Green Approach to Enhance the Recovery of Polyphenols from Blackcurrant and Bilberry Leaves: Evaluation of Microwave-Assisted and Pressurized Liquid Extraction.

The aim of the present study was to evaluate microwave-assisted (MAE) and pressurized liquid extraction (PLE) for the recovery of polyphenols from blackcurrant and bilberry leaves and the preservation of their antioxidant activity. The extractions were carried out varying the solvent/solid (SS) ratio, temperature and time. During MAE, increasing the SS ratio increased the polyphenol concentration in the extracts from blackcurrant and bilberry leaves, while increasing the temperature had a positive effect only on bilberry polyphenols. During PLE, only a temperature increase was a determining factor for the isolation of blackcurrant leave polyphenols. Based on polyphenol recovery, optimal extraction parameters were established resulting in a yield of 62.10 and 56.06 mg/g dw in the blackcurrant and bilberry MAE extracts and 78.90 and 70.55 mg/g dw in the PLE extracts. The optimized extracts were profiled by UPLC ESI MS2, and their antioxidant capacity was evaluated through FRAP, DPPH, ABTS and ORAC assays. The characterization of the extracts by UPLC ESI MS2 confirmed flavonols as the predominant compounds in both blackcurrant and bilberry leaves, while flavan-3-ols and procyanidins were the main compounds responsible for high antioxidant capacity as confirmed by the ABTS and ORAC assays. Due to the extract composition and antioxidant capacity, PLE proved to be a technique of choice for the production of blackcurrant and bilberry leave extracts with high potential for use as value-added ingredients in the food and nutraceutical industry.

From Waste to Green: Water-Based Extraction of Polyphenols from Onion Peel and Their Adsorption on Biochar from Grapevine Pruning Residues.

Onion peels (OP) are rich in bioactive compounds with a plethora of benefits for human health, but this valuable material is often wasted and underutilized due to its inedibility. Likewise, grapevine pruning residues are commonly treated as agricultural waste, but biochar (BC) obtained from this material has favorable characteristics as an adsorbent. This study investigated the potential of BC in removal of targeted polyphenolic compounds from OP extracts. The OP extracts were obtained adhering to green chemistry principles using deionized water amplified by three methods: maceration (MAC), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE). The extraction efficiency on the polyphenolic profile and antioxidant capacity was investigated with different extraction temperatures and solid-to-liquid (s/l) ratios. For further analysis, UAE at 90 °C with an s/l ratio of 1:100 was used due to higher polyphenolic compound yield. The BC adsorption capacity of individual polyphenols was fitted with the Langmuir and Freundlich isotherm models. Quercetin-3,4'-diglucoside obtained the highest R2 coefficient in both models, and the highest qmax value. The optimum conditions in the dosage experiment suggested an amount of 0.5 g of BC using 3 g/L extracts. The studied BC showed a high affinity for targeted phytochemicals from OP extracts, indicating its potential to be applied for the green adsorption of valuable polyphenolic compounds.

Optimization of the Spray-Drying Encapsulation of Sea Buckthorn Berry Oil.

The aim of this study was to evaluate the effect of spray-drying parameters on the physicochemical properties of encapsulated sea buckthorn berry oil. Different carriers (gum arabic, ß-cyclodextrin, and their mixture (1:1, w/w)), inlet air temperatures (120, 150, and 180 °C), and carrier-to-oil ratios (2, 3, and 4, w/w) were evaluated. The obtained powders were characterized in terms of the product yield (36.79-64.60%), encapsulation efficiency (73.08-93.18%), moisture content (0.23-3.70%), hygroscopicity (1.5-7.06 g/100 g), solubility (19.55-74.70%), bulk density (0.25-0.44 g/L), total carotenoid content (mg/100 g dm), and antioxidant capacity (871.83-1454.39 µmol TE/100 g dm). All physicochemical properties were significantly affected by the carrier-to-oil ratio and inlet air temperature. Higher carrier-to-oil ratios increased the product yield, encapsulation efficiency, solubility, and bulk density and decreased the powder hygroscopicity. Elevating the drying temperatures during spray drying also increased the product yield, encapsulation efficiency, and solubility, while it decreased the powder moisture content, total carotenoid content, and antioxidant capacity. Based on the physicochemical properties, the use of ß-cyclodextrin as a carrier, a drying temperature of 120 °C, and a carrier-to-oil ratio of 4 were selected as optimal conditions for the production of sea buckthorn berry oil powder. The obtained powder is a valuable material for a wide range of applications in the food and nutraceutical industries.

