rapid-high-throughput-amylose-determination-freeze-dried-potato-tuber

Rapid High Throughput Amylose Determination in Freeze Dried Potato Tuber Samples

This protocol describes a high through put colorimetric method that relies on the formation of a complex between iodine and chains of glucose molecules in ...

Colorado State University 

An Arabidopsis T-DNA insertion mutant that results in complete loss-of-function of the COBRA gene has been identified. The COBRA gene encodes a putative glycosylphosphatidylinositol (GPI)-anchored protein that modulates cellulose deposition and oriented cell expansion in roots. The loss-of-function mutant allele (named "cob-5") exhibits abnormal cell growth throughout the entire plant body and accumulates massive amounts of stress response chemicals such as anthocyanins and callose. To gain further insight into the mechanism by which COBRA affects cell growth and physiology, the whole-genome gene expression profile of cob-5 plants was compared with that of wild-type plants. Consistent with the mutant phenotype, many genes involved in anthocyanin biosynthesis were up-regulated in the cob-5 plants, whereas genes involved in cell elongation were down-regulated. The most striking feature of the gene expression profile of cob-5 was the massive and co-ordinate induction of defence- and stress-related genes, many of which are regulated by the plant stress signal jasmonic acid (JA). Indeed, the cob-5 plants over-accumulated JA by nearly 8-fold compared with wild-type plants. Furthermore, induction of cell elongation defects in conditional allele cob-3 plants triggers the expression of a defence-responsive gene. These results provide potential clues to the mechanisms by which plant cells initially perceive biotic stress at the cell surface.

Loss of function of COBRA, a determinant of oriented cell expansion, invokes cellular defence responses in Arabidopsis thaliana.

The effects of vanadyl sulphate on the formation of acrylamide have been studied in fried potato products, such as French fries and chips. Acrylamide formation was inhibited by 30.3%, 53.3% and 89.3% when the sliced potato strips were soaked in 0.001, 0.01 and 0.1 M vanadyl sulphate (VOSO(4)) solutions, respectively, for 60 min before frying. Moreover, 57.7%, 71.4% and 92.5% inhibition of acrylamide formation was observed when chips were soaked in the respective vanadyl sulphate solution before frying. In a separate model reaction, a solution containing an equimolar concentration of L-asparagine and D-glucose showed a significant inhibition of acrylamide formation when heated at 150 Â°C for 30 min in the presence of vanadyl sulphate (VOSO(4)). The results indicate that the binding of VO(2+) to asparagine and the decrease in the pH of the potato samples resulted in a significant reduction of acrylamide formation in fried potato products.

Reduction of acrylamide formation by vanadium salt in potato French fries and chips.

Biguanides such as metformin are widely used worldwide for the treatment of type-2 diabetes. The identification of guanidine and related compounds in French lilac plant (Galega officinalis L.) led to the development of biguanides. Despite of their plant origin, biguanides have not been reported in plants. The objective of this study was to quantify biguanide related compounds (BRCs) in experimentally or clinically substantiated antidiabetic functional plant foods and potatoes. The corrected results of the Voges-Proskauer (V-P) assay suggest that the highest amounts of BRCs are present in green curry leaves (Murraya koenigii (L.) Sprengel) followed by fenugreek seeds (Trigonella foenum-graecum L.), green bitter gourd (Momordica charantia Descourt.), and potato (Solanum tuberosum L.). Whereas, garlic (Allium sativum L.), and sweet potato (Ipomea batatas (L.) Lam.) contain negligible amounts of BRCs. In addition, the possible biosynthetic routes of biguanide in these plant foods are discussed.

Sastry S. Jayanty

Department of Horticulture and Landscape Architecture

Colorado State University

Rapid High Throughput Amylose Determination in Freeze Dried Potato Tuber Samples

Sastry S. Jayanty

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Horticulture and Landscape Architecture

Colorado State University

Rapid High Throughput Amylose Determination in Freeze Dried Potato Tuber Samples

Department of Horticulture and Landscape Architecture