Integrated volatile metabolome and transcriptome analyses provide insights into the warm aroma formation elicited by methyl jasmonate in carrot root.

Carrot is a highly significant vegetable cultivated worldwide and possesses a unique aroma with abundant edible and medicinal values. However, it remains largely unknown whether jasmonic acid could regulate aroma formation in carrot. Here, an integrated analysis of the volatile metabolome and transcriptome of carrot roots exposed to different concentrations of methyl jasmonate (MeJA) was performed. The results revealed 1,227 volatile organic compounds and 972 differential accumulated metabolites, with terpenes representing the largest portion. MeJA treatment evidently increased the relative odor activity values as well as the accumulation of most volatile compounds. In addition, 4,787 differentially expressed genes were identified and subjected to function enrichment analysis, indicating a role of terpene biosynthesis and metabolism in response to MeJA application. A network consisting of 4,680 transcription factor-structural pairs that showed highly significant positive correlations was constructed, which may be utilized as genetic targets for examining terpene accumulation and aroma formation elicited by methyl jasmonate. The results from the present work substantially improved our understanding of MeJA-mediated aroma formation in carrot.

Phenolic components from carrot (Daucus carota L.) pomace: Optimizing the extraction and assessing its potential antioxidant and antimicrobial activities.

Carrot pomace is a significant agricultural byproduct. Obtained during carrot juice processing. This residue is an appropriate reservoir of constituents with bioactive properties that could be investigated in the development of food constituents and nutritional supplements and in improving the quality and safety of foods. For this purpose, the objective of the present investigation was to extract the polyphenols from carrot pomace utilizing maceration and ultrasound-based extraction (UAE) procedures and to evaluate the antioxidant properties of phenolic constituents. To maximize the extraction of carrot pomace, a response surface approach was used. The optimal mixture of extraction time (A, min), ultrasonication power (B, w), and solvent type (C, v/v) for the highest yield of carrot pomace was found using a three-variable composite rotatable design (CRD). In order to assess different functional groups, Fourier transform infrared spectroscopy was utilized to investigate the extract collected under optimal circumstances. The highest polyphenols (26.53 %) were extracted by ethanol 70 % at 10 min with a sonication power of 250 w. The optimized extract also exhibited significant antioxidant and antimicrobial functions. The total phenolic compounds and scavenging of the DPPH radical were 85 mg GAE/gr and EC50: 55 ± 1 µg/mL, respectively. Together with Staphylococcus aureus, the highest zone of inhibition (12 mm) was identified. Our finding revealed that carrot pomace is an appropriate source of bioactive phenolic constituents, exhibiting antioxidant and antibacterial attributes, and could be applied as a natural preserver for promoting safety and quality properties in food products on an industrial scale.

Hydrogen sulfide alleviates cadmium stress in germinating carrot seeds by promoting the accumulation of proline.

Carrot (Daucus carota L.), a widely cultivated economically vegetable from the Apiaceae family, is grown globally. However, carrots can be adversely impacted by cadmium (Cd) pollution in the soil due to its propensity to accumulate in the fleshy root, thus impeding carrot growth and posing health hazards to consumers. Given the potential of hydrogen sulfide (H2S) to improve plant resistance against Cd stress, we treated germinating carrot seeds with varying concentrations of sodium hydrosulfide (NaHS), aiming to alleviate the toxic impacts of Cd stress on carrot seed germination. The results revealed that carrot seeds treated with a concentration of 0.25 mM NaHS displayed better seed germination-associated characteristics compared to seeds treated with NaHS concentrations of 0.1 mM and 0.5 mM. Further investigation revealed a rise in the expression levels of L-cysteine desulfhydrase and D-cysteine desulfhydrase, along with enhanced activity of L-cysteine desulfhydrase and D-cysteine desulfhydrase among the NaHS treatment group, thereby leading to H2S accumulation. Moreover, NaHS treatment triggered the expression of pyrroline-5-carboxylate synthase and pyrroline-5-carboxylate reductase and promoted the accumulation of endogenous proline, while the contents of soluble sugar and soluble protein increased correspondingly. Interestingly, since the application of exogenous proline did not influence the accumulation of endogenous H2S, suggesting that H2S served as the upstream regulator of proline. Histochemical staining and biochemical indices revealed that NaHS treatment led to elevated antioxidant enzyme activity, alongside a suppression of superoxide anion and hydrogen peroxide generation. Furthermore, high performance liquid chromatography analysis revealed that NaHS treatment reduced Cd2+ uptake, thereby promoting germination rate, seed vitality, and hypocotyl length of carrot seeds under Cd stress. Overall, our findings shed light on the application of NaHS to enhance carrot resistance against Cd stress and lay a foundation for exploring the regulatory role of H2S in plants responding to Cd stress.

