Total Glycoalkaloid Content Research Articles

Effect of method of irrigation on the total glycoalkaloid and nitrate-nitrogen content of Rosa potatoes

The effect of two irrigation methods, microjet mist and impact sprinkler, on the total glycoalkaloid (TGA) and nitrate-nitrogen (NO3−N) content ofSolanum tuberosum L. cv. Rosa was investigated. Potatoes irrigated by microjet mist were significantly higher in TGA and lower in NO3−N content than control potatoes receiving no irrigation. The impact sprinkler method produced potatoes significantly higher in NO3−N than controls. The TGA content of potatoes irrigated by the sprinkler method was not significantly different from controls. Mist-irrigated potatoes were higher in TGA and lower in NO3−N content than sprinkler-irrigated potatoes.

Antitumour effects of glycoalkaloids isolated from Solanum sodomaeum.

Glycoalkaloids extracted from SOLANUM SODOMAEUM L. show antineoplastic activity against Sarcoma 180 in mice. Approximately 33% of the total glycoalkaloid content consisted of the triglycoside solasonine and 33% of the triglycoside solamargine. The remainder was a mixture of mono- and diglycosides in which the aglycone was solasodine. Single dose studies of these glycoalkaloids with mice containing Sarcoma 180 indicated that the ED 50 was 9 mg/kg, whereas the LD 50 was 30 mg/kg resulting in a therapeutic index of 3.3. Single dosages of 8 mg/kg given on two consecutive days resulted in inhibition of tumour progression with greater than 40% survival. In contrast, the use of the same dosages given on three or four consecutive days resulted in greater than 90% survival.

Glycoalkaloids of Solanum Series Megistacrolobum and related potato cultigens

Glycoalkaloids were used as evidence of the affinities of nine taxa of Solanum Series Megistacrolobum and related potato cultigens from western Bolivia. S. boliviense, S. sanctae-rosae and S. toralapanum contain the commertetraose sugar moiety and appear to represent a relatively wild group within the Series. S. megistacrolobum, S. sogarandinum and S. raphanifolium show anomolous glycoalkaloid profiles that probably reflect hybridization associated with human disturbance. Primitive forms of the S. χ ajanhuiri cultigen are indistinguishable chemicaliy from conspecific weeds that were previously classified as S. megistacrolobum. Variation in total glycoalkaloid content within Series Megistacrolobum likely reflects direct selection by humans for reduced glycoalkaloid levels during the domestication process.

Total glycoalkaloid content of new potato cultivars

Abstract Three recent cultivars of potato (Solarium tuberosum L.), released by Crop Research Division (viz., ‘Iwa’, ‘Tekau’, and ‘Kaituna’), together with ‘Ilam Hardy’, were assayed for total glycoalkaloid content soon after harvest and after storage for 2, 4, and 6 months at 10°C. Total glycoalkaloid contents were generally low but were doubled by exposure to light. Iwa had the highest level of glycoalkaloid but, even when green, its glycoalkaloid content was still well below the 20 mg/100 g whole tuber level considered unsuitable for human consumption. Glycoalkaloid levels increased very slightly during storage.

Changes in the content of L-ascorbic acid, glucose, fructose, sucrose and total glycoalkaloids in potatoes (cv. Bintje) stored at 7, 16 and 28°C

We investigated the changes in the content of L-ascorbic acid (L-AA), glucose, fructose, surose and total glycoalkaloids (TGA) during storage of potatoes, cv. Bintje, for 12 weeks at 7,16 and 28°C. The initial amount of L-AA was 8.2 mg/100g fresh weight; after 12 weeks' storage at 7°C it had decreased, while at 16 and 28°C it had increased. The sugar content went up most in potatoes stored at 28°C, but remained below the level at which potatoes taste sweet. The sugar content rose slightly at 16°C, while it decreased in tubers stored at 7°C. The initial TGA content, in equivalent amounts of α-solanine, was 3.6 mg/100 g fresh weight; after 12 weeks' storage it had decreased slightly at all three storage temperatures.

Determination of the glycoalkaloid content of potato tubers by three methods including enzyme‐linked immunosorbent assay

AbstractPotato tuber samples of diverse genetic backgrounds were analysed independently for total glycoalkaloid content by three different procedures. Two of the methods used were conventional chemical assays, the third an enzyme‐linked immunosorbent assay (ELISA). Agreement between all three was extremely good, though the ELISA employed much simpler sample preparation, was technically easier to carry out, and could assay more rapidly large numbers of samples. For these and other reasons, the ELISA will find wider application in future.

Effect of Sprout Inhibitor Isopropyl‐N(3=Chlorophenyl)‐Carbamate on Total Glycoalkaloid Content of Potatoes

ABSTRACTThe effect of the sprout inhibitor, isopropyl‐N‐(3‐chlorophenyl)‐carbamate (CIPC) on total glycoalkaloid (TGA) content of potatoes was investigated. Katahdin and Chipbelle potatoes grown at Cornell Research Farms, Freeville, NY and Riverhead, NY, were used. Potatoes treated with CIPC were significantly (p < 0.05) lower in TGA content than the controls. Potatoes stored at 25°C were significantly (p < 0.05) higher in TGA content than those stored at 5°C and TGA content increased significantly (p < 0.05) with increasing storage time.

