Search Results (196)

Nitrogen (N) availability often limits primary productivity in terrestrial ecosystems, and arbuscular mycorrhizal fungi (AMF) can enhance plant N acquisition. This study investigated the interactive effects of N fertilization and AMF inoculation on N uptake, plant performance and phenolic acid content in Hyssopus officinalis L., with the aim of promoting sustainable N management in H. officinalis cultivation. A factorial randomized complete block design was employed to evaluate four AMF inoculation strategies (no inoculation, root inoculation, soil inoculation and combined root–soil inoculation) across three N application rates (0, 0.5 and 1,1 g N pot⁻¹ (7 L)) in a controlled greenhouse environment. Combined root and soil AMF inoculation alongside moderate N fertilization (0.5 mg N pot⁻¹) optimized N use efficiency, maximizing plant biomass and bioactive compound production. Compared to non-inoculated controls, this treatment combination increased N uptake by 30%, phosphorus uptake by 24% and potassium uptake by 22%. AMF colonization increased chlorophyll content and total phenolic compounds under moderate N supply. However, excessive N application (1 g N pot⁻¹) reduced AMF effectiveness and secondary metabolite accumulation. Notably, AMF inoculation without N fertilization yielded the highest levels of anthocyanin and salicylic acid, indicating differential N-dependent regulation of specific biosynthetic pathways. The interaction between AMF and N demonstrated that moderate N fertilization (0.5 g N pot⁻¹) combined with dual inoculation strategies can reduce total N input requirements by 50%, while maintaining optimal plant performance. These findings provide practical insights for developing N-efficient cultivation protocols in medicinal plant production systems, contributing to sustainable agricultural practices that minimize environmental N losses. Full article

The impact of processing time, temperature, and sample on solution ratio parameters, along with pulsing microwave pretreatment, was assessed in the osmotic dehydration of waxy skin highbush blueberries. Fresh blueberries were pre-treated with 20% microwave power for 90 s before being subjected to osmotic dehydration for 8 h in a 60 °Brix sucrose solution, with three different sample to solution ratios (1:4, 1:7, and 1:10). Changes in water loss, solid gain, total anthocyanin content, total phenolic content, and total soluble solid content during osmotic dehydration, as well as color and texture changes, were investigated at four temperature levels (room temperature, 60 °C, 65 °C, and 70 °C). The highest rate of reduction in the total soluble solid content in the osmotic solution was observed during the initial hours (0–4 h) of the process. The most effective combination for reducing the total soluble content of the osmotic agent involved the microwave-pretreatment of the blueberries at 70 °C, using a sample to solution ratio of 1:4, resulting in a decrease of 11.98%, compared to 7.83% for non-pretreated samples. The solid gain was found to be affected by the sample to solution ratio × temperature × pretreatment at a 1% probability level (p ≤ 0.01). The temperature, osmotic solution ratio, and microwave pretreatment interacted together to affect the quality parameters of the osmotically dehydrated blueberries, including total anthocyanin content, total phenolic content, and color. Higher temperatures, along with microwave pretreatment, showed the worst effects on the quality characteristics mentioned. Microwave pretreatment did not change the texture significantly in comparison with non-pretreated blueberry samples. The enhancing effect of microwave pretreatment and higher temperatures on the efficiency of the osmotic dehydration process was obvious. An optimized microwave pretreatment can reduce both the required processing time and temperature for the osmotic dehydration of waxy skinned blueberries, which in turn can lead to the higher quality preservation of processed blueberries and lower energy consumption. This could be especially useful for the large-scale processing of waxy skinned berries. Full article

