Tuber Composition Research Articles

Prediction of potato dry matter content by FT-NIR spectroscopy: Impact of tuber tissue on model performance

Potato, an important cash crop, is critically affected by supply chain losses that require attention of both research and industry to ensure sustainable production (SDG 12.3). Within potato supply chain management, dry matter (DM) determination is a key factor affecting the harvest quality, storability, food losses, designated user and tuber prices. Even though rapid methods like near-infrared spectroscopy (NIR) enable operators to carry out fast, reliable in situ measurements, the prediction results are often unsatisfactory due to inherent variability of tuber's composition. Thus, this study aims to evaluate Fourier Transformed-NIR based DM prediction in different potato tissues: i) periderm, ii) cortex, iii) outer medulla and iv) inner medulla of 12 different cultivars. The DM prediction models developed using standard chemometrics approaches (i.e., partial least squares, PLS; and interval-PLS, iPLS) showed that features selection by iPLS allowed for better performances. Among the evaluated tissues, the inner medulla had more precise and reliable measurements with RMSE and R2 prediction values of 0.93% and 0.90, respectively. This information can be used to develop more advanced systems inclusive of portable tools and advanced technologies for in situ evaluation to support operators and ensure better pre- and post-harvest management of potatoes.

Dinâmica de absorção de nutrientes de Gloriosa para flor de corte

Abstract Gloriosa superba L. is a recently introduced tropical species in Argentina, cultivated as a cut flower. It is extremely important to know the nutritional demands of the crop to provide the optimal amounts of nutrients at each stage, achieving quality and good yield in flowers, reducing production costs and environmental impact. The objective of this work was to determine the dynamics of nutrient absorption in the cultivation of G. superba for cut flowers, to facilitate the creation of a fertilization program, in order to avoid crop deficiencies and contribute to sustainable production. Tuber composition analyzes were carried out and, on the other hand, an essay was installed in greenhouse beds, taking samples at seven moments of the cycle. Fresh matter and dry matter of stems, leaves, flowers, tubers, roots and chemical analysis of aerial organs were measured to obtain the absorption curve. It was verified that only around 20% of each nutrient is provided by the tuber, being necessary the external contribution from initial stages of the crop. The rate of growth and accumulation of dry matter was shown as a double sigmoid, with maximum peaks in the vegetative stage of stem elongation and beginning of flowering. Nutrient amounts were absorbed in the following order: N>K>Mg>Ca>P>Fe>Mn>Zn>Cu. Fertilization rich in N, P, and Fe is recommended in the vegetative stage, balanced during the visible shoot stage, and rich in Ca, K, Mg, Mn, Zn, and Cu during flowering.

Effect of Drought Stress on Bioactives and Starch in Chilean Potato Landraces

Despite the importance that environmental stress plays in the agronomic performance of plants, there is little agreement on its effect on bioactive compounds in tuber crops. A field study was carried out with eight diverse Chilean potato landraces and the commercial variety Désirée. Plants were subjected to drought stress for 6 weeks starting at 88 or 110 days after planting. As expected, the treatments had a strong impact on the yield and the number of tubers produced per plant (P<0.01). Surprisingly, there was no significant effect of the treatments on the content of phenolic compounds, anthocyanins or antioxidant activity (P>0.05). Resistant starch content is reported for the first time in these landraces, with values between 26 and 44% DW for raw samples and 5 and 7% DW for boiled samples in plants under well-watered conditions. Bioactive content in general was genotype-dependent and it changed significantly after boiling. Furthermore, our results suggest that bioactive content in raw samples is not necessarily a good predictor for the composition of boiled samples. This is highly relevant considering that screening of varieties with high bioactive content is often carried out in raw tubers. Our results provide valuable information regarding the effect of drought stress in tuber composition and highlight the unexplored potential of the Chilean potato gene pool in the development of varieties with higher bioactive content.

