Total Anthocyanin Content Research Articles

Monitoring storage characteristics of gray mold inoculated strawberries treated with limonene liposome and oxygen absorbers and prediction of sensory shelf‐life with UV‐VIS‐NIR reflectance

AbstractIn this research, the effect of grey mold inoculation and subsequent postharvest treatment with limonene‐liposomes and oxygen absorbers is observed on the storage characteristics of strawberries. The survival analysis of the end of sensory shelf‐life indicated that inoculated strawberries were 9.96 times more likely to be rejected compared to uninoculated strawberries. The inoculation also resulted in lower firmness, higher rate of weight loss, higher CO2 respiration rates, and higher total polyphenol contents. Among the inoculated strawberries, limonene‐liposome treated strawberries had a longer average shelf‐life by 1.5 days compared to control inoculated strawberries. Similarly, oxygen absorber treated strawberries had lower respiration rates and lower rate of weight loss. The sequential addition of variables in the multiple linear models fitting days till rejection (DTR) show that up to 52% of the variation in DTR can be explained from days of storage, state of inoculation, firmness, respiration rate and total anthocyanin content. The models built from storage characteristics other than state of inoculation can explain up to 26% of variation in DTR. The partial least square regression (PLSR) models for the prediction of DTR built from two different types of spectral data, UV‐VIS and NIR, yielded evaluation R2 up to 0.778 and 0.765 respectively.

Antioxidant activity, total polyphenol, anthocyanin and benzyl-glucosinolate contents in different phenotypes and portion of Japanese Maca (Lepidiummeyenii)

Maca (Lepidium meyenii), mainly grown in Peru, is a traditional herbal medicine that is mostly used to improve sperm motility and serum hormone levels. Maca phenotypes are represented by purple, black, yellow, white, and mixed colors. Recently, a method for Maca cultivation has been established in Japan. Therefore, we determined the effects of different phenotypes and portions on the antioxidant activities and total polyphenols, anthocyanins, and benzyl-glucosinolate contents in Japanese Maca. Purple Maca skin possessed the highest contents of both total polyphenols, antioxidant activity and anthocyanin content in all Macas. Regarding the benzyl-glucosinolate content, white maca had the highest content and was not correlated with antioxidant activity. In the present study, we revealed that purple Maca skin is recommended for high polyphenol content, antioxidant activity, and anthocyanin content. The results of this study will be useful for selecting phenotypes for the improvement of antioxidant activity or hormone balance.

Mathematical modeling of extraction kinetics from black chokeberries enhanced by cold plasma pretreatment

The application of cold plasma as a pretreatment for extraction process is a recent development. This research investigates the impact of cold plasma (CP) treatment on the extraction process of bioactive compounds from black chokeberry samples. Utilizing a 12-h maceration process, various analyses, including total phenolic content (TPC), antioxidant capacity (DPPH, ABTS+, CUPRAC assays), total monomeric anthocyanin content (TMA), color parameters, and comprehensive mathematical modeling, were employed to assess the effectiveness of CP treatment. The kinetic modeling with Peleg, Power Law, Elovic's, and Two-site Kinetic Models emphasized the critical role of CP treatment duration in the extraction process. This study indicates that the power-law kinetic model provided the best fit for the experimental data from CP-treated samples, suggesting that this model most accurately describes the extraction kinetics under the conditions tested. In summary, this investigation underlines the crucial role of mathematical modeling in understanding the dynamics of bioactive compound extraction under CP treatment.

High-throughput color determination of red raspberry puree and correlation of color parameters with total anthocyanins

