Skip to main content
NCBI home page
Journal of Food Science and Technology logoLink to Journal of Food Science and Technology
. 2022 Feb 5;59(8):3201–3209. doi: 10.1007/s13197-022-05370-y

“Improved quality assessment of cornelian cherry (Cornus mas L.) fruit with regard to their processing potential”

Manfred Gössinger 1,✉, Florian Kuenz 1, Silvia Wendelin 2, Karin Korntheuer 2, Henry Jäger 3, Lothar Wurm 4, Monika Graf 1
PMCID: PMC9304497  PMID: 35872725

Abstract

The sensory properties and appropriateness of cornelian cherry (Cornus mas L.) for processing is very closely related to its ripening stage, recognizable by firmness and skin colour to some extent. Due to the non-uniform ripening on the trees the quality of the fruits offered on the market depends very much on the harvest-method. Today, processors, who usually do not buy fresh fruits but frozen fruits or puree on the market, don`t have a suitable means for the accurate quality assessment of the raw material they need for the processing of high-quality products. The results of this work show for the first time that from the selected parameters (carbohydrates, organic acids, phenols) only flavonols, especially kaempferol-3-glucoside is appropriate to determine the stage of ripeness of cornelian cherries properly independent from species, provenance and crop year. Kaempferol 3-O-glucoside of about 1.75 mg/Kg in wild genotypes and of about 0.80 mg/Kg in most big cornelian cherry species can serve as a reference for sufficient ripeness and therefore for high fruit quality.

Keywords: Cornelian cherry, Ripening stage, Flavonol, Quality assessment

Introduction

Cornelian cherry (Cornus mas L.), a rare type of fruit and mostly wild growing plant in the east and south of Europe and west Asia with oval red fruit, rich in reducing sugars, organic acids, vitamins and phenols, has been getting more and more attention by health-conscious consumers, and consequently chemical research, due to many nutritional and health-beneficial properties such as anti-oxidative and anti-inflammatory effects (Cosmlescu et al. 2019; Moldovan et al. 2016; De Biaggi et al. 2018; Szczepaniak et al. 2019; Tarko et al. 2014).

In many countries breeding-programs have been developing promising selections. One important goal of selection is fruit size. For almost 20 years some selected species with big red fruits (up to 8–10 g vs. 2–3 g of wild genotypes) and good taste, for instance Kasanlaker, Schumener, Bulgarico, Jolico, Schönbrunner Gourmetdirndl, Kaukasische have already been present on the European (Austrian) market (Pirc 2015).

Many studies have been conducted to determine the impact of selected genotypes, species, provenance and growing conditions (crop year) on the physical and chemical quality parameters of cornelian cherries worldwide (Akagic et al. 2020; Drkenda et al. 2014; Yilmaz et al. 2009). However, the ripening stage is mostly not considered properly, most studies tested fruit that were “ripe” or “at full maturity”, without providing a proper description of the mentioned ripening stage. Little research has been carried out on the impact of the ripening stage on the quality parameters of cornelian cherries (Gunduz et al. 2013; Szot et al. 2019; Yarilgac et al. 2019).

Usually, the fruit is used for the production of syrup, jam, juice, vinegar and distillate, and only rarely for the fresh market (Kava-Rygielska et al. 2018). Due to the non-uniform ripening on trees, for economic reasons fruit intended for processing are harvested at one time, either very late in the harvest-season, when all overripe fruits have already dropped on the ground (many fruits are already injured, danger of formation of acetic bacteria) or at an earlier harvest time by shaking the trees and using nets. With the latter form, which is also usually performed in Austria, unripe, ripe and overripe fruits are mixed up, because fruits do not ripen homogenously on the tree. However, only ripe cornelian cherry fruits taste excellent. Usually, the main criteria for the determination of the right ripening stage for harvest are the skin colour and the soluble solid content of the fruits. Based on the authors’ experience and as cited in literature (Drkenda et al. 2014), the criteria for high quality, however, is closely correlated to the colour and firmness of the fruits. Only the combination of dark red colour and a soft firmness ensures excellent sensory properties of the fruits. Mid-sized and big processing companies mostly do not obtain fresh cornelian cherry fruits, but puree or frozen fruit. In this case the quality of the raw material cannot be sufficiently determined by the processors.

Many ingredients of fruits are known to increase (e.g. soluble solid, sorbitol) or decrease (e.g. organic acids) during ripening (Gunduz et al. 2013; Szot et al. 2019; Yarilgac et al. 2019). This was observed in studies when green to dark red fruits were tested. However, no literature was found examining the changes during ripening of only completely red and dark red fruits. Moreover, looking over a period of several years the effect of ripening on the content of these ingredients is mostly overlapped by the effect of the crop year and provenance (weather conditions and rainfall) (Akagic et al. 2020). Due to the range caused by the crop year an exact determination of the ripening stage by means of these ingredients is not possible yet. Especially in the case of cornelian cherry, where the quality of the raw fruit and therefore also of the processed products made from these fruits depend very much on the ripening stage and the harvest method. The ripening-progress from the unripe to the overripe stage usually takes only a few (mostly 2–4) days on the tree depending on the weather conditions. Just in this time the sensory properties of the fruit increase significantly. Ripe and overripe fruit mostly drop from the tree even without shaking, unripe fruit mostly do not drop from the tree without shaking. In order to lower the harvest costs trees are usually shaken before a harvest pass to increase the yield of each pass. Thus many unripe fruit are harvested which decrease the quality of the raw material which is dedicated for processing. Therefore, the harvesting method has a big impact on the quality of the fruit obtained for processing. A parameter to assess the ripening stage is decidedly required by the processors.