Comparison of different thermal treatments on the physicochemical properties of Apios fortunei used for yellow wine fermentation

A novel material (Apios fortunei), which has a high starch content and potential healthcare functions, was used for yellow wine fermentation. To determine how the tuber's composition would be modified by thermal treatments and how those modifications would affect fermentation, the changes in the physicochemical properties of the A. fortunei tuber after steam cooking, traditional extrusion (extrusion without enzyme) and enzymatic extrusion (introduce the amylase into the extrusion) were investigated. The results showed a low degree of gelatinization (70.56%) in the steam-cooked sample, and the fermentation broth of the traditionally extruded sample was dense. However, the enzymatically extruded sample was almost completely gelatinized (99.09%) with an amorphous starch structure measured via X-ray diffraction and Fourier-transform infrared spectroscopy. The high water solubility index (61.66%), low water absorption index (1.68 g/g) and viscosity (<60 cP), indicated that the broth of enzymatically extruded sample had a fine fluidity. The results of the final wines indicated that enzymatic extrusion significantly increased the fermentation efficiency, from 62.22% (steam cooking) and 63.87% (traditional extrusion) to 73.47%. Meanwhile, enzymatic extrusion improved the quality characteristics of the final wines, including total amino acid (4559.20 mg/L), soluble solid content (7.35 g/100 g) and total acid (10.66 g/L).

Kinetic modelling of acrylamide formation during the frying of potato chips

The effect of potato tuber composition, frying time and temperature on acrylamide formation in potato chips was investigated and a mathematical model of the kinetics of acrylamide formation is provided. Moisture-temperature–time profiles were obtained for potato slices during frying to enable the determination of the ‘effective’ reaction time by identifying the critical moisture content (6% dwb) for acrylamide formation to commence and using dehydration curves to calculate subsequent frying time to finished product moisture content. The chemical kinetic model conformed to the following rate equation over a one hundred-fold range of acrylamide concentrations:d[acryl]dt=k1glucoseasn+k6[fructose][asn][TAA]where [TAA] represents total amino acid concentration. The timescale of the frying process meant that the chemical reactions were all in their initial rate phase. Kinetic parameters confirm that the fructose-dependent reaction (caramelization) contributes twice as much acrylamide as the reaction of glucose (Maillard reaction).

Dissecting the Genetics of Potato Tuber Composition

CSA NewsVolume 66, Issue 3 p. 24-24 SOCIETY SCIENCE Dissecting the Genetics of Potato Tuber Composition First published: 17 February 2021 https://doi.org/10.1002/csan.20404Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume66, Issue3March 2021Pages 24-24 RelatedInformation

Impact of the overexpression of the StDREB1 transcription factor on growth parameters, yields, and chemical composition of tubers from greenhouse and field grown potato plants.

Potato plants are often exposed to biotic and abiotic stresses that negatively impact their growth, development, and yield. Plants respond to different stresses by inducing large numbers of stress-responsive genes, which can be either functional or regulatory genes. Among regulatory genes, Dehydration Responsive Element Binding (DREB) genes are considered as one of the main groups of transcriptional regulators. The overexpression of these factors in several transgenic plants leads to enhancement of abiotic stress tolerance. However, a number of reports showed that the overexpression of DREB factors under control of constitutive promoter, affects their morphology and production. Therefore, it becomes interesting to evaluate the effect of the overexpression of this StDREB1 transcription factor on plant growth, morphology, yield and tuber composition under both greenhouse and field culture conditions. To our knowledge, there is no available data on the effect of DREBA-4 overexpression on potato plants morphology and yield. Indeed, most studies focused on DREB genes from A-1 and A-2 groups for other plant species. Our results showed that StDREB1, a A-4 group of DREB gene from potato (Solanum tuberosum L.), overexpressing plants did not show any growth retardation. On the contrary, they seem to be more vigorous, and produced higher tuber weight in greenhouse and field culture than the wild type (WT) plants. Moreover, the overexpression of StDREB1 transcription factor seemed to have an effect on tuber quality in terms of dry matter, starch contents and reducing sugars in comparison to the WT tubers. These data suggest that the StDREB1 gene from A-4 group of DREB subfamily can be a good candidate in potato breeding for stress tolerance.