Local mapping of root orientation traits by X-ray micro-CT and 3d image analysis: A study case on carrot seedlings grown in simulated vs real weightlessness.

BACKGROUND: Root phenotyping is particularly challenging because of complexity and inaccessibility of root apparatus. Orientation is one of the most important architectural traits of roots and its characterization is generally addressed using multiple approaches often based on overall measurements which are difficult to correlate to plant specific physiological aspects and its genetic features. Hence, a 3D image analysis approach, based on the recent method of Straumit, is proposed in this study to obtain a local mapping of root angles. RESULTS: Proposed method was applied here on radicles of carrot seedlings grown in real weightlessness on the International Space Station (ISS) and on Earth simulated weightlessness by clinorotation. A reference experiment in 1 g static condition on Earth was also performed. Radicles were imaged by X-ray micro-CT and two novel root orientation traits were defined: the "root angle to sowing plane" (RASP) providing accurate angle distributions for each analysed radicle and the "root orientation changes" (ROC) number. The parameters of the RASP distributions and the ROC values did not exhibit any significant difference in orientation between radicles grown under clinorotation and on the ISS. Only a slight thickening in root corners was found in simulated vs real weightlessness. Such results showed that a simple uniaxial clinostat can be an affordable analog in experimental studies reckoning on weightless radicles growth. CONCLUSIONS: The proposed local orientation mapping approach can be extended also to different root systems providing a contribution in the challenging task of phenotyping complex and important plant structures such as roots.

Molasses-based waste water irrigation: a friend or foe for carrot (Daucus carota L.) growth, yield and nutritional quality.

Management of molasses-based wastewater generated in yeast and sugar industries is a major environmental concern due to its high chemical oxygen demand and other recalcitrant substances. Several strategies have been used to reduce the inland discharge of wastewater but the results are not satisfactory due to high operating cost. However, reuse of molasses-based wastewater irrigation in agriculture has been a major interest nowadays to reduce the freshwater consumption. Thus, it is crucial to monitor the impacts of molasses-based waste water irrigation on growth, metabolism, yield and nutritional quality of crops for safer consumer's health. In present study, carrot seeds of a local cultivar (T-29) were germinated on filter paper in Petri dishes under controlled conditions. The germinated seeds were then transplanted into pots and irrigated with three different treatments normal water (T0), diluted molasses-based wastewater (T1), and untreated molasses-based wastewater (T2), in six replicates. Results revealed that carrot irrigated with untreated molasses-based waste water had exhibited significant reductions in growth, yield, physiology, metabolism, and nutritional contents. Additionally, accumulation of Cd and Pb contents in carrot roots irrigated with untreated molasses-based waste water exceed the permissible limits suggested by WHO and their consumption may cause health risks. While, diluted molasses-based waste water irrigation positively enhanced the growth, yield of carrot plants without affecting the nutritional quality. This strategy is cost effective, appeared as most appropriate alternative mean to reduce the freshwater consumption in water deficit regions of the world.

Challenges and Opportunities in the Sustainable Improvement of Carrot Production.