The aim of this study is to find a parameter that enables the processing companies to determine the quality of cornelian cherry not only by skin colour and firmness, but also by means of chemical analysis of ingredients depending on the ripening stage (unripe, ripe, overripe), method of harvest (shaking or not-shaking) of the fruit available on the local market. Thus, several species of cornelian cherries available on the Austrian market, as well as two wild genotypes, were analyzed at different ripening stages, completely red and dark red fruit of the final ripening process (ripening stages within the desired sensory properties of the fruits change significantly) in order to find a parameter for reliable assessment of the required ripening stage of the fruits for the first time.

Materials and methods

Fruit material

Cornelian cherries of 6 species (big fruit) available on the Austrian market (Kasanlaker (Bulgaria), Jolico (Austria), Schumener (Bulgaria), Schönbrunner Gourmetdirndl (Austria), Bulgarico (Bulgaria), Kaukasische (Austria)) and a wild genotype (small fruit) from the experimental orchard of the Federal College and Institute for Viticulture and Pomology Klosterneuburg, Lower Austria (precipitation: 600 mm, mean air temperature: 9.8 °C, altitude: 360 m), and Kasanlaker and Schumener as well as a wild genotype from one of the main cornelian cherry orchards in Austria, in Pillichsdorf, Lower Austria (precipitation: 300 mm, mean air temperature: 10.0 °C, altitude: 192 m) of the harvest years 2014, 2015 and 2016 were obtained. Only red and dark red fruits were collected from the orchards in August and September (two replicates) and classified into 3 degrees of ripeness according to their physical (and sensory) characteristics. The classification was done according to their firmness, because there are always too some red soft fruits or dark red firm fruits on the tree: unripe (completely red, but firm, unpleasant taste (sour and very astringent, bitter), less aromatic, low sensory quality); ripe (red and smooth (noticeably soft—less firm than unripe and firmer than overripe), fruity, pleasant taste (sweet, less sour) – for fresh market, high sensory quality); overripe (red or dark red and soft (too soft for fresh market), aromatic, high sensory quality for processing).

Analysis

Colour components were measured using the CIELAB-system. L*, a*, b*, C* and h°-values of frozen cornelian cherry pulp were measured with a Minolta CM 3500d (spectrophotometric method, D65, 30 mm, gloss excluded, Japan). An acceptance factor (AF = a*/h), in order to describe the colour changes empirically, was calculated according to previous studies (Gössinger et al. 2009). The firmness of 15 fresh fruits of a specific ripening stage was measured with a texture analyzer Mecmesin AFG 500 N with a Mecmesin M1000E (stamp: 5 mm, penetration speed 6, penetration depth: 3 mm, UK). The maximum force for penetrating the fruit is expressed as Kg/0.5cm2.

Soluble solid content (SSC) (expressed as °Bx) was measured using a refractometer REF711gB (Arcada, Germany). Total Acidity (TA) (0.1n NaOH, pH: 8.1) was measured using a pH-electrode SenTix 81 and a pH-meter pH 523 (WTW, Germany) and calculated as tartaric acid (factor: 0.75) (g/Kg)) (Graf et al. 2018; Association of Offical Analytical Chemists 1990).

The samples for ion-chromatography (IC) and HPLC analysis were prepared as follows: 250 g fruit of each replicate were selected, stones were removed and the pulp was homogenized with a food blender and stored at − 20 °C. The frozen mash was weighed and lyophilizied (180 mbar, 20 °C, 72 h) (type 1 m Alpha 1–4, Martin Christ, Germany). The lyophilisate was milled with a cryo mill (Retsch, Germany) and stored at − 21 °C until use (Wendelin et al. 2018). All values are expressed as mg/Kg fresh weight.

For the extraction of sugars and organic acids the lyophilisate was washed three times with deionised water, treated for 10 min in an ultrasound bath (Soronex RK 100, Bandelin, Germany) and centrifuged (10 min, 2200 × g) (Heraeus megafuge 40R, Thermo, USA). Carbohydrates (sugars) and organic acids were analyzed by IC (Dionex ICS 3000, Dionex, USA) with electrochemical detection (sugars: electrode ED 40 Gold electrode, Dionex, USA, organic acids: anion exchange column IonPac AG 11-HC and AS 11-HC, Dionex, USA); standards: sugar: D-glucose, D-fructose, galactose, myo-inositol (Merck, Germany), organic acids: L-malic acid, quinic acid, tartaric acid, citric acid monohydrate (Fluka-Sigma, USA), fumaric acid, oxalic acid, galacturonic acid (Merck, Germany)) as described previously (Weiss 1995) with modified gradients according to the work instructions Dionox AN122.

Phenolic components: cinnamic and benzoic acids and flavonoids were analyzed with a rapid resolution HPLC method (Vrhovsek 1997). The extraction was done with methanol (70%) and deionized water (30%). HPLC (Agilent 1200, Agilent, USA), RP-C18 column (Poroshell 120 SB-C18, Agilent, USA), detection: DAD at 280 nm, 320 nm and 362 nm, mobile phase: eluents: 0.5% formic acid and methanol. Standards: gallic acid, ferula acid, p-coumaric acid, quercetin 3-O-rutinoside (Roth, Germany), catechin, chlorogenic acid, caffeic acid, epicatechin, protocatechuic acid (Sigma, Japan) and quercetin 3-O-galactoside, quercetine 3-O-glucoside, quercetin 3-O-glururonide, quercetin 3-O-rhamnoside, kaempferol 3-O-glucoside (Extrasynthese, France).