Biochar from Grapevine Pruning Residues as an Efficient Adsorbent of Polyphenolic Compounds.

Agricultural waste, which is produced in large quantities annually, can be a threat to the environment. Biochar (BC) production represents a potential solution for reducing the amount of grapevine pruning residues and, accordingly, the impact on the environment and climate change. Biochar produced by the process of pyrolysis from grapevine pruning residues was investigated and characterized to be applied as an adsorbent of polyphenolic compounds with the aim of using the waste from viticultural production to obtain a quality product with adsorption and recovery potential. Standards of caffeic acid (CA), gallic acid (GA), and oleuropein (OLP) were used as polyphenolic representatives. The obtained data were fitted with the Langmuir and Freundlich isotherms models to describe the adsorption process. The best KL (0.39) and R2 (0.9934) were found for OLP using the Langmuir model. Furthermore, the adsorption dynamics and recovery potential of BC were investigated using an adapted BC column and performed on an HPLC instrument. The adsorption dynamics of biochar resulted in the adsorption of 5.73 mg CA g-1 of BC, 3.90 mg GA g-1 of BC, and 3.17 mg OLP g-1 of BC in a 24 h contact. The online solid phase extraction of the compounds performed on an HPLC instrument yielded a recovery of 41.5 ± 1.71% for CA, 61.8 ± 1.16% for GA, and 91.4 ± 2.10% for OLP. The investigated biochar has shown a higher affinity for low-polar compound adsorption and, consequently, a higher polar compound recovery suggesting its potential as an efficient polyphenolic compound adsorbent.

Phenolic, Headspace and Sensory Profile, and Antioxidant Capacity of Fruit Juice Enriched with Salvia officinalis L. and Thymus serpyllum L. Extract: A Potential for a Novel Herbal-Based Functional Beverages.

Since certain constituents are not naturally present in pure fruit juices, incorporating herbal extracts can provide specific sensory properties to the beverages and improve their biopotential. In our previous research, it was found that sage (Salvia officinalis L.), wild thyme (Thymus serpyllum L.), and combinations of their extracts had the highest total phenolic content and a unique composition of volatile compounds, which can contribute to the aromatic and antioxidant qualities of functional products. Therefore, this research aimed to investigate the potential of sage and wild thyme extracts, as well as their mixture (wild thyme:sage at 3:1, v/v), to enrich fruit juices (apple, pineapple, and orange). Obtained beverages were evaluated for sensory properties as well as phenolic and headspace composition (UPLC-MS/MS and HS-SPME/GC-MS analysis) and antioxidant capacity (ORAC assay). The incorporation of wild thyme extract in pineapple juice provided the most harmonious flavor and the highest content of volatile compounds (on PDMS/DVB fiber). The orange juice formulations were the most enriched with phenolic and volatile compounds (on DVB/CAR/PDMS fibers). The highest antioxidant capacity was observed in the formulation with orange juice and sage extract (22,925.39 ± 358.43 µM TE). This study demonstrated that enriching fruit juices with sage and wild thyme extracts could create functional beverages with improved sensory and health-promoting properties, providing valuable insights for the food and beverage industry to meet the growing demand of health-conscious consumers for natural and functional products.

Sterols and pentacyclic triterpenoids from nettle root: content and composition as affected by pressurized liquid extraction.