Genetic and environmental effects on levels of glycoalkaloids in cultivars of potato ( Solanum tuberosum L.)

Glycoalkaloids were assayed in fifty-five potato cultivars, fifty-four breeding lines and one other species ( S. stolonifer). The total glycoalkaloid content ranged from 16·3 μg/g FW for Alpha to 317·0 μg/g FW for Berita, with most values lying between 35 and 65 μg/g. The α-solanine content, as a percentage of total glycoalkaloids, ranged from 28·3% for Avenir to 57·0% for H42, with the majority of values lying between 38% and 46% α-solanine. There was a highly significant correlation between high total glycoalkaloid content and per cent α-solanine ( P < 1%). The presence of β 2-chaconine was also related in a highly significant way to high total glycoalkaloid content. Potatoes grown at Yanco (hot, dry, inland climate) contained more glycoalkaloids (∼60%) than when grown at Glen Innes (cooler, high altitude climate). However, there was no significant difference between total and relative glycoalkaloid levels of cultivars grown at Glen Innes and Healesville (coastal, temperate climate). A significantly higher per cent α-solanine content, but not total glycoalkaloid content, was observed for potatoes grown in the second year at Glen Innes.

Ozone-induced reduction in quantity and quality of two potato cultivars

Cherokee and Norchip cultivars of potato, which exhibit differential foliar sensitivity to ozone, were grown in the glasshouse and exposed to acute doses of the air pollutant once every 14 days throughout the growing season. Weight and number of tubers of both cultivars decreased, percent dry matter decreased and total reducing sugars increased in response to ozone in one or more of three experiments. Total glycoalkaloid content decreased in tubers of Norchip and increased in those of Cherokee.

Effect of cooking on the total glycoalkaloid content of potatoes.

Effect of cooking on the total glycoalkaloid content of potatoes.

Determination of Total Glycoalkaloids (TGA) in Dehydrated Potatoes

ABSTRACTA method was developed to optimize TGA extraction for dehydrated potato products. Maximum TGA content was obtained from uncooked dehydrated powder with hydration ratio (powder:water) of 1:4 (by weight) for the freshly prepared powder. Powders prepared from precooked potatoes required a hydration ratio (1:5) for optimum TGA extraction. For powders that were stored for 4 months, 1 hr of hydration was necessary for maximum TGA extraction. In all varieties tested the TGA content of powders was slightly less than the fresh tissue but these differences were not statistically significant. However, significant varietal differences were observed. The Chipbelle and Katahdin varieties were significantly higher in TGA content than Rosa and Pontiac varieties.

Acidity induced changes in growth and chemical constituents of potato

Foliage and tuber fresh matter and chlorophyll content in cvs. Atom alue, Multa, Kufri, Desiree and Patrones were decreased with the increase in soil acidity. However, tuberization was enhanced at pH 5.5 and decreased significantly at pH 4.5 in all cultivars tested. At pH 4.5 the specific mass of all the cultivars was slightly increased. The highest content of reducing sugars and proteins was found at pH 5.5. No definite pattern was observed in total glycoalkaloids content under different acidic range.

Effect of Growth-Location and Length of Storage on Glycoalkaloid Content of Roadside-Stand Potatoes as Stored by Consumers

Potato tubers were purchased from roadside stands at 25 locations in the State of Maine and were stored from 1 to 3 months under home storage conditions at 12.2°C. Initially and after 1 and 3 months of storage, tubers were analyzed for their α-chaconine, α-solanine and total glycoalkaloid (TGA) contents. Mean α-chaconine, α-solanine and total glycoalkaloid contents of the tubers ranged from 0.41 to 3.45, 0.35 to 1.51 and 0.75 to 6.16 mg/100 g of tuber (wet weight), respectively. Statistical analysis of the results indicated that the interaction of location and storage time had a significant (P<0.05) effect on concentration of the individual and total glycoalkaloids in the tubers. The results also demonstrated that storage under these suboptimum conditions did not cause an increase of glycoalkaloids to a toxic level.

Ocorrência de glicoalcalóides e esverdeamento em tubérculos de batata recém-colhidos e armazenados

Foram analisados 36 dos cultivares de batata (Solanum tuberosum L.) existentes no Instituto Agronômico, quanto ao teor de glicoalcalóides totais (TGA) na porção superficial dos tubérculos, e quanto à sua capacidade de esverdeamento, duas características importantes na comercialização do produto. As determinações foram feitas para tubérculos recém-colhidos, armazenados na ausência e na presença de luz, ambos por 25 dias. Os teores de TGA situaram-se na faixa de 3-24mg/100g de peso fresco. Tanto as condições de armazenamento quanto os cultivares influenciaram o teor de TGA e a capacidade de esverdeamento. Encontrou-se uma correlação linear significativa entre o teor de TGA e a capacidade de esverdeamento, independentemente de tratamentos e cultivares, negativa, porém, para tubérculos recém-colhidos. Os dados obtidos sugerem que ambos os fatores são influenciados por características genéticas peculiares a cada cultivar.

