Glycoalkaloids In Potato Tubers Research Articles

Combined Small RNA and Degradome Sequencing Reveals Important Roles of Light-Responsive microRNAs in Wild Potato (Solanum chacoense)

The accumulation of chlorophyll and antinutritional glycoalkaloids in potato tubers resulting from exposure to light has been widely recognized as a cause of unpredictable quality loss of potato tuber. While transcriptional regulation of light-induced chlorophyll and glycoalkaloids accumulation has been extensively investigated, the mechanisms of post-transcriptional regulation through miRNA remain largely unexplored. An experimental model, the tubers of Solanum chacoense, were used to identify light-responsive miRNA–target interactions (MTIs) related to tuber greening and glycoalkaloid biosynthesis by employing multi-omics approaches (miRNA-seq and degradome-seq). A total of 732 unique mature miRNAs have been identified in S. chacoense. In total, 6335 unique target transcripts were cleaved by 489 known miRNAs and 153 novel miRNAs. The results revealed that light-responsive miRNAs can be grouped into eight temporally related clusters and play important roles in various physiological processes such as plant growth, stress responses, and primary and secondary metabolism. Multi-omics analyses have revealed that the modulation of transcript abundance of MYB59, HSPs, and EBF1/EBF2 by light-responsive miRNAs is pivotal for their function in cross-tolerance responses to both abiotic and biotic stresses. Furthermore, our findings suggest that many light-responsive miRNAs are crucial regulators in various biosynthetic pathways, including tetrapyrrole biosynthesis, suberin biosynthesis, and steroid biosynthesis. These findings highlight the significant role of light-responsive miRNAs in secondary metabolic pathways, particularly in isoprenoid, terpenoid, and glycoalkaloid biosynthesis, and have implications for the precise manipulation of metabolic pathways to produce new potato varieties with improved resistance to greening and lower glycoalkaloid levels.

The Effect of Sinapis alba Mustard Seed Meal Extract on Potato Tuber Quality in Organic Potato Production

Utilizing innovative agricultural practices that enhance the nutritional quality of staple foods such as potatoes provides farmers with tools to successfully meet the challenges of feeding a rising global population while sustaining organic food production. In the present study, we have demonstrated the potential of white mustard (Sinapis alba) seed meal extract to improve potato nutritional properties. Sinapis alba extract is a low-cost by-product of mustard oil extraction that contains a relatively high concentration of biologically active compounds. When applied to soil, S. alba extract had a positive impact on nutritional quality of potatoes. For example, total phenolic content in potatoes treated with S. alba extract increased by ~1.5 times, and potato nitrogen content increased from 1.52% to 1.73% with one application of S. alba extract. At the same time, application of S. alba extract had limited impact on the accumulation of anti-nutrients such as glycoalkaloids in potato tubers. The ability to boost the phenolics content of potatoes by applying an organic amendment is a valuable tool in organic farming as it creates more nutritional crop. To the best of our knowledge, this is the first study to examine the effect of S. alba extract on the nutritional quality of potatoes, or indeed of any food crop.

A Review on Greening and Glycoalkaloids in Potato Tubers: Potential Solutions.

Greening is an undesirable trait that develops in potatoes upon light exposure. This condition lowers market value, increases tuber waste in retail stores, and consequently influences the price of product in the long run. When potatoes are subjected to artificial light, the amyloplast converts into chloroplast. Although the development of total glycoalkaloids (TGA) is independent of light, the greening induced by exposure of potato to artificial light is an indication of probable TGA acceleration, which could be present in a low amount initially. Several research studies on optimum postharvest factors (temperature, lighting condition, relative humidity, pretreatment, storage air composition, and packaging) have been carried out to avoid greening and TGA development. This current review highlights major postharvest factors and summarizes past research regarding cause of greening and TGA development in potatoes in retail stores. Additionally, it also portrays the potential solutions that could help mitigate this problem, ultimately reducing wastage and achieving food security.