From an agricultural perspective, carrots are a significant tap root vegetable crop in the Apiaceae family because of their nutritional value, health advantages, and economic importance. The edible part of a carrot, known as the storage root, contains various beneficial compounds, such as carotenoids, anthocyanins, dietary fiber, vitamins, and other nutrients. It has a crucial role in human nutrition as a significant vegetable and raw material in the nutraceutical, food, and pharmaceutical industries. The cultivation of carrot fields is susceptible to a wide range of biotic and abiotic hazards, which can significantly damage the plants' health and decrease yield and quality. Scientific research mostly focuses on important biotic stressors, including pests, such as nematodes and carrot flies, as well as diseases, such as cavity spots, crown or cottony rot, black rot, and leaf blight, caused by bacteria, fungi, and oomycetes. The emerging challenges in the field include gaining a comprehensive understanding of the interaction between hosts and pathogens in the carrot-pathogen system, identifying the elements that contribute to disease development, expanding knowledge of systemic treatments, exploring host resistance mechanisms, developing integrated control programs, and enhancing resistance through breeding approaches. In fact, the primary carrot-growing regions in tropical and subtropical climates are experiencing abiotic pressures, such as drought, salinity, and heat stress, which limit carrot production. This review provides an extensive, up-to-date overview of the literature on biotic and abiotic factors for enhanced and sustainable carrot production, considering the use of different technologies for the shelf-life extension of carrots. Therefore, it addresses the current issues in the carrot production chain, opening new perspectives for the exploration of carrots both as a food commodity and as a source of natural compounds.

Multiclass Analysis for the Determination of Pharmaceuticals and Their Main Metabolites in Leafy and Root Vegetables.

The irrigation of soils with reclaimed contaminated wastewater or its amendment with sewage sludge contributes to the uptake of pharmaceuticals by vegetables growing in the soil. A multiresidue method has been devised to determine five pharmaceuticals and nine of their main metabolites in leafy and root vegetables. The method employs ultrasound-assisted extraction, clean-up via dispersive solid-phase extraction, and analysis through liquid chromatography-tandem mass spectrometry. Box-Behnken design was used to refine variables such as extraction solvent volume, time of extraction, number of extraction cycles, and the type and amount of d-SPE sorbent. The method achieved linearity (R2) greater than 0.994, precision (relative standard deviation) under 16% for most compounds, and detection limits ranging from 0.007 to 2.25 ng g-1 dry weight. This method was applied to a leafy vegetable (lettuce) and to a root vegetable (carrot) sourced from a local market. Parent compounds were detected at higher concentrations than their metabolites, with the exception of carbamazepine-10,11-epoxide.

Health-Promoting Effects, Phytochemical Constituents and Molecular Genetic Profile of the Purple Carrot 'Purple Sun' (Daucus carota L.).

The purple carrot cultivar 'Purple Sun' (Daucus carota L.) is characterized by a relevant content of phenolic compounds and anthocyanins, which may play an important role in reducing the risk of chronic diseases and in the treatment of metabolic syndrome. In the present study, the genetic diversity, phytochemical composition, and bioactivities of this outstanding variety were studied for the first time. Genetic analysis by molecular markers estimated the level of genetic purity of this carrot cultivar, whose purple-pigmented roots were used for obtaining the purple carrot ethanol extract (PCE). With the aim to identify specialized metabolites potentially responsible for the bioactivities, the analysis of the metabolite profile of PCE by LC-ESI/LTQ Orbitrap/MS/MS was carried out. LC-ESI/HRMS analysis allowed the assignment of twenty-eight compounds, putatively identified as isocitric acid (1), phenolic acid derivatives (2 and 6), hydroxycinnamic acid derivatives (9, 10, 12-14, 16, 17, 19, 22, and 23), anthocyanins (3-5, 7, 8, 11, and 18), flavanonols (15 and 21), flavonols (20 and 24), oxylipins (25, 26, and 28), and the sesquiterpene 11-acetyloxytorilolone (27); compound 26, corresponding to the primary metabolite trihydroxyoctanoic acid (TriHOME), was the most abundant compound in the LC-ESI/HRMS analysis of the PCE, and hydroxycinnamic acid derivatives followed by anthocyanins were the two most represented groups. The antioxidant activity of PCE, expressed in terms of reactive oxygen species (ROS) level and antioxidant enzymes activity, and its pro-metabolic effect were evaluated. Moreover, the antibacterial activity on Gram (-) and (+) bacterial strains was investigated. An increase in the activity of antioxidant enzymes (SOD, CAT, and GPx), reaching a maximum at 0.5 mg/mL of PCE with a plateau at higher PCE concentrations (1.25, 2.5, and 5.0 mg/mL), was observed. PCE induced an initial decrease in ROS levels at 0.1 and 0.25 mg/mL concentrations, reaching the ROS levels of control at 0.5 mg/mL of PCE with a plateau at higher PCE concentrations (1.25, 2.5, and 5.0 mg/mL). Moreover, significant antioxidant and pro-metabolic effects of PCE on myoblasts were shown by a reduction in ROS content and an increase in ATP production linked to the promotion of mitochondrial respiration. Finally, the bacteriostatic activity of PCE was shown on the different bacterial strains tested, while the bactericidal action of PCE was exclusively observed against the Gram (+) Staphylococcus aureus. The bioactivities of PCE were also investigated from cellular and molecular points of view in colon and hematological cancer cells. The results showed that PCE induces proliferative arrest and modulates the expression of important cell-cycle regulators. For all these health-promoting effects, also supported by initial computational predictions, 'Purple Sun' is a promising functional food and an optimal candidate for pharmaceutical and/or nutraceutical preparations.