Glandular pubescence, glycoalkaloid composition, and resistance to the green peach aphid, potato leafhopper, and potato fleabeetle inSolanum berthaultii

Fifteen accessions ofSolarium berthaultii Hawkes andS. berthaultii xS. tarijense Hawkes were assessed for resistance to field infestations of the green peach aphid,Myzus persicae (Sulzer), potato leafhopper,Empoasca fabae (Harris), and potato fleabeetle,Epitrix cucumeris (Harris). Accessions bearing both Type A and Type B glandular trichomes were much more resistant to the green peach aphid and potato leafhopper than accessions bearing Type A hairs alone. All accessions had significantly smaller populations of these 3 pests than S.tuberosum cultivars. Total glycoalkaloid (TGA) content of foliage and tubers was not correlated with insect populations. Foliar TGA levels of field-grown plants varied among accessions, ranging from < 2–240 mg/100 g fresh wt. Solasonine and solamargine were the major foliar glycoalkaloids while solamarines predominated in tubers.

A rapid screening method for the estimation of total glycoalkaloids in potato tubers

AbstractA rapid method for estimating the total glycoalkaloid (TGA) content of potato tubers is described which allows TGA content to be classified into three groups: (i) low TGA containing (&lt; 15 mg TGA 100 g−1 fresh weight); (ii) high TGA containing (&lt; 15‐35 mg TGA 100 g−1 fresh weight); and (iii) very high TGA (&gt; 35 mg TGA 100 g−1 fresh weight). The method is intended for use by plant breeders, particularly when high TGA content might be expected in hybrid clones where one or both parents is derived from a wild species. The TGA concentration in juice expressed from potato periderm and cortex tissue was assayed by thin layer chromatography. The method utilises a direct relationship which was established between the glycoalkaloid concentration in expressed juice and the TGA content of the whole tuber and enables up to 50 analyses to be completed in 1 day by one operator without the need for expensive equipment.

TOTAL AND INDIVIDUAL GLYCOALKALOID COMPOSITION OF STORED POTATO SLICES

The quantitation of α-chaconine and α-solanine by thin-layer chromatography agreed with the total glycoalkaloid (TGA) content as determined by titration. The TGA level of potato slices approximately doubled to 26–30 mg/100g fresh weight during the 7-h incubation period. Soaking of potato slices resulted in lower increases. Incubation at 25°C resulted in higher TGA levels than at 5°. The initial α-chaconine/α-solanine ratio was 1.42 but with time and temperature changed to 2.4–2.8 in unsoaked slices and 1.5–1.6 in soaked slices.

Determination of total glycoalkaloids in potato tubers using a modified titration method

A new method for determining total glycoalkaloid content of potatoes (TGA) was developed by extensively modifying the comprehensive titration procedure of Fitzpatrick and Osman (1). This modified titration method eliminates the need to hydrolyze the glycoalkaloids and to purify the resulting aglycones by partitioning them into an organic solvent such as benzene or methylene chloride. Instead the glycoalkaloids are precipitated using ammonium hydroxide with the precipitate being dissolved in a tetrahydrofuran-water-acetonitrile (50:30:20) mixture. An aliquot is evaporated and quantitated using the nonaqueous titration procedure developed by Fitzpatrick and Osman (1). A comparison between this modified method and a high-performance liquid Chromatographic (HPLC) procedure was made using three commercial potato varieties and five experimental selections. Results from the two methods compared favorably.

The relationship between glycoalkaloids and resistance to the white potato cyst nematode, Globodera pallida in potato clones derived from Solanum vernei

SUMMARYNo relationship was found between the degree of resistance to Globodera pallida and total glycoalkaloid content of the roots or tubers of a number of potato clones derived from Solanum vernei × S. tuberosum. Nematode infestation of the roots did not lead to increases in the glycoalkaloid content of susceptible or resistant potatoes.

A simplified method for the determination of total glycoalkaloids in potato tubers

AbstractA simplified method for the determination of total glycoalkaloids (TGA) in potato tubers has been developed in which potato tissue is extracted with dilute sulphuric acid and the extract is hydrolysed directly. Analysis is completed in less than 4 h using very simple apparatus and reagents. A colorimetric procedure employing bromothymol blue is used for quantitation. A study of the hydrolysis of α‐solanine and α‐chaconine and the stability of solanidine and solanthrene under hydrolysis conditions, which was made in order to define optimum conditions for the method, showed that hydrolysis time and temperature are quite critical if reproducible aglycone recovery is to be obtained. The results obtained using the method for tubers of fourteen experimental samples with a wide range of TGA contents compare well with corresponding results obtained using a lengthier and more tedious literature method. Its simplicity makes it a suitable method for plant breeders to use to measure the TGA content of new cultivars of potatoes.