Agro-Industrial Plant Proteins in Electrospun Materials for Biomedical Application.

Plant proteins are receiving a lot of attention due to their abundance in nature, customizable properties, biodegradability, biocompatibility, and bioactivity. As a result of global sustainability concerns, the availability of novel plant protein sources is rapidly growing, while the extensively studied ones are derived from byproducts of major agro-industrial crops. Owing to their beneficial properties, a significant effort is being made to investigate plant proteins' application in biomedicine, such as making fibrous materials for wound healing, controlled drug release, and tissue regeneration. Electrospinning technology is a versatile platform for creating nanofibrous materials fabricated from biopolymers that can be modified and functionalized for various purposes. This review focuses on recent advancements and promising directions for further research of an electrospun plant protein-based system. The article highlights examples of zein, soy, and wheat proteins to illustrate their electrospinning feasibility and biomedical potential. Similar assessments with proteins from less-represented plant sources, such as canola, pea, taro, and amaranth, are also described.

Quantitatively Unraveling Hierarchy of Factors Impacting Virgin Olive Oil Phenolic Profile and Oxidative Stability.

A single phenolic group and even a compound play different roles in the sensory properties and stability of virgin olive oil (VOO), which in turn are strongly influenced by several factors. Understanding the causes of differences in phenolic compound composition and oxidative stability (OS) in VOOs is essential for targeted and timely harvest and processing while maintaining desired oil quality. The phenolic profile and OS of two monocultivar VOOs (Oblica and Leccino) grown in two geographical sites of different altitudes (coastal plain and hilly hinterland) were analyzed throughout the ripening period over two years. Concentration of secoiridoids was 30% higher in the Oblica than in the Leccino VOOs, which in turn had significantly higher values of OS. Both cultivars had more than twice as high concentrations of the two most abundant phenolic compounds, the dialdehyde form of decarboxymethyl oleuropein aglycone and the dialdehyde form of decarboxymethyl ligstroside aglycone, and OS values in a colder growing site of higher altitude. Among the studied monocultivar VOOs, the secoiridoid group did not behave equally during ripening. The hierarchy of different influencing factors was investigated using multivariate statistics and revealed: cultivar > geographical site > harvest period > growing season. In addition, the possibility of traceability of VOO using molecular markers was investigated by establishing SSR profiles of oils of the studied cultivars and comparing them with SSR profiles of leaves.

Assessment of Pumpkin Seed Oil Adulteration Supported by Multivariate Analysis: Comparison of GC-MS, Colourimetry and NIR Spectroscopy Data.

Because of its high market value, pumpkin seed oil is occasionally adulterated by cheaper refined oils, usually sunflower oil. The standard method for detecting its authenticity is based on expensive and laborious determination of the sterol composition. Therefore, the objective of this study was to determine the sterol content and authenticity of retail oils labelled as pumpkin seed oil and also to investigate the potential of near-infrared spectroscopy (NIR) and colourimetry in detecting adulteration. The results show that due to the significant decrease in Δ7-sterols and increase in Δ5-sterols, 48% of the analysed oils can be declared as adulterated blends of pumpkin seed and sunflower oil. Significant differences in NIR spectroscopy data, in the range of 904-922 nm and 1675-1699 nm, and colourimetric data were found between the control pumpkin seed oil and sunflower oil, but only the NIR method had the potential to detect the authenticity of pumpkin seed oil, which was confirmed by principal component analysis. Orthogonal projection on latent structures (OPLS) discriminant analysis, resulted in working classification models that were able to discriminate pure and adulterated oil. OPLS models based on NIR spectra were also able to successfully predict the content of ß-sitosterol and Δ7,22-stigmastadienol in the analysed oils.

Oxidative Stability, Microbial Safety, and Sensory Properties of Flaxseed (Linum usitatissimum L.) Oil Infused with Spices and Herbs.