Does Daucus carota L. leaf provide a high potential as a source of bioactive constituents: A case study about the influences of process/storage conditions.

The current study focused on the valorization of carrot leaves, Daucus carota L. because of their high amount of ascorbic acid (AA), phenolic compounds, and the related antioxidant activity. In this study, the changes in carrot leaves caused by different drying techniques (freeze, vacuum, microwave-assisted infrared, oven) and different storage conditions (room temperature and refrigerator) were investigated. AA contents of fresh, dried, and stored carrot leaf samples were chromatographically determined. Additionally, analysis of TPA (total phenolic content), TAC (total antioxidant capacity), total chlorophyll, carotenoid, and color were carried out. Additionally, fresh leaves were analyzed to compare their results with the corresponding values of processed or stored samples. TPA, TAC, AA, total chlorophyll, and carotenoid values of the samples stored in the refrigerator were 889 ± 63 mg/100 g d.b., 504 mg/100 g d.b., 269 A.A./100 g d.b., 253 mg/100 g d.b., and 2497 mg/100 g d.b., respectively, while the values of the samples dried at room temperature 620 ± 35 mg/100 g d.b., 303 ± 15 mg/100 g d.b., 110 ± 21 mg A.A./100 g d.b., 44 ± 3 mg/100 g d.b., 641 ± 16 mg/100 g d.b., respectively. Consequently, fresh carrot leaves have a higher vitamin C content than many leafy vegetables and even its own family, parsley. Fresh samples stored at room temperature and in the refrigerator for 7 days provided high ascorbic acid retention. Dried leaves with the MW + IR combined system provided better protection than others in terms of bioactive components. However, OD treatment at 40°C provided better protection and was one step ahead in terms of AA content.

Generating high purity and yield of capsanthin and capsorubin carrot germplasm through synthetic metabolic engineering.

Capsanthin and capsorubin are red κ-xanthophylls exclusively found in a handful of other plant species. Currently, capsanthin and capsorubin are only extracted from red pepper. Here, high purity production of capsanthin and capsorubin has been achieved in carrot taproot by synthetic metabolic engineering strategy. Expression of a capsanthin-capsorubin synthase gene (CaCCS) from pepper resulted in dominant production of capsanthin whereas expression of a LiCCS gene from tiger lily resulted in production of both capsanthin and capsorubin in carrot taproot. The highest content of capsanthin and capsorubin was obtained in LiC-1 carrot taproot hosting the LiCCS gene, 150.09 µg/g DW (dry weight). Co-expression of DcBCH1 with CCS could improve the purity of capsanthin and capsorubin by eliminating the non-target carotenoids (eg. α-carotene and ß-carotene). The highest purity of capsanthin and capsorubin was obtained in BLiC-1 carrot taproot hosting DcBCH1+LiCCS genes, 91.10% of total carotenoids. The non-native pigments were esterified partially and stored in the globular chromoplast of carrot taproot. Our results demonstrated the possibility of employing carrot taproot as green factories for high purity production of capsanthin and capsorubin. The capsanthin/capsorubin carrot germplasms were also valuable materials for breeding colorful carrots cultivars.

