Franci Stampar

University of Ljubljana · Biotechnical Faculty

The aim of this study was to compare peeled and unpeeled dehydrated apple slices of the red-fleshed ‘Baya Marisa’ and the white-fleshed ‘Golden Delicious’, to analyze the difference in the content of sugars, organic acids, and phenolic compounds during the heat process of dehydration, and to compare it with our previous study on fresh apples of the...

Different climatic conditions are known to affect the synthesis of primary and secondary metabolites. Therefore, the phenolic contents in new growing areas could affect the quality and flavor of hazelnuts. The aim of this study was to determine the variability of the phenolic contents of the kernels in different commercial hazelnut cultivars depend...

We analyzed the red-fleshed apple cultivar ‘Baya Marisa’ and compared it with the traditional, white-fleshed apple cultivar ‘Golden Delicious’. The objective of this study was to compare sugars, organic acids, and phenolic compounds of ‘Baya Marisa’ with the widely known and consumed white-fleshed apple cultivar ‘Golden Delicious’. In addition, fle...

The study was aimed at assessing chemical composition of fruits of plum cultivars ʻČačanska Lepoticaʼ and ʻJojoʼ grafted on four rootstocks with different mechanisms of resistance to Plum pox virus (PPV): sensitivity, ʻWavitʼ and ʻWeiwaʼ and hypersensitivity, ‘Docera 6’ and ‘Dospina 235’. The cultivar significantly influenced on content of sugars a...

The polyphagous brown marmorated stink bug (Halyomorpha halys Stål.) is an important pest in many countries. Recently it was noticed that it can feed on and cause damage to strawberries (Fragaria × ananassa Duch.). The metabolic response of strawberries to brown marmorated stink bug attacks was studied. Brown marmorated stink bugs attacked strawber...

Lamb's lettuce is a popular winter salad, often grown in private vegetable plots, small local farms or in intensive vegetable production. It is usually marketed as a ready-to-eat produce in supermarkets. The aim of the study was to evaluate the changes in biochemical composition and degradation of bioactive compounds during consumer-relevant time o...

Nitrogen is an integral element of foliar sprays during apple fruit formation. However, in red cultivars, the application may have adverse effects on color in the second stage of fruit development. The effect of a low-dose foliar application of urea was monitored on ‘Topaz’ apple pomometric (fruit mass, firmness, total solids, starch content, skin...

The brown marmorated stink bug (BMSB; Halyomorpha halys Stal.) has become a significant pest in Slovenia, especially in apple, pear, peach, and cherry orchards. In our study, apple fruit of the apple cultivar ‘Red Pinova’ were evaluated for visual injury and sugar, organic acid, and phenolic contents. The chemical composition of the area around the...

BACKGROUND Japanese dogwood (Cornus kousa Burg.) is a popular ornamental plant which develops edible compound fruit utilized in traditional Asian medicine. Previous compositional studies have focused on a small fraction of secondary metabolites at a single maturity stage. In order to address the question of optimal ripeness of Japanese dogwood frui...

Drying fruit is one of the simplest ways to extend the shelf-life of fruit, especially berries. Both higher temperature and time of heating significantly change the contents of some primary and secondary metabolites in honeysuckle fruit. Differences in their contents arising from different heat treatments were determined with the aid of high-perfor...

Honeysuckle berries are becoming an attractive organically grown fruit with many aspects as a new functional food. They have the benefit of containing health-promoting compounds, such as saponins, ascorbic acid, iridoids, flavonoids, and anthocyanins. Fruit berries can be processed into many products with various contents of selected bioactive comp...

Despite fruit seeds being considered fruit waste, they have good potential in human diet. The present research investigated the levels of bioactive compounds (phenolics and cyanogenic glycosides)in apple seeds of the cultivar ‘Golden Delicious’ grown in four different orchards in the world and their change over the course of 8 months of storage. Bo...

The aim of this study was to assess content of primary and secondary metabolites of 18 plum cultivars selected in Serbia. Autochthonous cultivar 'Crvena Ranka' exhibited the highest level of total sugars (174.3 g/kg FW) while cultivar 'Mildora' had the highest sugars/acids ratio (17.2). Cultivar 'Nada' also contained high sugars/acid ratio as well...

BACKGROUND: Sambucus species have been used for various purposes. Many people know that some of the Sambucus species display high antioxidant activity, but it is much less well-known that they also contain harmful compounds – cyanogenic glycosides. OBJECTIVE: Different cyanogenic glycosides and phenolics were determined in three different Sambucus...

