Explore the vast range of titles available.

List of abbreviations: DPPH - 2,2-diphenyl-1-picrylhydrazyl assay EPS - exopolisaccharides G-C - gas chromatograpy GC-MS - gas chromatography-mass spectrometry HTLT - high temperature-long time HTST - high temperature-short time MTLT - mild temperature-long time MTST - mild temperature-short time TBRS - thiobarbituric acid reactive substances assay INTRODUCTION Daucus carota L. (carrot) belongs to Apiaceae family and is the most significant plant of that family (Silva Dias, 2014). [...]a rosette of leaves is formed (in the spring and summer) along with the extended taproot which stores large volume of sugars that will be used by the plant in the second year to form flowers (Shakheel et al., 2017). Configuration and color are affected by genetic factors as well as environmental circumstances but also varies between different plant development stages (Kjellenberg, 2007). c. Distribution Wild carrot is native to Western or the near East Asia and it can be found in the Mediterranean area, Southwest Asia, Tropical Africa, Australia and North and South America. First carrots were purple and yellow, firstly characterized in the 10th century in Iran and northern Arabia (Simon, 2000).

Summary Purple carrots, the original domesticated carrots, accumulate highly glycosylated and acylated anthocyanins in root and/or petiole. Previously, a quantitative trait locus (QTL) for root‐specific anthocyanin pigmentation was genetically mapped to chromosome 3 of carrot. In this study, an R2R3‐MYB gene, namely DcMYB113, was identified within this QTL region. DcMYB113 expressed in the root of ‘Purple haze’, a carrot cultivar with purple root and nonpurple petiole, but not in the roots of two carrot cultivars with a purple root and petiole (Deep purple and Cosmic purple) and orange carrot ‘Kurodagosun’, which appeared to be caused by variation in the promoter region. The function of DcMYB113 from ‘Purple haze’ was verified by transformation in ‘Cosmic purple’ and ‘Kurodagosun’, resulting in anthocyanin biosynthesis. Transgenic ‘Kurodagosun’ carrying DcMYB113 driven by the CaMV 35S promoter had a purple root and petiole, while transgenic ‘Kurodagosun’ expressing DcMYB113 driven by its own promoter had a purple root and nonpurple petiole, suggesting that root‐specific expression of DcMYB113 was determined by its promoter. DcMYB113 could activate the expression of DcbHLH3 and structural genes related to anthocyanin biosynthesis. DcUCGXT1 and DcSAT1, which were confirmed to be responsible for anthocyanins glycosylation and acylation, respectively, were also activated by DcMYB113. The WGCNA identified several genes co‐expressed with anthocyanin biosynthesis and the results indicated that DcMYB113 may regulate anthocyanin transport. Our findings provide insight into the molecular mechanism underlying root‐specific anthocyanin biosynthesis and further modification in carrot and even other root crops.

Short shelf-life and poor microbial quality of minimally processed foods of plant origin pose a serious problem for the food industry. Novel techniques of minimal treatment combined with disinfection are being researched, and, for fresh juice, the addition of antimicrobial agents appears to be a promising route. In this research, fresh, nonfiltered, unpasteurized carrot juice was mixed with four potential antimicrobials (bourbon vanilla extract, peppermint extract, cannabidiol oil, and grapefruit extract). All four variants and the reference pure carrot juice were analyzed for metapopulational changes, microbial changes, and physicochemical changes. The potential antimicrobials used in the research have improved the overall microbial quality of carrot juice across 4 days of storage. However, it is important to notice that each of the four agents had a different spectrum of effectiveness towards the groups identified in the microflora of carrot juice. Additionally, the antimicrobials have increased the diversity of the carrot juice microbiome but did not prevent the occurrence of pathogenic bacteria. In conclusion, the use of antimicrobial agents such as essential oils or their derivatives may be a promising way of improving the microbial quality and prolonging the shelf-life of minimally processed foods, such as fresh juices, but the technique requires further research.

