The potato (Solanum tuberosum L.) tuber follows only rice and wheat in world importance as a food crop for human consumption. Cultivated potatoes have spread from the Andes of South America where they originated to 160 countries around the world. Consumption of fresh potatoes has declined while processed products have increased in popularity. As the potato becomes a staple in the diets of an increasing number of humans, small differences in potato nutritional composition will have major impacts on population health. The potato is a carbohydrate-rich, energy-providing food with little fat. Potato protein content is fairly low but has an excellent biological value of 90-100. Potatoes are particularly high in vitamin C and are a good source of several B vitamins and potassium. The skins provide substantial dietary fiber. Many compounds in potatoes contribute to antioxidant activity and interest in cultivars with pigmented flesh is growing. This review will examine the nutrient and bioactive compounds in potatoes and their impact on human health.

A response surface method was used to optimize the microwave-assisted extraction parameters such as extraction time (t) (min), solvent (methanol) concentration (S) (v/v) and microwave power level (MP) for extraction of antioxidants from potato peels. Max. total phenolics content of 3.94 mg g−1 dry weight (dw) was obtained at S of 67.33%, t of 15 min and a MP of 14.67%. For ascorbic acid (1.44 mg g−1 dw), caffeic acid (1.33 mg g−1 dw), ferulic acid (0.50 mg g−1 dw) max contents were obtained at S of 100%, t of 15 min, and MP of 10%, while the max chlorogenic acid content (1.35 mg g−1 dw) was obtained at S of 100%, t of 5 min, and MP of 10%. The radical scavenging activity of the extract was evaluated by using the DPPH assay and optimum antioxidant activity was obtained at S of 100%, t of 5 min, and MP of 10%.

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The leaf, petiole, stem and root anatomy of an aseptically cultured red raspberry clone (Rubus idaeus L.) was studied before and 5 weeks after transfer to soil under controlled environmental conditions. Tissues persistent from culture showed little or no change with time in soil; they grew minimally and slight secondary wall deposition occurred. New organs formed in successive weeks after transplantation showed a graded increase in potential size and development. Some features, such as collenchyma formation, rapidly returned to control levels; this was seen in new leaves expanding in the first week after transplantation. Other features, such as sclerenchyma formation, did not occur in leaves expanding during the first 2 weeks after transplantation, even when these were a month or more in age. Some sclerenchyma was seen in leaves expanding in the third week after transplantation, increasing in later-formed leaves. Increasing the light intensity of transplant accelerated the return to control-type organ size and appearance. During acclimatization transitional forms of leaves, petioles, stems and roots develop that ranged anatomically from culture-to control-type. This trend is analagous to the normal developmental sequence of organ formation as it affects the potential for development of successily formed organs.

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This study confirms that amaranth is a suitable forage for ruminant animals. Its chemical composition is comparable, for most variables, to that of other commonly used forage species.

SummaryThree in vitro bioassays (single-node cutting, root tip segment and microtuberization) gave similar results in ranking the salinity (NaCI) tolerance of several potato genotypes (Solanum spp.) and were verified by tuber yield criteria in a field lysimeter trial with salinized irrigation water. Salinity stress consistently depressed growth in the single-node cutting and root tip segment bioassays, reduced microtuber yield in the microtuberization bioassay and decreased tuber yield in field lysimeters. The single-node cutting bioassay was simpler to perform than the root tip segment and microtuberization bioassays and did not exclude certain genotypes as did the microtuberization bioassay. The single-node cutting bioassay can be recommended as a substitute for more labour-intensive and costly field assessments of salinity effects on yield.