Jonas Viškelis

Lithuanian Research Centre for Agriculture and Forestry · Institute of Horticulture

The fruits of Vaccinium oxycoccos L. are an important source of bioactive compounds with antibacterial, antifungal, and anti-inflammatory effects. Studies on the phytochemical analysis of cranberry fruit samples showed that the qualitative and quantitative composition of biologically active compounds varied in cranberry fruit samples collected from...

Citrus fruits have been the subject of extensive research over the years due to their impressive antioxidant properties, the health benefits of flavanones, and their potential use in the prevention and treatment of chronic diseases. Grapefruit have been shown in studies to improve overall health, with numerous potential benefits, including improved...

Mosquitoes act as vectors of pathogens that cause most life-threatening diseases, such as malaria, Dengue, Chikungunya, Yellow fever, Zika, West Nile, Lymphatic filariasis, etc. To reduce the transmission of these mosquito-borne diseases in humans, several chemical, biological, mechanical, and pharmaceutical methods of control are used. However, th...

Because of the recent global crises and lifestyle trends, anthocyanin-rich fruits are receiving more attention due to their medicinal qualities. Many studies have concluded that higher anthocyanin consumption tends to correlate with health benefits. Furthermore, research has shown great promise for anthocyanin application in treating fever and neur...

This study aimed to utilize two by-products, acid whey and apple pomace, as well as an indigenous Lactococcus lactis LL16 strain with the probiotic potential to produce a sustainable cheese with functional properties. Acid whey protein cheese was made by thermocoagulation of fresh acid whey and enhancing the final product by adding apple pomace, L....

Silver nanoparticles (AgNPs) biosynthesized using aqueous medical plant extracts as reducing and capping agents show multiple applicability for bacterial problems. The aim of this study was to expand the boundaries on AgNPs using a novel, low-toxicity, and cost-effective alternative and green approach to the biosynthesis of metallic NPs using Calen...

Common buckwheat (Fagopyrum esculentum M.) is highly rich in starches and polysaccharides. Nowadays, the use of common buckwheat in brewing processes and functional product development is gaining popularity as it is gluten-free and therefore suitable for those suffering from coeliac disease. Moreover, enzyme-assisted extraction for common buckwheat...

Silver nanoparticles (AgNPs) biosynthesized using by-products of tomatoes extracts as reducing and capping agents show multiple possibilities for solving various biological problems. The aim of this study was to expand the boundaries on AgNPs using novel low toxicity and production cost phytochemical method for the biosynthesis of nanoparticles fro...

Enzyme-assisted extraction is a valuable tool for mild and environmentally-friendly extraction conditions to release bioactive compounds and sugars, essential for silver nanoparticle (AgNP) green synthesis as capping and reducing agents. In this research, plant and fungal kingdoms were selected to obtain the enzyme-assisted extracts, using green sy...

Avena sativa (A. sativa) oats have recently made a comeback as suitable alternative raw materials for dairy substitutes due to their functional properties. Amylolytic and cellulolytic enzyme-assisted modifications of oats produce new products that are more appealing to consumers. However, the biochemical and functional alteration of products and ex...

Cranberries are used in the production of medicinal preparations and food supplements, which highlights the importance of triterpene compounds determination in cranberry fruit raw material. The aim of our study was to develop and validate for routine testing suitable UPLC-DAD methodology for the evaluation of triterpene acids, neutral triterpenoids...

Plant primary and secondary metabolites are a significant source for many applications, including extractions of functional components, green synthesis development, and producing higher-added value products. However, in the variety of botanicals, Aralia cordata Thunb. plant is getting attention for its similarity to ginseng. This study comprehensiv...

Production of cottage cheese leaves up to 90 percent of acid whey as a byproduct which is considered as a waste material by small and medium dairy plants. It contains significant amounts of fat, lactose, galactose, calcium phosphate, and lactic acid, all of which potentially have value and can be converted into nutritional and functional food produ...

Silver nanoparticles (AgNPs) biosynthesized using plant extracts as reducing and capping agents show multiple possibilities for solving various biological problems. The aim of this study was to expand the boundaries of AgNPs using a novel low toxicity and production cost phytochemical method for the biosynthesis of nanoparticles from Eucalyptus glo...

The aim of this study was to characterize the variation in biologically active compounds, antioxidant activity and physico-chemical properties in naturally grown bilberries gathered from different sites in Northern Europe. The variability in the biologically active compounds, antioxidant capacity and physico-chemical properties, as well as the deve...

The scientific community and industrial companies have discovered significant enzyme applications to plant material. This rise imparts to changing consumers’ demands while searching for ‘clean label’ food products, boosting the immune system, uprising resistance to bacterial and fungal diseases, and climate change challenges. First, enzymes were us...

Apples are seasonal fruits, and it is important to prepare them adequately for storage and ensure proper storage conditions. In this study, we used ten different apple cultivars: ‘Alva’, ‘Auksis’, ‘Connell Red’, ‘Cortland’, ‘Ligol’, ‘Lodel’, ‘Noris’, ‘Rubin’, ‘Sampion’, and ‘Spartan’. We studied the qualitative and quantitative composition of pheno...

