Functional Elements From Asparagus for Human Health

Jishi

Komura

et al. 2012

The objective of this study was to clarify the factors that influence saponin biosynthesis, with an emphasis on protodioscin, a major saponin compound in white asparagus spears. We investigated the effects of methyl jasmonate (MeJM) treatment on protodioscin content in white spears harvested by spring semi-forced and winterforced cultivation. Protodioscin content was determined using high performance liquid chromatography equipped with an evaporative light scattering detector. Protodioscin was mainly localized in the lower region of the spears. In the spring semi-forced cultivation system using the film-cover method, the protodioscin content in white spears harvested from the MeJM plot was significantly higher than in those harvested from the control plot throughout the sampling period. MeJM also significantly enhanced protodioscin biosynthesis in a dose-dependent manner in the experiment conducted under winter-forced cultivation. These results suggest that saponin biosynthesis in white spears is associated with plant defensive reactions triggered by jasmonate. In addition, bitterness in filmcovered white spears could be artificially controlled in commercial fields by MeJM treatment.

Section: Introductionmentioning

confidence: 73%

Methyl Jasmonate Treatment Enhanced Protodioscin Biosynthesis in White Asparagus (Asparagus officinalis L.) Spears

Jishi

Komura

et al. 2012

“…Some compounds from asparagus such as flavonoids, phenolic acids, and saponins have been reported to show biological and pharmacological activities (Deschner et al, 1991;Hartung et al, 1990;Wang et al, 2003). Rutin is one of the major flavonoids present in asparagus (Chin et al, 2002;Deeds and Couch, 1948;Maeda et al, 2005) and has been reported to exert biological effects such as suppressing the weakening of capillaries associated with hemorrhagic disease (Griffith et al, 1944) and reducing hypertension in humans (Hellerstein et al, 1951). The anthocyanins, caffeic acid, and other phenolic compounds from asparagus were also reported to show biological and/or pharmacological activities (Vinson et al, 1995;Yamanaka et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Light Condition Influences Rutin and Polyphenol Contents in Asparagus Spears in the Mother-fern Culture System during the Summer–Autumn Harvest

Honda

Sonoda

et al. 2010

We investigated the variation in rutin and total polyphenol contents in asparagus spears under different conditions of mother-fern culture. Rutin and polyphenol contents were highest at early spring harvest at all test sites. The contents gradually decreased during the harvest season. In particular, a considerable decrease was observed after the growth of mother ferns. The absorption of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was weaker in summer. Rutin content in the spears of plants grown outdoors was generally higher than in these grown in a greenhouse, except at early spring harvest. Rutin contents decreased in the spears of plants grown under a shading net or an ultraviolet (UV) radiation-filtering film. These results suggest that cultivation conditions, especially light conditions, have a great influence on rutin and polyphenol contents. We evaluated two new methods to increase rutin content by improving light conditions. Light conditions in asparagus rows were improved by using light-reflecting sheets and net screens; however, a significant increase in rutin content was observed only when net screening was used, implying that this method is better than light reflecting sheets to increase the rutin content.

“…Asparagus (Asparagus officinalis L.) is becoming increasingly popular as a health-promoting vegetable (Chin et al, 2002;Kitazawa et al, 2011;Maeda et al, 2005Maeda et al, , 2010Shao et al, 1996;Tsushida et al, 1994), and is available in most supermarkets throughout the year. Although green asparagus is the most commonly cultivated form, the consumption of fresh white asparagus has increased in Japan because of its pleasing taste, and some growers now cultivate white spears for the fresh market.…”

Section: Introductionmentioning

confidence: 99%

Effects of Blanching Method on Sugar and Protodioscin Contents of White Asparagus Spears

Jishi

Honda

et al. 2012

In Japan, white asparagus spears are grown using two blanching methods to block sunlight: the traditional soilmound and the film-cover methods. The objective of this study was to investigate the influence of the film-cover and soil-mound methods on components of white asparagus spears related to flavor, especially sweetness and bitterness. We investigated the effects of the two blanching methods on sugar (fructose, glucose, and sucrose) and protodioscin (a major furostanol saponin in white spears) contents in white spears by conducting a spring field survey and an experiment using winter-forcing cultures. No significant differences were observed in sugar content or composition in spears cultivated by the two methods in either the field survey or the experiment. Protodioscin content tended to be higher in spears blanched by the soil-mound method than in spears blanched by the filmcover method in both the field survey and the experiment. These results suggest that differences in the flavor of white spears grown using the two blanching methods are caused mainly by bitterness associated with saponin content, and saponin content may be influenced by soil-borne stresses.