In our study, we assessed whether the addition of basil, fennel, oregano, rosemary, and chili can improve oxidative stability and sensory properties of flaxseed oil (FO) during 180 days of storage or induce oil contamination by microorganisms. Results showed that addition of spices and herbs in FO affected the hydrolytic changes, but far less than 2% of free fatty acids after storage, which was in line with regulations. Further, the addition of spices and herbs in FO decreased peroxide value (even up to 68.7% in FO with oregano) vs. FO whose value increased during storage, indicating increased oxidative stability and prolongation of shelf life of infused oils. The antioxidant activity of the infused oils ranged from 56.40% to 97.66%. In addition, the phenol content was higher in all infused oils (6.81-22.92 mg/kg) vs. FO (5.44 mg/kg), indicating that herbs and spices could scavenge free radicals and inhibit lipid peroxidation, while sensory analysts showed that FO infused with chili had the lowest bitterness intensity. According to the presence of certain microorganisms, results highlighted the need to develop new methods for inactivating microorganisms that would not only provide a microbial safety, but also preserve the beneficial properties of the oils/products.

Virgin Olive Oil Phenols, Fatty Acid Composition and Sensory Profile: Can Cultivar Overpower Environmental and Ripening Effect?

The authenticity and typicity of monocultivar oils and knowledge of the changes that environmental olive growing conditions bring to naturally present antioxidants and sensory attributes of virgin olive oils (VOO) are important for quality and safety improvement. This study delivers a comprehensive evaluation of the factors affecting phenolics, fatty acid composition and sensory characteristics of cultivars Oblica and Leccino VOOs throughout ripening season at two distinct olive growing environments during three consecutive crop years, and ranks the importance of each factor. Specified parameters were significantly influenced by olive growing environmental conditions. At the colder location of higher altitude, both cultivars gained higher amount of stearic, linoleic and linolenic fatty acids, as well as a higher proportion of phenolic compounds, but lower amounts of oleic fatty acid. At the warmer location of lower altitude, both cultivars had oils with lower level of fruitiness, bitterness and pungency. Analysis of the main components showed that VOOs were primarily differentiated by the cultivar, then main groups were divided with regard to the growing site, while harvest period affected the biosynthesis of natural VOOs antioxidants but had the least impact. These results reveal that the composition of fatty acids, phenolic content and sensory profile are predominantly characteristics of a cultivar.

Differentiation Between Unfiltered and Filtered Oblica and Leccino cv. Virgin Olive Oils.

The quality parameters, a variety of microcomponents, and the sensory characteristics of Oblica and Leccino cv. virgin olive oils (VOOs) were evaluated before and after filtration process adopted in order to estimate the individual varietal compositional changes. The dynamics of the formation of hydrolytic and oxidative changes in unfiltered (UF) and filtered (F) oils was asses by comparing level of free fatty acids (FFA), peroxide value (PV), and spectrophotometric indices periodically during 1 year of oil storage. An analysis of phenolics, tocopherols, and fatty acids was determined by chromatographic (HPLC and GC) and spectrometric methods, oxidative stability by Rancimat method while sensory analyses of obtained olive oils were performed by a trained professional panel. Single monovarietal VOO loses phenols in different rate with the applied filtration. Total secoiridoids decreases significantly in "Oblica" VOOs while no changes in their concentrations were found between unfiltered and filtered "Leccino" oils. Intensity of desired sensory properties decreases with filtration. In "Leccino" VOOs decrease of oxidative stability was more pronounced. After 12 months of storage, filtered "Leccino" VOOs had significantly lower FFA values than observed for the unfiltered counterparts. Further, there were no significant changes in PV and K270 values between unfiltered and filtered oils of both studied varietal oils. Storage time influenced more studied quality parameters than filtration, during which PV of unfiltered oils faster deteriorate. The highest changes between stored and corresponding fresh samples were exhibited in unfiltered "Oblica" VOOs. PRACTICAL APPLICATION: Quality enhancement of olive oil is constantly being done professionally and scientifically. The information provided in this study can be used in the industry of olive oil for improve the phenolic content, oxidative stability, and the sensory quality of virgin olive oils. The findings of stability test could be guidelines for mindful leading of the oil finishing up to bottling.