Characterization of aroma and aroma-active compounds of black carrot (Daucus carota L. ssp. sativus var. atrorubens Alef.) pomace by aroma extract dilution analysis.

The aim of this study was to characterize the aroma and aroma-active compounds of black carrot pomace, a valuable by-product of black carrot juice industry. Aroma compounds were analyzed using GC-MS-O and extracted via the SAFE technique. The extract samples were determined to represent the odor of black carrot pomace quite well according to the results of the representative test. Accordingly, the aromatic extract scored 77.7 mm for intensity and 87 mm for similarity on a 100 mm unstructured scale. A total of 47 volatile constituents were identified and quantified including terpenes (20), alcohols (11), acids (7), esters (4), ketones (4), and lactone (1). It was observed that terpenes were the major aroma group. The use of aroma extract dilution analysis (AEDA) revealed only 29 of these compounds as aroma-active constituents. Phenylethyl alcohol (FD:512, OAV: 2488, rose) and phenylethyl acetate (FD:256, OAV:280, rose) were the aroma substances providing the strongest rose odor. Following these compounds, acetic acid (vinegar), dimethyl-propanedioic acid (pungent), (E)-ß-caryophyllene (salty cheese) and elemicin (spicy) were identified as other strong aroma-actives with FD values of 128 contributing to the characteristic odor of the black carrot pomace samples. The odor activity values (OAVs) ranged from 1 to 2488. The highest OAVs represent the high aromatic active compounds (FD ≥ 128). The distinctive aroma and rich color of black carrot pomace make it a recommended choice for enhancing flavor and adding natural coloring to food products.

Immunochromatographic strip for rapid and sensitive detection of bupirimate residues in peach, orange, and carrot.

Bupirimate (BPM) is a high-efficiency and low-toxicity fungicide used to combat powdery mildew in crops. To mitigate potential health risks to consumers resulting from improper BPM usage, we prepared a monoclonal antibody against BPM based on novel hapten synthesis, which has high sensitivity and strong specificity, and then successfully designed a colloidal gold-based immunochromatographic (ICG) strip. The newly designed ICG strip was then employed for detecting BPM residues in peach, orange, and carrot. The results show that for the peach, orange, and carrot samples, the calculated detection limits of the ICG strip are 9.36, 0.79, and 0.57 ng/g, respectively, and that it is resistant to the matrix effect and meets the maximum residue limit requirements of European Commission for BPM. Therefore, this developed ICG strip is expected to enable swift detection of BPM residues on the spot.

Novel tributyl phosphate-based deep eutectic solvent: Application in microwave assisted extraction of carotenoids.

A contribution to the use of deep eutectic solvents (DES) and microwave-assisted extraction (MAE) was made for bioactive compounds recovery, especially those with lipophilic character, from tomato and carrot samples rich in carotenoids. For the first time, a novel deep eutectic solvent was synthesized, comprising tributyl phosphate (TBP) as a hydrogen bond acceptor and acetic acid (AcOH) as a hydrogen bond donor. The total antioxidant capacity (TAC) of tomato and carrot extracts obtained by MAE, in which optimization of operational parameters and modeling were made with the use of Box-Behnken design of the response surface methodology (RSM), was evaluated using the Cupric Reducing Antioxidant Capacity (CUPRAC) method. For the highest TAC, operational parameters that best suit the MAE procedure were set at 80 °C, 35 min, and 25 mL/2.0 g. The TAC values of extracts obtained by MAE using TBP:AcOH, 1:2 (mol/mol) were examined against those of extracts acquired by classical solvent extraction using a mixture of hexane, ethanol and acetone (H:E:A, 2:1:1 (v/v/v)) mixture. TAC of extracts in DES varied between 5.10 and 0.71 lycopene equivalents (mmol LYC kg-1). The highest extraction yield comparable to conventional organic solvents was obtained with TBP:AcOH (1:2). It was observed that, in addition to lipophilic antioxidants, some hydrophilic antioxidant compounds were partially extracted with the proposed DES. Moreover, the extracted antioxidant compounds were identified and quantified by HPLC analysis. The proposed DES and MAE process will find potential application for hydrophobic antioxidant extraction from tomatoes and carrots on an industrial scale after further studies.