Biochemical tuber composition of promising potato hybrids

The consumption of potato as a food product in Ukraine is currently the main type of use. The Potato Research Institute of Sumy National Agrarian University implements a breeding program for the creation of new nematode-resistant intensive varieties with increased energy value. During 2016-2018, the biochemical composition of tubers of 21 hybrids, including 6 early-maturing, 12 middle-early, 3 middle-maturing, was studied using an infrared analyzer. Increased starch content (84%-80% per dry weight) was observed in 10%, high (73%-72%)-in 14% of the hybrids. Protein content in the tubers was at the level of 6.4% per dry weight, early-maturing hybrids turned out to be the most valuable ones (8.9-8.6%). The high content of vitamin C (89-86 mg%) was accumulated by the middle-early and middle-maturing hybrids, vitamin K (0.26-0.19 mg%)-by the early-maturing hybrids. 28% of hybrids with the maximum (2.2 mg%) potassium content were selected. The amount of nitrate in tubers of 48% of the hybrids did not exceed the maximum permissible concentration. The hybrids with increased and high starch content had a high caloric value ranging from 58 to 55 calorie/100 g. The selection of high-calorie hybrids will enable us to increase the competitiveness of future potato varieties of Sumy NAU breeding in the modern food market.

Effect of Urea Fertilizer and Poultry Manure on Nitrate Reductase Activity of Potato and some Tuber Composition

Introduction Nowadays, increasing environmental risks to human health have caused increasing attention to use chemical nitrogen sources efficiently or nitrogen supplying from organic amendments. In this respect, chicken manure seems to be a good alternative to chemical nitrogen fertilizers. The purpose of this experiment is to investigate the role of urea and poultry manure and ecological factors (climate) on the quantity of some chemical compositions of the potato tuber. Materials and Methods To study the effects of urea and poultry manure on some potato tuber compositions, the factorial experiment was conducted in 2015-2016 during the growing season in 2 regions; Azna and Khorramabad which is located in Lorestan province in the west of Iran. The factors were 2 different sources of nitrogen supply including urea fertilizer and poultry manure. Results Results show that the highest activity of nitrate reductase (NR) in both sites was observed using 10304 kg of poultry manure ha-1. The results also showed that the tuber nitrate content was only affected by the fertilizer source. In both studied places, the highest tuber nitrate was associated with high levels of urea fertilizer. Based on the results, the vitamin C of potato tubers grown by poultry manure were also superior to the relative vitamin C content. According to the results of this experiment, the accumulation of more than 2 times the nitrate in the tubers was obtained from urea fertilizer (244.2 versus 100 ppm). Conclusions In order to achieve food security and an efficient and sustainable food chain, chemical fertilizers must be replaced with organic fertilizers. Thus, the belief that the use of organic fertilizers, at any level, would not cause any problem for the health of products is definitely incorrect.

Metabolite profiling of yam (Dioscorea spp.) accessions for use in crop improvement programmes

IntroductionNinety-seven percent of yam (Dioscorea spp.) production takes place in low income food deficit countries (LIFDCs) and the crop provides 200 calories a day to approximately 300 million people. Therefore, yams are vital for food security. Yams have high-yield potential and high market value potential yet current breeding of yam is hindered by a lack of genomic information and genetic resources. New tools are needed to modernise breeding strategies and unlock the potential of yam to improve livelihood in LIFDCs.ObjectivesMetabolomic screening has been undertaken on a diverse panel of Dioscorea accessions to assess the utility of the approach for advancing breeding strategies in this understudied crop.MethodsPolar and lipophilic extracts from tubers of accessions from the global yam breeding program have been comprehensively profiled via gas chromatography-mass spectrometry.ResultsA visual pathway representation of the measured yam tuber metabolome has been delivered as a resource for biochemical evaluation of yam germplasm. Over 200 compounds were routinely measured in tubers, providing a major advance for the chemo-typing of this crop. Core biochemical redundancy concealed trends that were only elucidated following detailed mining of global metabolomics data. Combined analysis on leaf and tuber material identified a subset of metabolites which allow accurate species classification and highlighted the potential of predicting tuber composition from leaf profiles. Metabolic variation was accession-specific and often localised to compound classes, which will aid trait-targeting for metabolite markers.ConclusionsMetabolomics provides a standalone platform with potential to deliver near-future crop gains for yam. The approach compliments the genetic advancements currently underway and integration with other ‘–omics’ studies will deliver a significant advancement to yam breeding strategies.

