difference () is colour change represents by distance vector between

the initial colour values (fresh samples) and the dehydrated/reyhdrated colour coordinates

(Roy Choudhury, 2015). Total colour difference were calculates as follows:

 󰇛

󰇜󰇛

󰇜󰇛

󰇜

where 



 and 

 are the colour parameters of fresh leaves of A. ursinum samples, and 

, and  are dehydrated/rehydrated colour parameters.

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Drying characteristics

The quality index of a dried product were observed and in this terms following parameters

was calculated: dehydration ratio (), and rehydration ratio (). The  is important

parameter to show the bulk reduction in the weight of dried sample (higher the , better the

quality of drying process). The  is quality index for all dried product and higher the , better

the quality of product. Dehydration ratio was calculated by taking the weights of sample before

drying in gram () and weights of sample after drying in gram () (Kaur et al., 2008):

 



To express ability of the dried material to absorb water the  was used, and estimated

according to method of Ranganna (2004). Approximately 5 g of dried samples of A. ursinum were

placed in a 100 ml distilled water and bring to boil within 3 min. After 5 min of mild boiling, the

mixture was cooled and then filtered under vacuum and weighed (mass of drained weight).

Rehydration ratio was calculated by taking the drained weight (g) of rehydrated sample (), and

the weight (g) of dry sample used for rehydration () (Lewicki, 1998):

 



Sample extract preparation

The extract from the leaves of A. ursinum was obtained by adding 2.5 g of fresh or dried leaf

powder to 25 mL of absolute methanol and stirring with a magnetic stirrer for 30 minutes. The

resulting mixture was stored in the dark at 4 °C for 24 hours and then filtered. The resulting extract

was stored at 4 °C until further analysis (Dewanto et al., 2002).

Determination of total phenolic content

The total phenolic content () was determined spectrophotometrically according to the

method Singleton et al. (1965) with gallic acid as standard. The 0.3 mL of the extract sample was

mixed with diluted (1:10) Folin reagent (1.5 mL) and mixed vigorously for three min. Then 6.0%

sodium carbonate solution (1.5 mL) was added and shaken. After standing for 90 minutes in dark

at room temperature, the absorbance was measured at 760 nm using a UV-VIS spectrophotometer

(Shimadzu, UV-1280, Germany).  of fresh and dried leaves was expressed using the

calibration curve with gallic acid (0–500 μg/mL) as grammes of gallic acid equivalents (GAE)

per 100 gramme of dry matter (g GAE /100 g d.b.).

Determination of antioxidant activity

Antioxidant activity () of the extracts was measured according the Brand-Williams et al.

(1995) method based on using 2.2-diphenyl-1-picrylhydrazyl (DPPH). The reaction mixture was

prepared using 0.1 mL of extract and 3.9 mL of DPPH methanol solution (0.1 mM). The mixture

was shaken, left in the dark for 30 min, and absorbance was measured using the UV – VIS

spectrophotometer (Shimadzu, UV-1280, Germany) at 517 nm. The  was expressed as the

percentage inhibition of the DPPH radical.

Statistical analysis

Each drying test was performed in triplicate and all analyses were performed in at least five

replicates, unless otherwise stated in a specific analysis. One-way analysis of variance (ANOVA)

and multiple comparison post-hoc Fisher LSD (least significant-difference) test were used to

evaluate the significant difference of the data at p < 0.05. Data were expressed as means ±standard

deviation. Statistica 14 from StatSoft was used for statistical analysis.

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Results and discussion

Determination of physicochemical characteristics

The results of the physicochemical properties of the leaves of A. ursinum are shown in

Table 1. It can be seen that the average values of dry matter, crude fat content, total acidity

and pH in the fresh leaf samples are 9.42, 8.84, 3.72, 0.90 and 5.50, respectively, and are in

agreement with the results of other studies (Blazewicz-Wozniak et al., 2011; Dyduch et al.,

2019).

Table 1

Physicochemical characteristics of fresh leaves of A. ursinum L.

Dry matter,

Ash content,%

Crude fat

content,

Tittratable acidity,

g acid/100 g plant

d.b.

9.42±0.48

8.84±0.52

3.72±0.29

0.90±0.03

5.50±0.09

Results are expressed as mean ± standard deviation.

Colour degradation

Product colour is an important quality parameter that must be maintained during drying.

The leaves of the A. ursinum samples were dried at 40, 50, and 60 °C to the desired moisture

content. The colour of the samples was measured before (fresh) and after drying (dehydrated

and rehydrated). The effect of the different air temperatures on the colour characteristics of

the A. ursinum samples is shown in Figures 2–7.

Figure 2. Effect of drying air temperature on lightness () of fresh, dehydrated and rehydrated

A. ursinum leaves

The data are presented as the mean ± standard deviation. Bars with different letters are significantly

different (p < 0.05)

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The colour of the leaves of A. ursinum was characterised by higher colour parameters

and  of the dried plant material compared to fresh leaves. The value of hue angle

(󰇜 was lower in the dried material than in the raw or rehydrated material. Significant

differences were observed in all analysed colour parameters between the fresh, dehydrated,

and rehydrated leaves of A. ursinum dried at different air temperatures. Adverse changes in

the colour of A. ursinum leaves are mainly due to the degradation of chlorophyll contained

in them. Chlorophyll content decreases with increasing temperature, process duration (Lin et

al., 2010; Krokida et al., 1998), and the presence of oxygen, leading to oxidation of the

unsaturated colour compounds contained in the material (Negi et al., 2001), which

contributes to unfavourable changes in the colour determinants of the dried material. Heating

at higher temperatures caused the colour of A. ursinum leaves to change from green to olive

brown, which is attributed to pheophytinization (Nido et al., 2003; Martins et al., 2002).