Environmentally-conscious organic strawberry fruit producers are mostly cultivating plants in non-heated greenhouses and striving to produce fruit early in season. Several strategies have been proposed to advance strawberry fruit formation, among them the use of seaweed extract in combination with silicon. The aim of the present research was to eva...

Walnut husk fly (WHF) is the main pest of common walnut. Its negative impact on external fruits’ properties is frequently reported, while inner kernel quality loss remains unknown. Brown (Bw), dark brown (Db) and black (Bl) kernels, infested by WHF were compared with non-infested bright kernels (B) in ten walnut cultivars in order to see how much s...

Walnut husk fly (WHF) is the main pest of common walnut. Its negative impact on external fruits' properties is frequently reported, while inner kernel quality loss remains unknown. Brown (Bw), dark brown (Db) and black (Bl) kernels, infested by WHF were compared with non-infested bright kernels (B) in ten walnut cultivars in order to see how much s...

High yields and good apple fruit quality depend on the appropriate training system. Long-term monitoring of solaxe and spindle training systems was conducted in western Slovenia. ‘Golden Delicious’, ‘Fuji Kiku 8’, ‘Gala Galaxy’, ‘Braeburn Hillwell’, ‘Fuji Raku Raku’, ‘Rubinola’, ‘Pink Rose’ (‘Pink Kiss’) and ‘Juliet’ (‘Coop 43’) were included in th...

The aim of the study was to evaluate in which way nine cultivars of sweet cherry fruit cope with postharvest, artificial inoculation with Monilinia laxa pathogenic fungus through changes in sugars, organic acids and polyphenolic compounds, as well as which phenolics compounds are crucial participants in coping with the disease. Contents of sugars i...

Organically grown blue honeysuckle berries have become extremely popular in the last few years, mainly because of their taste and high ascorbic acid content. With the spectrophotometer and aid of high-performance liquid chromatography (HPLC) coupled with mass spectrophotometry (MS) we compare the content of organic and ascorbic acids, sugars, indiv...

Chemical composition and colorimetric parameters of alcoholic liqueurs prepared from rose petals were evaluated by comparing the potential of three cultivars (‘Amadeus’ ‘Colossal Meidiland’ and ‘Rosanna’) and three traditional methods of preparation (fresh/air-dried petals extracted in 50% ethanol or aqueous sucrose syrup). Extraction was performed...

Common cyclamen (Cyclamen pururascens Mill.) is a very interesting species not only for various breeding programs but also as an ornamental plant. The plants possess interesting floral and foliage characteristics, nice fragrances, and a very useful flavonol profile. The last is very important from the point of view of protecting against diseases an...

The content of selected compounds was compared among different spear sections (the tip, the middle, and the base) of green (Ariane F1, Dariana F1, Darsiane F1, Mondeo F1, Primaverde F1, and Viridis F1) and purple (Burgundine F1 and Pacific Purple F1) asparagus cultivars. Sugars, organic acids, anthocyanins, flavonols, flavones, and hydroxycinnamic...

Background: Interest in organic blue honeysuckle berries has increased in recent years. They are rich in various health promoting compounds, which are sensitive to different environmental factors and are modified during the growing season. Results: Honeysuckle berries from different locations significantly differed in contents of primary and sec...

In fruit production seeds are mostly regarded a waste, but for plants they represent a beginning of new life. Seeds accumulate toxic or health-beneficial compounds and the elucidation of their metabolic profile is especially important to people who consume the entire fruit, including the seeds. The present research quantifies the levels of bioactiv...

The occurrence of the abscission signal in young developing fruits on apple trees (Malus domestica) was studied. Apple has a natural system of fruitlet shedding, so called June drop. Although physiological fruit drop is unable to guarantee production of marketable apples and avoid alternate bearing, knowledge of this is a key background for success...

Detailed anthocyanin and flavonol profiles were investigated in three flower segments of four different hybrid primrose (Primula ×polyantha) cultivars, and individual compounds were identified using high-performance liquid chromatography (HPLC)/mass spectrometry system. Chlorophyll a and b and total carotenoids were evaluated spectrophotometrically...

The value of plant provenance (plant origin) is well-known phenomena in woody plants, but less is known in herbaceous plants (perennials). This study with common cyclamen (Cyclamen purpurascens Mill.) was conducted to reveal the importance of specific environmental site properties of plant origin for plant growth and plant quality in the next years...

European hazelnut (Corylus avellana L.), cultivated in several areas of the world including Europe, Anatolia, and the USA, is an economically important nut crop due to its high mineral, oleic acid, amino acid, and phenolic compound content and pleasant flavor. This study examined molecular genetic diversity and population structure of 54 wild acces...