BACKGROUND: Nettle is a medicinal plant rich in bioactive molecules. The composition of nettle leaves and stems has been extensively studied, whereas the root has been insufficiently investigated. Therefore, the present study aimed to optimize the parameters of advanced extraction technique, pressurized liquid extraction (PLE), for the lipid fraction of nettle root rich in triterpenoid derivatives and to compare the efficiency of isolation under optimal conditions with conventional Soxhlet extraction (SE). RESULTS: The PLE yields ranged from 0.39-1.63%, whereas the total content of triterpenoid derivatives ranged from 43.50-78.26 mg 100 g-1 , with nine sterols and three pentacyclic triterpenoids identified and quantified within a total range of 42.81-76.57 mg 100 g-1 and 0.69-1.68 mg 100 g-1 dried root, respectively. The most abundant sterol and pentacyclic triterpenoid were ß-sitosterol and ß-amyrin acetate, with mean values of 50.21 mg 100 g-1 and 0.56 mg 100 g-1 dried root. CONCLUSION: The optimal PLE conditions were 150 °C/5 min/four cycles and showed significantly better performance compared to SE (68 °C, 8 h), establishing an excellent technique for the isolation of the nettle root lipid fraction. Also, triterpenoid derivatives from nettle could be used as functional ingredients for the development of new foods and dietary supplements. © 2022 Society of Chemical Industry.

Valorization of Olive Leaf Polyphenols by Green Extraction and Selective Adsorption on Biochar Derived from Grapevine Pruning Residues.

Given today's increasingly intensive agriculture, one key problem area considers the valorization and reuse of wastes from food and agricultural production with minimal impact on the environment. Due to its physicochemical characteristics, biochar (BC) derived from grapevine pruning residue has shown considerable potential for use as an adsorbent. High-value phytochemicals found in abundance in the olive leaf (OL) can be employed in many different industrial sectors. The potential application of BC in the removal of specific polyphenolic components from OL extracts has been investigated in the present study. Water, as the most available and greenest of solvents, was investigated as to its use in the extraction of polyphenols, which was carried out by comparing maceration, ultrasound-assisted extraction, and microwave-assisted extraction, considering different temperatures and solid-to-liquid (s/l) ratios. The BC adsorption capacity of selected polyphenols was fitted with both the Langmuir and Freundlich isotherm models. The Freundlich model fitted better relative to OL polyphenols adsorption. Oleuropein was the most abundant compound identified in the extracts, obtaining the highest Kf value (20.4 (mg/g) × (L/g)n) and R2 coefficient (0.9715) in the adsorption on the biochar's surface. The optimum conditions in the dosage experiment suggest the use of 0.5 g of BC using 3 g/L extracts, with an exception for oleuropein and hydroxytyrosol, for which the highest biochar dose (2.5 g) performed better. Considering the compounds' concentrations and the BC dose, BC from grapevine pruning residues demonstrated a potential use in the uptake of specific polyphenols from olive leaves, making it a promising adsorbent for such applications.

Effect of UV-C Irradiation on the Shelf Life of Fresh-Cut Potato and Its Sensory Properties after Cooking.