Canolol Dimer, a Biologically Active Phenolic Compound of Edible Rapeseed Oil.

Rapeseed and its oil are the source of many biologically active substances. From crude rapeseed oil, canolol is isolated and from edible oil its dimer. Herein, we tested the biological activity of those two compounds isolated from the oils by determining their antioxidant capacity and in vitro cytotoxicity on human tumor cell lines. Canolol and its dimer showed antiproliferative activity on both cell lines with IC50 values of 46.45 µM in HeLa, and 51.19 µM in MCF7 cells, respectively. Evaluation of cell death was also done, while the oxygen radical absorbance capacity method confirmed that the canolol dimer has higher antioxidant potential than canolol. Stability of canolol and its dimer under different storage conditions showed that for a longer period of time both compounds should be stored in a freezer, but also that the dimer is more stable against degradation than canolol. Presented results indicate possible applications of canolol and its dimer in the food and pharmaceutical industry as a natural antioxidant and an anticancer agent, respectively.

Ready-to-use green polyphenolic extracts from food by-products.

To establish environmentally friendly polyphenolic extracts from grape and olive pomace, natural deep eutectic solvents (NADES) were used coupled with alternative energy sources - ultrasound and microwave irradiation. Obtained extracts were characterized by HPLC analysis, while antioxidant capacity was determined by ORAC method. Furthermore, in vitro cytotoxicity of prepared extracts was assessed by antiproliferation assay on two tumour cell lines, whereas for investigation of type of cell death or cell cycle arrest a flow cytometric analysis was applied. In addition, a detection of compounds with DNA/RNA-bindingaffinity in extracts was investigated by UV/Vis and circular dichroism spectroscopy. Grape pomace extract in NADES showed to be the best of all extracts tested, with regard to extraction of total polyphenolic compounds (p < 0.05) and related biological activities such as antioxidant and antiproliferative activity. Prepared polyphenolic extracts in NADES could be considered as ready-to-use in food and pharmaceutical industry without demanding and expensive downstream purification steps.

Influence of Conditioning Temperature on the Quality, Nutritional Properties and Volatile Profileof Virgin Rapeseed Oil.

Heating the rapeseed prior to the oil extraction is conducted to increase the oil yield but it can also induce changes of various components of the seed. These changes may affect the composition of the volatile and non-volatile compounds of produced virgin rapeseed oil. The aim of our study is to determine the impact of different conditioning temperatures (60, 80 and 100 °C) on the quality, nutritional value, aroma profile and sensory characteristics of virgin rapeseed oil. Conditioning the seeds at all three temperatures had no influence on the quality and major nutritional components (fatty acids and tocopherols) of the produced oil. However, temperature increase caused an exponential increase of canolol and significant changes in the aroma and sensory profile of the produced oil samples. The dominant volatile compounds of cold-pressed and virgin oil produced at 60 °C were enzymatic degradation products of glucosinolates (isothiocyanates and epithionitriles), responsible for pronounced seed-like flavour of these types of oil. Increasing production temperature deactivated enzymes and caused thermal decomposition of seed components and increment of nitriles, aldehydes, pyrazines and furanes, carriers of nutty and roasty flavour. These results can help producers to design virgin rapeseed oil with specific and desirable sensory characteristics.

Changes in 4-vinylsyringol and other phenolics during rapeseed oil refining.

The aim of the present study was to examine changes in phenolic compounds during refining of rapeseed oil. In crude rapeseed oil, 4-vinylsyringol (canolol) is the dominant phenolic compound, accounting for 85% of total phenolics. Refining decreased the total amount of phenolic compounds by 90%. NMR and MS analyses of edible rapeseed oil phenolic extracts identified 4-vinylsyringol dimer as the dominant phenolic compound. This phenolic compound appears to form through acid-catalyzed dimerization-aromatic substitution of 4-vinylsyringol monomers. Analysis of rapeseed oils from different stages of the refining process suggest that 4-vinylsyringol dimer forms during the neutralization phase, when H3PO4 acts as a catalyst, or during bleaching, when acid-activated bleaching earth acts as the catalyst. Whether 4-vinylsyringol forms during one or the other phase appears to depend on the phospholipid content of the crude oil. These insights may be useful for designing rapeseed oil refining processes that maximize levels of 4-vinylsyringol dimer.