BackgroundRed raspberry fruit color is a key driver of consumer preference and a major target of breeding programs worldwide. Screening for fruit color typically involves the determination of anthocyanin content and/or the assessment of color through a colorimeter. However, both procedures are time-consuming when the analyses involve hundreds or thousands of samples. The objectives of this study were to develop a high-throughput method for red raspberry puree color measurement and to test the correlations between color parameters and total anthocyanin content. Color coordinates were collected with a colorimeter on 126 puree samples contained in Petri dishes and with the Tomato Analyzer Color Test (TACT) module to assess the same samples prepared in Petri dishes and in 96-well plates. An additional 425 samples were analyzed using only 96-well plates. Total anthocyanins were extracted from all 551 samples.ResultsRegression models for L*, a*, b* measured with the colorimeter and TACT using Petri dishes were all significant (p < 0.001), but very consistent only for L* (R2 = 0.94). Significant (p < 0.001) and very consistent regressions (R2 = 0.94 for L* and b*, R2 = 0.93 for a*) were obtained for color parameters measured with TACT using Petri dishes and TACT using plates. Of the color parameters measured with the colorimeter, only L*, a*/b*, and hue significantly correlated with total anthocyanins (p < 0.05), but, except for L* (R = − 0.79), the correlations were weak (R = − 0.23 for a*/b* and R = 0.22 for hue). Conversely, all correlations with total anthocyanins and color parameters measured with TACT were significant (p < 0.001) and moderately strong (e.g., R = − 0.69 for L* and R = 0.55 for a*/b*). These values were indicative of darker colors as total anthocyanin content increased.ConclusionsWhile the colorimeter and TACT-based methods were not fully interchangeable, TACT better captured color differences among raspberry genotypes than the colorimeter. The correlations between color parameters measured with TACT and total anthocyanins were not strong enough to develop prediction models, yet the use of TACT with 96-well plates instead of Petri dishes would enable the high-throughput measurement of red raspberry puree color.

Enhancing the Nutritional Profile of Crataegus monogyna Fruits by Optimizing the Extraction Conditions

Crataegus monogyna (CM) fruits are highly regarded for their rich nutritional content, boasting elevated levels of various beneficial secondary metabolites like total polyphenols, including anthocyanins, and ample amounts of ascorbic acid and antioxidant activity. Despite the acknowledged benefits of CM fruits, researchers have directed more attention toward its leaves and flowers. Consequently, the current research attempts to optimize extraction techniques for CM fruit using a multifaceted approach involving varied durations, temperatures, and concentrations of ethanol solvent to isolate the diverse range of bioactive components present effectively. High-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) is employed for the identification and quantification of polyphenolic compounds. According to the results, by following the optimum extraction parameters (50% ethanolic solvent, 50 °C extraction temperature, and 60 min extraction time), the total polyphenol content can be increased up to 410%, reaching 55.59 mg gallic acid equivalents/g. Using 50% ethanolic solvent, 80 °C extraction temperature, and extraction time of 90 min, the total anthocyanin content can be enhanced by more than 560%, reaching a quantity of 51.83 μg cyanidin equivalents/g. Moreover, the antioxidant activity of CM fruit extracts can reach 415.95 μmol ascorbic acid equivalents (AAE)/g dw (by FRAP method), using 50% ethanolic solvent, 50 °C extraction temperature, and 60 min extraction time, and 270.26 μmol AAE/g dw (by DPPH method) and 1053.28 mg/100 g dw ascorbic acid content, using 50% ethanolic solvent, 80 °C extraction temperature, and 90 min extraction time. This comprehensive study seeks to augment the already substantial content of bioactive compounds found in CM, resulting in an extract with promising applications across the pharmaceutical, food, and cosmetics industries.

The influence of potassium nanoparticles as a foliar fertilizer on onion growth, production, chemical content, and DNA fingerprint

Potassium is an important macro-fertilizer for plant growth but can be lost from the soil after application via irrigation. Slow-release nano-fertilizers can achieve sustainable crop cultivation and production, so this study evaluated the influence of potassium nanoparticles (K-NPs) with various concentrations (0, 50, 100, and 200 mg/l) on onion development, production, pigments, chemical content, and DNA fingerprint during two sequential agriculture seasons in 2021 and 2022 at a private farm in Zagazig, Sharkia Governorate, Egypt. Spraying onion plants with K-NPs (200 mg/l) significantly improved the vegetative characteristics of onion plant growth and production, as well as increasing the plant pigments and the content of carbohydrate, oil, total indole, and phosphorus in onion bulbs. Similarly, 50 mg/l of K-NPs considerably increased the content of nitrogen, potassium, protein, antioxidant activity, and phenols in the onion bulbs. The content of total flavonoids and anthocyanin was increased with 100 mg/l of K-NPs. In conclusion, the foliar application of K-NPs improves the onion plant yield and quality and can achieve agricultural sustainability.

