A selection of commercially available mushrooms was obtained from Taiwan and screened for phenolic contents and antioxidant activity in aqueous extracts using various chemical measurements, namely scavenging of 2,2´-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical cation (TEAC), Ferric reducing antioxidant power (FRAP), scavenging of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and Folin-Ciocalteu reaction. According to the antioxidant activity perceived, Cordyceps militaris, Pleurotus citrinopileatus, Trametes versicolor, Hericium erinaceus, Ganoderma lucidum and Auricularia auricula-judae were selected for in vitro digestion and cellular antioxidant assay. After the in vitro digestion steps, the antioxidant activity in the extracts of C. militaris had significantly decreased, (in TEAC 22% and 27 % decrease, in hot- and cold-water extracts, respectively, in FRAP 42% and 21% decrease, in hot- and cold-water extracts, respectively and in DPPH 78% and 21% decrease in hot- and cold-water extracts, respectively). The hot-water extract of A. auricula-judae and cold-water extracts of H. erinaceus showed no significant increase in TEAC assay after enzymatic digestion. There was a significant increase in antioxidant activity in the other mushroom extracts after in vitro enzymatic digestion. P. citrinopileatus exhibited the most potent antioxidant activity in the TEAC (from 24 to 2 times higher and 10 to 1.5 times higher than other mushrooms in hot- and cold-water extracts, respectively) and DPPH assays (from 6.4 to 1.2 times higher and from 27 to 1.6 times higher than the other five mushrooms in hot- and cold-water extracts, respectively) after digestion steps. T. versicolor showed the most potent ferric reducing power after digestion steps (from 29 to 5 times higher and 14 to 1.1 times higher than the other five mushrooms in hot- and cold-water extracts, respectively). These results indicate that most of the potential antioxidant compounds within the mushroom extracts could be released after digestion steps, whereas the potential antioxidant compounds of C. militaris might be degraded after digestion steps. The results suggest that determination of antioxidant activity in selected mushroom extracts may underestimate the real antioxidant activity that may be in close contact with the intestinal lumen. Chemical estimates of potential antioxidant compounds within the mushroom extracts may not accurately indicate the complex nature of the antioxidant activity of mushroom extracts within cells. In this study, human hepatoma cell lines (Huh 7) were used to measure cellular antioxidant activity using 2´, 7´- dichlorodihydrofluorescein diacetate as a fluorescent probe. In artificially induced peroxyl radicals, among the selected mushroom extracts tested, C. militaris and T. versicolor had the highest cellular antioxidant activity, whereas H. erinaceus had the lowest. In addition, in chemical assays (TEAC and DPPH), the antioxidant activity of T. versicolor was less than that of P. citrinopileatus (64% and 67 % less in TEAC in hot-and cold- water extracts, respectively and 70% and 82% less in DPPH in hot- and cold-water extracts respectively). Even though the antioxidant activity of C. militaris was decreased after digestion steps, C. militaris exhibited far stronger cellular antioxidant activity than the other five mushrooms (p < 0.001). Based on the different antioxidant assay methods, the antioxidant activity of each antioxidant assay gave different antioxidant trends and antioxidant activity value depending on the type of extract method (hot- and cold-water extracts). Using cellular antioxidant assays may produce bioactivity results of the antioxidant activity of mushroom extracts within cells. These findings could suggest that the aqueous extracts from C. militaris and T. versicolor associated with health benefits and other traditional remedies, at least in part, might be their potent antioxidant activity.

Sweetpotato (Ipomoea batatas (L.) Lam.) is an important food security crop in many parts of the developing world. Despite its economic value and growing contribution to nutrition and health in tropical and sub-tropical countries, sweetpotato has a short postharvest life. Inhibition of sprout growth to permit long-term storage and marketing of the roots is a major challenge in the sweetpotato industry. To date, no technically and economically satisfactory method is available to extend the tropical storage of sweetpotato. Previous studies have demonstrated the efficacy of both exogenous ethylene and the ethylene perception inhibitor 1-methylcyclopropene (1-MCP) in suppressing sprout growth in other root crops such as potato and onion, which display differential endodormancy. It has been proposed, through studies by others, that ethylene and 1-MCP may also enhance sweetpotato storage. In the present study, the physiological and biochemical effects of exogenously applied ethylene and 1-MCP were further investigated. Cont/d.

Potatoes are widely consumed in UK and many other countries. There is a continuous demand for potatoes all year around both from consumers and retailers such that several postharvest technologies are being used to meet this demand. Sprouting is the main phenomenon affecting both the quality and marketability of potatoes during long term storage. Several sprout suppressants are widely used (e.g. maleic hydrazide and chloropropham), but there are concerns over their toxicity such that alternatives have been sought. Continuous exposure of potato tubers to ethylene (usually 10 µL L- 1 ) during storage was approved by the Chemicals Regulation Directorate since 2003. Even though potatoes have been regarded as non climacteric, this study aimed to examine the effect of different ethylene regimes in combination with or without 1-methylcyclopropene on physiological, biochemical and mechanical characteristics of a selection of important UK cultivars. In 2008-2009, ten potato cultivars were examined for their response to four different ethylene regimes during storage. Storage time and ethylene treatments had a cultivar specific effect on all the measured parameters (sprouting, sugars, texture). Ethylene applied after first indication of sprouting was as effective at sprout inhibition as when applied continuously for certain potato cultivars; therefore this could be considered as a more environmentally and economical alternative for sprouting inhibition. In addition, sugar accumulation was retarded when tubers were subjected to ethylene at the first indication of sprouting compared to those treated with continuous ethylene. In 2009-2010, four potato cultivars were studied and the effect of 1-MCP either before or after ethylene treatment on sprouting, respiration rate, endogenous ethylene production and texture was investigated. 1-MCP is believed to interact with ethylene receptors and therefore prevent or retard ethylene dependent responses. 1-MCP seemed to effectively block ethylene binding sites when applied before storage of tubers in ethylene resulting in less tuber sugar accumulation. In 2010- 2011, the effect and timings of 1-MCP and ethylene treatments on sprouting, tuber respiration, endogenous ethylene production and sugars on two potato cultivars was studied. 1-MCP effectively suppressed the action of ethylene in terms of the increase in the respiration rate or ethylene production and sugar accumulation. Selected potato samples were also analysed quantitavely for an array of phytohormone using a newly developed UPLC QToF MS method. This method had the advantage of quantifying simultaneously a significant number of plant growth regulators that are present in potato (ABA and its metabolites, cytokinins and gibberellins).