Soil drench treatment with ß-aminobutyric acid increases drought tolerance of potato.

The non-protein amino acid β-aminobutyric acid (BABA) is known to be a priming agent for a more efficient activation of cellular defence responses and a potent inducer of resistance against biotic and abiotic stresses in plants. Nevertheless, most of the studies on priming have been carried out in Arabidopsis. In potato, the effect of BABA was demonstrated only on biotic stress tolerance. We investigated the effect of BABA on the drought tolerance of potato and found that soil drenched with BABA at a final concentration of 0.3 mM improves the drought tolerance of potato. Water loss from the leaves of the primed plants is attenuated and the yield is increased compared to the unprimed drought-stressed plants. The metabolite composition of the tubers of the BABA-treated plants is less affected by drought than the tuber composition of the non-treated plants. Nitric oxide and ROS (reactive oxygen species) production is increased in the BABA-treated roots but not in the leaves. In the leaves of the BABA-treated plants, the expression of the drought-inducible gene StDS2 is delayed, but the expression of ETR1, encoding an ethylene receptor, is maintained for a longer period under the drought conditions than in the leaves of the non-treated, drought-stressed control plants. This result suggests that the ethylene-inducible gene expression remains suppressed in primed plants leading to a longer leaf life and increased tuber yield compared to the non-treated, drought-stressed plants. The priming effect of BABA in potato, however, is transient and reverts to an unprimed state within a few weeks.

Effects of Nitrogen and Sulfur Fertilization on Free Amino Acids, Sugars, and Acrylamide-Forming Potential in Potato

Nitrogen (N) fertilizer is used routinely in potato (Solanum tuberosum) cultivation to maximize yield. However, it also affects sugar and free amino acid concentrations in potato tubers, and this has potential implications for food quality and safety because free amino acids and reducing sugars participate in the Maillard reaction during high-temperature cooking and processing. This results in the formation of color, aroma, and flavor compounds, but also some undesirable contaminants, including acrylamide, which forms when the amino acid that participates in the final stages of the reaction is asparagine. Another mineral, sulfur (S), also has profound effects on tuber composition. In this study, 13 varieties of potato were grown in a field trial in 2010 and treated with different combinations of N and S. Potatoes were analyzed immediately after harvest to show the effect of N and S fertilization on concentrations of free asparagine, other free amino acids, sugars, and acrylamide-forming potential. The study showed that N application can affect acrylamide-forming potential in potatoes but that the effect is type- (French fry, chipping, and boiling) and variety-dependent, with most varieties showing an increase in acrylamide formation in response to increased N but two showing a decrease. S application reduced glucose concentrations and mitigated the effect of high N application on the acrylamide-forming potential of some of the French fry-type potatoes.

Allocation of Experimental Resources Used in Potato Breeding to Minimize the Variance of Genotype Mean Chip Color and Tuber Composition

Breeders strive to select superior genotypes despite the challenges that environmental variation and environment × genotype interactions bring in increasing phenotypic variance. Effective selection requires experimental design that minimizes variance of genotype means and therefore allows for the identification of superior genotypes. The variance components calculated from three extensive datasets were used in modeling experiments to determine how experimental replication and sampling affected the variance of genotype mean for composition or fried chip color of tubers from Solanum species including the cultivated potato Solanum tuberosum L. Maximizing experimental replication over years and locations with limited sampling minimized variance of genotype means for chip color, tuber sugar concentrations, and tuber dry matter. It is suggested that in the early stages of a potato breeding program, more precise evaluations of the genetic potential of individual clones would be achieved through the use of small plots evaluated over several locations and/or years rather than increased replication at one location.