Figure 2 shows that the lightness () ranged from 22.59±0.06 to 36.89±0.14 regardless

of drying temperature, with the lowest  values obtained for fresh samples (22.59±0.06) and

the highest for samples dried at 60 °C (36.89±0.14). The drying temperature had a significant

effect on the  values of the dehydrated and rehydrated samples. The  values increased

proportionally with the drying temperature. The  values for the rehydrated samples were

lower compared to the dehydrated samples. Rudy et al. (2020) also reported decrease in 

values after convection drying. A negative  value represents a green colour, while a

positive value represents a red colour.

Figure 3. Effect of drying air temperature on colour parameter  (redness – greenness) of

fresh, dehydrated and rehydrated A. ursinum leaves

The data are presented as the mean ± standard deviation. Bars with different letters are significantly

different (p < 0.05)

The results of chromatic component redness – greenness (󰇜 of A. ursinum leaves are

presented in Figure 3 where can it be seen that  values ranged from -12.99±0.30 to

-5.21±0.14 regardless of drying temperature, with the lowest  values obtained for fresh

samples (- 12.99±0.30) and the highest (-5.21±0.14) for samples dried at 60 °C. The green

colour is dominant in all samples, although the green hue is more pronounced in fresh and

rehydrated samples. The drying temperature had a significant effect on the  values of the

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dehydrated and rehydrated samples, and the  values for the dehydrated samples were lower

compared to the rehydrated samples processed at the same temperature. Thus, the dehydrated

leaves showed a much lower intensity of green colour than the fresh leaves. This effect is

more pronounced at higher drying temperatures (60 °C) due to chlorophyll degradation

(Guine et al., 2012).

The results of chromatic component yellowness – blueness () of A. ursinum leaves are

presented in Figure 4 where can it be seen that  values ranged from 14.78±0.19 to

21.10±0.13 regardless of drying temperature, with the lowest  values obtained for fresh

samples (14.78±0.19) and the highest for dehydrated samples (21.10±0.13) dried at 60 °C.

The positive  value, representing the yellow colour, increases significantly after drying and

rehydration. Arslan et al., (2010) reported similar results. There were statistically differences

between dehydrated and rehydrated samples. The  values for the rehydrated samples were

smaller compared to the dehydrated samples processed at the same temperature.

Figure 4. Effect of drying air temperature on colour parameter  (yellowness – blueness) of

fresh, dehydrated and rehydrated A. ursinum leaves

The data are presented as the mean ± standard deviation. Bars with different letters are significantly

different (p < 0.05)

The hue angle () values ranged from 103.87 ±0.31 to 131.30 ±0.99 regardless of drying

temperature (Figure 5), with the lowest  values obtained for the samples dried at 60 °C

(103.87 ±0.31) and the highest for the fresh samples (125.10 ±0.13). The dried leaves of A.

ursinum had lower  values than the raw material. There were statistical differences between

dehydrated and rehydrated samples, with drying resulting in a significant decrease in 

values of the dried material. The  values of the dehydrated samples were smaller compared

to the rehydrated samples processed at the same temperature. The hue angle of the dehydrated

sample decreased with increasing heating temperature. The decrease in hue angle

corresponds to a decrease in the intensity of the green and an increase in the yellow colour.

The decrease in hue angle in this study is consistent with the results reported by Lau et al.,

(2000) that prolonged heating of green vegetables leads to deterioration of chlorophyll

pigments and a change in colour from green to olive green.

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─── Ukrainian Food Journal. 2022. Volume 11. Issue 1 ───

Figure 5. Effect of drying air temperature on hue angle () of fresh, dehydrated and

rehydrated A. ursinum leaves

The data are presented as the mean ± standard deviation. Bars with different letters are significantly

different (p < 0.05)

The results of colour saturation (󰇜 of A. ursinum leaves are presented in Figure 6. It

can be seen that  ranged from 18.12±0.18 to 21.72±0.15 regardless of drying temperature,

with the lowest  values obtained for dehydrated samples dried at 40 °C (18.12±0.18) and

the highest at 60 °C (21.72±0.15). Increasing the temperature of the drying air resulted in an

increase in colour saturation during drying. There were no statistical differences between

dehydrated and rehydrated samples. The  values for the rehydrated samples were smaller

compared to the dehydrated samples processed at the same temperature.

Total colour difference () is a colorimetric parameter used to estimate the colour

change of food during processing. Figure 7 shows that  values ranged from 5.91±0.10

to 17.47±0.19 regardless of drying temperature, with the lowest  values obtained for

rehydrated samples dried at 40 °C (11.60±0.01) and the highest for dehydrated samples dried

at 60 °C (17.47±0.19). There were statistical differences between dehydrated and rehydrated

samples. The  values for the rehydrated samples were smaller compared to the

dehydrated samples processed at the same temperature. It is evident that drying at higher

temperature results in greater colour change (Kumar et al., 2004).