INFLUENCE OF THE CONTENT OF PHENOLIC COMPOUNDS ON THE TASTE CHARACTERISTICS OF FOOD CARROTS

Исследовано изменение содержания фенольных соединений при хранении корнеплодов столовой моркови 14 сортов, перерабатываемых на предприятиях Беларуси. Отбор образцов моркови осуществляли из специализированных овощехранилищ 1 раз в месяц в течение 5 мес. Содержание фенольных соединений определяли по методике, адаптированной авторами для матрицы моркови, на основе реакции окисления фенольных соединений реактивом Фолина–Чокальтеу и последующей фотометрией при длине волны 765 нм. Общую сумму фенольных соединений определяли в пересчете на феруловую кислоту. Установлено, что наименьшее количество фенольных соединений содержали свежеубранные корнеплоды моркови (2,10–7,21 мг/100 г в зависимости от сорта). После 5 мес хранения концентрация водорастворимых фенольных соединений в корнеплодах в зависимости от сорта составила 16,07–40,78 мг/100 г, что превысило исходное содержание в 2,9–7,5 раза. Содержание фенольных соединений в корнеплодах моркови повышалось неравномерно в течение хранения. В 6 образцах рост характеризовался линейной зависимостью с коэффициентами корреляции 0,95 Ј R2 Ј 0,99, в 8 – экспоненциальной (0,92 Ј R2 Ј 0,99). Ощутимая горечь во вкусе появилась во всех образцах корнеплодов моркови после 4 мес хранения. В 11 образцах наблюдалась корреляция 0,91 между показателем ощущения горечи и содержанием фенольных соединений. По совокупности оцененных показателей наиболее предпочтительными для переработки на сок прямого отжима являются сорта столовой моркови Витаминная-6, Белградо, Лявониха, Монанта, Нантская 4. The change in the content of phenolic compounds during the storage of table carrot root crops of 14 varieties processed at Belarusian enterprises has been investigated. Carrot samples were taken from specialized vegetable storages once a month for 5 months. The content of phenolic compounds was determined by the method adapted by us for the carrot matrix, based on the oxidation reaction of phenolic compounds with the Folin–Chocalteu reagent and subsequent photometry at a wavelength of 765 nm. The total amount of phenolic compounds is determined in terms of ferulic acid. It was found that freshly harvested carrot roots contained the least amount of phenolic compounds (2,10–7,21 mg/100 g, depending on the variety). After 5 months of storage, the concentration of water-soluble phenolic compounds in root crops, depending on the variety, was 16,07–40,78 mg/100 g, which exceeded the initial content by 2,9–7,5 times. The content of phenolic compounds in carrot roots increased unevenly during storage. In 6 samples, the growth was characterized by a linear dependence with correlation coefficients of 0,95 Ј R2 Ј 0,99, in 8 – exponential (0,92 Ј R2 Ј 0,99). Palpable bitterness in taste appeared in all samples of carrot root crops after 4 months of storage. A correlation of 0,91 between the feeling of bitterness and the content of phenolic compounds was observed in 11 samples. According to the totality of the estimated indicators, the varieties of food carrots Vitaminnaya-6, Belgrado, Lyavonikha, Monanta, Nanta 4 are. most preferred for processing into juice of direct extraction.

Genetic characterization of carrot root shape and size using genome-wide association analysis and genomic-estimated breeding values

Key message The principal phenotypic determinants of market class in carrot—the size and shape of the root—are under primarily additive, but also highly polygenic, genetic control. Abstract The size and shape of carrot roots are the primary determinants not only of yield, but also market class. These quantitative phenotypes have historically been challenging to objectively evaluate, and thus subjective visual assessment of market class remains the primary method by which selection for these traits is performed. However, advancements in digital image analysis have recently made possible the high-throughput quantification of size and shape attributes. It is therefore now feasible to utilize modern methods of genetic analysis to investigate the genetic control of root morphology. To this end, this study utilized both genome wide association analysis (GWAS) and genomic-estimated breeding values (GEBVs) and demonstrated that the components of market class are highly polygenic traits, likely under the influence of many small effect QTL. Relatively large proportions of additive genetic variance for many of the component phenotypes support high predictive ability of GEBVs; average prediction ability across underlying market class traits was 0.67. GWAS identified multiple QTL for four of the phenotypes which compose market class: length, aspect ratio, maximum width, and root fill, a previously uncharacterized trait which represents the size-independent portion of carrot root shape. By combining digital image analysis with GWAS and GEBVs, this study represents a novel advance in our understanding of the genetic control of market class in carrot. The immediate practical utility and viability of genomic selection for carrot market class is also described, and concrete guidelines for the design of training populations are provided.