The anthocyanin content was measured by HPLC following the modified method (Eder et al. 1990). HPLC: Agilent 1090, Agilent, USA, RP-C18 column (LiChromCart-cartridge 250–4, Merck, Germany), detection: DAD at 525 nm, mobile phase: 0.05 mM phosphate puffer (pH value: 1.8) and methanol, standards: pelargonidin 3-O-glucoside and cyanidin 3-O-glucoside. Extraction was done with methanol (85%), deionized water (15%) and acetic acid (0.5%). Total anthocyanins are expressed as cyanidin 3-O-glucoside equivalent (mg/Kg fresh weight).

Total phenolic content was determined by the Folin–Ciocalteau assay (Zoecklein et al. 1994). The extraction was done with methanol (70%) and deionized water (30%). Folin–Ciocalteau reagent (Merck, Germany), spectrometer: Agilent 8453 (Agilent, USA), detection at 765 nm. The results are expressed as caffeic acid equivalent (mg/Kg fresh weight).

In order to define the potential of each parameter for the description of the ripening stages the “sensitivity” of each parameter was calculated as follows: difference-amount of the mean of the unripe value and ripe value (sensitivity UR) or unripe value and overripe value (sensitivity UO) devided each to the average standard deviation of the two ripening stages, respectively.

Statistical analysis (mean, standard deviation, analysis of variance (ANOVA), Tukey-HSD) was carried out using SPSS 26 (Statistical Package for the Social Science) and Microsoft Excel (Microsoft GmbH).

Results and discussion

Generally, results of the analyzed parameters of cornelian cherries found in literature show a wide range due to the variety of methods and equipment used (Szot et al. 2019; Yarilgac et al. 2019) (e.g. different colour measurement conditions, spectrometers and calculation of data) and probably because of the different stages of ripeness of the analyzed fruit. Moreover, the constituents of the raw fruit are very much dependent on the weather and provenance (Akagic et al. 2020; Drkenda et al. 2014). Furthermore, selected species and wild genotypes of cornelian cherries are described, whose compositions differ clearly in most cases (Ercisli et al. 2011; Szczepaniak et al. 2019).

In this study the constituents are shown separately for species and wild genotypes because the breeding selection of cornelian cherries with big fruits out of smaller wild genotype fruits is mostly accompanied by a significant decrease of several constituents, as can easily be seen in Table 1 (e.g. °Bx, TA, total anthocyanins).

Table 1.

Means of physical and chemical parameters depending on ripening stage of big and small cornelian fruits