The main purpose of the present study was to evaluate the diversity and content of various phenolic compounds in floral infusions of 14 elderberry genotypes (3 species and 9 interspecific hybrids). Detailed phenolic analysis was performed using HPLCMS. Hydroxycinnamic acids (HCAs) were the major phenolic group identified and 3-, 4-, and 5-caffeoylq...

Introduction. Anthracnose disease causes severe economic losses in strawberry (Fragaria × ananassa) production. Plant response to the pathogen attack is closely linked to its content and composition of polyphenols. In order to reduce the damage caused by pathogens, organic and inorganic fungicides are applied. The aim was to determine the influence...

Background: Elderberry (Sambucus nigra L.) possesses high antioxidant activity and has been used to ail numerous medicinal disorders. In addition to their antioxidant properties, elderberry parts accumulate toxic cyanogenic glycosides (CGG). It has been proven that altitude influences the biosynthesis of many secondary metabolites. In the present...

Blueberry fruits are frequently processed to different products, which are subjected to different temperature regimes during their manufacture. Therefore, the aim of this study was to evaluate the impact of different temperatures (4 °C, room temperature, 50 °C, 75 °C and 100 °C) on the stability of soluble solids, pH value, color and primary and se...

Sugars, organic acids, carotenoids, tocopherols, chlorophylls, and phenolic compounds were quantified in fruit of 4 wild growing Prunus species (wild cherry, bird cherry, blackthorn, and mahaleb cherry) using HPLC-DAD-MSn. In wild Prunus, the major sugars were glucose and fructose, whereas malic and citric acids dominated among organic acids. The m...

Stock mother plants have gained importance in the process of adventitious rooting of woody plants in recent years. The present study reveals the role of the cutting position from a stock mother plant for subsequent rooting. Cuttings of Prunus subhirtella Miq. var. Autumnalis which originated from suckers at the bottom of a tree developed a rooting...

Differences in the content of sugars, organic acids, total phenolics and antioxidative activity have been evaluated among three different elderberry species (Sambucus nigra, Sambucus cerulea, Sambucus javanica) and seven interspecific hybrids. The highest content of sugars has been determined in the fruits of JA × CER hybrid and the lowest in fruit...

Background: Three different irrigation regimes (upper limit of field capacity-UFC (-12 hPa), lower limit of field capacity-LFC (-33 hPa) and deficit irrigation-DI (-70 hPa)) were established on silty-loam soil and monitored with tensiometers. Yield and fruit quality of 'Flamenco' and 'Eva's Delight' ever-bearing strawberry cultivars have been moni...

Wild albino and blue bilberry fruit were analyzed to compare different fruit characteristics linked to the composition of primary and secondary metabolites. Compounds were identified using HPLC-MS and standard quality parameters were determined. Albino berries were significantly smaller, accumulated less water and were characterized by 23% higher d...

Phenolic compounds are not directly involved in the primary metabolism of plants but possess a number of important roles: (1) serving as attractants for pollinators and various animals, involved in the transfer of seeds, (2) plant protection from herbivores and against pathogen infection, (3) defining plant-plant relationships and the symbiosis bet...

Elderberry fruit and its food products are not only a rich source of phenolics, boosting their antioxidant activity, but also contain harmful cyanogenic glycosides. In order to assess the potential positive/negative effects of consuming elderberry-based products their biochemical profile and levels of individual compounds were identified with the a...

The abscission process and the modifications in the levels of selected metabolites were monitored on ‘Golden Delicious’ apples in a two-year study. Individual sugars were analyzed using HPLC-RI and individual phenolics by UHPLC–PDA–MS. Fruitlets from lowest positions were most likely to shed. Moreover, fruits from the position nearest to the king f...

Popular liqueurs made from apricot/cherry pits were evaluated in terms of their phenolic composition and occurrence of cyanogenic glycosides (CGG). Analyses consisted of detailed phenolic and cyanogenic profiles of cherry and apricot seeds as well as beverages prepared from crushed kernels. Phenolic groups and cyanogenic glycosides were analyzed wi...

Morphological parameters (size, weight, color), the content of sugars, organic acids, lycopene, β-carotene, and phenolics were determined in hips of Rosa canina (RCA), Rosa sweginzowii (RSW), Rosa rugosa (RUG), and selected ornamental Rosa cultivars Fru Dagmar Hastrup (FDH), Repandia (REP), Veilchenblau (RVB), Aloha (RAL), Bonica (BON), and Golden...