Aroma profiles of shalgam: Effect of purple carrot (Daucus carota) amount.

Shalgam is a fermented product characterized by its color and aroma compounds. However, there is no standard regarding the amount of use of purple carrot, which is the major raw material in production and affects the fermentation and aroma compounds of the product. This present research was designed to examine the effect of purple carrot concentrations on aroma compounds, which are one of the most important characteristics that reflect the quality characteristics of shalgam and affect consumer preferences. Aroma compounds in shalgam juices produced using five different amounts of carrots were analyzed by gas chromatography-flame ionization detector-mass spectrometry (GC-FID-MS). As expected, since the difference between the produced shalgam beverages was only the amount of purple carrots, a qualitative similarity and a quantitative difference were determined in the aroma profiles in general. In the aroma categories defined, terpenes (26 compounds) were the most abundant compounds, followed by esters (17 compounds) and higher alcohols (11 compounds). 88 aroma compounds have been identified in shalgam, and a total of 28 ACs, including 7 terpenes, 7 esters, 3 alcohols, 4 volatile acids, 3 volatile phenols, 1 lactone, 1 norisoprenoid, and 2 naphthalenes, were detected for the first time. The concentration of aromas in the samples varied from 5471.5 to 6490.1 µg/L (p < .05). According to principal component analysis, it was determined that the correlation between the position of the shalgam samples in the coordinate system and the aroma groups was significant. This study shows that purple carrots also affect the aroma compounds of shalgam beverages.

The Use of Carrot Fiber and Some Gums in the Production of Block-Type Melting Cheese.

In this study, the effect of carrot fiber and certain gums on the physicochemical, textural, microbiological, and sensory properties of block-type melting cheese, which holds a significant place in our daily food consumption, was investigated. The study also aimed to determine the impact of carrot fiber and other gums on cheese properties, as well as on yield and meltability. Carrot fiber was used at levels of 2.5% and 5.0% by weight, while carrageenan and xanthan gum were each used at levels of 0.25% and 0.50%. The cheeses were analyzed on days 1, 15, and 30. At the end of the study, it was determined that the highest total dry matter, fat, and protein values were found in the control sample due to the addition of water when preparing the cheeses with fiber and gum. The highest dry matter, fat, salt, and protein ratios were 59.65%, 29.40%, 1.48%, and 24.48%, respectively, in the control sample. The lowest fat, salt, and protein ratios were 25.00%, 1.31%, and 22.07%, respectively, in the 5.0% carrot fiber sample. The lowest dry matter value was found in the 0.5% xanthan sample, namely 53.62%. The highest L* value was measured in the control sample at 86.89, while the lowest was measured in the 5.0% carrot fiber sample at 81.86. The lowest a* and b* values were 2.82 and 29.42, respectively, in the control sample, while the highest values were 6.20 and 37.37, respectively, in the 5.0% carrot fiber sample. It was observed that the use of carrot fiber imparted an orangish color to the cheese. It was observed that the pH values of the samples were similar. According to the sensory evaluation results, the most liked sample was the control sample with 8.5 points, followed by the 0.25% xanthan sample with 8.0 points. The 5.0% carrot fiber sample received the lowest sensory appreciation with 6.1 points. It was understood that the use of carrot fiber gave the cheese an orangish color. Although the meltability varied according to the amount of gum and fiber used, it was measured at 6.92 cm in the 0.25% carrageenan sample on the first day and at 6.79 cm in the control sample on the last day of storage. It was observed that the use of fiber decreased the total bacterial count, while the use of gum increased it.

Physical Treatments Modified the Functionality of Carrot Pomace.