Determination of suitability of different potato (Solanum tuberosum L.) varieties with white and pigmented pulp for processing into potato products

The article provides an overview of the current state of research in the field of requirements for the quality of potatoes for processing them into potato products. It is noted that the quality of potatoes with white pulp is determined by the mass fraction of: dry matter over 20 %; reducing sugars 0.2-0.5 %, glycoalkaloids no more than 200 mg/kg; starch not less than 16 %. For potatoes with pigmented pulp in addition to these indicators it is necessary to take into account the mass fraction of anthocyanins (over 0.5 %), which are effective antioxidants. The review presents the information on changes in the content of glycoalkaloids in potato tubers with pigmented pulp depending on the type of processing. The objective of experimental research is to analyze the qualitative indicators of native potato varieties with white and pigmented pulp to determine the practicability of their processing into potato products and further using as a starting material for selection. As research objects were selected 21 potato varieties with white pulp and 8 potato varieties with pigmented (colored) pulp. As a result of evaluation of the feasibility of using potatoes with white pulp 7 varieties out of 21 varieties of potatoes can be recommended for the production of potato products (Kamelot, Fritella, Rubin, Triumf, Ariya, Izyuminka, Mirazh). It is shown that the program «Statistica 12» can be used to assess the quality of potatoes on indicators of their suitability for processing into potato products. It was determined that the mass fraction of glycoalkaloids in the potato tuber is an important characteristic of the variety for its using in the production of potato products and as a table potato. Correlations between the mass fraction of potato dry matter and the mass fraction of glycoalkaloids (r = 0.47) and between the mass fraction of reducing sugars and the mass fraction of glycoalkaloids (r = 0.37) were established. The increasing in the mass fraction of these compounds is unwanted, and therefore, it is necessary to control their concentrations for choosing varieties for processing and as a starting material for the selection. Based on the analysis of the results of the evaluation of 8 experimental samples of potatoes with pigmented pulp, one sample was selected to be recommended for processing into potato products (VNIIKX-1), and two samples can be recommended as a starting material for the selection of table varieties with a high anthocyanin mass fraction (VNIIKX-4 and Indigo).

Ratio of starch, protein, and glycoalkaloids in potato tubers during the growing season

Ratio of starch, protein, and glycoalkaloids in potato tubers during the growing season

Indices for the Assessment of Glycoalkaloids in Potato Tubers Based on Surface Color and Chlorophyll Content

Glycoalkaloids (GAs) are toxic to humans at higher concentrations. However, studies also suggest the health benefits of GAs depending on the dose and conditions of use. Methods that have been used to determine GA content in potato tubers are destructive and time-consuming and require skilled personnel and high-performance laboratory equipment. We conducted this study to develop indices for the prediction of the level of total GAs in potato tubers at different greening stages based on surface color readings and chlorophyll (Chl) development. Color values (Hunter L*, a*, b*, a*/b*), Chls (Chl a, Chl b, and total Chls) and GA (α-solanine, α-chaconine, and total GAs) content were measured from tubers of ‘Atlantic’ and ‘Trent’ potato cultivars at three-week intervals in up to six greening stages during the storage at room conditions (22 °C, 12-h shift of light-dark cycles). The results have revealed that greening, Chls, and GA content significantly increased for the two cultivars as the stage proceeded. The toxic level of GAs (>200 mg kg−1 FW) was accumulated at the late greening stages, accompanied by the highest Chl content. Finally, indices were developed based on surface color and Chl content for estimation of the safe GA levels for the consumption of the two commercially and commonly used potato cultivars. Moreover, the developed indices could be used as basic information to adapt to other potato cultivars.

The distribution and changes of glycoalkaloids in potato tubers under different storage time based on MALDI-TOF mass spectrometry imaging

Glycoalkaloids (GAs) are toxic secondary metabolites in potatoes, which are harmful to human body. The storage time has a great influence on the biosynthesis and distribution of GAs. In present study, an imaging mass microscope (iMScope) was used to investigate the distribution and changes of GAs in potato tubers under different storage time (0, 10, 15, 20, 30, 40 and 60 days). We established a growth model with logistic equation to evaluate the growth trends of four major GAs in sprout, periderm and medulla. The results showed that the growth rate and relative contents of four GAs in sprout and periderm were significantly higher than that in medulla. In addition, four GAs also presented different change trends. For dehydrosolanine and α-solanine, rapid growth period of these two GAs in sprout (about at the day 23, similar to these in medulla) was later than which period in periderm (about at the day 17), while rapid growth of dehydrochaconine and α-chaconine appeared at almost the same time (about at the day 20). Based on the biosynthesis and metabolism of GAs, we have made possible explanations for these results. This study is useful for comprehending the metabolism of GAs in different parts and monitoring food safety in potatoes.