Influence of Climate, Variety and Production Process on Tocopherols, Plastochromanol-8 and Pigments in Flaxseed Oil.

The objective of this study is to compare the influence of genotype, environmental conditions and processing methods after maturation and harvesting of four varieties of flaxseed (Altess, Biltstar, Niagara and Oliwin) on the levels of tocochromanols, carotenoids and chlorophyll in flaxseed oil. Samples were produced by cold pressing of dry seeds and seeds heated for 30 min at 60 °C. Temperature, sunshine and rainfall were primary environmental conditions included. Grand mean of mass fraction of γ-tocopherol was (522±29), of plastochromanol-8 (305±2) and total tocochromanols (831±3) mg per kg of oil. The highest levels of these compounds and strongest antioxidant activity were found in cold- -pressed oil of Biltstar variety. During seed maturation, levels of γ-tocopherol and plastochromanol-8 increased with average temperature and total sunshine and decreased with total rainfall. Fifth week after flowering was identified as the maturation period with best climate conditions to achieve optimal tocochromanol content. Grand mean of mass fraction of carotenoids expressed as ß-carotene was (1.83±0.01) and of chlorophyll expressed as pheophytin a (0.43±0.10) mg per kg of oil. Altess variety had the highest levels of pigments. Antioxidant activity decreased with the increase of chlorophyll, while correlations with carotenoids were not determined. Generally, oil obtained by cold pressing had higher levels of tocochromanols and lower levels of pigments but similar antioxidant activity to the oil after seed conditioning. The results of this study contribute to identifying the flaxseed variety that is the best for oil production with the highest antioxidant activity and nutritive value, and provide better understanding of tocochromanol biosynthesis depending on different climate conditions.

Glycemic index and phenolics of partially-baked frozen bread with sourdough.

Different lactic acid bacteria starters were used to prepare sourdough to make partially-baked frozen wholemeal wheat bread. The sourdough was prepared with a pure culture of Lactobacillus plantarum or with commercial starters containing Lactobacillus brevis combined with Saccharomyces cerevisiae var. chevalieri (LV4), Lactobacillus fermentum (PL1), or Lactobacillus fermentum with phytase (PL3). We determined the acetic and lactic acid concentrations in sourdough, bread chemical composition, total phenolics content and glycemic index (GI) in vivo. Depending on the starter, the lactic to acetic acid ratio in the sourdough was significantly different. The GI of control bread without sourdough (70) was significantly higher than that of bread containing sourdough prepared with LV4 starter (50), PL1 starter (56) or PL3 starter (56), but not from bread with L. plantarum sourdough (60). The addition of 10% sourdough with a lower molar ratio of lactic to acetic acid ( ≤ 4) and higher total phenolics content is preferable for generating bread with medium and low GI.

Optimization of bioprocess for production of copper-enriched biomass of industrially important microorganism Saccharomyces cerevisiae.

The production of Saccharomyces cerevisiae cells enriched with copper and the effects of adding copper ions to different media on yeast cell growth and ethanol production were studied. In the media Cu(2+) concentrations of up to 0.094 mM had no effect on alcoholic fermentation, whereas higher Cu(2+) concentrations markedly decreased yeast cell growth rate and ethanol production. Under static conditions, the maximum amounts of copper uptake (i.e., 1.16 mg/g, 1.2 mg/g and 0.81 mg/g dry matter yeast biomass for glucose, sucrose and molasses media, respectively) were obtained after 8 h of fermentation, whereas under dynamic conditions smaller amounts of copper uptake (i.e., 0.98 mg/g, 1.02 mg/g and 0.7 mg/g dry matter yeast biomass for glucose, sucrose and molasses media, respectively) were obtained after 6 h of fermentation.