Potatoes (Solanum tuberosum L.) are the most important food crop in the world after rice and wheat. Potato tubers contain many types of essential nutrients. They contain high concentrations of carbohydrates and also vitamins, minerals and protein. They also contain toxic compounds called glycoalkaloids. Potato is classed as a protective vegetable because of its high vitamin C content. The objectives of this study were to determine the effects of different fertiliser types (composted cattle manure, mineral NPK fertiliser), pre-crop (beans, barley) crop protection protocols (organic, conventional) and growing season on the nutritional quality of vitamin C, glycoalkaloids and minerals and yield of different varieties of potato (Sante, Sarpo Mira, Nicola, Fontane, Agria and Cara). Field experiments were carried out during the 2010 and 2011 growing seasons at Nafferton Farm (Newcastle University). The experiment was a split split split plot-design. The main plot was crop rotation, the sub-plot was crop protection, the sub-sub plot was fertility management and sub-sub-sub plot was variety. The vitamin C content was determined by two different methods of analyses; colorimetric titration and high- performance liquid chromatography (HPLC). Mineral content was assessed by the Dumas combustion method at Sabanci University, Turkey. Total glycoalkaloids were determined according to the AOAC method 997. 13. A significant effect of fertilisation was detected for potato yield for both of years. In plots treated with NPK fertilisers, higher yield, compared to compost was obtained for both seasons. In addition conventional crop protection increased yield in both years. Pre-crop significantly affected yield in both years, with higher yields being recorded after beans than barley in 2010 while, a pre-crop of barley resulted in the significantly higher yield than beans in 2011. However, no significant difference between varieties was detected. Also, no significant interactions were detected for tuber yield in 2010. However a significant 2-way interaction between crop protection and pre-crop was observed in 2011, with a pre-crop of beans resulting in the highest yields under conventional crop protection, while a pre-crop of barley resulted in the significantly higher yield under organic crop protection systems. Results of the second growing season (2011) were based on the NUE potato experiment and showed that there was significant difference (P < 0.05) in yield between varieties, fertilisation iii and crop protection. A significant interaction between fertilisation and variety was detected for the yield. There was a significant effect of variety on tuber vitamin C content (P < 0.001), in 2010 and 2011. The concentrations were higher in Sante than Sarpo Mira. There were no significant influences of other treatments (fertility, rotation, crop protection). However, a 2-way interaction between fertilisation and variety was detected in 2011. In 2011 there was a significant effect of varieties on vitamin C content, but no significant effect of fertility and crop protection treatments. However, a significant interactions between fertility, variety and crop protection treatments was detected but only for the titration analysis for vitamin C content. There were no significant effects (P > 0.05) of fertilisation, pre-crop and crop protection on glycoalkaloid concentrations. However, a significant 3-way interaction between fertilisation, variety and rotation was detected for alpha solanine in 2011. A significant 3-way interaction between crop protection, fertilisation and variety was detected for alpha chaconine in 2010. In 2010 the mineral content (N, P, K, Na and Ca) of potatoes was significantly affected by fertilisation treatments. N, P and Ca contents were significantly increased by NPK application while the K and Na contents were significantly increased by compost application. In 2011 Ca contents were affected by fertilisation treatments only. Effects of variety, rotation and crop protection and interactions between factors were also detected for macro mineral contents. However, in 2011 no effect of pre-crop on tuber macronutrient concentration was detected. There was a significant difference in micronutrient concentration between variety, fertilisation and crop protection. No significant effect of rotations was detected for micronutrient concentrations in both of seasons. In conclusion, in both years, 2010 and 2011, variety significantly affected vitamin C content of potato tubers, but there were no significant effects of fertility, pre-crop and crop protection treatments irrespective of the analytical method (titration and HPLC) analysis. Sante tubers contained about 20% more vitamin C than Sarpo Mira. Therefore, it appears that variety choice is a reliable means of manipulating vitamin C as a component of tuber quality compared with other agronomic treatments. In addition, mineral content was also affected by treatments (fertility, variety, rotation and crop protection) and was highly variable. iv For the two years, similar results were obtained in alpha solanine and alpha chaconine content. Significant interactions between rotation, fertilisation and variety were only detected on alpha solanine content during 2011. Also, significant interactions between variety, fertility and crop protection were observed on alpha chaconine content during 2010. The 2010 and 2011 growing seasons appeared to have a significant effect on alpha solanine, macro minerals and micro minerals but did not appear to affect yield, vitamin C and alpha chaconine contents.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.