Thermotolerant acetic acid bacteria in the production of a red wine vinegar by surface culture at different temperatures: volatile and polyphenolic composition

This work aims to determine the effect on the aromatic profile and phenolic content of red wine vinegars produced by surface culture at two different temperatures (30 °C and 37 °C) and using different inocula of acetic acid bacteria (Acetobacter malorum, Gluconobacter oxydans and a mixture of bacteria isolated from a Sherry vinegar). Fifty-seven volatile compounds and 23 polyphenolic and furfural compounds were identified. Vinegars obtained at 37 °C had poorer volatile profiles, with no significant influence of the strain of acetic bacteria. For polyphenolic content, temperature was also the most significant variable, so that the vinegars produced at higher temperatures had lower total anthocyanin contents, while no clear trend was observed regarding the influence of temperature on the low-molecular-weight phenolic constituents. The total tannin content in the vinegars obtained experienced slight increases after acetification, although this was not affected by temperature, and it was observed that when using the mixture of acetic acid bacteria from the Sherry vinegar, the total tannin content was significantly higher than when individual bacteria cultures of Acetobacter malorum or Gluconobacter oxydans were used. Temperature appears as a key parameter for the volatile and phenolic composition of red wine vinegar versus the use of different acetic acid bacteria.

Metabolomics of Vitis davidii Foëx. grapes from southern China: Flavonoids and volatiles reveal the flavor profiles of five spine grape varieties

The spine grapes (Vitis davidii Foëx.) are wild grape species that grow in southern China, and can be used for table grapes, juicing and winemaking. To systematically investigate the flavor profiles of spine grapes, flavonoids and volatile compounds were detected in five spine grape varieties (Seputao, Ziqiu, Miputao, Tianputao and Baiputao) using HPLC-QqQ-MS/MS and GC–MS. The content of flavonoids highly depended on the variety, such as the total concentrations of anthocyanins (91.43–328.85 mg/kg FW) and flavonols (33.90 to 83.16 mg/kg FW). The volatile compounds with higher odor active value were selected to describe the aroma of spine grapes. Hexanal, (E)-2-hexenal and (E, Z)-2,6-nonadienal contributed to the higher herbaceous flavor to Baiputao and Ziqiu. β-Damascenone and (E)-2-nonenal gave Baiputao a flavor with more floral, fruity and earthy. Their characteristic flavor compounds were subsequently revealed using multivariate statistical analysis. The results helped producers to further develop and utilize the spine grapes.

Application of anthocyanins from blue pea flower in yoghurt and fermented milk: An alternate natural blue colour to spirulina

Studies investigating the application of blue pea flower anthocyanins in fermented dairy products are limited. In this study, the application of anthocyanin extracts from blue pea flower (Clitoria ternatea) in yoghurt and fermented milk at 1 and 2% (w/v) concentrations was investigated and compared to a commercial blue colourant from spirulina. The total anthocyanin content (TAC), antioxidant activity (DPPH free radical and ferric reducing antioxidant power assays), pH, titratable acidity, syneresis, colour, and viable cell count were measured at 6 days intervals for 30 days at 4 °C storage. The TAC of yoghurt with blue pea flower anthocyanin extract demonstrated high stability, but the TAC of fermented milk with blue pea flower anthocyanin extract decreased significantly. The yoghurt and fermented milk with blue pea flower anthocyanin extract demonstrated higher antioxidant activity than the negative control and samples containing spirulina. The total colour change (ΔE) of yoghurt with blue pea flower anthocyanin extract was less than that of yoghurt containing spirulina during storage. However, the colour of fermented milk with blue pea flower anthocyanin extract was less stable than samples containing spirulina. The average colour acceptability of yoghurt and fermented milk containing 2% (w/v) blue pea flower anthocyanin extracts and those containing spirulina colourant was not significantly different. Therefore, an anthocyanin extract from blue pea flowers at 2% (w/v) concentration was a better blue colourant than spirulina in yoghurt. Spirulina was a better colourant compared to blue pea flower anthocyanins for fermented milk.