Research background: Potato tissue is damaged during fresh-cut production, which makes fresh-cut potato susceptible to the quality loss and microbiological spoilage. At the same time, such products are desirable due to their convenience; however, they are extremely sensitive and have short shelf life. The main challenge of the fresh-cut potato industry is to find possibilities to overcome these drawbacks. UV-C treatment, known for its antibacterial activity, is a promising technique and it shows a potential to improve shelf life of fresh-cut potato products. Experimental approach: The influence of the UV-C treatment on the safety and quality, as well as sensory traits of fresh-cut potato (Solanum tuberosum L. cv. Birgit) during storage was examined. For this purpose, 0-, 3-, 5- and 10-min UV-C irradiation was applied on vacuum-packed potato slices pretreated with sodium ascorbate solution. During 23 days of storage at (6±1) °C, microbiological, physicochemical and sensory properties of raw samples were monitored, along with sensory properties of boiled and fried fresh-cut potatoes. Results and conclusions: The 5- and 10-min UV-C treatments significantly reduced microbial growth, increased total solids and lightness (L*), and positively affected odour and firmness of raw potatoes. Cooked UV-C-treated samples were described with more pronounced characteristic potato odour and taste. Overall, UV-C-treated fresh-cut potato retained its good quality and sensory traits up to 15 days at (6±1) °C. Novelty and scientific contribution: To the best of our knowledge, this is the first scientific article dealing with the effect of UV-C light on durability (safety, quality and sensory traits) of fresh-cut potato cv. Birgit and its suitability for boiling and frying. In general, UV-C treatment is a known antimicrobial technique, but its application on fresh-cut potato is poorly explored. Results confirmed that vacuum-packed fresh-cut potato treated only with UV-C and sodium ascorbate as anti-browning agent, without the addition of chemical preservatives, had twofold longer shelf-life at (6±1) °C than the fresh-cut potato not treated with UV-C. Fresh-cut potato treated with UV-C retained good overall quality and sensory properties either raw, boiled or fried. Results of this study could also be useful for producers in terms of potential UV-C application as a strategy for prolonging the shelf-life of fresh-cut potato.

Non-Volatile and Volatile Bioactives of Salvia officinalis L., Thymus serpyllum L. and Laurus nobilis L. Extracts with Potential Use in the Development of Functional Beverages.

Functional beverages based on herbal extracts are highly demanded products due to the presence of bioactives with promising health benefits and interesting and characteristic sensory properties. Mediterranean medicinal and aromatic herbs contain a wide range of bioactives (non-volatile polyphenols, volatile terpenes) that are important constituents of herbal extracts and essential oils. The antioxidant capacity and potential health benefits of these bioactives could be associated with their synergistic effects. Therefore, this study aimed to characterize the non-volatile and volatile bioactives of sage (Salvia officinalis L.), wild thyme (Thymus serpyllum L.) and laurel (Laurus nobilis L.) aqueous extracts and their two- and three-component mixtures as well as their antioxidant capacity. The content of total phenols, flavonoids, hydroxycinnamic acids and flavonols was determined spectrophotometrically. Individual polyphenols were analyzed by LC-MS/MS, the volatiles were analyzed by HS-SPME/GC-MS, and the antioxidant capacity was analyzed by ORAC and DPPH assays. The results showed that aqueous extracts of all examined herbs and their mixtures contained a high content of phenolic compounds ranging from 0.97 to 2.79 g L-1 of the sample, among which the most common were flavonols. At the same time, mono- and sesquiterpenes were the main volatiles. All extracts showed high antioxidant capacity, especially L. nobilis (781.62 ± 5.19 µmol TE mL-1 of the sample in the DPPH assay; 1896.10 ± 8.77 µmol TE mL-1 of the sample in the ORAC assay) and the two-component mixture of L. nobilis and T. serpyllum (679.12 ± 5.19 µmol TE mL-1 in the DPPH assay; 1913.38 ± 8.77 µmol TE mL-1 in the ORAC assay). Mixtures of herbal extracts have been shown to possess additive or synergistic effects, consequently contributing to higher antioxidant capacity. Therefore, two-component mixtures of herbal extracts showed promising potential for the production of functional beverages.

Antioxidant and Anti-Atherogenic Activities of Essential Oils from Myrtus communis L. and Laurus nobilis L. in Rat.