Effect of soil conditioner (UG<sub>max</sub>) application on the content of phenols and glycoalkaloids in potato tubers

The objective of the study was to determine the effect of the soil conditioner UG<sub>max</sub> application on phenol and glycoalkaloid content in the tubers of two table potato cultivars. The following factors were examined: factor I − cultivars: Satina and Tajfun; factor II − five application methods of the soil conditioner UG<sub>max</sub>: (1) control − no UG<sub>max</sub> application; (2) 1.0 L/ha UG<sub>max</sub> before planting; (3) 0.5 L/ha UG<sub>max</sub> before planting + 0.25 L/ha at potato height of 10–15 cm + 0.25 L/ha in flower bud phase; (4) 1.0 L/ha UG<sub>max</sub> before planting + 0.50 L/ha at potato height of 10–15 cm + in 0.50 L/ha in flower bud phase; (5) UG<sub>max</sub> applied after emergence when plants were 10–15 cm high at the rate of 0.5 L/ha, and at the stage of flower buds at the rate of 0.5 L/ha. The highest concentration of phenols and glycoalkaloids was recorded in plots where UG<sub>max</sub> was applied prior to potato planting at the rate of 1.0 L/ha, when plants were 10–15 cm high at the rate of 0.5 L/ha and at the stage of flower buds at the rate of 0.5 L/ha.

Distribution of Glycoalkaloids in Potato Tubers of 24 Korean Cultivars

Distribution of Glycoalkaloids in Potato Tubers of 24 Korean Cultivars

Direct analysis for the distribution of toxic glycoalkaloids in potato tuber tissue using matrix-assisted laser desorption/ionization mass spectrometric imaging

► For the first time, MALDI-MSI method was developed for detection and spatial distribution of glycoalkaloids. ► The uniform matrix coating method was effective for MALDI-MSI analysis. ► Matrix 2,5-DHB was more suitable than 2,4,6-THAP for analysis of glycoalkaloids. ► Relative amounts of glycoalkaloids were directly compared in various parts of potato tuber using MALDI-MSI. A simple and rapid analytical method for detection and spatial distribution of glycoalkaloids in potato tubers has been developed for the first time using matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI). For effective MALDI-MSI analysis, we have developed a uniform matrix coating method using 2,5-dihydroxybenzoic acid (2,5-DHB) as the preferred matrix which results in better sensitivity than 2,4,6-trihydroxyacetophenone (2,4,6-THAP) using MALDI-TOF. The relative concentrations of two major and two minor glycoalkaloids, α-chaconine and α-solanine, dehydrochaconine and dehydrosolanine, were clearly detected and distinguished in various parts of potato tuber and their relative amounts were directly compared. We also successfully showed the relative concentrations of glycoalkaloids that were accumulated by light exposure during storage using MALDI-MSI. Therefore, MALDI-MSI has been shown to be a useful technique for screening toxic and bioactive metabolites in foods and medicinal plants.

Glycoalkaloids in potato tubers: The effect of peeling and cooking in salted water

The important glycoalkaloids in potatoes are α-solanine and α-chaconine. Their natural function is probably to serve as stress metabolites or phytoalexins for the protection of the potato when attacked by insects, fungi, etc. They contribute flavour to potatoes but at higher concentrations cause bitterness and are toxic to humans. α-Solanine and α-chaconine appear to have two main toxic actions, one on cell membranes and another one on acetylcholinesterase. Symptoms of α-solanine/α-chaconine poisoning involve an acute gastrointestinal upset with diarrhea, vomiting and severe abdominal pain. An instrumental high-performance thin-layer chromatography (HPTLC) method was applied for the quantification of α-solanine and α-chaconine in peeled potato skin, raw potato pulp and cooked peeled potato tubers. The limit of quantification (LOQ) for α-solanine and α-chaconine was found to be 5.0 mg kg −1 for each glycoalkaloid. In this study the factors of potential loss of α-solanine and α-chaconine in potato tubers during peeling (factor=0.8) and cooking into edible stage in salted water (factor=0.8) were examined. The combined loss factor of peeling and cooking for sum of both glycoalkaloids in potato tubers was 0.64. These factors were practically used for the probabilistic exposure assessment of the intake of potato glycoalkaloids in the Czech Republic.