Different frequencies of water deficit irrigation treatments improve fruit quality of Zitian seedless grapes under on-tree storage

In this study, we assessed the impact of varied water deficit irrigation frequencies (T1: 2.5 L/4 days; T2: 5 L/8 days; CK: 5 L/4 days) on Zitian Seedless grapes from veraison to post-ripening. Notably, total soluble solids increased during on-tree storage compared to at maturity, while total anthocyanin content decreased, particularly in CK (60.16%), T1 (62.35%), and less in T2 (50.54%). Glucose and fructose levels increased significantly in T1 and T2, more so in T2, but slightly declined in CK. Tartaric acid content increased by 41.42% in T2. Moreover, compared to regular irrigation, water deficit treatments enhanced phenolic metabolites and volatile compounds, including chlorogenic acid, various flavonoids, viniferin, hexanal, 2-nonenal, 2-hexen-1-ol, (E)-, 3-hydroxy-dodecanoic acid, and 1-hexanol, etc. Overall, the T2 treatment outperformed T1 and CK in maintaining grape quality. This study reveals that combining on-tree storage with water deficit irrigation not only improves grape quality but also water efficiency.

Exogenous melatonin prolongs raspberry postharvest life quality by increasing some antioxidant and enzyme activity and phytochemical contents

There is a growing trend towards enhancing the post-harvest shelf life and maintaining the nutritional quality of horticultural products using eco-friendly methods. Raspberries are valued for their diverse array of phenolic compounds, which are key contributors to their health-promoting properties. However, raspberries are prone to a relatively short post-harvest lifespan. The present study aimed to investigate the effect of exogenous melatonin (MEL; 0, 0.001, 0.01, and 0.1 mM) on decay control and shelf-life extension. The results demonstrated that MEL treatment significantly reduced the fruit decay rate (P ≤ 0.01). Based on the findings, MEL treatment significantly increased titratable acidity (TA), total phenolics content (TPC), total flavonoid content (TFC), and total anthocyanin content (TAC). Furthermore, the MEL-treated samples showed increased levels of rutin and quercetin content, as well as antioxidant activity as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reduction activity potential (FRAP). Additionally, the samples exhibited higher levels of phenylalanine ammonia-lyase (PAL) and catalase (CAT) enzymes compared to the control samples. Moreover, the levels of pH, total soluble solids (TSS), and IC50 were decreased in the MEL-treated samples (P ≤ 0.01). The highest amount of TA (0.619 g/100 ml juice), rutin (16.722 µg/ml juice) and quercetin (1.467 µg/ml juice), and PAL activity (225.696 nm/g FW/min) was observed at 0.001 mM treatment, while, the highest amount of TAC (227.235 mg Cy-g/100 ml juice) at a concentration of 0.01 mM and CAT (0.696 u/g FW) and TAL activities (9.553 nm/100 g FW) at a concentration of 0.1 mM were obtained. Considering the lack of significant differences in the effects of melatonin concentrations and the low dose of 0.001 mM, this concentration is recommended for further research. The hierarchical cluster analysis (HCA) and principal component analysis (PCA) divided the treatments into three groups based on their characteristics. Based on the Pearson correlation between TPC, TFC, TAC, and TAA, a positive correlation was observed with antioxidant (DPPH and FRAP) and enzyme (PAL and CAT) activities. The results of this study have identified melatonin as an eco-friendly compound that enhances the shelf life of raspberry fruits by improving phenolic compounds, as well as antioxidant and enzyme activities.