Parameters Big fruits (species) Small fruits (wild genotyps)
Unripe Ripe Overripe Unripe Ripe Overripe
firmness [Kg/cm2] 1.55 ± 0.78b 0.49 ± 0.24a 0.26 ± 0.2a 1.31 ± 0.29b 0.41 ± 0.24a 0.14 ± 0.07a
L* 34.01 ± 4.65b 29.74 ± 3.93b 27.10 ± 3.08a 28.40 ± 1.42b 27.28 ± 1.87 ab 22.20 ± 4.65 a
a* 47.47 ± 1.94b 46.27 ± 2,07ab 44.94 ± 2.30a 48.09 ± 1.10a 47.44 ± 0.98a 42.52 ± 5.19a
b* 23.01 ± 1.77 a 22.66 ± 1.70 a 22.11 ± 1.58 a 25.29 ± 1.84 a 25.65 ± 1.41 a 22.14 ± 2.83 a
C* 52.78 ± 2.04 a 51.53 ± 2.46 a 50.09 ± 2.68 a 54.37 ± 0.26 a 53.96 ± 0.27 a 47.95 ± 5.91 a
h° 25.86 ± 1.77 a 26.08 ± 1.17 a 26.18 ± 0.88 a 27.74 ± 2.24 a 28.41 ± 1.80 a 27.50 ± 0.23 a
AF 1.85 ± 0.17 a 1.78 ± 0.1 a 1.72 ± 0.09 a 1.74 ± 0.18 a 1.68 ± 0.14 a 1.55 ± 0.18 a
°Bx 14.3 ± 2.30 a 14.9 ± 2.80 a 15.1 ± 2.50 a 18.1 ± 1.87 a 18.6 ± 2.20 a 19.4 ± 2.40 a
glucose [g/Kg] 45.96 ± 12.43 a 49.76 ± 12.20 a 49.05 ± 9.67 a 44.15 ± 9.31 a 46.92 ± 10.36 a 50.57 ± 10.24 a
fructose [g/Kg] 45.43 ± 11.51 a 49.43 ± 12.20 a 49.56 ± 9.44 a 42.45 ± 8.36 a 42.50 ± 4.79 a 50.10 ± 7.17 a
galactose[mg/Kg] 26.49 ± 36.27 a 85.91 ± 94.15 ab 115.67 ± 86.42 b 33.92 ± 39.43 a 105.11 ± 23.99 ab 147.38 ± 48.45 b
xylitol [mg/Kg] 1851 ± 1010 a 1911 ± 928 a 1962 ± 942 a 1268 ± 446 a 1298 ± 512 a 1247 ± 400 a
myo-inositol [mg/Kg] 344 ± 149 a 289 ± 93 a 342 ± 122 a 354 ± 78 a 395 ± 96 a 502 ± 142 a
Total acidity [g/Kg] 33.13 ± 3.10 a 32.86 ± 4.40 a 31.98 ± 4.53 a 37.01 ± 2.04 a 36.08 ± 1.08 a 36.21 ± 2.35 a
malic acid [g/Kg] 21.89 ± 5.01 b 20.92 ± 6.08 ab 17.92 ± 5.13 a 26.21 ± 5.82 a 24.24 ± 3.71 a 20.72 ± 1.87 a
quinic acid [g/Kg] 14.46 ± 2.20a 14.61 ± 2.30a 14.31 ± 2.37 a 15.40 ± 3.73 a 16.12 ± 1.81 a 15.94 ± 2.40 a
tataric acid [mg/Kg] 1060 ± 368a 1040 ± 310a 985 ± 265a 1055 ± 346a 1171 ± 390a 1143 ± 347a
citric acid [mg/Kg] 446 ± 153a 431 ± 149a 405 ± 1451a 533 ± 204a 642 ± 275a 543 ± 207a
fumaric acid [mg/Kg] 814 ± 1032a 669 ± 424a 609 ± 312a 838 ± 670a 757 ± 512a 637 ± 283a
oxalic acid [mg/Kg] 377 ± 112a 376 ± 144a 318 ± 108a 470 ± 247a 457 ± 161a 364 ± 151a
galacturonic acid [mg/Kg] 227 ± 206a 324 ± 181a 325 ± 219a 346 ± 238 a 443 ± 323a 369 ± 126
caffeic acid [mg/Kg] 0.64 ± 0.56a 0.56 ± 0.20a 0.51 ± 0.21a 0.43 ± 0.19a 0.40 ± 0.27a 0.57 ± 0.17a
p-coumaric acid [mg/Kg] 0.25 ± 0.15a 0.28 ± 0.11ab 0.35 ± 0.17b 0.33 ± 0.15a 0.30 ± 0.14a 0.33 ± 0.13a
ferulic acid [mg/Kg] 1.40 ± 0.71a 1.49 ± 0.72a 1.44 ± 0.64a 2.77 ± 0.97a 2.62 ± 0.75a 2.78 ± 0.62a
chlorogenic acid [mg/Kg] 4.13 ± 2.54a 5.18 ± 3.70a 5.34 ± 3.71a 21.98 ± 6.90a 23.61 ± 4.33a 26.13 ± 3.9a
gallic acid [mg/Kg] 9.13 ± 5.24a 12.25 ± 7.58 a 24.66 ± 16.80b 6.07 ± 1.58 a 8.11 ± 1.87a 15.97 ± 3.3b
protocatechuic acid [mg/Kg] 2.11 ± 0.84 a 2.20 ± 0.98 a 2.26 ± 1.21a 1.80 ± 1.23a 3.00 ± 1.91a 2.63 ± 1.44a
catechin [mg/Kg] 4.18 ± 5.40a 3.96 ± 5.27a 3.30 ± 3.15a 2.97 ± 1.54a 3.83 ± 2.1a 4.90 ± 3.06a
epicatechin [mg/Kg] 2.51 ± 2.35a 2.63 ± 1.89 a 3.97 ± 2.65a 5.55 ± 5.65a 7.56 ± 5.84a 7.10 ± 5.30a
Pel-3-glu [mg/Kg] 17.63 ± 13.54a 32.91 ± 27.05ab 43.43 ± 41.21b 15.46 ± 13.61a 21.90 ± 12.76a 25.74 ± 16.83a
Cy-3-glu [mg/Kg] 16.38 ± 11.72a 36.55 ± 33.08ab 48.92 ± 51.48b 17.23 ± 12.31a 22.89 ± 13.70a 26.60 ± 16.76a
total anthocyanins [mg/Kg] 877 ± 271 a 1322 ± 897 b 1362 ± 680 b 1304 ± 784 a 1938 ± 315 a 2054 ± 224 a
Qu-3-gal [mg/Kg] 1.25 ± 0.76 a 2.25 ± 1.15 b 2.84 ± 1.15 b 2.17 ± 1.15 a 3.73 ± 1.35 ab 5.28 ± 1.11 b
Qu-3-glur [mg/Kg] 11.78 ± 6.06 a 16.45 ± 8.63 ab 18.29 ± 10.89 b 26.78 ± 12.72 a 30.85 ± 12.85 a 41.52 ± 13.87 a
Qu-3-glu [mg/Kg] 6.59 ± 2.13 a 7.30 ± 2.64 a 7.88 ± 3.90 a 7.18 ± 3.63 a 6.48 ± 3.60 a 7.85 ± 4.13 a
Qu-3-rut [mg/Kg] 1.14 ± 0.56 a 1.45 ± 0.59 ab 1.61 ± 0.65 b 2.55 ± 1.28 a 2.65 ± 0.67 a 3.35 ± 0.95 a
Qu-3-rham [mg/Kg] 0.36 ± 0.19 a 0.50 ± 0.34 a 0.56 ± 0.53 a 0.75 ± 0.51 a 1.00 ± 0.79 ab 2.08 ± 0.92 b
Kae-3-glu [mg/Kg] 0.50 ± 0.27 a 0.93 ± 0.32 b 1.08 ± 0.41 b 1.05 ± 0.39 a 1.75 ± 0.51 b 1.97 ± 0.38 b
Total phenols [mg/Kg] 8996 ± 2008 a 8363 ± 2235 a 7930 ± 1989 a 7637 ± 2545 a 7723 ± 1641 a 8463 ± 1539 a
Open in a new tab

values are presented as mean ± standard deviation of all big fruits or small fruits according to their ripening stage

mean values with same letters in line of big fruits or small fruits mean no significant differences for analysed parameters, Tukey`s test at P < 0,05