Essential oils (EOs) from aromatic and medicinal plants, such as myrtle (Myrtus communis L.) and Laurel (Laurus nobilis L.), are gaining popularity as a potential ingredient in functional foods and nutraceuticals. This study aims to investigate whether the essential oils (EOs) could be effective in weight control, antioxidative and antilipidemic status of rats by affecting microbiota and its enzymes activity and whether changes in intestinal enzyme activity affect the health of rats. The intragastric application of laurel and myrtle EOs to rats for two weeks affects weight loss, reduces glycolytic activity, lipid parameters (cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C)) and atherogenic indicators, leading to cardiovascular protection. Laurel EO can be an excellent candidate for the treatment of drug-induced obesity and related diseases, since it affects lipid metabolism in the liver and inhibits the enzymes responsible for the metabolism of carbohydrates into glucose in the digestive tract, leading to weight loss. In contrast, myrtle EO shows a better antioxidant capacity in most tissues, except kidneys, where it causes a pro-oxidative effect, compared to laurel EO. Myrtle EO increases the permeability and instability of the erythrocyte membrane, resulting in a loss of selectivity for the entry of toxic substances into the cell. On the other hand, myrtle EO leads to intestinal inflammation by reducing the number of probiotic bacteria and increasing Enterobacter.

The Potential of Olive Leaf Extract as a Functional Ingredient in Yoghurt Production: The Effects on Fermentation, Rheology, Sensory, and Antioxidant Properties of Cow Milk Yoghurt.

BACKGROUND: Yoghurt has been traditionally consumed for its high nutritional value and health-promoting benefits. The addition of plant extracts as a source of phenolic compounds and bio-flavonoids has attracted much attention recently since milk and dairy products are deficient in these health-protecting components. Accordingly, olive leaf extract (OLE) has been considered due to the presence of bioactive compounds, primarily polyphenols. Thus, the aim of this research was to investigate the possibility of adding OLE into cow milk yoghurt as a potential functional ingredient. METHODS: Yoghurts enriched with OLE (1.5, 3, and 5% v/v) were produced and compared with yoghurt without OLE. In all samples acidity, viscosity, colour, syneresis, water holding capacity (WHC), microbiological parameters, sensory properties, total phenols, and antioxidant activity (DPPH and FRAP methods) were determined. RESULTS: The addition of OLE resulted in shorter fermentation and lower pH, but it had no adverse effect on the viability of yoghurt starter bacteria. OLE-enriched yoghurts showed increased syneresis, higher total phenols content, and antioxidant activity, while WHC and viscosity decreased. Sensory properties were slightly poorer for yoghurts containing higher OLE concentrations. Considering all of the obtained results, the addition of 1.5% OLE appeared to be optimal.

Isolation of Laurus nobilis Leaf Polyphenols: A Review on Current Techniques and Future Perspectives.

In recent years, the market demand for products enhanced with ingredients derived from natural products, such as polyphenols, is rapidly increasing. Laurus nobilis L., known as bay, sweet bay, bay laurel, Roman laurel or daphne is an evergreen Mediterranean shrub whose leaves have traditionally been used in cuisines and folk medicine due to their beneficial health effects, which can nowadays be scientifically explained by various biological activities of the leaf extracts. Many of these activities can be attributed to phenolic compounds present in L. nobilis leaves which include flavonoids, phenolic acids, tannins (proanthocyanidins) and lignans. In order to enable efficient industrial utilization of these valuable compounds, it is crucial to establish optimal extraction procedures resulting in the highest yields and quality of the extracts. This paper offers the first systematic review of current literature on the influence of conventional and advanced extraction techniques, including microwave-assisted, ultrasound-assisted, enzyme-assisted, supercritical-CO2 and mechanochemical-assisted extraction on the phenolic content of L. nobilis leaf extracts, allowing more efficient planning of further research and simplifying the steps towards industrial utilization of this plant.

Physical, Chemical and Sensory Characterization of Deep-Fried Fresh-Cut Potatoes Coated with Hydrocolloid/Herbal Extracts.