Physicochemical characterization of a composite flour: Blending purple sweet potato and rice flours

In this study, the physicochemical characterization of different ratios of purple sweet potato flour (PSPF) and rice flour was investigated to improve the nutritional value and enrich the variety of rice-based staple food. The results showed that adding PSPF increased total dietary fiber and anthocyanin content whereas decreased amylose content of the composite flours. Additionally, the composite flours exhibited lower thermodynamic parameters and displayed darker, redder, and bluer colors. There were no noticeable changes in the functional group structure of the composite flours. The addition of PSPF decreased the crystallinity and water-holding capacity of the composite flours, whereas increased the average particle size and iodine blue value. PSPF increased the pasting temperature of the flours whereas decreased the breakdown and setback values. Overall, the addition of PSPF significantly affects the nutrition, color and physicochemical properties of the composite flours.

Optimization of ultrasonic assisted ethanolic extraction for natural pigments from butterfly pea flower applied in Thai dessert using Box-Behnken approach

Butterfly pea is a natural color source used in food and dessert. This study optimized ultrasound-assisted extraction with ethanol for pigments from butterfly pea flowers (BPF) using a Box-Behnken method. Key factors explored were solid-to-solvent ratio, ultrasound extraction time, and ethanol concentration. The extracted compounds were evaluated for extraction yield (EY), total phenolic content (TPC), total anthocyanin content (TAC), and DPPH antioxidant activity. EY increased significantly with reduced ethanol concentration. Optimal conditions were predicted and experimentally validated. BPF extracts showed distinct absorption wavelengths at different pH levels. BPF extract was used in coconut milk jelly, resulting in the lowest b* value. These findings highlight the value of optimal ultrasonic-assisted extraction for enhancing BPF's natural colorant extraction and promoting sustainable use in food and dessert applications.

Lactic acid bacteria fermentation improves physicochemical properties, bioactivity, and metabolic profiles of Opuntia ficus-indica fruit juice

Lactic acid bacteria (LAB) fermentation has been proven to promote human health. The effect of different LAB fermentation on the quality of Opuntia ficus-indica fruit juice (OFIJ) was investigated. OFIJ was an excellent substrate for fermentation, with colony counts of more than 8 log CFU/mL after fermentation. The fermentation altered the acid and sugar contents. Simultaneously, the total phenolic and anthocyanin contents significantly increased. Antioxidant activity enhanced significantly in Lactiplantibacillus plantarum HNU082-fermented OFIJ, primarily in ABTS+ (increased by 16.81%) and DPPH (increased by 23.62%) free radical scavenging ability. Lacticaseibacillus paracasei HNU502-fermented OFIJ showed the most potent inhibition of xanthine oxidase (IC50 = 31.01 ± 3.88 mg TAC/L). Analysis of volatile and non-volatile compounds indicated that fermentation changed the flavor quality and metabolic profiles and caused the most significant modifications in amino acid metabolism. These findings offer valuable information into processing of OFIJ, making it a great choice for functional foods.

Composite coating of xanthan gum with sodium nitroprusside alleviates the quality deterioration in strawberry fruit

Strawberry is an important and highly nutritious fruit crop that undergoes various postharvest qualitative losses. Therefore, the present study aimed to assess the synergistic effect of xanthan gum (XG) coatings with sodium nitroprusside (SNP) on the antioxidant defense system of strawberries during 16 days of storage by dipping method. The results on the 16th day of storage revealed that in comparison to control, the composite coating of XG 0.50 % + SNP reduced fruit weight loss (31.35 %) and spoilage incidence (87.22 %), along with effectively delayed respiration rates (16.44 %). Furthermore, the coatings maintained the biochemical properties of fruit including soluble solids content (7.05 %), titratable acidity (30.05 %), total flavonoid content (31.05 %), total anthocyanins content (17.59 %) and total phenols content(38.20 %) as compared to untreated fruit. The XG 0.50 % + SNP coated fruits also registered significantly (p < 0.05) higher total antioxidant activity (TAA) and antioxidant enzyme activities including catalase), peroxidase, and phenylalanine ammonia-lyase throughout the storage. Additionally, functionalized coating of XG with SNP suppressed the activity of polyphenol oxidase (PPO). This study proved that the application of coating of XG 0.50 % + SNP 2.0 mM is a potential treatment to preserve the postharvest quality of strawberries.

Effect of common horsetail extract on growth characteristics, essential oil yield and chemical compositions of basil (Ocimum basilicum L.)