Ultrasound-assisted extraction (UAE) was used to extract carotenoids from the carrot pomace. To investigate the effect of independent variables on the UAE, the response surface methodology (RSM) with central-composite design (CCD) was employed. The study was conducted with three independent variables including extraction time (min), temperature (°C), and ethanol concentration (%). The results showed that the optimal conditions for UAE were achieved with an extraction time of 17 min, temperature of 32 °C, and ethanol concentration of 51% of total carotenoids (31.82 ± 0.55); extraction time of 16 min, temperature of 29 °C, and ethanol concentration of 59% for a combination of β-carotene (14.89 ± 0.40), lutein (5.77 ± 0.19), and lycopene (2.65 ± 0.12). The non-significant (p > 0.05) correlation under optimal extraction conditions between predicted and experimental values suggested that UAE is the more productive process than conventional techniques for the extraction of carotenoids from the carrot pomace.

In this study, the effect of high-pressure microfluidization on the colour and nutritional qualities of the orange carrot juice was investigated. The juice was processed at three different pressures (34.47 MPa, 68.95 MPa and 103.42 MPa) with three different passes (1, 2 and 3 passes). After that, total phenolic content (TPC), antioxidant activity, carotenoids, color properties, and total soluble solids content of the processed carrot juice were evaluated. As a result, no specific trends in TPC and antioxidant activity of the juice were observed through the variations of processing conditions. However, microfluidization significantly (p < 0.05) improved the carotenoids content in carrot juice. With increasing number of pass, concentrations of β-carotene and lutein had increased significantly. Similarly, increasing process pressure initially increased carotenoid content significantly (up to 68.95 MPa), further increase pressure to 103.42 MPa did not cause significant changes in carotenoid concentration. Furthermore, color properties such as lightness, redness, yellowness, and chroma value were reduced significantly with the increase of pressure and the number of passes. The results indicated that high-pressure microfluidization could be used as a novel alternative nonthermal technology to heat pasteurization to improve the color and nutritional qualities in orange carrot juice, resulting in a desirable, high-quality juice for consumers.

ABA increased during salt stress triggers binding of AREB/ABFs to DcPSY2 promoter, boosting carotenoid and ABA levels as a positive feedback mechanism Abstract Phytoene synthase (PSY) is the first committed enzyme of the carotenoid biosynthesis pathway and the most important point of regulation. Carotenoids are precursors of abscisic acid (ABA), which mediates abiotic stress tolerance responses in plants. ABA activates the synthesis of its own precursors through induction of PSY expression. Carrot, a species that accumulates very high amounts of carotenoids in its reserve root, has two PSY paralog genes that are expressed differentially in the root. Here, we determined that DcPSY2 expression is induced by salt stress and ABA. A DcPSY2 promoter fragment was obtained and characterized. Bioinformatic analysis showed the presence of three ABA responsive elements (ABREs). Through overexpressing pPSY2:GFP in Nicotiana tabacum we determined that all three ABREs are necessary for the ABA response. In the carrot transcriptome, we identified three ABRE binding protein (DcAREB) transcription factor candidates that localized in the nucleus, but only one, DcAREB3, was induced under ABA treatment in carrot roots. We found that AREB transcription factors bind to the carrot DcPSY2 promoter and transactivate the expression of reporter genes. We conclude that DcPSY2 is involved in ABA-mediated salt stress tolerance in carrot through the binding of AREB transcription factors to its promoter.