Genetic and Transcription Profile Analysis of Tissue-Specific Anthocyanin Pigmentation in Carrot Root Phloem

In purple carrots, anthocyanin pigmentation can be expressed in the entire root, or it can display tissue specific-patterns. Within the phloem, purple pigmentation can be found in the outer phloem (OP) (also called the cortex) and inner phloem (IP), or it can be confined exclusively to the OP. In this work, the genetic control underlying tissue-specific anthocyanin pigmentation in the carrot root OP and IP tissues was investigated by means of linkage mapping and transcriptome (RNA-seq) and phylogenetic analyses; followed by gene expression (RT-qPCR) evaluations in two genetic backgrounds, an F2 population (3242) and the inbred B7262. Genetic mapping of ‘root outer phloem anthocyanin pigmentation’ (ROPAP) and inner phloem pigmentation (RIPAP) revealed colocalization of ROPAP with the P1 and P3 genomic regions previously known to condition pigmentation in different genetic stocks, whereas RIPAP co-localized with P3 only. Transcriptome analysis of purple OP (POP) vs. non-purple IP (NPIP) tissues, along with linkage and phylogenetic data, allowed an initial identification of 28 candidate genes, 19 of which were further evaluated by RT-qPCR in independent root samples of 3242 and B7262, revealing 15 genes consistently upregulated in the POP in both genetic backgrounds, and two genes upregulated in the POP in specific backgrounds. These include seven transcription factors, seven anthocyanin structural genes, and two genes involved in cellular transport. Altogether, our results point at DcMYB7, DcMYB113, and a MADS-box (DCAR_010757) as the main candidate genes conditioning ROPAP in 3242, whereas DcMYB7 and MADS-box condition RIPAP in this background. In 7262, DcMYB113 conditions ROPAP.

Weed Suppression Potential of Living Mulches, Newspaper Hydromulches, and Compost Blankets in Organically Managed Carrot Production

Direct seeding into strip-tilled zones (STZs) of living mulches may require weed suppression tactics for soil surfaces exposed within the STZ. Three surface mulch options (hydromulch, compost blanket, and a no-mulch control) were evaluated for their ability to suppress weeds and improve crop performance when applied in STZs seeded to carrot (Daucus carota). These STZs were located within one of five living mulch options [red clover (Trifolium pratense), white clover (Trifolium repens), perennial ryegrass (Lolium perenne), a weed-free control, and a weedy control]. From measurements spanning 2 years at two North Dakota locations, dry weed biomass was lower in STZs where hydromulch or compost blankets were applied compared with the no-mulch control (12, 13, and 82 g·m−2, respectively). The presence of a living mulch adjacent to the STZ reduced carrot root biomass by 49% to 84% compared with the weed-free control. Further research should 1) investigate methods for reducing yield loss from living mulches, and 2) develop biodegradable alternatives to plastic mulches.

Substantiation of the Lattice Ripper Parameters of the Carrot Digger in Conditions of the Republic of Uzbekistan

The authors showed that during carrot harvesting by diggers, strong soil lumps were formed that were poorly separated from root crops and complicated the separation process, which leaded to machines overloading, due to the variability of the physical and mechanical soil properties. A lattice loosening working body was developed that improved the digger elevator separating ability.(Research purpose) To substantiate lattice ripper parameters of the carrot digger, which provides intensive loosening of the soil and thereby increases the impurities separation completeness with minimal root crops damage.(Materials and methods) The authors researched geometric, kinematic parameters of lattice ripper of the carrot digger. They theoretically substantiated the design parameters of the mechanism and its kinematic parameters after they studied the physicomechanical properties of the carrot bed.(Results and discussion) The authors found that during the interaction of the lattice ripper with soil layers on the elevator, soil lumps were destroyed, the soil was loosened with the following parameters: the ripper radius was not more than 9.5 centimeters, the height of the shaft was 20 centimeters, the blade submerged part was 6 centimeters, the width of the lattice ripper was 47 centimeters.(Conclusions) It was revealed that lattice ripper promoted intensive separation of the soil layer without damage and loss of carrot root crops. The authors proved that the peripheral speed of the lattice ripper should be no more than 2.5 meters per second, the kinematic mode of the separation intensification means should be 2.5, and the radius of the ripper should be no more than 9.5 centimeters.