To investigate the effect of horsetail extract containing high silicon on morphological traits, growth, content, and compositions of essential oil of sweet basil (Ocimum basilicum L.) an experiment turned into carried out in the shape of a randomized complete block design with three replications. Foliar treatment of horsetail extract with zero, 0.5, 1, and 2% concentrations was applied on 6–8 leaf plants. The assessed traits include plant height, number of leaves per plant, number of sub-branches, leaf area index, plant fresh weight, plant dry weight, total anthocyanin, the content of total phenol and total flavonoid, antioxidant activity, essential oil content, and compounds were measured. The findings demonstrated that the increase of silicon-containing horsetail extract enhanced the improved increase in growth and phytochemical trait values. The use of horsetail extract in the 2% treatment increased plant height, the number of leaves per plant, the number of sub-branches, leaf area index, fresh weight, and dry weight of the plant by 49.79, 45.61, 91.09, 99.78, 52.78 and 109.25%, respectively, compared to the control. The highest content of total phenol (2.12 mg GAE/g DW), total flavonoid (1.73 mg RE/g DW), total anthocyanin (0.83 mg C3G/g DW), and antioxidant activity (184.3 µg/ml) was observed in the 2% extract treatment. The content of essential oil increased with increasing the concentration of horsetail extract, so the highest amount of essential oil was obtained at the concentration of 2%, which increased by 134.78% compared to the control. By using GC–MS, the essential oil was analyzed. The main components of the essential oil include methyl eugenol (12.93–25.93%), eugenol (17.63–27.51%), 1,8-cineole (15.63–20.84%), linalool (8.31–19.63%) and (Z)-caryophyllene (6.02–14.93%). Increasing the concentration of horsetail extract increased the compounds of eugenol, 1,8-cineole, and linalool in essential oil compared to the control, but decreased the compounds of methyl eugenol and (Z)-caryophyllene. Foliar spraying of horsetail extract, which contains high amounts of silicon, as a stimulant and biological fertilizer, can be a beneficial ingredient in increasing the yield and production of medicinal plants, especially in organic essential oil production.

Non-destructive prediction of anthocyanin concentration in whole eggplant peel using hyperspectral imaging

Accurately detecting the anthocyanin content in eggplant peel is essential for effective eggplant breeding. The present study aims to present a method that combines hyperspectral imaging with advanced computational analysis to rapidly, non-destructively, and precisely measure anthocyanin content in eggplant fruit. For this purpose, hyperspectral images of the fruits of 20 varieties with diverse colors were collected, and the content of the anthocyanin were detected using high performance liquid chromatography (HPLC) methods. In order to minimize background noise in the hyperspectral images, five preprocessing algorithms were utilized on average reflectance spectra: standard normalized variate (SNV), autoscales (AUT), normalization (NOR), Savitzky–Golay convolutional smoothing (SG), and mean centering (MC). Additionally, the competitive adaptive reweighted sampling (CARS) method was employed to reduce the dimensionality of the high-dimensional hyperspectral data. In order to predict the cyanidin, petunidin, delphinidin, and total anthocyanin content of eggplant fruit, two models were constructed: partial least squares regression (PLSR) and least squares support vector machine (LS-SVM). The HPLC results showed that eggplant peel primarily contains three types of anthocyanins. Furthermore, there were significant differences in the average reflectance rates between 400–750 nm wavelength ranges for different colors of eggplant peel. The prediction model results indicated that the model based on NOR CARS LS-SVM achieved the best performance, with a squared coefficient of determination (R2) greater than 0.98, RMSEP and RMSEC less than 0.03 for cyanidin, petunidin, delphinidin, and total anthocyanin predication. These results suggest that hyperspectral imaging is a rapid and non-destructive technique for assessing the anthocyanin content of eggplant peel. This approach holds promise for facilitating the more effective eggplant breeding.

Characterizing the antioxidant and antifungal properties of nano-encapsulated pistachio hull extract in fenugreek seed gum to maintain the quality and safety of fresh pistachio.