Anthocyanins are important phenolic compounds in grape skins, affecting the color, oxidation resistance, and aging ability of red wine. In recent years, global warming has had a negative effect on anthocyanin biosynthesis in grape berries. Ethylene serves as a crucial phytohormone regulating the development and ripening processes of fruit; however, the specific molecular mechanism and the regulatory network between ethylene signaling and the anthocyanin biosynthesis pathway remain incompletely understood. In this study, 400 mg/L ethephon (ETH) solution was sprayed onto the surface of grape berries at the lag phase (EL-34), and the changes in anthocyanin-related genes and metabolites were explored through transcriptomic and metabolomic analysis. The results showed that ETH treatment increased Brix and pH in mature berries. In total, 35 individual anthocyanins were detected, in which 21 individual anthocyanins were enhanced by ETH treatment. However, the anthocyanin profile was not affected by exogenous ethylene. Transcriptomics analysis showed that there were a total of 825 and 1399 differentially expressed genes (DEGs) 12 h and 24 h after treatment. Moreover, key structural genes in the anthocyanin synthesis pathway were strongly induced, including VvPAL, VvCHS, VvF3H, VvF3′5′H, VvDFR and VvUFGT. At the maturity stage (EL-38), the expression levels of these genes were still higher in EHT-treated berries than in the control. ETH treatment also influenced the expression of genes related to hormone biosynthesis and signal transduction. The ethylene biosynthesis gene (VvACO), ethylene receptor genes (VvETR2, VvERS1 and VvEIN4), ABA biosynthesis gene (VvNCED2), and ABA receptor gene (VvPYL4) were up-regulated by ETH treatment, while the auxin biosynthesis gene (VvTAA3) and seven genes of the auxin-responsive protein were inhibited by exogenous ethylene. Meanwhile, ETH treatment promoted the expression of the sugar transporter gene (VvEDL16) and two sucrose synthase genes (VvSUS2 and VvSUS6). In EHT-treated berries, 19 MYB and 23 ERF genes were expressed differently compared with the control (p < 0.05). This study provides the theoretical foundation and technical support for the regulation of anthocyanin synthesis in non-climacteric fruit. Full article

Cabbage (Brassica oleracea L.) is a globally significant vegetable crop that faces productivity challenges due to fungal and bacterial pathogens. This review highlights the potential of spectral imaging techniques, specifically multispectral and hyperspectral methods, in detecting biotic stress in cabbage, with a particular emphasis on pathogen-induced responses. These non-invasive approaches enable real-time assessment of plant physiological and biochemical changes, providing detailed spectral data to identify pathogens before visible symptoms appear. Hyperspectral imaging, with its high spectral resolution, allows for distinctions among different pathogens and the evaluation of stress responses, whereas multispectral imaging offers broad-scale monitoring suitable for field-level applications. The work synthesizes research in the existing literature while presenting novel experimental findings that validate and extend current knowledge. Significant spectral changes are reported in cabbage leaves infected by Alternaria brassicae and Botrytis cinerea. Early-stage detection was facilitated by alterations in flavonoids (400–450 nm), chlorophyll (430–450, 680–700 nm), carotenoids (470–520 nm), xanthophyll (520–600 nm), anthocyanin (550–560 nm, 700–710 nm, 780–790 nm), phenols/mycotoxins (700–750 nm, 718–722), water/pigments content (800–900 nm), and polyphenols/lignin (900–1000). The findings underscore the importance of targeting specific spectral ranges for early pathogen detection. By integrating these techniques with machine learning, this research demonstrates their applicability in advancing precision agriculture, improving disease management, and promoting sustainable production systems. Full article

Plums are one of the most important stone fruits worldwide. Surprisingly, the effect of UV-C light on improving their bioactive compounds and its effect during storage has not been explored. This research aimed to assess the effect of UV-C light on the bioactive compounds and antioxidant capacity of plums, as well as to evaluate the storage conditions on the quality attributes of these fruits. Plums were UV-C light-irradiated (0, 0.175, and 0.356 kJ/m²) to analyze their effect on phenolic compounds, total anthocyanins, and antioxidant capacity. A selected dose of UV-C light treatment was applied to plums as a pretreatment to assess the effect of packaging (non-packed, packed in closed polyethylene boxes, and packed in closed polyethylene boxes with perforations) and temperature (5, 15, and 20 °C) on the quality characteristics of plums using a 3² experimental design. The results showed that phenolic compounds (3–10%), total anthocyanins (22–39%), and antioxidant capacity (8–15%) increased with the UV-C light treatment (0.356 kJ/m²). In storage, firmness remained constant, and color parameters (a* and b*) were reduced in all conditions, whereas weight loss was lower in plums stored in closed packages. Moreover, total anthocyanins and antioxidant capacity were enhanced under all storage conditions. The microbial load decreased due to the UV-C light treatment and remained constant during storage time (<100 CFU/g). Storing the plums at a low temperature in a closed package effectively preserved the quality attributes of plums for 40 days without affecting the sensory acceptance. Full article

