Antioxidant Capacity of Dark Red Corn – Biochemical Properties Coupled with Electrochemical Evaluation

Biochemistry coupled with electrochemical approach is employed in a fast, relatively simple, yet highly precise detection of a plant extract antioxidant properties. Antioxidant capacity of dark red corn grains was investigated electrochemically using cyclic voltammetry (CV) on glassy carbon electrode (GC). The linear polarization resistance (LPR) measurements were performed for examining the corrosion inhibitive behavior of polyphenolics on mild steel. The consistent positive correlation (r=0.99) was established between total phenolic and flavonoid contents obtained by CV measurements and spectrophotometric antioxidant assay (DPPH test). Both analyses confirm the high antioxidant activity of tested pigments. Determination of the corrosion inhibition efficiency revealed that the red corn pigments have anti-corrosion effect on mild steels

Sugars and organic acids content in unripe and ripe fruits of Sambucus nigra

Elderberry (Sambucus nigra L.) is a common plant used for its medicinal and nutritional properties, as for the beverages, jams, liqueurs, flavourings etc. Plant material examined were leaves and fruits of wild edible, and cultivated elderberry plants (’Haschberg’ and ’Ljubostinja’ selections). Determination of organic acids and sugars was performed using high-performance liquid chromatography. Organic acids found in the tested fruit samples were citric, tartaric, malic, quinic, shikimic and fumaric acids, out of which quinic acid content was the highest in unripe, while citric acid content was the highest in ripe fruits. Wild plants had higher contents of organic acids in unripe fruits (16.7 g 100 g-1dw) than cultivated (’Haschberg’ 6.6, and ’Ljubostinja’ 6.3 g 100 g-1dw). ’Ljubostinja’ selection had significantly higher organic acids content (10.2 g 100 g-1dw) in ripe fruits compared to wild specimen and ’Haschberg’ plants which had similar organic acids content (7.0 and 7.4 g 100 g-1dw). The major organic acid in ripe elderberry fruits was citric acid. When it comes to sugars content the presence of sucrose, glucose, fructose and sorbitol was established. Wild specimen had significantly higher sugars content (2.2 in unripe, and 8.4 g 100 g-1dw in ripe fruits)

Total and individual phenolics in wild and cultivated elderberry during development

Compounds which add to bioactivity of elderberry (Sambucus nigra L.) are mostly phenolic compounds. One wild edible and two cultivated genotypes (’Haschberg’ and ’Ljubostinja’ selections) have been chosen. Leaves and fruits were collected in four stages (April-September). Total phenolics (TP) content was determined from MeOH extracts by Folin-Ciocalteau method while determination of individual compounds was performed using HPLC-DAD-ESI-MSn analysis with a DAD at 280, 350 and 530 nm. TP content in leaves varied through developmental stages, being higher in II and III stage. Leaves and fruits (both unripe and ripe) of ’Ljubostinja’ plants had higher content of TP compared to wild ripe fruits (1.5-fold). Leaves had caffeic acid derivatives (0.3-0.7% in wild, 0.2-0.3% in ’Haschberg’ and 0.4-0.6% in ’Ljubostinja’ in dry weigh) and caffeoylquinic acid derivatives, while fruits had more caffeoylquinic acid derivatives, particularly unripe fruits. The major phenolic acid present in leaves, especially during the II stage of development, was chlorogenic acid (approx. 4% dw) and the same was recorded in fruits (0.03% dw in unripe fruits of wild plants). Content of phenolic acids decreased during ripening of elderberry fruits and the similar was detected in the leaves

Changes in quality characteristics of fresh blueberries: Combined effect of cultivar and storage conditions