Firmness and colour components

Immediately after harvest the red and dark red fruits were manually classified into the three ripening stages according to their firmness. Due to the experience of the authors that most but not all dark red and many red coloured fruits are of high sensory quality and therefore the colour of the cornelian cherries does not always correlate sufficiently with the desired ripening stages (sensory quality, astringency), the main criterion in classifying the ripening stage was the firmness of the fruit. Table 1 gives an overview of the mean values of firmness, AF and colour components of the species (big fruit) and wild genotypes (small fruit) according to their ripening stage. Although the colour components and firmness are hardly comparable to those found in literature, the main characteristics and extent of changes are the same. The L*, a*, b* and C*-values, as well as the AF decrease (darker colour) during ripening. However, looking at the mean and standard deviation of the samples, in most cases, no significant differences could be detected, except in L*-values and a*-values of the species. The differences do not allow a significant differentiation of the unripe, ripe and overripe fruit due to the impact of species, provenance and crop year.

Significant differences in firmness between the ripening stages were observed in both cases, as expected (Table 1). Red or dark red fruits softer than about 0.5 kg/0.5cm2 are of high sensory quality. The significant increase of sensory parameters between the defined ripening stages unripe and ripe has not been mentioned in literature. In this study the selected ripening stages are characterized properly for the first time. As processing companies obtain not fresh, but frozen fruit or puree, however, the parameter firmness cannot serve as an adequate reference for quality assessment of the raw material.

Total acidity (TA) and soluble solid content (SSC)

The values of TA and SSC vary greatly, depending on the atmospheric conditions (rainfall, sunshine hours, temperature), age of trees and yield (TA: 27–37 g/L, species (big fruit): 12–18.5°Bx, wild genotypes (small fruit): 16–22°Bx). It is well known that the SSC as well as the TA do not change much during the last ripening stages (Graf et al. 2018). In this study there was no significant correlation between the ripening stage and the content of SSC or TA either. Therefore, these data cannot be recommended to determine the quality (ripening stage) of the cornelian cherries.

Carbohydrates (sugars) and organic acids

In order to determine the quality of cornelian cherries (stage of ripeness) not from fresh fruit but from frozen fruit, pulp or puree some carbohydrates (sugars) and organic acids, whose concentrations usually change during ripening, were analyzed. The organic acid contents differ significantly from those in literature even though the TA is more or less equal to some species (Akagic et al. 2020). To give an overview, the impact of the ripening stages on sugar and organic acid values of species and wild genotypes are shown in Table 1. The contents of most of the analyzed organic acids and sugars vary more within the crop years than within the ripening stages. In Table 2 the mean of selected acids and sugars of big and small fruit depending on the harvest year are shown. Galactose differed significantly between unripe and overripe fruit of the species as well as of the wild genotypes (Table 1). However, no clear differentiation between unripe and ripe fruit could be made. Unexpectetly in 2016 galactose could not even be dedected (Table 2). Unripe fruit showed a significantly higher malic acid content than overripe but not ripe fruit of the species. Thus neither organic acid nor sugar contents can be recommended as a reference for distinguishing between the unripe and ripe cornelian cherries to a satisfying degree.

Table 2.

Mean of selected acids, sugars and flavonols of big and small cornelian fruit depending on the harvest year

2014 2015 2016
malic acid [g/Kg] Small fruits 22.85 ± 1.98 a 25.92 ± 4.14 a 22.42 ± 6.33 a
Big fruits 21.17 ± 3.14 b 15.84 ± 3.74 a 25.51 ± 3.52 c
quinic acid [g/Kg] Small fruits 15.57 ± 1.17 a 17.42 ± 4.18 a 22.42 ± 6.33 a
Big fruits 13.73 ± 2.83 a 14.20 ± 2.00 a 15.16 ± 2.17 a
gallic acid [mg/Kg] Small fruits 9.92 ± 4.02 a 9.73 ± 2.97 a 10.50 ± 7.57 a
Big fruits 19.05 ± 2.97 b 18.76 ± 10.30 b 9.05 ± 7.57 a
p-coumaric acid [mg/Kg] Small fruits 0.32 ± 0.08 ab 0.45 ± 0.08 b 0.20 ± 0.11 a
Big fruits 0.19 ± 0.46 a 0.38 ± 0.16 b 0.22 ± 0.09 a
glucose [g/Kg] Small fruits 54.00 ± 5.18 b 51.31 ± 5.68 b 36.33 ± 7.10 a
Big fruits 47.10 ± 9.13 b 56.79 ± 7.59 c 37.74 ± 6.98 a
fructose [g/Kg] Small fruits 49.22 ± 6.14 a 43.69 ± 5.33 a 42.15 ± 9.96 a
Big fruits 43.75 ± 9.71 a 55.06 ± 8.85 b 41.62 ± 9.46 a
galactose [mg/Kg] Small fruits 98.35 ± 17.77 101.60 ± 86.84 nn
Big fruits 121.51 ± 69.43 58.53 ± 83.32 nn
Kae-3-glu [mg/Kg] Small fruits 1.83 ± 0.51 b 1.75 ± 0.50 ab 1.18 ± 0.55 a
Big fruits 1.13 ± 0.35 b 0.71 ± 0.28 a 0.84 ± 0.51 a
Qu-3-gal [mg/Kg] Small fruits 4.60 ± 1.70 a 3.01 ± 1.96 a 3.52 ± 1.40 a
Big fruits 1.96 ± 1.03 a 2.29 ± 1.29 a 1.96 ± 1.24 a
Open in a new tab

values are presented as mean ± standard deviation of all big fruits or small fruits according to the harvest year

mean values with same letters in line of big fruits or small fruits mean no significant differences for analysed parameters, Tukey`s test at P < 0,05