The quality of pistachio, one of the export products of Iran, will be decreased during storage as a result of mold spoilage, toxins production, and oil oxidation. This study aimed to investigate the capability of pistachio hull extract (PHE) loaded in fenugreek seed gum (FSG):whey protein isolate (WPI) nanoemulsion to control oil oxidation, and fungi growth in fresh pistachio nut during storage at 4°C. The total anthocyanin and total phenolic content of the PHE were 125.44 μg/g and 675.18 mg/g, respectively. The DPPH radical scavenging activity of PHE at 100 ppm was higher than that of tert-butylhydroquinon (TBHQ). In comparison with other concentrations, 50 ppm showed the strongest antifungal activity against Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomius. All nanoemulsions have a mean size lower than 265 nm. The polydispersity index (PDI) of different nanoemulsions was lower than 0.3, and a negative zeta potential was observed. The encapsulation efficiency was higher than 67.0% and all nanoemulsions had spherical morphology. The pistachio nuts were coated with different coating solutions containing 0 and 100 ppm of PHE and stored at 4°C for 8 weeks. The results showed that the pistachio sample coated with a composite coating of WPI and FSG containing 100 ppm of PHE has a higher moisture content and lower changes in L*, a*, and b* indexes, oil oxidation, fungi development, and total mold and yeast count. This treatment exhibited higher overall acceptance than other samples at the end of storage time. The results of this study suggest the use of biodegradable coatings enriched with natural extracts that have high antioxidant and antifungal activities.

The Effects of Pigeage, Délestage, Remontage and Oxygenation Treatments Applied during Maceration on Phenolic Content, Aroma Composition and Sensory Properties of Red Teran (Vitis vinifera L.) Wine

The aim of this study was to evaluate the effects of mechanical (pigeage, délestage and remontage) and oxygenation treatments on the phenolic and aromatic compounds and sensory characteristics of Teran wines. The experiment included a 20-day maceration period, during which the above-mentioned treatments were applied, as well as the post-fermentation processes of pressing and first rack. The analysis of phenolic, chromatic and aroma compounds and the sensory characterization of the wines were used to describe the effects of the treatments investigated. After the observed maceration period, remontage resulted in wines with the highest total phenols (2682.0 ± 14.8 mg GAE/L). In contrast, délestage resulted in the lowest total phenols (2499.1 ± 17.6 mg GAE/L) and total anthocyanins (530.1 ± 2.8 mg/L) and had the strongest effects on chromatic characteristics. The post-fermentation processes (pressing, racking) showed similar trends and resulted in higher phenolic concentrations in the remontage wine, while the délestage was again characterized by lower total phenol and anthocyanin concentrations. In addition, the délestage wine contained a higher concentration of almost all analyzed esters and two higher alcohols (2-methylpropan-1-ol and 1-hexanol), while the remontage wine had the highest concentration of 2-phenylethanol and 3-methylbutyl acetate. Finally, maceration proved to be a key factor in defining the wines’ sensory characteristics, with the remontage-treated wine showing the best overall quality.

Trehalose signaling regulates metabolites associated with the quality of rose flowers under drought stress

Drought is an environmental factor affecting the yield and quality of rose flowers, but the potential molecular regulatory mechanism remains unclear. Here, the physiological indexes and related compound contents of rose flowers were determined under drought stress, of which flower size, fresh/dry weight, and carbohydrate accumulation were significantly reduced, whereas the contents of total phenols, total flavonoids, total anthocyanins, and volatile compounds increased compared with normal growth conditions. Transcriptome profiling identified that trehalose signaling may be involved in this process, and that the expression level of various trehalose anabolic pathway genes such as trehalose-6-phosphate synthases and trehalose phosphatases were repressed, whereas the contents of trehalose (Tre) and its precursor trehalose-6-phosphate (T6P) decreased under drought stress. Furthermore, exogenous spraying of Tre and T6P could alleviate the wilting phenomenon caused by drought stress and promote the accumulation of starch, soluble sugar, and lignin in the petals. Results indicated that T6P or Tre, as a positive regulatory signal, improves the drought tolerance of rose plants and maintains the quality of rose flowers under drought conditions, which provides new insights into the effects of drought stress on flower quality.