As blueberries ripen successively and are commercially harvested over a period of several weeks, their composition may be altered during the harvest. The aim of this study was to compare blueberry fruit composition during the entire harvest season. Fully ripe fruits of two northern highbush blueberry cultivars (Bluecrop and Jersey) were harvested w...

Aim: Two different yield reductions based on cluster thinning (CT) were performed to determine their impact on vine growth, yield, and grape and wine composition of 'Blauer Portugieser' grapevine variety. Methods and results: Two levels of cluster thinning (limited CT1 – 20-30 % and severe CT2 – 40-50 % cluster reduction) were applied at the pea-s...

The changes in indole-3-acetic acid (IAA) and indole-3-acetic acid aspartate (IAA-Asp) levels in leafy cuttings of Prunus subhirtella ‘Autumnalis’ were studied in 2011. Leafy cuttings were severed from mature, semi-mature and juvenile stock plants on 20th of June when a half of them were treated with indole-3-butyric acid (IBA) powder (0.5% IBA + 1...

The purpose of this study was to investigate composition and content of phenolic compounds in seeds of common buckwheat (Fagopyrum esculentum Moench) cultivars from Western, Central and Southeastern Europe grown in the Balkan area, and to compare them with cultivars from the Balkan. Mostly detected hydroxycinnamic acids in seeds of the investigated...

Background: Persimmon is a seasonal fruit and only available in fresh form for a short period of year. In addition to freezing, drying is the simplest substitute for the fresh fruit and accessible throughout the year. The effect of mellowing and drying was evaluated in 'Tipo' persimmon, an astringent cultivar. Results: 'Tipo' firm fruit containe...

Apple trees (Malus domestica Borkh.) develop an abundance of flowers and shed the majority of fruitlets in the first developmental stages. In this study the process of abscission was monitored in cultivar 'Golden Delicious' and linked with the position of fruitlets in the cluster, focusing on differences among central or king flower/fruit (K1), flo...

The composition of non-infected and Colletotrichum nymphaeae infected strawberry fruits (cultivar 'Asia') in three different stages of ripeness were evaluated. Additionally, the effect of infection on strawberry runners was monitored. C. nymphaeae infection caused a significant increase in total sugar content in mature fruits (1.1 fold) and a decre...

The aim of this study was to investigate a detailed composition and content of phenolic compounds in fruits of 4 elderberry species (Sambucus nigra, S. cerulea, S. ebulus, and S racemosa) and 8 interspecific hybrids. Hydroxycinnamic acids (HCAs) represented the major share of phenolics in analyzed elderberries; caffeoylquinic and p-coumaroylquinic...

Background: Watercore is a physiological disorder affecting fruit of some apple (Malus domestica Borkh.) cultivars. Intercellular spaces are filled with fluid, which reduces intercellular air space volume. In this study individual phenolic content, sugars and organic acids in watercore affected flesh have been identified and quantified. Peroxidase...

The red color of skin is a much desired property in apple production. For better red fruit coloration the applications of foliar fertilizers on the basis of calcium and phosphorus are used. In the present study 'Braeburn' apple trees were sprayed twice with Phostrade Ca (phosphorus), 5 and 3 weeks before harvest. In 7-days intervals fruit color, th...

The distribution of betalains in peel, flesh, and petioles of yellow and red beetroot cultivars has been investigated using an High-performance liquid chromatography (HPLC) system with electrospray mass spectrometry. Differences in the levels of betacyanins and betaxanthins between different colored cultivars were individually determined for 3 plan...

Leafy cuttings of Prunus subhirtella Miq. 'Autumnalis' were harvested from mature, semi-mature and juvenile stock plants at four dates during the vegetative period 2011 (on 16th of May, on 30th of May, on 20th of June and on 11th of July) and their auxin levels (IAA, IAA-Asp) and sugar content (glucose, sucrose, sorbitol) were quantified. The IAA a...

The influence of various rootstocks for peach [Prunus persica (L.) Batsch] on the phenolic content in the phloem above and below the graft union was investigated, based on the role of phenols in graft incompatibility. Assays of phloem with cambium from 7-year-old peach trees of 'Royal Glory' cultivar, which were grafted on different rootstocks ('GF...

There are no defined maturity parameters for berry fruit which often results in harvesting and marketing of inedible, immature or over ripe berries. In the present study the changes in quality characteristics of different white-, red-, and black-currant cultivars as well as gooseberry and jostaberry fruit were investigated at three maturity stages....

Leafy cuttings of Prunus subhirtella Miq. ‘Autumnalis’ were harvested from mature, semi-mature and juvenile stock plants at four dates during the vegetative period 2011 (on 16th of May, on 30th of May, on 20th of June and on 11th of July) and their auxin levels (IAA, IAA-Asp) and sugar content (glucose, sucrose, sorbitol) were quantified. The IAA a...