Phenolic components

The contents of selected cinnamic and benzoic acids as well as flavanols as a function of the ripening stage are shown in Table 1. No significant difference between the selected ripening stages, except the content of p-coumaric acid of species and gallic acid of species and wild genotypes could be measured, mostly due to the differences within the crop years (Tables 1 and 2). But even in these cases a clear differentiation of unripe and ripe fruits is not possible, only between unripe and ripe versus overripe fruits.

There are reports of a significant increase of flavonoids during ripening in literature (Agdham et al. 2019). In this study this can only be confirmed in some cases (anthocyanins, flavonols) within the selected ripening stages. The content of total anthocyanins as well as of pelargonidin 3-O-glucoside (main anthocyanin in cornelian cherry (Pawlowska et al. 2010)) and cyanidin 3-O-glucoside increase significantly during ripening of the species, but not of the wild genotypes (Table 1). The pelargonidin 3-O-glucoside and cyanidin 3-O-glucoside content differ significantly between unripe and overripe fruits of the species, but not between unripe and ripe fruits. However, it is possible to adequately differentiate between unripe and ripe cornelian cherry species by means of the total anthocyanin content.

Many of the measured flavonols show significant changes within the ripening stages over the years. While unripe and overripe (not ripe fruits) cornelian cherries show significant different contents of quercetin 3-O-glururonide, quercetin 3-O-rutinoside and quercetin 3-O-rhamnoside only of either species or wild genotypes, but not in both cases, this is the case for quercetin-3-O-galactoside and kaempferol-3-O-glucoside, which have a high potential for quality assessment (determining the ripening stage) of cornelian cherries. Quercetin-3-O-galactoside may serve as an adequate parameter to distinguish between unripe and ripe fruits of species and unripe and overripe fruits of wild genotypes (Table 3). Especially kaempferol 3-O-glucoside is eligible to distinguish between unripe, ripe and overripe cornelian cherries independent of the fruit size (species and wild genotypes) (Table 1), provenience and variability of the years (Table 2). All samples showed a significant increase in kaempferol-3-O-glucoside within the ripening stages. In literature an increase of these two flavonols is described as a factor of altitude and precipitation (Drkenda et al. 2014). In low and dry locations values are lower than in mountainous areas with heavy rainfall. In literature there are also other flavonols described to some extent in much higher concentrations (Pawlowska et al. 2010). Further studies are necessary to obtain more information about the impact of ripening on the content of several flavonols. Nevertheless, they are an appropriate parameter for distinguishing unripe from ripe and overripe Austrian cornelian cherries. No general absolute value for all cornelian cherries (species and wild genotypes) can be defined for the differentiation of improper and proper fruits for processing. However, in light of the fact that the content of kaempferol-3-O-glucoside in each species, as well as the wild genotypes, increases significantly with ongoing ripening in each year, this parameter can be recommended as a reference for raw material assessment for fruit processors. A value of about 1.75 mg/Kg for wild genotypes and of about 0.90 mg/Kg for big cornelian cherry species could be an indicator for high quality fruits adequate for processing satisfactory products.

Table 3.

sensitivity of parameters for characterization of the ripening stages of big and small fruit (sensitivity between unripe and ripe (UR) and unripe and overripe (UO))

Parameters BIG fruits Small fruits
Sensitivity UR Sensitivity UO Sensitivity UR Sensitivity UO
firmness [Kg/cm²] 2.08 2.55 3.40 6.50
Kae-3-glu [mg/Kg] 1.46 1.71 1.56 2.39
Qu-3-gal [mg/Kg] 1.05 1.66 1.25 2.75
L* 1.00 1.79 0.68 2.04
galactose[mg/Kg] 0.91 1.45 2.25 2.58
Cy-3-glu [mg/Kg] 0.90 1.03 0.44 0.64
total anthocyanins [mg/Kg] 0.76 1.02 1.15 1.49
Pel-3-glu [mg/Kg] 0.75 0.94 0.49 0.68
Qu-3-glur [mg/Kg] 0.64 0.77 0.32 1.11
a* 0.60 1.19 0.63 1.77
C* 0.56 1.14 1.55 2.08
Qu-3-rut [mg/Kg] 0.54 0.78 0.10 0.72
Qu-3-rham [mg/Kg] 0.53 0.56 0.38 1.86
AF 0.52 1.00 0.38 1.06
galacturonic acid [mg/Kg] 0.50 0.46 0.35 0.13
gallic acid [mg/Kg] 0.49 1.41 1.18 4.03
myo-inositol [mg/Kg] 0.45 0.01 0.47 1.35
fructose [g/Kg] 0.34 0.39 0.01 0.99
chlorogenic acid [mg/Kg] 0.34 0.39 0.29 0.76
glucose [g/Kg] 0.31 0.28 0.28 0.66
Total phenols [mg/Kg] 0.30 0.53 0.04 0.40
Qu-3-glu [mg/Kg] 0.30 0.43 0.19 0.17
°Bx 0.24 0.33 0.25 0.61
p-coumaric acid [mg/Kg] 0.23 0.63 0.21 0.00
caffeic acid [mg/Kg] 0.21 0.34 0.13 0.78
b* 0.20 0.54 0.22 1.35
fumaric acid [mg/Kg] 0.20 0.31 0.14 0.42
malic acid [g/Kg] 0.17 0.78 0.41 1.43
h° 0.15 0.24 0.33 0.19
ferulic acid [mg/Kg] 0.13 0.06 0.17 0.01
citric acid [mg/Kg] 0.10 0.05 0.46 0.05
protocatechuic acid [mg/Kg] 0.10 0.15 0.76 0.62
Total acidity [g/Kg] 0.07 0.30 0.60 0.36
quinic acid [g/Kg] 0.07 0.07 0.26 0.18
xylitol [mg/Kg] 0.06 0.11 0.06 0.05
tataric acid [mg/Kg] 0.06 0.24 0.32 0.25
epicatechin [mg/Kg] 0.06 0.58 0.35 0.28
catechin [mg/Kg] 0.04 0.21 0.47 0.84
oxalic acid [mg/Kg] 0.01 0.54 0.06 0.53
Open in a new tab