This study addressed the critical issue of food waste, particularly focusing on carrot pomace, a by-product of carrot juice production, and its potential reutilization. Carrot pomace, characterized by high dietary fiber content, presents a sustainable opportunity to enhance the functional properties of food products. The effects of physical pretreatments-high shearing (HS), hydraulic pressing (HP), and their combination (HSHP)-alongside two drying methods (freeze-drying and dehydration) on the functional, chemical, and physical properties of carrot pomace were explored. The results indicated significant enhancements in water-holding capacity, fat-binding capacity, and swelling capacity, particularly with freeze-drying. Freeze-dried pomace retained up to 33% more carotenoids and demonstrated an increase of up to 22% in water-holding capacity compared to dehydrated samples. Freeze-dried pomace demonstrated an increase of up to 194% in fat-binding capacity compared to dehydrated samples. Furthermore, HSHP pretreatment notably increased the swelling capacity of both freeze-dried (54%) and dehydrated pomace (35%) compared to pomace without pretreatments. Freeze-drying can enhance the functional properties of dried carrot pomace and preserve more carotenoids. This presents an innovative way for vegetable juice processors to repurpose their processing by-products as functional food ingredients, which can help reduce food waste and improve the dietary fiber content and sustainability of food products.

Seed priming with potassium nitrate alleviates the high temperature stress by modulating growth and antioxidant potential in carrot seeds and seedlings.

Early season carrot (Daucus carota) production is being practiced in Punjab, Pakistan to meet the market demand but high temperature hampers the seed germination and seedling establishment which cause marked yield reduction. Seed priming with potassium nitrate breaks the seed dormancy and improves the seed germination and seedling growth potential but effects vary among the species and ecological conditions. The mechanism of KNO3 priming in high temperature stress tolerance is poorly understood yet. Thus, present study aimed to evaluate high temperature stress tolerance potential of carrot seeds primed with potassium nitrate and impacts on growth, physiological, and antioxidant defense systems. Carrot seeds of a local cultivar (T-29) were primed with various concentration of KNO3 (T0: unprimed (negative control), T1: hydroprimed (positive control), T2: 50 mM, T3:100mM, T4: 150 mM, T5: 200 mM, T6: 250 mM and T7: 300 mM) for 12 h each in darkness at 20 ± 2℃. Seed priming with 50 mM of KNO3 significantly enhanced the seed germination (36%), seedling growth (28%) with maximum seedling vigor (55%) and also exhibited 16.75% more carrot root biomass under high temperature stress as compared to respective control. Moreover, enzymatic activities including peroxidase, catalase, superoxidase dismutase, total phenolic contents, total antioxidants contents and physiological responses of plants were also improved in response to seed priming under high temperature stress. By increasing the level of KNO3, seed germination, growth and root biomass were reduced. These findings suggest that seed priming with 50 mM of KNO3 can be an effective strategy to improve germination, growth and yield of carrot cultivar (T-29) under high temperature stress in early cropping. This study also proposes that KNO3 may induces the stress memory by heritable modulations in chromosomal structure and methylation and acetylation of histones that may upregulate the hormonal and antioxidant activities to enhance the stress tolerance in plants.

Ultra violet-C pretreatment enhances the antimicrobial efficacy of unpeeled carrots against subsequent contamination with Listeria monocytogenes.

To our knowledge, this study is the first to elucidate the bactericidal efficacy of unpeeled carrots (hereafter referred to as carrots) pretreated with Ultra Violet-C (UV-C) against subsequent contamination with Listeria monocytogenes. Carrots pretreated with UV-C (240 mJ/cm2) exhibited a significant antilisterial effect within 2 h. In fact, the population of UV-C-pretreated carrots decreased from 7.94 log CFU/cm2 to levels below the limit of detection (LOD; <1.65 log CFU/cm2) within 24 h. For carrots that were not pretreated with UV-C, 3-4 log reductions were found after 24 h. Carrots pretreated with UV-C exhibited antimicrobial activity against another gram-positive pathogen, Staphylococcus aureus, but not against the gram-negative pathogens, E. coli O157:H7 and Salmonella enterica. Pretreatment with UV-C created a lasting antimicrobial effect as introducing L. monocytogenes on carrots, 72 h post-UV-C treatment, still maintained the antilisterial effect. Notably, all UV-C doses in the range of 48-240 mJ/cm2 induced a lasting antilisterial effect. The bactericidal effects against L. monocytogenes were confirmed in three varieties of washed and unwashed carrots (Danvers, Nantes, and Chantenay). Fluorescence microscopy confirmed the bactericidal effect of UV-C-pretreated carrots on the survival of L. monocytogenes. Conclusively, pretreating carrots with UV-C can reduce the population of L. monocytogenes to levels below the LOD and may further prevent pathogen growth during cold storage. Additional studies are necessary to discern the mechanism underlying the bactericidal efficacy of UV-C-pretreated carrots.