Background As a part of the ongoing interest in nutritional and nutraceutical properties of locally produced fruits, the aim of the article was to determine sugars, organic acids, polyphenols and antioxidant capacity of wild bilberries grown in Slovenia. Primary and secondary metabolite composition of bilberry fruit was compared among six phyto-cli...

The effect of fruit size (<26 mm, 26-28 mm, >28 mm) and fruit colour (Ctifl 4 and Ctifl 6) of ‘Kordia’ sweet cherry on composition of nutritive (sugars, organic acids) and bioactive (phenolics) compounds, on content of vitamin C, total phenolic content (TPC) and total antioxidant activity (TAA) was evaluated. The compositional data analysis was use...

Primary and secondary metabolites of Rosa canina hips were determined by HPLC/MS during ripening and after frost damage. Rose hips were harvested six times from the beginning of September until the beginning of December. Color parameters a*, b* and L* decreased during maturation. Glucose and fructose were the predominant sugars representing up to 9...

Traditional elderflower beverages are very popular due to their pleasing taste and pro-health properties. Phenolics were quantified in three elderflower extracts (methanolic extraction and two water extracts prepared as fresh drinks according to local recipes) with HPLC-MS. Chromatographic patterns of methanolic and water extracts were quite simila...

A broad range of anthocyanins (glycosides of cyanidin, pelargonidin, peonidin, delphinidin, malvidin, and petunidin) was identified and quantified in the fruit of 24 wild and cultivated berry species using HPLC-DAD-MS2. The anthocyanin composition in species of Ribes, Rubus, Vaccinium, and Fragaria genus as well as in less known species of Crataegu...

The quality of fruit from PPV (Plum pox virus)-infected plum (Prunus domestica L.) trees, was investigated during the last 3 weeks of ripening using healthy tree (T3), tree with short-term infection (T2) and tree with long-term infection (T1). The pomological variables (presence of necrosis on fruit, colour of fruit, colour of flesh, firmness, solu...

Extreme weather events like high solar radiation can cause stress in apple fruits (Malus domestica Borkh.). The aim of the study was to make a screening of individual phenols and peroxidase activity in apple peel as a response to sunburn and different sun-exposure in the period when weather conditions are suitable for sunburn occurrence. Apple frui...

The influence of eggplant grafting on tomato rootstock was evaluated during the two growing seasons. Yield, quality traits and individual phenolics in fruits were assessed. Three commercial varieties and one landrace were used as scions. Grafting significantly increased eggplant yield and decreased the presence of calyx prickles. The effect of graf...

The focus of our investigation was the influence of various rootstocks for peach of different genetic origin on phytochemical composition in the phloem above and below the graft union, and the role of phenols in graft compatibility/incompatibility. Assays of phloem with cambium from 6-year-old ‘Royal Glory’ peach trees, grafted on rootstocks of var...

The paper reports the phenolic content of kernels, bagasse pellets (residue of oil pressing) and oils from'five different cultivars and a mix of cultivars. Phenolic compounds were identified by high-performance liquid chromatography coupled with mass spectrometry. Two compounds, glansreginin A and glansreginin B, were detected for the first time in...

A total of 19 different anthocyanins have been detected in four elderberry species and eight hybrids and quantified with the use of HPLC-MSn. The profile and content levels of anthocyanins varied considerably among the analyzed elderberry species and hybrids. Cyanidin-3-O-sambubioside and cyanidin-3-O-glucoside were the most abundant anthocyanins i...

The effect and rate of anthracnose infection was evaluated on four French bean cultivars: 'Paulista' and 'Berggold' (tolerant), and 'Topcrop' and 'Re dei Burri' (susceptible). Artificial inoculation with Colletotrichum lindemuthianum was performed and the infection rate assessed on technologically mature bean pods. Healthy tissue, symptomatic spot,...

The study focuses on the response of apple primary and secondary metabolism and some important quality parameters to three living mulch treatments, classical herbicide fallow and black polypropylene strip application in two apple cultivars. Primary and secondary metabolites were analyzed after ten years of ground cover experiments. Soluble solids,...

Fruit diameter increase was monitored in four apple cultivars during three consecutive years (2006-2008) from t-stage until harvest. Individual fruit diameter increase was described using a negative exponential equation. Fruit growth curves of early ('Gala Brookfield'), mid-season ('Golden Delicious Reinders') and late ripening apple cultivars ('Br...