131 research outputs found
Model studies on the pattern of volatiles generated in mixtures of amino acids, lipid oxidation-derived aldehydes, and glucose
The development of flavor and browning in thermally treated foods results mainly from the Maillard reaction and lipid degradation but also from the interactions between both reaction pathways. To study these interactions, we analyzed the volatile compounds resulting from model reactions of lysine or glycine with aldehydes originating from lipid oxidation [hexanal, (E)-2-hexenal, or (2E,4E)-decadienal] in the presence and absence of glucose. The main reaction products identified in these model mixtures were carbonyl compounds, resulting essentially from amino-acid-catalyzed aldol condensation reactions. Several 2-alkylfurans were detected as well. Only a few azaheterocyclic compounds were identified, in particular 5-butyl-2-propylpyridine from (E)-2-hexenal model systems and 2-pentylpyridine from (2E,4E)-decadienal model reactions. Although few reaction products were found resulting from the condensation of an amino acid With a lipid-derived aldehyde, the amino acid plays an important role in catalyzing the degradation and further reaction of these carbonyl compounds. These results suggest that amino-acid-induced degradations and further reactions of lipid oxidation products may be of considerable importance in thermally processed foods
Comprehensive evaluation of antioxidant and antimicrobial properties of different mushroom species
Antioxidant properties of mushroom extracts sequentially isolated by cyclohexane, dichloromethane, methanol, and water from Phaeolus schweinitzii, Inonotus hispidus, Tricholoma columbetta, Tricholoma caligatum, Xerocomus chrysenteron, Hydnellum ferrugineum, Agaricus bisporus and Pleurotus ostreatus were evaluated by DPPH, ABTS+ scavenging capacity, ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and Folin–Ciocalteu total phenolic content (TPC) methods. The integrated values (‘antioxidant scores’) for evaluating antioxidant potential of extracts and dry mushroom substances are proposed. Antimicrobial activity was screened against Gram-positive (Bacillus cereus), Gram-negative (Pseudomonas aeruginosa) bacteria and fungi (Candida albicans) by agar diffusion method. The highest antioxidant capacity values (in μM TE/g extract dw) were found for methanol fractions of P. schweinitzii (9.62 ± 0.03 in DPPH; 109 ± 3 in FRAP; 164 ± 1 in ABTS+; 340 ± 3 in ORAC assays) and I. hispidus (9.5 ± 0.04 in DPPH; 54.27 ± 0.46 in ABTS+; 88.31 ± 1.96 in FRAP; 290 ± 1 in ORAC assays). Extracts of other species possessed considerably lower antioxidant activities. The extracts of I. hispidus were more effective against tested microbial species than other mushrooms. In conclusion, our results show that some wild mushrooms might be promising dietary sources of natural antioxidants and antimicrobial agents
Application of Raw and Defatted by Supercritical CO₂ Hemp Seed Press-Cake and Sweet Grass Antioxidant Extract in Pork Burger Patties
Received: 29 May 2021; Accepted: 12 August 2021; Published: 16 August 2021.There is an increasing tendency toward the application of plant origin ingredients in meat
products. This study evaluates the physicochemical properties and oxidative stability of pork
burger patties produced with the addition of dried raw and defatted by supercritical CO2 extraction
hemp seed press-cake as protein-rich ingredients (1.5–2.0%) and sweet grass ethanolic extract (0.5%)
as a strong natural antioxidant. The main aim of using such a combination was to assess the possibility
of mitigating the negative effects of hemp seed press-cake, containing approx. 10% of highly
unsaturated oil, on the oxidation of meat products. The patties were compared with the control
sample (without additives) during storage on days 0, 4, 8, 15, and 21 at 4 °C in modified atmosphere
conditions. Plant ingredients reduced the lightness of pork patties, while their effects on other physicochemical
characteristics were insignificant. The patties with fully defatted hemp seed flour
showed the lowest grilling losses. Based on the measurement of thiobarbituric acid reactive substances,
raw hemp seed press-cake increased the oxidative rate of pork patties; however, remarkably,
the addition of sweet grass extract completely inhibited oxidation during the whole period of
storage. The sensory characteristics of the products were acceptable; however, the patties with sweet
grass extract received lower evaluation scores.Funding: This study was supported by the European Union’s Horizon 2020 research and innovation
programme project ERA Chair for Food (By-) Products Valorisation Technologies of Estonian University
of Life Sciences—VALORTECH (grant agreement No 810630); by the Estonian Ministry of
Education and Research programme “Support for research and development on resource valorization”,
ResTA focus theme “Food: Innovative valorisation of food and food ingredients“ research
project, and RESTA28 “Valorization of cereal and oilseed crops”; and by the Estonian Agricultural
Registers and Information Board, Innovation cluster MTÜ Liivimaa Lihaveis (project number
616116780016)
Primjena imobilizirane lipaze iz kvasca Candida antarctica u superkritičnoj fluidnoj ekstrakciji ulja od sjemenki boražine (Borago officinalis L.)