Research background: Recently, natural plant extracts have been used to increase the nutritional value of food and to potentially reduce the absorbed fat and the formation of acrylamide in fried foods. Literature data on the use of edible polymers with nettle or olive leaf extracts are scarce. Experimental approach: The effect of novel coatings on colour, fat absorption, phenolic and sugar content, and acrylamide formation in deep-fat-fried fresh-cut potatoes was evaluated. Extracts of olive and nettle leaves were incorporated in carboxymethyl cellulose (CMC) and gum arabic, used as coatings for potatoes and applied before frying. This aimed to improve the nutritional quality of deep-fat-fried fresh-cut potatoes. Results and conclusions: Enrichment of the edible coatings with extracts resulted in a significant change in the visible colour of the potatoes before frying. Significant effect of the extract amount on the sensory characteristics of potatoes was also observed. Most importantly, the perception of characteristic potato odour and taste was not significantly affected by the coating. Although higher amounts of the extract (1.5%) resulted in higher phenolic mass fraction in fried potatoes, the sensory scores decreased. After frying, fat mass fraction in the coated potatoes was reduced by about 15% compared to the uncoated samples. The type of extract affected the total sugar mass fraction in fried potatoes, which was lower in the samples with coatings enriched with olive leaf than in those with nettle leaf. Only gum arabic coating had a reducing effect on acrylamide mass fraction by 17%. Based on all the obtained results, CMC and gum arabic coatings did not influence sensory properties, so they can be recommended as carriers of functional compounds or as a frying pre-treatment for potatoes with favourable effect on fat and acrylamide content. Novelty and scientific contribution: The knowledge obtained in this study can be exploited for preparation of coatings with functional compounds used as a pre-treatment for fried food with favourable effect on fat and acrylamide content.

Phenolic Profile, Antioxidant Capacity and Antimicrobial Activity of Nettle Leaves Extracts Obtained by Advanced Extraction Techniques.

Nettle is a widely known plant whose high biological activity and beneficial medicinal effects are attributed to various bioactive compounds, among which polyphenols play an important role. In order to isolate polyphenols and preserve their properties, advanced extraction techniques have been applied to overcome the drawbacks of conventional ones. Therefore, microwave-assisted extraction (MAE) has been optimized for the isolation of nettle leaves polyphenols and it was compared to pressurized liquid extraction (PLE) and conventional heat-reflux extraction (CE). The obtained extracts were analyzed for their individual phenolic profile by UPLC MS2 and for their antioxidant capacity by ORAC assay. MAE proved to be the more specific technique for the isolation of individual phenolic compounds, while PLE produced extracts with higher amount of total phenols and higher antioxidant capacity. Both techniques were more effective compared to CE. PLE nettle extract showed antimicrobial activity against bacteria, especially against Gram-negative Pseudomonas fragi ATCC 4973 and Campylobacter jejuni NCTC 11168 strains. This suggests that PLE is suitable for obtaining a nettle extract with antioxidant and antimicrobial potential, which as such has great potential for use as a value-added ingredient in the food and pharmaceutical industry.

Composition and Antioxidant Properties of Pigments of Mediterranean Herbs and Spices as Affected by Different Extraction Methods.

This study examined the composition and properties of chlorophyll and carotenoid extracted from the leaves of several Mediterranean evergreen shrubs and subshrubs (Myrtus communis L., Pistacia lentiscus L., Thymus vulgaris L., Salvia officinalis L. and Laurus nobilis L.) commonly used as herbs and spices. In order to fully assess their composition over a wide polarity range, pigments were extracted by successive solvent extraction with hexane, 80% acetone and 96% ethanol. Agitation-assisted extraction (AAE), ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) were employed and compared regarding their effect on the pigments' yield and composition. Individual chlorophylls and carotenoids were analyzed by HPLC-DAD, while the content of total pigments and the extracts' antioxidant capacity were determined spectrophotometrically. Throughout the experiments, pheophytin a, b and b' were dominant chlorophyll molecules, while lutein and ß-carotene were dominant carotenoids. Overall, the extracted pigments were determined as being in the range of 73.84-127.60 mg 100 g-1 and were the lowest in T. vulgaris, with no significant differences between other species. M. communis and P. lentiscus had the highest antioxidant capacities, showing a moderate positive correlation with carotenoid and chlorophyll levels. Significant differences were found in the levels of individual pigments with most of them showing a medium level of polarity due to the dissolution in acetone as a medium polar solvent. AAE and PLE demonstrated similar efficacy in the extraction of both carotenoids and chlorophylls; however, preference can be given to PLE, being a novel method with numerous advantages, e.g., shorter extraction time and lower solvent consumption. The examined plant species certainly expressed great diversity and showed the potential for application in the production of various functional products.