The influences of two storage conditions (regular atmosphere-RA and modified-atmosphere packaging-MAP) and different storage time on fruit textural parameters, chemical composition, and total quality index (TQI) of two blueberry cultivars were investigated. Freshly harvested fruit of mid and late season cultivars (‘Bluecrop’ and ‘Liberty’, respectively) were placed in plastic punnets, packed into low-density polyethylene bags of 25 μm thickness with two perforations of 3 mm and stored at 2 ◦C and 90% relative humidity for 30 days, either in RA or in MAP. Changes in gas composition inside the package and fruit quality characteristics were analyzed at 10- day intervals during storage: 0, 10, 20, and 30 days. ‘Liberty’ was dominant over ‘Bluecrop’ in terms of hardness (428 g and 296 g, respectively), as well as individual and total sugars (100 and 76 g⋅kg–1, respectively), organic acids (19 and 12 g⋅kg–1, respectively) and most subclasses of phenolic compounds (anthocyanins, flavonols, and hydroxycinnamic acids). In addition, a novel mathematical index of TQI was introduced to compare all evaluated parameters in order to obtain a quantitative single score, as an indicator of overall fruit quality. ‘Liberty’ had the better TQI score in RA, whereas ‘Bluecrop’ behaved better in MAP. Accordingly, for longer storage of blueberry fruit MAP should not be assumed to be uniformly helpful, since the effect of storage duration in the specific type of atmosphere substantially depends on the proper cultivar selection

Changes in quality characteristics of fresh blueberries: Combined effect of cultivar and storage conditions

The influences of two storage conditions (regular atmosphere-RA and modified-atmosphere packaging-MAP) and different storage time on fruit textural parameters, chemical composition, and total quality index (TQI) of two blueberry cultivars were investigated. Freshly harvested fruit of mid and late season cultivars (‘Bluecrop’ and ‘Liberty’, respectively) were placed in plastic punnets, packed into low-density polyethylene bags of 25 μm thickness with two perforations of 3 mm and stored at 2 ◦C and 90% relative humidity for 30 days, either in RA or in MAP. Changes in gas composition inside the package and fruit quality characteristics were analyzed at 10- day intervals during storage: 0, 10, 20, and 30 days. ‘Liberty’ was dominant over ‘Bluecrop’ in terms of hardness (428 g and 296 g, respectively), as well as individual and total sugars (100 and 76 g⋅kg–1, respectively), organic acids (19 and 12 g⋅kg–1, respectively) and most subclasses of phenolic compounds (anthocyanins, flavonols, and hydroxycinnamic acids). In addition, a novel mathematical index of TQI was introduced to compare all evaluated parameters in order to obtain a quantitative single score, as an indicator of overall fruit quality. ‘Liberty’ had the better TQI score in RA, whereas ‘Bluecrop’ behaved better in MAP. Accordingly, for longer storage of blueberry fruit MAP should not be assumed to be uniformly helpful, since the effect of storage duration in the specific type of atmosphere substantially depends on the proper cultivar selection

Утицај секторијалне резидбе на продуктивност, вегетативни раст и квалитет плода сорте боровнице „Duke“ (Vaccinium corymbosum L.) гајене у супстрату

Рад приказује резултате компаративног испитивања утицаја секторијалне (СР) и конвенционалне резидбе (КР) биљака високожбунасте боровнице на параметре генеративног и вегетативног потенцијала, као и физичке и хемијске особине плода. СР, као нова стратегија резидбе боровнице која се примењује у Чилеу, подразумева да се сваке године уклони само 1/4 од укупног броја базалних грана у жбуну, без уклањања и скраћивања грана у осталим секторима жбуна, што може допринети: 1) олакшаном и бржем извођењу резидбе; 2) смањењу утрошка радне снаге; 3) побољшању осветљености у централном делу жбуна; 4) повећању приноса. Испитивања су вршена у периоду од 2019. до 2021. године у комерцијалном засаду боровнице, који се налази у месту Гружа (општина Кнић). Засад је подигнут у пролеће 2017. године садњом двогодишњих биљака сорте "Duke" у саксије запремине 113 l, које су испуњене супстратном смешом састављеном од струготине четинара и белог тресета (однос 50:50). Саксије су постављене на растојању од 0,8м у реду и 3,0м између редова (4170 биљака/ha). Добијени резултати су показали да је у третману са СР регистрован значајно нижи број плодова (1.233) и принос по жбуну (2,16 kg/жбуну), који се повећавао током година испитивања, достижући највишу вредност од 3,06 kg у 2021. години. Значајно повећање у вегетативном расту је забележено само код пречника базалних грана у третману са КР, док се висина и ширина жбуна нису значајно разликовале у зависности од примењеног начина резидбе. КР је испољила позитиван утицај на масу, димензије плода, број семенки у плоду и садржај укупних шећера, са доминантним учешћем фруктозе и глукозе (40,3 и 37,6 g/kg FW по редоследу), док је у третману са СР забележено значајно повећање садржаја укупних киселина (17,08 g/kg FW са највећим уделом лимунске и квинске киселине (7,14 и 9,17 g/kg FW по редоследу). Садржај укупних антоцијана, деривата хидроксициметних киселина, укупних флавонола и флаванола је био значајно већи у плодовима убраним у третману са СР