Abstract: P351 ASSOCIATIONS OF CHRONIC INTAKE OF POTATO CHIPS AND CORONARY ARTERY DISEASE RISK FACTORS. A POSSIBLE ROLE OF ACRYLAMIDE

Despite its status as a food of global importance, the potato tuber contains toxic glycoalkaloids (GA) that cause sporadic outbreaks of poisoning in humans. Probably because GA are natural compounds present in a staple food that has been used for millenia, their effects on humans have not been investigated as thoroughly as they would have been had they been synthetic additives-the use of which is stringently regulated. As a result, a number of lingering uncertainties remain concerning both the presence of GA in potato tubers and potato products and their effects on humans.

Distribution of Glycoalkaloids in Potato Tubers of 59 Accessions of Two Wild and Five Cultivated Solanum Species

Steroidal glycoalkaloids are naturally occurring, secondary plant metabolites that are found in foods, including potatoes and tomatoes. Their content in plants is controlled by both genetic and environmental factors. Glycoalkaloid profiles can be passed to progenies during breeding and hybridization of wild and cultivated potatoes designed to develop improved potatoes. The most common potato, Solanum tuberosum, contains primarily the glycoalkaloids, alpha-solanine and alpha-chaconine. However, wild-type potatoes being used for breeding new varieties contain other, less common glycoalkaloids. Because glycoalkaloid composition is a major criterion for the release of new potato cultivars, we used HPLC, TLC, GC, and GC/MS to determine their nature and content in several Solanum species widely used in potato breeding and hybridization programs. Solanum tuberosum, as well as S. andigena and S. stenotomum, contained alpha-solanine and alpha-chaconine. S. canasense was found to contain only dehydrocommersonine. S. acaule contained alpha-tomatine and demissine. S. juzepczukii and S. curtilobum contained demissine and two previously unidentified glycoalkaloids. We characterized them as demissidine-glucose/rhamnose (1/1 ratio) and demissidine-galactose/glucose/rhamnose (1/1/1 ratio), tentatively named dihydro-beta(1)-chaconine and dihydrosolanine, respectively. We found extensive variability in the glycoalkaloid profiles in the tested potato varieties. The possible significance of these findings for plant breeding and food safety is discussed.

Acute Toxicity of High Doses of the Glycoalkaloids, α-Solanine and α-Chaconine, in the Syrian Golden Hamster

Sprouted, stressed, or spoiled potato tubers have reportedly led to human acute intoxication, coma, and death when consumed in high amounts. These effects have been attributed to glycoalkaloids (GAs), primarily alpha-solanine and alpha-chaconine, naturally present in all potatoes. The level of GAs in potato tubers has previously been shown to increase substantially as a result of improper handling and postharvest storage. A short-term study was performed to investigate the dose-response profile of alpha-solanine and alpha-chaconine alone or in combination, administered daily by oral gavage to Syrian Golden hamsters. Daily doses of 100 mg of alpha-solanine [kg body weight (BW)] (-1) induced death in two of four hamsters within 4 days, when administered by gavage to female Syrian hamsters. Doses of 100 mg of alpha-chaconine alone or alpha-solanine and alpha-chaconine combined in a ratio of 1:2.5, in doses of 75 or 100 mg (kg BW) (-1), induced death in one of four hamsters within the same period. Animals dosed with alpha-solanine alone or in combination with alpha-chaconine suffered from fluid-filled and dilated small intestines. The GA administration had no effect on acetyl cholinesterase (AChE) or butyryl cholinesterase (BuChE) activity in plasma or brain. Liquid chromatography-mass spectrometry-based metabolomics showed that there was a specific accumulation of alpha-chaconine in the liver tissues. In addition, metabolomics gave direct evidence of glycolytic metabolism of the GA with the beta 1, beta 2, and gamma-GAs detected in the urine and, to a lesser extent, the feces. Doses from 75 mg (kg BW) (-1) of alpha-chaconine, alpha-solanine, or the two compounds combined were potentially lethal within 4-5 days in the Syrian Golden hamster. However, the cause of death in these studies could not be established. No synergistic effects of alpha-solanine combined with alpha-chaconine were evident.

Biosensors for assay of glycoalkaloids in potato tubers

The possibility of commercial application of biosensors based on pH-sensitive field-effect transistors and butyrylcholinesterase to glycoalkaloid analysis in potato tubers was studied. The main analytical features of the designed biosensors and measurement conditions were optimized. The biosensor was applied to quantitative analysis of glycoalkaloids in tubers of different potato varieties. The results proved to be in good agreement with those obtained by conventional protocols. Experiments on glucose assay were performed. An inverse correlation between the contents of glucose and glycoalkaloids in potato tubers was demonstrated.