The total phenol content varies too much within the ripening stages over the years and is therefore not adequate to indicate high quality (ripening stage) of fruits. Whereas in our study (7.6–9.0 g/Kg) the values are quite high, in the literature lower (2.5–9.0 g/Kg) (Szczepaniak et al. 2019) and higher (12.0–23.0 g/Kg) (Yarilgac et al. 2019) contents are described.

Even the calculated rates of several sugars, organic acids and phenolic components do not give more information about the ripening stage. No significant improvement of quality assessment of any calculated rate could be stated. Results are therefore not shown in detail.

Conclusions

To serve as a reference in order to distinguish between poor and good quality of raw material, parameters are necessary that show on the one hand significant changes between the ripening stages, and on the other hand none or only little variability due to provenance and crop year (weather conditions). Many ingredients and parameters of cornelian cherry of different species and ripening stages were analysed in order to best assess the quality of cornelian cherries for processing. Due to the impact of the crop year (weather conditions) and to some extent the species, none of the parameters, except flavonols, especially kaempferol-3-O-glucoside, could be defined as a reference for determining the proper ripening stage for processing (Table 2 and 3). This is a surprising result, as the sensory qualities (astringency, bitterness, sourness) of the cornelian cherries of the various selected ripening stages differed significantly. This work, for the first time in research, presents a constituent that allows the classification of ripening stages and therefore an adequate assessment of the quality of cornelian cherries for processing. Moreover, the issue of a clear definition of the ripening stage should be considered to a greater extent when interpreting results of former studies and characterizing cornelian cherry species in upcoming research.

Authors’ contributions

MG: conceived and wrote the MS, fruit sourcing. FK: carried out the experiments (fruit analysis, physical parameters). SW: carried out the experiments (phenol analysis). KK: carried out the experiments (carbohydrate analysis). HJ: assistance, correct the MS. LW: fruit sourcing. MG: fruit analysis, assistance, correct the MS.

Funding

Not applicable.

Availability of data and material

The datasets used and analysed during the study (means are shown in Table 1) are available from the corresponding author on reasonable request.

Code availability

Not applicable.

Declarations

Conflict of interest

Not applicable.

Ethical approval

Not applicable.

Consent to participate

Not applicable.

Consent for publication

Not applicable.