Modern apple orchard systems should guarantee homogeneity of fruit internal and external qualities and fruit maturity parameters. However, when orchards reach productive age, a variation of these parameters takes place and mostly it is related to uneven light distribution within the tree canopy. The aim of the study was to evaluate the canopy posit...

Berries of Actinidia kolomikta (A. kolomikta) are known for high ascorbic acid content, but the diversity of phenolic compounds has been little studied. The present research aimed to investigate phenolic compounds and antioxidant activity in berries and leaves of twelve A. kolomikta cultivars. The UHPLC-ESI-MS/MS technique was used to determine dif...

Optimization of the extraction procedure using a multienzymes cocktail for common buckwheat (Fagopyrum esculentum M.) is important due to the yield, fermentable sugars, oligosaccharides and bioactive compounds for creating higher added value products. This study was undertaken to find out the optimum multienzymes-water extraction on yield and total...

Sea buckthorn (Hippophae rhamnoides L. (HR)) leaf powders are the underutilized, promising resource of valuable compounds. Genotype and processing methods are key factors in the preparation of homogenous, stable, and quantified ingredients. The aim of this study was to evaluate the phenolic, triterpenic, antioxidant profiles, carotenoid and chlorop...

The novelty of this study is twofold: AgNPs were obtained and characterized using Artemisia absinthium (A. absinthium), Humulus lupulus (H. lupulus), and Thymus vulgaris (T. vulgaris) plants extracts; moreover, a green and environmentally friendly approach for the synthesis of silver nanoparticles (AgNPs) using aqueous extracts was developed. This...

Apples are an important component of the diet and are used in the food industry in the production of food products and beverages. The aim of the study was to determine the changes in the biochemical composition and physicochemical properties of apples stored in a controlled atmosphere. We studied the biochemical composition (sugars, ascorbic acid,...

Apples are seasonal fruits, and thus after harvesting apples of optimal picking maturity, it is important to prepare them properly for storage and to ensure proper storage conditions in order to minimize changes in the chemical composition and commercial quality of the apples. We studied the quantitative composition of triterpenic compounds in the...

Raspberry (Rubus idaeus L.) seed oil (RSO) is considered as a source of high value bioactive compounds as fatty acids, tocopherols, tocotrienols, carotenoids, flavonoids, phytosterols, antioxidants, monoterpenes and many other chemical constituents. These compounds are appreciated as a source of nutrition for humans, as additives in cosmetic produc...

Supercritical carbon dioxide extraction (SCE-CO2) is an attractive, green technology that is used for the recovery of biologically active compounds from plant material. The antioxidant potential of lipophilic fractions (extract obtained with SCE-CO2) and hydrophilic fractions (extracts obtained from the residue after extraction) obtained from a mat...

Lonicera caerulea L. is an early fruit-bearing plant that originates from harsh environments. Raw materials contain a body of different phenolic origin compounds that determine the multidirectional antioxidant and pharmacological activities. The aim of this study was to comprehensively evaluate the phenolic composition, antioxidant capacities, vege...

Background: Recent evidence indicates that elevating plasma nitrites through dietary nitrates (NO3-) supplementation is associated with enhanced muscle efficiency, fatigue resistance and performance. Beetroot (in various forms) is the dominant source of dietary NO3- primarily due to its vast availability and the simple form of preparation suitable...

The aim of this study was to determine the composition and content of phenolic compounds in ethanol extracts of eight different cultivars of American cranberry (Vaccinium macrocarpon Aiton) fruit using spectrophotometric and UPLC-ESI-MS/MS analysis and to evaluate the antioxidant activity in vitro of these extracts. The highest total amount of phen...

The effect of tree growth-control technologies on apple tree vegetative development, productivity and fruit quality was investigated with apple cultivar ‘Rubin’ on dwarf rootstock P 60 at the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry in 2015–2018. Eight treatments were established combining tree trunk incisi...

Apple (Malus domestica Borkh.) fruits are rich in phenolic glycosides, triterpenic acids and other biologically active compounds. The apples are widely used as food products due to their biologically active compounds that have specific biological effects. It is important to use high quality apples or their recycling products, so it is necessary to...

Over the past five years, the popularity of dietary nitrates as an ergogenic device among athletes has increased significantly. Hypoxic and acidic conditions that occur during exercise facilitate the conversion of nitrite to nitric oxide (NO) and increase the physiological efficiency of exogenously produced nitrite. After a few years of our team pr...

Products of lingonberries are widely used in the human diet; they are also promising beauty and health therapeutic candidates in the cosmetic and pharmaceutical industries. It is important to examine the sugar profile of these berries, due to potential deleterious health effects resulting from high sugar consumption. The aim of this study was to de...

A multi-location trial was performed in apple orchards planted in 2005 under a uniform scheme in Poland, Lithuania, Latvia and Estonia. The aim of this study was to evaluate the impact of the geographical apple-tree growing location on the accumulation of dominant bioactive compounds in apple fruits: phenolics and triterpenes as the most valuable s...