This study aims at the investigation of the possibilities to use immobilised lipase from Candida antarctica in supercritical fluid extraction (SFE) of borage (Borago officinalis L.) see doil. The first series of experiments was performed to measure the extract yields obtained with pure CO2 and with the added entrainer (ethanol). The yield increased more than twice after increasing the extraction pressure from 15 to 25 MPa. Further increase to 35 MPa was less effective. The effect of the entrainer was not significant in most cases. Palmitic (13.1–16.1 %), oleic (13.4–23.8 %), linoleic (33.8–48.4 %) and linolenic (8.8–16.3 %) acids were dominant in all extracted oils. Further experiments involved the use of enzyme. In this case the first extractor was loaded with ground borage seeds, the second one was filled with the enzyme. The total yield obtained at 15, 25 and 35 MPa was (8.8±0.2), (23.6±0.2) and (28.9±1.1) %, respectively. Thin layer chromatography (TLC) of fatty acid ethyl esters showed that the content of esters was higher in the extract obtained in one extractor system at 15 MPa, compared to 35 MPa.U ovom je radu istražena mogućnost primjene imobilizirane lipaze iz kvasca Candida antarctica pri superkritičnoj fluidnoj ekstrakciji ulja od sjemenki boražine (Borago officinalis L.). Prva serija pokusa provedena je radi mjerenja prinosa ekstrakta dobivenog s čistim CO2 i etanolom. Prinos je dvostruko i više porastao nakon povećanja tlaka s 15 na 25 MPa, dok povećanje na 35 MPa nije imalo učinka. Utjecaj otapala većinom je bio neznatan. U svim ekstrahiranim uljima prevladavale su palmitinska (13,1-16,1 %), oleinska (13,4-23,8 %), linolna (33,8-48,4 %) i linolenska (8,8-16,3 %) kiselina. Daljnje ispitivanje provedeno je pomoću enzima. Prvi ekstraktor napunjen je mljevenim sjemenkama boražine, a drugi enzimom. Ukupni prinos pri 15 MPa iznosio je (8,8±0,2) %, pri 25 MPa (23,6±0,2) %, a pri 35 MPa (28,9±1,1) %. Tankoslojnom kromatografijom etilnih estera masnih kiselina dokazano je da je veći udio estera u ekstraktu dobivenom pri 15 MPa nego sa 35 MPa
Essential oils from 11 Cannabis sativa cultivars isolated by different methods and toxicological evaluation of their components
Industrial hemp is grown for numerous applications, traditionally for the production of textile fiber, pressing oil from the seeds and in foods. More recently, non-psychotropic phytocannabinoids have attracted an increasing interest of researchers and medics due to their health benefits. Industrial hemp accumulates comparatively low amounts of essential oil (EO); however, it is considered as an important ingredient for some hemp oil based products. The aim of this study was to expand the existing knowledge on the composition of EO compounds isolated from eleven Cannabis sativa cultivars using Clevenger hydrodistillation and supercritical CO2 extraction (SFE-CO2) for their isolation. In addition, microwave (MAD) and ultrasound (UAD) assisted distillation has been tested in order to evaluate their advantages. The dried plant material was ground using a 0.5-mm hole size sieve before EO isolation, while the fresh material was used undried. MAD was applied to the fresh material without its dilution with water, while SFE-CO2 was performed in Helix extractor using 2 separators operating at different pressure and temperature. EO collecting vessel was cooled from -40 to +20 in order to evaluate possible losses of volatile constituents during system depressurization. The yield of EOs varied from 0.07 to 0.35% depending on the cultivar, extraction method, plant harvesting time, drying and SFE-CO2 parameters. The main volatile components identified and quantified in C. sativa cultivars by GC´GC-TOF/MS and GC-FID, respectively, were b-caryophyllene (16.6-34%), humulene (13.1-30.0%), a-pinene (0.1-31.2%), caryophyllene oxide (4.3-10.2%), b-pinene (0.1-8.3%), myrcene (0.2-9.5%), limonene (0.1-2.7%), eucalyptol (0.1-3.1%), humulene epoxide II (1.4-3.6%) and trans-b-farnesene (1.3-4.6%). The toxicology of the main EO components was reviewed based on the previously reported data. In the second part of this study acetone extracts of the solid residue and water extracts consisting of the liquid phase after hydrodistillation were used for evaluating their antioxidant activities and total phenolic content in order to assess the possibility of using plant distillation residues as a source of various functional non-volatile ingredients. It was recently reported that the biorefining approach may give several valuable fractions from hemp threshing residues [1]
Essential oils from five Nepeta spp. cultivated in Lithuania and toxicological evaluation of their main components