Footnotes

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

  1. Agdham MS, Kakavand F, Rabiei V, Zaare-Nahandi F. y-Aminobutyric acid and nitric oxide treatments preserve sensory and nutritional quality of cornelian cherry fruits during postharvest cold storage by delaying softening and enhancing phenols accumulation. Sci Hortic. 2019;246:812–817. doi: 10.1016/j.scienta.2018.11.064. [DOI] [Google Scholar]
  2. Akagic A, Oras AO, Zuljevic SO, Spaho N, Drkenda P, Bijedic A, Memic S, Hudina M. Geographic variability of sugars and organic acids in selected wild fruit species. Foods. 2020;9:462. doi: 10.3390/foods9040462. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Association of Official Analytical Chemists (1990) Official methods of analysis, virginia, association of official analytical chemists INC.
  4. Cosmulescu S, Trandafir I, Cornescu F. Antioxidant capacity, total phenols, total flavonoids and colour component of cornelian cherry (Cornus mas L.) wild genotypes. Not Bot Horti Agrobo. 2019;47(2):390–394. doi: 10.15835/nbha47111375. [DOI] [Google Scholar]
  5. De Biaggi M, Donno D, Mellano MG, Riondato I, Rakotoniaina EN, Beccaro GL. Cornus mas (L.) fruit as a potential source of natural health-promoting compounds: physico-chemical characterisation of bioactive components. Plant Foods Hum Nutr. 2018;73:89–94. doi: 10.1007/s11130-018-0663-4. [DOI] [PubMed] [Google Scholar]
  6. Drkenda P, Saphic A, Begic-Akagic A, Gasi F, Vranac A, Hudina M, Blanke M. Pomological characteristics of some autochthonous genotypes of cornelian cherry (Cornus mas L.) in Bosnia and Herzogovina. Erwerbs-Obstbau. 2014;56:59–66. doi: 10.1007/s10341-014-0203-9. [DOI] [Google Scholar]
  7. Eder R, Wendelin S, Barna J. Auftrennung der monomeren rotweinanthocyane mittels hochdruckflüssigkeitschromatographie (HPLC) – methodenvergleich und Vorstellung einer neuen Methode. Mitt Klosterneuburg. 1990;40:68–75. [Google Scholar]
  8. Ercisli S, Yilmaz SO, Gadze J, Dzubur A, Hadziabulic S, Aliman J. Some fruit characteristics of cornelian cherries (Cornus mas L.) Not Bot Hort Agrobot Cluj. 2011;39(1):255–259. doi: 10.15835/nbha3915875. [DOI] [Google Scholar]
  9. Gössinger M, Mayer F, Radocha N, Höfler M, Boner A, Groll E, Nosko E, Bauer R, Berghofer E. Consumer`s color acceptance of strawberry nectars from puree. J Sens Studies. 2009;24:78–92. doi: 10.1111/j.1745-459X.2008.00196.x. [DOI] [Google Scholar]
  10. Graf M, Korntheuer K, Gössinger M. Bestimmung des optimalen reifegrades von marillen für die verarbeitung. Mitt Klosterneuburg. 2018;68:27–38. [Google Scholar]
  11. Gunduz K, Saracoglu O, Özgen M, Serce S. Antioxidant, physical and chemical characteristics of cornelian cherry fruits (Cornus mas L.) at different stages of ripeness. Acta Sci Pol, Hortorum Cultus. 2013;12(4):59–66. [Google Scholar]
  12. Kava-Rygielska J, Adamenko K, Kucharska A, Piorecki N. Bioactive compounds in cornelian cherry vinegars. Molecules. 2018;23:379. doi: 10.3390/molecules23020379. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Moldovan B, Filip A, Clichici S, Suharoschi R, Bolfa P, David L. Antioxidant activity of cornelian cherry (Cornus mas L.) fruits extract and the in vivo evaluation of its anti-inflammatory effects. J Funct Foods. 2016;26:77–87. doi: 10.1016/j.jff.2016.07.004. [DOI] [Google Scholar]
  14. Pawlowska AM, Camangi F, Braca A. Quali-quantitative analysis of flavonoids of Cornus mas L. (Cornaceae) fruits. Food Chem. 2010;119:1257–1261. doi: 10.1016/j.foodchem.2009.07.063. [DOI] [Google Scholar]
  15. Pirc H. Enzyklopädie der wildobst und seltenen obstarten. Graz: Leopold Stocker Verlag; 2015. [Google Scholar]
  16. Szczepaniak OM, Kobus-Cisowska J, Kusek W, Przeor M. Functional properties of cornelian cherry (Cornus mas L.): a comprehensive review. Eur Food Res and Techn. 2019;245:2071–2087. doi: 10.1007/s00217-019-03313-0. [DOI] [Google Scholar]
  17. Szot I, Szot P, Lipa T, Sosnowska B, Dobrzanski B. Determination of physical properties of cornelian cherry (Cornus mas L.) fruits depending on degree of ripening and ecotypes. Acta Sci Pol Hortorum Cultus. 2019;18(2):251–262. doi: 10.24326/asphc.2019.2.22. [DOI] [Google Scholar]
  18. Tarko T, Duda-Chodak A, Satora P, Sroka P, Pogon P, Machalica J. Chaenomeles japonica, Cornus mas, Morus migra fruits characteristics and their processing potential. J Food Sci Technol. 2014;51(12):3934–3941. doi: 10.1007/s13197-013-0963-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Vrhovšek U (1997) Quantitative bestimmung von hydroxyzimtsäuren und hydroxyzimtsäurederivaten (Hydroxycinnamaten) in Weißwein mittels HPLC. Dissertation, Universität für Bodenkultur Wien
  20. Weiß J (1995) Ionenchromatographie (2. Ausg.),VCH Verlagsgesellschaft, Weinheim
  21. Wendelin S, Korntheuer K, Baumann R, Brandes W. Vergleich von Wildheidelbeeren (Vaccinium myrtillus) und Kulturblaubeeren (Vaccinium carymbosum) hinsichtlich ausgewählter Inhaltsstoffe. Mitt Klosterneuburg. 2018;68:221–240. [Google Scholar]
  22. Yarilgac T, Kadim H, Ozturk B. Role of maturity stages and modified-atmosphere packaging on the quality attributes of cornelian cherry fruits (Cornus mas L.) throughout shelf life. J Sci Food Agric. 2019;99:421–428. doi: 10.1002/jsfa.9203. [DOI] [PubMed] [Google Scholar]
  23. Yilmaz KU, Ercisli S, Zengin Y, Sengul M, Kafkas EY. Preliminary characterisation of cornelian cherry (Cornus mas L.) genotypes for their physico-chemical properties. Food Chem. 2009;114:408–412. doi: 10.1016/j.foodchem.2008.09.055. [DOI] [Google Scholar]
  24. Zoecklein BW,Fugelsang KC, Gump BH, Nury FS (1994) Wine analysis and production. Chapmann and Hall

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

The datasets used and analysed during the study (means are shown in Table 1) are available from the corresponding author on reasonable request.

Not applicable.

Articles from Journal of Food Science and Technology are provided here courtesy of Springer

RESOURCES