Natural deep eutectic solvents (NaDESs) are emerging solvents for their yield when used for extraction of different molecules, including polyphenols. NaDESs are a cutting-edge technology that offers numerous advantages, including cheap cost, safety, effectiveness and environmental friendliness. However, due to NaDES’ high boiling point, the recovery and separation of compounds after the extraction is the bottleneck of the process. In this work, two affordable methods were tested for the recovery of phenolic compounds from three binary NaDESs (composed of choline chloride mixed separately with lactic acid, tartaric acid or glycerol as hydrogen bond donors): the antisolvent and the liquid–liquid extraction methods. The former was assessed by diluting the extracts with different aliquots of water, employed as antisolvent, which was ineffective. For the liquid–liquid extraction method, ethyl acetate (EtOAc), acetonitrile (ACN), 2-chlorobutane (2-CB) and 2-methyltetrahydrofuran (2-MeTHF) were compared. Except for ACN, all solvents were perfectly immiscible with the three NaDESs, forming biphasic systems that were analyzed by colorimetric assays and HPLC/MS. 2-MeTHF applied on a 10-fold water dilution of the NaDES extract reached recovery percentages higher than 90% for most of the non-anthocyanin phenols and good recovery (up to 80%) for some anthocyanins. 2-MeTHF appears to be the first known solvent capable of extracting anthocyanins from NaDESs. Finally, a two-step liquid–liquid extraction performed firstly with EtOAc and subsequently with 2-MeTHF is proposed for the separation of different phenolic fractions. Full article

This study evaluated the combined effects of freeze–thaw and osmotic dehydration (OD) pretreatments on the physicochemical, functional, and sensory qualities of umbu slices. Fresh and thawed umbu slices (thawed at 26 ± 3 °C for approximately 1 h after being frozen for at least 8 days) were submitted to OD or directly processed. All slices were then dehydrated by convective drying. Treatments varied by drying temperature (50 and 60 °C) and sucrose concentration (40, 50, and 60 °Brix), resulting in sixteen conditions, including four without OD. Freeze–thaw pretreatment significantly enhanced sucrose uptake (24.11–49.89%) during OD, affecting the slices’ physicochemical and functional attributes. It also improved appearance, color, and texture, leading to a higher sensory acceptance. Among OD treatments, experiment 2 (non-pre-frozen, 50 °Brix at 50 °C) exhibited the highest total phenolics (71.95 mg/100 g) and lowest phenolic losses during in vitro digestion. Experiment 1 showed the highest flavonoids (3.94 mg/100 g), anthocyanins (0.62 mg/100 g), and chlorophylls (0.78 mg/100 g). Phenolic bioaccessibility ranged from 10.88% (experiment 14) to 52,90% (experiment 16). Experiment 13 (pre-frozen, 40 °Brix at 60 °C) had the highest antioxidant activity among freeze–thawed samples and was notable for its greater perceived sweetness. Therefore, frozen storage combined with osmoconvective dehydration is a promising strategy for conserving and adding value to umbu fruit. Full article

Tomato is a crop with high potential to be used in various food industry co-products, such as sauces. In addition to increasing the supply of differentiated products, processed foods have improved shelf life. However, as a consequence of thermal processing, there may be some important nutritional losses. In this context, the choice of suitable varieties for each type of processing based on the assessment of food losses is extremely important to both the processing industry and the consumer. Therefore, this work aimed to predict the percentage of concentration loss in tomatoes during cooking for sauce production using an artificial neural network (ANN). The prediction was made by analyzing the fresh fruit and comparing it to the cooked product. The study investigated bioactive compounds (vitamin C, ascorbic acid, phenolic compounds, flavonoids, carotenoids, anthocyanins, lycopene, and β-carotene), antioxidant activity (DPPH and FRAP), soluble solids, pH, titratable acidity, ratio, and total sugar. Nine commercial and non-commercial tomato varieties were evaluated. The artificial neural network used was the multilayer perceptron, and its results were compared with first-, second-, and third-degree polynomial regression techniques, evidencing its superiority. This superiority was confirmed by the higher correlation achieved using the ANN (R² = 0.9025), outperforming the first-, second-, and third-degree regressions (R² = 0.8817, 0.8819, and 0.8941, respectively). Furthermore, the ANN achieved a lower mean squared error (MSE = 0.000999) and strong validation performance, reinforcing its greater precision and reliability compared to traditional models. Full article

Blood oranges grown in subtropical and tropical regions have low anthocyanin levels and a pale internal color at the point of commercial maturity. Since blood oranges are cold-dependent and can enhance anthocyanin during postharvest storage, the effects of various non-chilling storage temperatures (10, 15, and 20 °C) on ‘Moro’ blood orange fruit quality and biochemical changes over a period of up to 42 days were investigated for total anthocyanin concentration (TAC), total phenolic content (TPC), total antioxidant activity (TAA), juice attributes, and physical qualities. Fruit weight and firmness losses increased during storage, with the lowest losses occurring at 10 °C. Titratable acidity (TA) decreased, with the lowest values recorded at 20 °C. Total soluble solids (TSSs) and the TSS/TA ratio increased, with the highest values observed at 20 °C. The sucrose content showed slight changes, while glucose and fructose levels increased during storage, with the highest concentrations of glucose and fructose noted at 20 °C. TAC, TPC, and TAA significantly increased during storage, with the highest values recorded at 10 °C, suggesting upregulation of the fruit antioxidant system and associated bioactive components in response to the lower temperature. Throughout the storage period, peel color parameters, such as L*, b*, C*, and h°, decreased at all temperatures, whereas a*, citrus color index (CCI), and total color difference (ΔE) increased. This study concludes that a storage temperature of 10 °C proved effective in enhancing TAC, TPC, and TAA during storage, as well as in maintaining the other physicochemical attributes. Full article