Morphometric and biochemical screening of old mulberry trees (Morus alba L.) in the former sericulture region of Slovenia

Over centuries, in many European countries, the white mulberry trees (Morus alba L.) became an integral part of the cultural landscape, bearing witness to past sericulture activities. The distribution records of white mulberry trees in the cultural landscape are incomplete and in general poorly documented. The aim of the presented research was to collect data regarding geographical locations of mulberry trees and to define their morphological and biochemical variability in Goriška region, one of the historical sericulture regions in Slovenia. Principal component analysis of all morphometrical leaf traits allowed us to characterize two separate groups of morphotypes. Recordings of the tree pruning management revealed that annual base cutting is traditionally used in Goriška region. Significant correlations between pruning management and leaf morphology traits showed that frequently pruned trees form larger leaves. Biochemically, mulberry leaves are shown to be rich in proteins containing threonine, arginine, asparagine, serine, and glutamine as the most prominent free amino acids. The main phenolic compounds were identified as caffeoylquinic acid derivatives, quercetin malonyl-hexoside, rutin, kaempferol acetyl-hexoside, quercetin-3-glucoside, and p-coumaric acid derivatives. The difference in concentrations of the investigated metabolites is correlated either with the pruning management or the morphotype. Pruning significantly affected the levels of asparagine, alanine, and serine, which were higher in the annually pruned trees regardless of the morphotype. Furthermore, we were able to confirm a significant effect of pruning on total phenolics as well as on the levels of rutin, quercetin malonyl-hexoside, and quercetin-3-glucoside contents. Multivariate analysis allowed us to determine seven chemotypes with distinctive biochemical traits. Our results are the basis for defining superior high-yielding genotypes with optimum metabolic composition for both silkworm feeding as well as for innovative usage in food processing and pharmaceutical industries

Novel insights to the anti-proliferative activity of rosemary (Rosmarinus officinalis L.) co-treatment

The aim of this study was to characterize volatile and non-volatile compounds of rosemary from the North Adriatic region and to determine its antiproliferative activity, alone or in combination with radiomimetic bleomycin (BLM) on three malignant and one non-transformed human cell line. Chemical analysis of the volatile compounds revealed the presence of monoterpenes (93.8%), in which 1.8-cineol (32.9%) and camphor (15.5%) were the dominant compounds. Also, obtained results showed that the major polyphenolic constituents in rosemary extract were phenolic acids (rosmarinic acid and its derivatives up to 69.2 mg 100 g-1), as well as flavones and flavonols in the following order: luteolin>isorhamnetin>quercetin>kaempferol>apigenin. Cell growth test showed that rosemary extract alone exerted moderate antiproliferative activity, as well as a synergistic antiproliferative effect with bleomycin (EC50 344.3-461.5 µg mL-1 and 58.6-292 µg mL-1, respectively). The anti-tumor effect of rosemary extract in combination with BLM was much stronger, compared to BLM itself on the breast cancer cells. Through their proposed sensitizing effect, rosemary extracts, in combination with the standard chemotherapeutics, could be used for the investigations of possible therapeutic modalities