Effect of UV-C Irradiation, Storage and Subsequent Cooking on Chemical Constituents of Fresh-Cut Potatoes.

UV-C irradiation successfully reduces the growth of microorganisms, but it can also affect the content of phenolics and sugars of fresh-cut potatoes (FCP). This could consequently alter antioxidant capacity of FCP or its potential for acrylamide formation. Therefore, this paper investigates the influence of UV-C irradiation on the content of phenolics [chlorogenic acid (CA)] and individual sugars during storage of FCP as well as after cooking. Acrylamide was also monitored in FCP after frying. Potato slices pre-treated with sodium ascorbate solution and vacuum-packaged were UV-C irradiated for 0, 3, 5, and 10 min in order to obtain irradiation doses of 0, 1.62, 2.70, and 5.40 kJ m-2, respectively, stored for 23 days (+6 °C), and subsequently boiled and fried. As the applied dose and storage duration increased, the CA content in raw FCP decreased (it retained for 75.53-88.34%), while the content of sugars as well as acrylamide in fried FCP increased. Although the increase was the most noticeable at the applied dose of 2.70 kJ m-2, the acrylamide content was always below proposed limit. Boiling and frying reduced the content of CA and sugars. In spite of certain alterations, applied doses of irradiation can ensure acceptable product in regard to phenolics and sugars, and acrylamide content particularly.

Characterization of Food Packaging Films with Blackcurrant Fruit Waste as a Source of Antioxidant and Color Sensing Intelligent Material.

Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young's modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by DSC, were reduced by 18 °C for chitosan-based samples and of 32 °C lower for the pectin-based samples with blackcurrant powder, indicating a disturbance in polymer stability. The antioxidant activity of active films was increased up to 30-fold. Lightness and redness of dry films significantly changed depending on the polymer type. Significant color changes, especially in chitosan film formulations, were observed after exposure to different pH buffers. This effect is further explored in formulations that were used as color change indicators for intelligent biopackaging.

Chemical constituents of fresh-cut potato as affected by cultivar, age, storage, and cooking.

Certain changes in phenolics and sugars can occur during the storage of potatoes, where particularly amounts of sugars represent the critical factor as they are involved in potentially harmful acrylamide (AA) formation during frying. This research investigates the impact of cultivars (Birgit and Lady Claire), tuber's age (1, 5, and 9 months), and storage duration (1, 5, and 8 days at 10 °C) on the content of phenolics and sugars in raw, boiled, and fried fresh-cut potato (FCP). The influence of these factors on the formation of AA in fried FCP was also assessed. Significant differences in phenolics and sugars were observed between cultivars (cv. Birgit contained 5.77 mg of phenolics 100 g-1 of dry weight (DW) and 1.75 g of sugars 100 g-1 DW, while cv. Lady Claire contained 10.13 mg of phenolics 100 g-1 DW and 0.65 g of sugars 100 g-1 DW). The content of phenolics significantly decreased, while sugars increased during tubers' aging. FCP storage time had no significant influence on the content of phenolics and sugars. The phenolics and sugars were the highest in the raw samples and the lowest in the boiled ones. Although the AA level in fried samples was significantly influenced by cultivar (Birgit > Lady Claire) and it increased with FCP storage time, it was below European Food Safety Authority (EFSA) regulation's approved maximum value (750 µg kg-1 FW) in both cultivars. Therefore, cvs. Birgit and Lady Claire could be considered as promising FCP cultivars and for frying purposes. PRACTICAL APPLICATION: The results of this research reveal that quantitative changes of chemical constituents occurring during storage and cooking of fresh-cut slices of potato cultivars Birgit and Lady Claire are not a concern. This is of particular importance to fresh-cut producers and customers. Phenolics were reduced during storage, but they were still present in all cooked samples independently of the cooking method. The analysis of sugars showed that tubers as old as 9 months could be used for fresh-cut potato processing, providing safe frying without critical levels of acrylamide.