Influence of fermentation conditions, and the blends of sorghum and carrot pulp supplementation on the nutritional and sensory quality of tef injera.

Tef [Eragrostis tef (Zucc.) Trotter], an ancient cereal primarily grown in Ethiopia, is becoming increasingly popular worldwide due to its high iron content and gluten-free nature. However, it has been reported that injera produced only with tef flour lack certain vital nutrients. Therefore, this specific study was conducted to supplement tef injera with other food materials of better nutritional value and compensate its expensive market price with sorghum cereal flour. The effect of fermentation conditions, and the sorghum and carrot pulp blending ratio on the nutritional value and sensory quality of tef injera was investigated. The factorial approach of the experimental design was conducted considering the nutritional value and sensory quality of the injera made of three main blending ratios of tef, sorghum, and carrot (60% tef: 30% sorghum: 10% carrot pulp, 45% tef: 45% sorghum: 10% carrot pulp and 30% tef: 60% sorghum: 10% carrot pulp) as experiential variables. The raw materials and injera were characterised for their proximate composition, physicochemical property, mineral composition, microbial analysis, and sensory attributes, using standard methods. The results of the study show that fermentation conditions and blending ratios have a significant effect on the nutritional, anti-nutritional, mineral content, microbial quality, and sensory properties of blended injera products, where higher values of ash, crude protein, crude fat, Total titratable acidity (TTA), Fe, Zn, and Ca (2.30%, 11.34%, 2.62%, 3.53, 32.97 mg/100 g, 2.98 mg/100 g and 176.85 mg/100 g, respectively) were analyzed for the co-fermented injera sample. In addition, a lower microbial count was observed in co-fermented injera samples, whereas microbial counts in injera samples prepared from carrot pulp-supplemented dough after the co-fermentation of tef and sorghum flours were observed to be higher. The injera product made using blending ratio of 60% tef: 30%sorghum: 10% carrot co-fermented was found to be the optimum result due to its very good nutritional improvement (i.e., reduction of some anti-nutritional factors, microbial contents, pH and increased contents of some minerals, crude protein, crude fat, TTA and improved most of the sensory quality of the supplemented injera product). According to this study, sorghum and carrot supplementation on tef could improve the nutritional value of injera while also providing an instant remedy for the growing price of tef.

Anthocyanin glucosylation mediated by a glycoside hydrolase family 3 protein in purple carrot.

Purple carrot accumulates anthocyanins modified with galactose, xylose, glucose, and sinapic acid. Most of the genes associated with anthocyanin biosynthesis have been identified, except for the glucosyltransferase genes involved in the step before the acylation in purple carrot. Anthocyanins are commonly glycosylated in reactions catalyzed by UDP-sugar-dependent glycosyltransferases (UGTs). Although many studies have been conducted on UGTs, the glucosylation of carrot anthocyanins remains unknown. Acyl-glucose-dependent glucosyltransferase activity modifying cyanidin 3-xylosylgalactoside was detected in the crude protein extract prepared from purple carrot cultured cells. In addition, the corresponding enzyme was purified. The cDNA encoding this glucosyltransferase was isolated based on the partial amino acid sequence of the purified protein. The recombinant protein produced in Nicotiana benthamiana leaves via agroinfiltration exhibited anthocyanin glucosyltransferase activity. This glucosyltransferase belongs to the glycoside hydrolase family 3 (GH3). The expression pattern of the gene encoding this GH3-type anthocyanin glucosyltransferase was consistent with anthocyanin accumulation in carrot tissues and cultured cells.