Changes in the content of glycoalkaloids in potato tubers according to soil tillage and weed control methods

A field experiment was carried out in the fields of the Experimental Farm in Zawady owned by the University of Podlasie in Siedlce. An influence of soil tillage methods and herbicides application on the content of glycoalkaloids in edible potato tubers of the Viking cultivar was studied. The results obtained indicated that the content of glycoalkaloids in non-peeled tubers significantly depended on the method of soil tillage and weed control as well as on the research year, whereas in peeled tubers the content significantly depended only on the weather conditions in the growing season. The content of glycoalkaloids in the tubers subjected to the initial treatment (peeling) decreased to 46.81−55.3%, compared to the level of glycoalkaloids before peeling.

Effect of light and temperature on the formation of glycoalkaloids in potato tubers

This study was designed to determine the influence of two light sources and temperature on the total glycoalkaloid (TGA) content of potato tubers cultivated in Brazil. Tubers of cv Monaliza were exposed during 14 days to the following conditions: (1) indirect sunlight, (2) fluorescent light, (3) storage in darkness under refrigeration, and (4) storage in darkness under room temperature. The glycoalkaloids α-solanine and α-chaconine were determined using a reversed phase C18 HPLC column with a photodiode array detector. Exposure of potato tubers to fluorescent light resulted in the highest TGA levels. Smaller tubers presented the highest TGA concentrations, irrespective of the light source and temperature. Although the TGA levels at the end of the experiments were higher than the initial content, a steady increase of TGA concentration was observed only in tubers exposed to fluorescent light. The levels of TGA found in the analysed potato samples were below 200 mg kg −1, value that has been considered to be safe for human consumption.

Simple and sensitive method for determination of glycoalkaloids in potato tubers by high-performance liquid chromatography with chemiluminescence detection

A novel, simple and sensitive high-performance liquid chromatographic method for the determination of the potato glycoalkaloids, α-solanine and α-chaconine, based on the chemiluminescent reaction of tris(2,2′-bipyridine)ruthenium(III) has been developed. The calibration graph was linear in the range of 5 ng/ml–10 μg/ml for both α-solanine and α-chaconine. The detection limits of α-solanine and α-chaconine were 1.2 and 1.3 ng/ml, respectively. This method was successfully applied to a potato tuber sample without cleanup, pre-concentration, and derivatization steps. The recoveries (mean ± standard deviation, %) of α-solanine and α-chaconine spiked in tuber pith at 10 μg/g ( n = 6) were 101.0 ± 4.4% and 103.6 ± 7.1%, respectively.

Determination of potato glycoalkaloids using high-pressure liquid chromatography-electrospray ionisation/mass spectrometry.

A method for quantifying two toxic glycoalkaloids, alpha-solanine and alpha-chaconine, in potato (Solanum tuberosum) tuber tissue was developed using HPLC-electrospray ionisation (ESI)/MS. Potato samples were extracted with 5% aqueous acetic acid, and the extracts were subjected directly to HPLC-ESI/MS after filtration. By determining the intensities of the protonated molecules of alpha-solanine (m/z 868) and alpha-chaconine (m/z 852) using selected ion monitoring (positive ion mode), a sensitive assay was attained with detection limits of 38 and 14 ppb for the two glycoalkaloids, respectively. The high sensitivity and selectivity of MS detection effectively reduced the time of analysis thus enabling a high throughput assay of glycoalkaloids in potato tubers.

The effect of herbicide applications on the content of ascorbic acid and glycoalkaloids in potato tubers

Field experiments were conducted at Zawady Experimental Station (UniversityofPodlasie) in 1999–2001 to test the effect of herbicides (Sencor 70 WG, Basagran 600 SL) and their mixtures (Sencor 70 WG with Fusilade Super, Basagran 600 SL with Focus Ultra) on the content of ascorbic acid and glycoalkaloids in tubers of three potato cultivars. The application of herbicides to potato fields caused an increase in the content of ascorbic acid in comparison with the control. The statistical analysis showed a significant effect of potato cultivars on ascorbic acid and glycoalkaloid concentrations.