The phenology, yield and tuber composition of ‘early’ crop potatoes: A comparison between organic and conventional cultivation systems

AbstractPotato production in several Mediterranean countries is focused on the ‘early’ crop type, and is generally associated with intensive applications of farming inputs. Here we report, for the first time, a comparison of crop performance between organic and conventional cultivation systems. Three cultivars were tested over two seasons (2007 and 2008) to record their phenology, yield and tuber chemical composition. The organic cultivation system was less productive than the conventional one across both years with respect to total yield, but in the season (2008) when late blight infection was not severe the difference was narrowed from 7% (Ditta) to 20% (MN 2-1577 S1). The Italian breeding clones (MN 1404 O5 and MN 2-1577 S1) deserve specific consideration due to their higher total yield and nutritional value (in terms of total protein and vitamin C content) under organic cultivation system than the cultivar Ditta. In addition, the organic farming produced tubers with a lower nitrate content, an important benefit in the context of human health. In conclusion, our results indicate that organic cultivation of ‘early’ potatoes can deliver acceptable agronomic and qualitative performances. However, the response of the ‘early’ crop potato to organic farming depends upon both seasonal conditions and cultivar choice. In particular, the selection of appropriate cultivars is one of the key aspects to optimize this environmentally friendly production system.

Effects of sulphur nutrition during potato cultivation on the formation of acrylamide and aroma compounds during cooking

Lack of sulphur nutrition during potato cultivation has been shown to have profound effects on tuber composition, affecting in particular the concentrations of free asparagine, other amino acids and sugars. This is important because free asparagine and sugars react at high temperatures to form acrylamide, a suspect carcinogen. Free amino acids and sugars also form a variety of other compounds associated with colour and flavour. In this study the volatile aroma compounds formed in potato flour heated at 180 °C for 20 min were compared for three varieties of potato grown, with and without sulphur fertiliser. Approximately 50 compounds were quantified in the headspace extracts of the heated flour, of which over 40 were affected by sulphur fertilisation and/or variety. Many of the 41 compounds found at higher concentrations in the sulphur-deficient flour were Strecker aldehydes and compounds formed from their condensation, whereas only one compound, benzaldehyde, behaved in the same way as did acrylamide and was found at higher concentrations in the sulphur-sufficient flour. The reasons for these effects are discussed.

Extensive Variation in Fried Chip Color and Tuber Composition in Cold-Stored Tubers of Wild Potato (Solanum) Germplasm

Cold-induced sweetening and browning in the Maillard reaction have driven extensive research in the areas of plant physiology, biochemistry, and food science in Solanum tuberosum because of its importance to the potato-processing industry. Prior research has not characterized wild Solanum relatives of potato for tuber composition and has not determined if relationships between tuber composition and chip color after cold storage in wild species are comparable to those found for cultivated potato. Extensive inter- and intraspecific variation for chip color and tuber composition were found in the wild Solanum species examined. Tuber sugar profiles suggested that invertase activity at low temperatures differed between and within species. Tuber fructose, glucose, and sucrose concentrations partially explained chip color variation in most accessions, but asparagine concentration and percent dry matter did not. Most wild species had reducing sugar concentrations and chip color scores after 2 degrees C storage that were less than those in S. tuberosum cultivar Snowden. Sugar profiles and relationships between specific sugars and chip color in Solanum pinnatisectum were unique among the species examined.

Tubers from potato lines expressing a tomato Kunitz protease inhibitor are substantially equivalent to parental and transgenic controls

Recombinant protease inhibitors represent useful tools for the development of insect-resistant transgenic crops, but questions have been raised in recent years about the impact of these proteins on endogenous proteases and chemical composition of derived food products. In this study, we performed a detailed compositional analysis of tubers from potato lines expressing the broad-spectrum inhibitor of Ser and Asp proteases, tomato cathepsin D inhibitor (SlCDI), to detect possible unintended effects on tuber composition. A compositional analysis of key nutrients and toxic chemicals was carried out with tubers of SlCDI-expressing and control (comparator) lines, followed by a two-dimensional gel electrophoresis (2-DE) proteomic profiling of total and allergenic proteins to detect eventual effects at the proteome level. No significant differences were observed among control and SlCDI-expressing lines for most chemicals assayed, in line with the very low abundance of SlCDI in tubers. Likewise, proteins detected after 2-DE showed no quantitative variation among the lines, except for a few proteins in some control and test lines, independent of slcdi transgene expression. Components of the patatin storage protein complex and Kunitz protease inhibitors immunodetected after 2-DE showed unaltered deposition patterns in SlCDI-expressing lines, clearly suggesting a null impact of slcdi on the intrinsic allergenic potential of potato tubers. These data suggest, overall, a null impact of slcdi expression on tuber composition and substantial equivalence between comparator and SlCDI-expressing tubers despite reported effects on leaf protein catabolism. They also illustrate the usefulness of proteomics as a tool to assess the authenticity of foods derived from novel-generation transgenic plants.