The aim of the current research was to evaluate the effect of pre-treatment and drying methods on the properties of dried carrots. Carrots were blanched (B) (1 or 3 min) or osmotic dehydrated (OD) (15 or 30 min) and dried by either convection (CD), microwave-convection (MW-CD), microwave-vacuum (MVD), or freeze-drying (FD). FD carrots showed the highest dry matter content (93.6–95.8%) and the lowest water activity (0.24–0.38). MVD carrots had lower dry matter content (79.5–95.8%) and two times more water activity (0.447–0.637) than FD. The highest color difference (∆E) in relation to raw material was noted in MVD samples (22–35) and the smallest in CD and FD (7–18), mainly due to the increase in brightness of the dried carrot. In general dried MCD carrot samples were characterized by the highest max force (hardness) (21.6–42.5 N; on average 34.7 N) in the breaking test and the lowest hardness was observed in the CD (10.8 N) ones. Pre-treatment and drying caused a significant decrease in the content of carotenoids (2.0–2.7 times) and chlorophyll (2.7–4.5 times) compared to the fresh carrot but a retention or increase in the total content of phenolics and antioxidant activity, especially in microwave-vacuum-dried carrots with an increase of even 2.7–2.9 times compared to raw material. High phenolic content (195.6–277.4 mg GA/100 g d.m.) was found in pre-osmotic dehydrated samples, and lower phenolic content was found in blanched samples (110.7–189.6 mg GA/100 g d.m.). Significantly, the highest average antioxidant activity was found in microwave-vacuum-dried samples (228.9 µmol Trolox/100 g d.m.). The results of this study indicate that microwave-vacuum-drying as an alternative to freeze-drying, including in combination with thermal or osmotic treatment, is very promising for the production of dried carrot snacks.

Carrots are a multi-nutritional food source. They are an important root vegetable, rich in natural bioactive compounds, which are recognised for their nutraceutical effects and health benefits. This review summarises the occurrence, biosynthesis, factors affecting concentration, and health benefits of phytochemicals found in Daucus carota. Two hundred and fifty-five articles including original research papers, books, and book chapters were analysed, of which one hundred and thirty articles (most relevant to the topic) were selected for writing the review article. The four types of phytochemicals found in carrots, namely phenolics, carotenoids, polyacetylenes, and ascorbic acid, were summarised. These chemicals aid in the risk reduction of cancer and cardiovascular diseases due to their antioxidant, anti-inflammatory, plasma lipid modification, and anti-tumour properties. Numerous factors influence the amount and type of phytochemicals present in carrots. Genotype (colour differences) plays an important role; high contents of α and β-carotene are present in orange carrots, lutein in yellow carrots, lycopene in red carrots, anthocyanins in the root of purple carrots, and phenolic compounds abound in black carrots. Carotenoids range between 3.2 mg/kg and 170 mg/kg, while vitamin C varies from 21 mg/kg to 775 mg/kg between cultivars. Growth temperatures of carrots influence the level of the sugars, carotenoids, and volatile compounds, so that growing in cool conditions results in a higher yield and quality of carrots, while higher temperatures would increase terpene synthesis, resulting in carrots with a bitter taste. It is worthwhile to investigate the cultivation of different genotypes under various environmental conditions to increase levels of phytochemicals and enhance the nutritional value of carrot, along with the valorisation of carrot by-products.

Anthocyanins are used for food coloring due their low toxicity and health benefits. They are extracted from different sources, but black carrot has higher anthocyanin content compared with common fruits and vegetables. Here, we study alcoholic anthocyanin extracts from black carrot to enhance their stability. The objective of our research is to determine if microencapsulation with tetraethyl orthosilicate (TEOS) is a feasible option for preventing black carrot anthocyanin degradation. Extraction solvents were solutions of (1) ethanol/acetic acid and (2) ethanol/citric acid. Samples were purified through a resin column and microencapsulated using TEOS. Fourier Transformed Infrared Spectroscopy (FTIR) spectra of samples were obtained, and degradation studies were performed under different conditions of UV radiation, pH and temperature. Antioxidant activity was evaluated with radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and electrochemical cupric reducing antioxidant capacity (CUPRAC). Color evaluation on food models were performed with CIE Lab at the beginning of experiments and after 25 days of storage. Results indicate that the more stable extracts against pH media changes are samples obtained with ethanol/acetic acid solution as extraction solvent. Extract purification through resin and TEOS microencapsulation had no significant effect on extract stability. In conclusion, although TEOS microencapsulation has proven to be effective for some dried materials from natural extracts in our previous research, we do not recommend its use for black carrot extracts considering our results in this particular case.