RESEARCH RESULTS OF THE PROCESS OF CLEANING POTATO TUBERS AND CARROT ROOT CROPS USING ULTRASOUND

The most promising of the known ways to reduce the content of soil bolsters during machine harvesting of tuberous roots should be considered pre-harvest moisturization of the soil layer in which the tuberous root are located. This significantly reduces the content of soil impurities in harvested tuberous roots. However, atomized spray of water, even under pressure, is not able to ensure its instant flow to the depth of tuberous roots and, moreover, to moisten the soil to the state that provides further intensification of the process of separation of tuberous roots from soil bolsters that are comparable to them. To eliminate this defect, it is necessary to provide an intensification of the water spraying process by one of the methods of physical influence, which provides instant soil moisture to the depth of tuberous roots. The article presents instrumentation for research of technological parameters of ultrasonic treatment on the quality of the cleaning roots crops from soil impurities, the method and results of laboratory studies of ultrasound effect on the cleaning process of potato tubers of the "Red Scarlet" variety and carrot root crops of «Shantane» variety . The optimal parameters of ultrasound influence that intensifies the process of cleaning root crops from soil impurities were determined. The results of comparative laboratory studies of cleaning potato tubers and carrot root crops from various root crops on the physical and mechanical composition of soil impurities (sandy loams and loam soils) allow us to conclude that the best indicators of intensification of ultrasonic influence with increase in the completeness of cleaning, despite the weight and type of contamination, are observed when processing carrot root crops, the completeness of cleaning is on average higher by 13...20 %.

Accuracy of carrot yield forecasting using proximal hyperspectral and satellite multispectral data

Proximal and remote sensors have proved their effectiveness for the estimation of several biophysical and biochemical variables, including yield, in many different crops. Evaluation of their accuracy in vegetable crops is limited. This study explored the accuracy of proximal hyperspectral and satellite multispectral sensors (Sentinel-2 and WorldView-3) for the prediction of carrot root yield across three growing regions featuring different cropping configurations, seasons and soil conditions. Above ground biomass (AGB), canopy reflectance measurements and corresponding yield measures were collected from 414 sample sites in 24 fields in Western Australia (WA), Queensland (Qld) and Tasmania (Tas), Australia. The optimal sensor (hyperspectral or multispectral) was identified by the highest overall coefficient of determination between yield and different vegetation indices (VIs) whilst linear and non-linear models were tested to determine the best VIs and the impact of the spatial resolution. The optimal regression fit per region was used to extrapolate the point source measurements to all pixels in each sampled crop to produce a forecasted yield map and estimate average carrot root yield (t/ha) at the crop level. The latter were compared to commercial carrot root yield (t/ha) obtained from the growers to determine the accuracy of prediction. The measured yield varied from 17 to 113 t/ha across all crops, with forecasts of average yield achieving overall accuracies (% error) of 9.2% in WA, 10.2% in Qld and 12.7% in Tas. VIs derived from hyperspectral sensors produced poorer yield correlation coefficients (R2 < 0.1) than similar measures from the multispectral sensors (R2 < 0.57, p < 0.05). Increasing the spatial resolution from 10 to 1.2 m improved the regression performance by 69%. It is impossible to non-destructively estimate the pre-harvest spatial yield variability of root vegetables such as carrots. Hence, this method of yield forecasting offers great benefit for managing harvest logistics and forward selling decisions.

ОПТИМАЛЬНЫЕ ПРИЕМЫ ВОЗДЕЛЫВАНИЯ ПЕРСПЕКТИВНЫХ ГИБРИДОВ МОРКОВИ

В статье рассмотрено влияние основных урожаеобразующих факторов и совершенствование агротехники возделывания столовой моркови при капельном орошении, на рост и развитие корнеплодов моркови. На примере гибридов Каскад F1, Кордоба F1, Абако F1 и Тангерина F1.The article considers the influence of the main crop-forming factors and improvement of agricultural techniques for growing table carrots with drip irrigation on the growth and development of carrot root crops. Using the example of the Cascade F1, Cordoba F1, Abaco F1 and Tangerine F1 hybrids.