Bioactive Compounds in Wild Nettle (Urtica dioica L.) Leaves and Stalks: Polyphenols and Pigments upon Seasonal and Habitat Variations.

This study evaluated the presence of bioactives in wild nettle leaves and stalks during the phenological stage and in the context of natural habitat diversity. Thus, wild nettle samples collected before flowering, during flowering and after flowering from 14 habitats situated in three different regions (continental, mountain and seaside) were analyzed for low molecular weight polyphenols, carotenoids and chlorophylls using UPLC-MS/MS and HPLC analysis, while the ORAC method was performed for the antioxidant capacity measurement. Statistical analysis showed that, when compared to the stalks, nettle leaves contained significantly higher amounts of analyzed compounds which accumulated in the highest yields before flowering (polyphenols) and at the flowering stage (pigments). Moreover, nettle habitat variations greatly influenced the amounts of analyzed bioactives, where samples from the continental area contained higher levels of polyphenols, while seaside region samples were more abundant with pigments. The levels of ORAC followed the same pattern, being higher in leaves samples collected before and during flowering from the continental habitats. Hence, in order to provide the product's maximum value for consumers' benefit, a multidisciplinary approach is important for the selection of a plant part as well as its phenological stage with the highest accumulation of bioactive compounds.

Fresh-cut potato quality and sensory: Effect of cultivar, age, processing, and cooking during storage.

This work examined the influence of cultivar, tubers' age, antibrowning agent, package atmosphere, and storage time on fresh-cut potatoes' (FCPs) physical, chemical, and sensory properties. Potato slices of cv. Birgit and Lady Claire tubers sampled during the first, fifth, and ninth months of storage were dipped in solutions of (1) sodium chloride (1%) and (2) sodium ascorbate (2%), and stored for 8 days in (1) vacuum and (2) active modified atmosphere (MAP) (10.0% CO2 , 3.0% O2 , and 87.0% N2 ) at 10 °C. During storage, O2 and CO2 content (%) within packages was measured and samples were analyzed for weight loss, total solids (TS) and soluble solids (SS), pH, color, texture, and sensory properties of raw, boiled, fried, and baked FCP. Results showed that 9 months' aging had a significant impact on almost all investigated FCP properties, but differences among first, fifth, and ninth months were numerically feeble for some parameters in raw samples: TS changed from 22.14% to 20.98%, SS 5.53% to 6.93%, pH 6.02 to 5.98, L* 70.10 to 68.87, C* 35.75 to 36.70, H° 89.29 to 88.15, and firmness 7.25 to 8.13N. Furthermore, 9 months of aging had no significant influence on the characteristic odor of raw, boiled, fried, and baked FCP and characteristic taste of fried and baked FCP, whereas boiled FCP characteristic taste remained unchanged for 5 months of aging. Fried FCP was better sensory evaluated than baked ones, cv. Birgit was more suitable for the FCP production compared to cv. Lady Claire as well as vacuum packaging and sodium ascorbate better preserved samples quality and sensory than sodium chloride and MAP. PRACTICAL APPLICATION: This study could be helpful to fresh-cut potato (FCP) producers because results indicate that for FCP processing, along with the selection of cultivar, antibrowning agent, and packaging type, tubers' age also requires attention. A further contribution of this research is related to the adequate way of FCP cooking, where frying shows the best results according to the quality and sensory assessment.