Natural polyphenols, especially the ones in their glycosylated form like hesperidin, rutin, and anthocyanins, are the most abundant phenolic compounds in citric fruits, apples, and red fruits, respectively. They stand out for their high nutraceutical potential, with various reported properties, like antioxidant, anti-inflammatory, anticarcinogenic, and cardioprotective. Nevertheless, these compounds have low bioavailability and are rapidly excreted and released by the organism. Therefore, the main goal of this work was to obtain polyphenols with increased bioactivity by functionalizing biocompounds in fruit juices, namely, orange, apple, and red fruits. This modification was achieved via hesperidinase, an enzyme that catalyzes the hydrolysis of several natural bioactive compounds. Hesperidinase was produced with Penicillium sp. The activity and stability of the produced enzyme, in its free and immobilized form, using the sol–gel method, were assessed, as well as the bioactivity of the bioprocessed juices. Moreover, after immobilizing hesperidinase in sol–gel lens-shaped particles, the activity and operational stability of the bioencapsulates were evaluated by measuring the residual activity over several runs. Using the specific substrate p-NPG, β-D-glucosidase retained 31% of its activity in the second run, 22.6% in the third, and 35% in the fourth. For α-L-rhamnosidase, using the substrate p-NPR, residual activity was 31.1% in both the fourth and fifth runs. In fruit juices, the bioencapsulates exhibited residual activities around 100% in the second run, approximately 81% in the third, and around 90% in the fourth. The antioxidant and anti-inflammatory activities of the bioprocessed juices were evaluated, and an increase in the anti-inflammatory activity was observed when compared with the non-processed juices. Full article

Raspberries (Rubus idaeus L.) are valued as both a food source and a medicinal plant, with expanding production driven by premium market demand. Primocane varieties, such as “Regina” are prized for their ability to produce two harvests per year, offering extended availability into autumn and providing significant commercial benefit. Their high polyphenol content, particularly in anthocyanins and flavonoids, contributes to antioxidant and health properties. However, their extraction and quantification are influenced by factors such as genetic variability, environmental conditions, fruit maturity, storage, and processing techniques. This study analyzed the metabolic profiles of “Regina” raspberries harvested in June (RiJ) and September (RiS). Out of 748 compounds listed in the Phenol-Explorer database, 377 metabolites were identified and categorized. Principal component analysis (PCA) revealed significant differences between harvests, with RiS samples showing higher concentrations of most flavonoid and non-flavonoid compounds. Heatmap and volcano plot analyses confirmed that significant metabolites were enriched in RiS samples. Correspondingly, antioxidant capacity, measured via ABTS and FRAP assays, was higher in RiS raspberries. These findings highlight the metabolic and antioxidant differences between harvest periods and lay the groundwork for understanding how these compounds could be modulated through the application of postharvest treatments. Full article

This study examined the effects of three sterilization techniques—heat, microwave, and high hydrostatic pressure (HHP)—on the phytochemicals, flavor, and antioxidant properties of high-acidity mulberry vinegar. High-acidity vinegar is valued for its unique sensory properties, preservation potential, and potential health benefits, yet its quality can be significantly impacted by processing methods. Understanding how sterilization affects high-acidity vinegar is crucial for optimizing its functional and nutritional properties while maintaining consumer appeal. Thermal processing (TP) involved heating samples at 85 °C for 15 min, while microwave heating (MH) was performed at 600 W for 40 s. HHP treatments subjected samples to pressures of 400 MPa, 500 MPa, and 600 MPa at ambient temperature (~25 °C) for 15 min. Results showed that total soluble solids (TSS) remained stable at approximately 6.90% across treatments, confirming effective sterilization, especially with HHP. pH values were consistent (3.53–3.55), while total acidity varied, with HHP treatments achieving lower acidity (5.00 g/L). Phytochemical analysis indicated the control (CK) treatment preserved the highest total anthocyanin content (TAC), but HHP₅₀₀ maintained notable levels. HHP treatments also yielded the highest total phenolic (TPC) and total flavonoid content (TFC), highlighting non-thermal sterilization’s advantage in preserving health-promoting compounds. Antioxidant activity, particularly DPPH, was best retained in HHP samples. HHP₅₀₀ showed minimal reductions in key phenolic acids, with decreases of 6.16% in p-hydroxybenzoic acid and 7.81% in total phenolic acid. Volatile organic compound analysis revealed increased ester production, with ethyl acetate peaking at 1775.71 μg/L in HHP₆₀₀. Overall, HHP at 500 and 600 MPa proved superior for producing high-quality mulberry vinegar, supporting the demand for minimally processed, health-focused food products. Full article