Tuber Water and Pressure Potentials Decrease and Sucrose Contents Increase in Response to Moderate Drought and Heat Stress

Environmental stress during the growing season can reduce the quality of stored Solanum tuberosum (potato) tubers. Changes in greenhouse grown Russet Burbank tuber water potential and tuber composition following periods of moderate drought, heat, or drought and heat stress were characterized. Decreased leaf and tuber water potentials were observed at the end of stress treatments. Decreased tuber water potential caused dramatic declines in tuber pressure potential. Tuber sucrose content increased with the severity of stress. Changes in tuber glucose and malic acid contents were also observed. Stress during early tuber bulking had a larger effect on tuber sugars at the end of the stress period than stress during late bulking. Stem-end glucose concentration of tubers at harvest after vine senescence was greater in tubers from plants stressed at early tuber bulking compared to late bulking.

Cold storage, reconditioning potential and chip processing quality of spring potato (Solanum tuberosum L. cv. Hermes) tubers in response to differential nitrogen fertilisation

AbstractBACKGROUND: Crop management has been implicated in tuber sugar accumulation and potato processing quality. However, reports on potato postharvest behaviour, tuber composition and processing quality in response to crop nitrogen (N) fertilisation have been sparse and inconclusive. In this study, chipping potato cv. Hermes was treated with four preplanting N rates (0, 100, 200 and 300 kg ha−1) to evaluate the effect of N fertilisation on sugar accumulation profiles and processing quality at harvest, after cold storage at 4.5 °C for up to 200 days and after reconditioning at 16 °C for 10–30 days.RESULTS: Preharvest leaf petiole analysis and tuber nitrate analysis at harvest confirmed crop response to N rates. At harvest, tuber specific gravity decreased marginally beyond 200 kg N ha−1. Chip colour as well as tuber sucrose and reducing sugar (RS) content was unaffected by N fertilisation rate. During cold storage and reconditioning, tuber fresh weight loss and sprout growth were unaffected by N rate, while its effect on tuber sugar levels was either statistically or practically insignificant. Tuber sucrose and RS contents correlated highly with chip colour (r = − 0.729, P &lt;0.001 and r = −0.791, P &lt;0.001 respectively). Importantly, postharvest chip colour was also unaffected by N rate, though it declined markedly with the onset of cold storage and improved significantly throughout reconditioning. Differences in chip colour between years were limited but potentially critical in meeting the commercial standard.CONCLUSION: Completion of physiological crop senescence of the spring potato crop under Mediterranean climatic conditions seems to mitigate the potential interference of preplanting N fertilisation with tuber maturation and subsequently cold storage performance, reconditioning potential and processing quality. Copyright © 2009 Society of Chemical Industry

Comparison of potato varieties between seasons and their potential for acrylamide formation

AbstractBACKGROUND: Acrylamide is a probable human carcinogen produced during food preparation, including frying of potato products. The aim of this study was to investigate the impact of seasonal variation on tuber composition and its acrylamide generation potential.RESULTS: The chemical composition of potato varieties used respectively for French fry (Bintje and Ramos) and crisp (Lady Rosetta and Saturna) production was studied throughout a storage period of 9 months during two growing seasons (2003 and 2004), in addition to their acrylamide generation potential during preparation of French fries. A significant impact of variable climatological conditions on the reducing sugar, dry matter, total free amino acid and free asparagine contents of tubers was observed. Exceptionally warm summers gave rise to a lower reducing sugar content (expressed on a dry matter basis) and thus a lower susceptibility to acrylamide generation during frying.CONCLUSION: It cannot be excluded that potato growers and the potato‐processing industry are confronted with some harvests that are more prone to acrylamide generation than others owing to climatological variability, thus confirming the importance of a multifactorial approach to mitigate acrylamide generation in potato products. Copyright © 2007 Society of Chemical Industry