The genus Nepeta (Lamiaceae) is widespread in central and southern Europe, Asia, the Middle East and North Africa; it has also been naturalized in North America and comprises about 300 perennial species [1]. N. cataria (catnip), which has been used for ornamental and culinary purposes and as a domestic folk-medicine remedy, is the most intensively studied among Nepeta species, [2]. Essential oils (EOs) of Nepeta spp. possess strong antimicrobial, antibacterial, antifungal, antiviral, anti-inflammatory, repellent and other activities [3,4]. The composition depends on the variety, growing site, climatic conditions, growth phase and analysis method. In general, the following main chemotypes can be distinguished: with nepetalactones, citral derivatives, 1,8-cineole and/or linalool as the dominant EO compounds [1,2]. Therefore, it was of interest to study the composition of EOs isolated from five Nepeta spp., namely N. cataria var. citriodora, N. transcaucasica, N. melissifolia, N. sibirica var. citriodora and N. nuda cultivated in Lithuania. It was determined that the yield of the hydrodistilled EO varied from 0.1 (N. nuda) to 0.6% (N. cataria var. citriodora). More than 140 volatiles were identified in the studied Nepeta spp. by GC-FID and GC´GC-TOF/MS. N. cataria var. citriodora and N. nuda may be characterized by 4aα,7α,7aα- and 4aα,7α,7aβ-nepetalactones, while N. melissifolia and N. sibirica var. citriodora contained large percentages of 1,8-cineole and caryophyllene oxide. The composition of N. transcaucasica was more complex and the oil contained citronellol, 4aα,7α,7aα- and 4aα,7α,7aβ-nepetalactones, geranial, neral, geraniol, 1,8-cineole and caryophyllene oxide as the major components. The toxicology of the main identified EO components was reviewed based on the previously reported data. In the second part of this study acetone extracts (using the solid phase obtained after hydrodistillation) and water extracts (liquid phase after hydrodistillation) from Nepeta spp. were prepared and evaluated for their antioxidant activities and total phenolics content in order to reveal the possibility of using Nepeta plants as a source of various functional food ingredients
ANTIOXIDANT ACTIVITIES AND PHENOLIC COMPOSITION OF EXTRACTS FROM NEPETA PLANT SPECIES
Abstract The aim of this study was to assess antioxidant properties of four in Lithuanian growing Nepeta varieties, namely N. cataria, N. cataria var. citriodora, N. transcaucasica and N. bulgaricum. The plants were extracted using different polarity solvents, namely acetone, methanol, ethanol and water. The antioxidant properties were assessed by determining total content of phenolics, using free DPPH• radical scavenging assay, accelerated oil stability test and peroxide value measurement. Antioxidant activities of the analysed herb extracts were greatly dependent on the extraction solvent. Methanolic extract of N. cataria exhibited significantly higher antioxidant capacity comparing to other extracts. The sub-fractions isolated from the plant material were analysed by HPLC-MS and the concentration of some phenolic acids was determined. Rosmarinic acid was the major component in all extracts; luteolin, and caffeic acid were other identified constituents, however present in considerably lower amounts
Phytochemical-rich antioxidant extracts of <i>Vaccinium vitis-idaea L</i>. leaves inhibit the formation of toxic Maillard reaction products in food models
Thermal treatment of proteinaceous foods generates heat-induced Maillard reaction substances including toxic advanced glycation end products (AGEs) and heterocyclic amines (HAs). It is known that plant phenolic compounds may influence Maillard reaction. This study investigated the impact of lingonberry leaf extracts on the formation of Nε-(carboxymethyl)lysine (CML) and Nε-(2-furoylmethyl)-L-lysine (furosine) in milk model system and HAs in meat-protein and meat model systems. In addition, lingonberry leaf extracts obtained by different solvents were characterized by radical scavenging, Folin-Ciocalteu assays and ultra-high pressure liquid chromatography quadruple-time-of flight mass spectrometry (UPLC-qTOF-MS). Water extract (WE) stronger suppressed CML than furosine formation in milk model system: CML levels were reduced by nearly 40%. Moreover, quinic acid and catechin which were abundant in WE, were effective in inhibiting CML and furosine formation. WE and acetone extract (AE) at 10 mg/mL significantly inhibited HAs formation in both model systems. However, higher suppressing effect on HAs formation showed AE which had lower antioxidant capacity and total phenolic content values than WE. WE contained higher amounts of hydroxycinnamic acids, proanthocyanidins and flavonols, while AE was richer in flavan-3-ols and arbutin derivatives. It indicates that the composition of phenolics might be a major factor for explaining different effect of extracts from the same plant on HAs formation. In general, the results suggest that lingonberry leaves is a promising source of phytochemicals for inhibiting toxic Maillard reaction products and enriching foods with plant bioactive compounds
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