Pico Island is one of the islands of the Azores archipelago located in the North Atlantic Ocean, where there are very specific conditions for vine cultivation. In this context, there is scarce knowledge related to grape ripening under these conditions. Thus, the aim of this study was to evaluate several physicochemical parameters, the phenolic composition, antioxidant capacity, and varietal aromatic potential, of the “Merlot”, Syrah”, and “Saborinho” grape varieties cultivated on Pico Island over three vintages. The outcomes obtained demonstrated that “Merlot” grapes showed a tendency for significantly higher values of estimated alcohol degree, total phenols, flavonoid and non-flavonoid phenols, total anthocyanins, color intensity, and antioxidant capacity over the three vintages. In addition, for individual anthocyanins, “Merlot” and “Syrah” grapes showed a predominance of acetyl-anthocyanins in relation to p-coumaroylated forms, while for “Saborinho” grapes, an oppositive tendency was observed. For varietal aromatic potential, only in the 2021 vintage was it possible to detect significantly different values between the three grape varieties studied. In this case, “Merlot” and “Syrah” grapes showed the significantly highest values. Considering all parameters analyzed, the results obtained for the “Merlot” grape variety seem to show a better adaptation of this variety to the conditions of Pico Island than the remaining two varieties studied. Full article

Background: Thermovinification is a non-conventional winemaking practice that replaces the traditional method of grape maceration. Methods: This study evaluated the influence of thermovinification temperature on the quality of Syrah wines. The treatments included traditional winemaking with 7 days of maceration during alcoholic fermentation at 23 °C (TW—control); and thermovinification for 2 h at 55 °C (TV55), 65 °C (TV65), and 75 °C (TV75). The red wines were made through microvinification (10-litre glass). Phenolic compounds (n = 26) were quantified by high-performance liquid chromatography and a colour analysis using the CIELab/CIEL*C*h systems and a sensory analysis was conducted to evaluate the acceptability of the thermovinified wine. Results: The results indicate that thermovinification increased the content of bioactive compounds and intensified the colour of the wine, reducing L* and a*. However, the content of phenolic acids decreased, except for trans-caftaric acid, which was approximately 50 times higher. A higher temperature of thermovinification (75 °C) promoted the degradation of all anthocyanins. Among flavonols, kaempferol-3-O-glucoside, quercetin-3-β-D-glucoside, and isorhamnetin-3-O-glucoside were higher in TV65 and TV75 wines. Greater amounts of stilbenes were quantified in TV65. Among the flavan-3-ols, TV75 stood out, especially for (+)-catechin, (−)-epicatechin, procyanidin A2, and procyanidin B1. Conclusions: The thermovinification at 65 °C is optimal for minimising anthocyanin degradation and improving Syrah wine quality. Full article

Brassinosteroids (BRs), a new family of plant hormones, have been used in a range of food staples, oil crops, and cereals. However, the scientific literature pertaining to their use in fleshy fruits remains scarce. This review presents, for the first time, the knowledge developed over the last decade on the role of BR preharvest treatments in crop yield and fruit quality properties at harvest and during storage, although information about the effects of BR postharvest treatments is also addressed. This review revealed that 24-epibrassinolide is the most used BR analogue in research experiments, either as a pre- or postharvest treatment, with doses ranging from 0.1 to 15 μM. Additionally, most of the research has been conducted on non-climacteric fruit species. In most of these preharvest treatments, an increase in crop yield has been reported, as well as enhanced anthocyanin concentration in red-coloured fruit. In addition, increases in firmness, total soluble solids, and phenolic content have also been observed. On the other hand, BR postharvest treatments led to the maintenance of these fruit quality properties during storage due to increased antioxidant systems, either enzymatic or non-enzymatic ones. Finally, as future perspectives, it is proposed to extend the research about BR treatments to other climacteric fruits and to deepen the knowledge of how BRs regulate physiological aspects from preharvest to postharvest. Furthermore, it is essential to investigate the role of BRs in the prevention of rot and biotic stress. Full article