Eucalyptus globulus is employed as herbal tea and therapeutical purposes. In this work, it is investigated for first time the neuroprotective activities, based on antioxidant properties, of varying polarity extracts (acetone, ethanol and methanol) from E. globulus leaves and elucidate their main bioactive constituents. Methanol and acetone extracts...

Regardless of the numerous investigations of secondary metabolites, the impact of new growing technologies or individual technological means on fruit internal quality, particularly triterpene concentration in apple fruits has not been studied yet. Apple-tree (Malus × domestica Borkh.) growing technologies and geographical location of the growing si...

The ultrasound-assisted extraction of flavonoids from apple samples was modelled using response surface methodology. A three-level-three-factor central composite design using the response surface methodology (RSM) was employed to optimise three extraction variables, including temperature, extraction time and ultrasonic power, for the achievement of...

A new technique for the rapid detection and analysis of triterpenic compounds in apple extracts using HPLC was developed and validated. The main advantage of this technique is the short duration of the analysis – this makes this technique superior to others currently applied for the routine HPLC analysis of triterpenic compounds. The developed, opt...

The specific HPLC analytical procedure was developed and validated for the determination of phenolic compounds in pear samples of different popular cultivars “Conference,” “Concordia,” “Grabova,” and “Patten.” HPLC mobile phase consisted of 0.05% (v/v) trifluoroacetic acid in water and 100% (v/v) acetonitrile. The HPLC method was used to identify a...

Phenolic content of apples from an integrated and organic apple tree orchard was analysed at the Institute of Horticulture of Lithuanian Research Centre for Agriculture and Forestry in 2012-2013. Apples of 'Lodel' and 'Aldas' cultivars on rootstock B.396 in 8-9th leaf were tested. Nitrogen and potassium fertilizers were applied annually at the rate...

Nutrient uptake and transport depend on the root system of a tree. Various apple rootstock genotypes may interact fruit tree nutrition. The effect of apple (Malus × domestica Borkh.) rootstocks (M.9, M.26, B.396, P22, P59, P61, P62, P66, P67, Pure 1 and PB.4) on the mineral nutrition of leaf and fruit was studied in 2013–2015. The leaf and fruit mi...

The trial was carried out at the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry in 2013-2015. Cv. ‘Auksis’ was tested on 12 rootstocks: B.396, B.9, M.9, M.26, P 22, P 59, P 61, P 62, P 66, P 67, PB.4, and Pure 1. Accumulation of phenolic compounds depended on fruit yield and average fruit weight. On average, sign...

Maturity at harvest is very important attribute to tomatoes quality. This research showed that fully ripen tomato fruits had the highest amount of lycopene and β-carotene respectively 46.68 and 6.22 g kg-1. Therefore, it was determined correlation between amount of carotenoids and tomato ripening stages. Tomato fruit flesh lost it's firmness throug...

The methods recently applied for decontamination of fruits and vegetables are not always efficient, human and ecologically friendly. In this context, photosensitization might serve as really promising tool. Obtained data indicated that Botrytis spp. was susceptible to photosensitization and its growth inhibited 14 % and reduced 18 % rotten strawber...

Apples (Malus domestica L.) are the most common source of phenolic compounds in northern European diet. Besides pectins, dietary fibers, vitamins, and oligosaccharides they contain phenolic compounds of different classes. Apple powders are convenient functional forms retaining significant amounts of phenolic antioxidants. In this study reducing and...

The research objective was determination of ripening attributes of intact tomato (Lycopersicon esculentum Mill.) cv. ‘Rutuliai’ using near infrared (NIR) spectroscopy and reference analysis. Tomatoes were picked at six different ripening stages in order to evaluate the correlation between data obtained by near infrared spectra and physical-chemical...

One of the most important postharvest diseases of strawberry and raspberry is grey mould, caused by Botrytis cinerea Pers.: Fr. New non-chemical food safety technologies reducing berry rots and extending storage time were tested. Photosensitization is an innovative method for inhibition of pathogens in berry and is based on the interaction of light...

This work was done to evaluate the optimal postharvest storage parameters and shelf life of baby spinach. Baby spinach (50 g) was sealed in three different polypropylene (PP) and polyethylene (PE) packaging materials: 30 m (PP), 35 m (PE) & 40 m (PE), and were stored in darkness for 3 and 9 days at 0 °C, 4 °C, 8 °C & 16 °C ( 1 °C). Total conten...

Juices and beverages with bioactive compounds are consumed for their nutritive and health benefits. Beverages fortified with various functional ingredients are an important product category within the functional food segment. In this study tomato juice with various proportions of apple, carrot and sweet corn juice together with isomerised lycopene...

The study was done with the two peppermint (Mentha × piperita L.) cultivars – ‘Krasnodarskaja’ and ‘Peppermint’, whose leaves were dried using different methods. Investigation of fresh and dried herbs was carried out according to the biochemistry and technology methods. Essential oil was extracted using the hydro distillation method, the amount of...

The lycopene content in food may be increased by thermal and mechanical processing. Food processing is beneficial because it disrupts food matrices facilitating the release and solubilisation of lycopene resulting in increased carotenoid bioavailability for the formation of cis-isomers. A lycopene-rich and β-carotene oil-based system was used in th...