title: Influence of cold stress on contents of soluble sugars, vitamin C and free amino acids including gamma-aminobutyric acid (GABA) in spinach (Spinacia oleracea).
abstract: The contents of soluble sugars (sucrose, fructose, glucose, maltose and raffinose), vitamin C and free amino acids (34 compounds, essential and non-essential) were quantified in open-field and greenhouse-grown spinaches in response to cold stress using liquid chromatography. In general, greenhouse cultivation produced nutritionally high value spinach in a shorter growing period, where the soluble sugars, vitamin C and total amino acids concentrations, including essential were in larger amounts compared to those grown in open-field scenarios. Further, low temperature exposure of spinach during a shorter growth period resulted in the production of spinach with high sucrose, ascorbate, proline, gamma-aminobutyric acid, valine and leucine content, and these constitute the most important energy/nutrient sources. In conclusion, cultivation of spinach in greenhouse at a low temperature (4-7°C) and exposure for a shorter period (7-21days) before harvest is recommended. This strategy will produce a high quality product that people can eat.
authors.affiliation: Division of Applied Life Science (BK21 Plus), Gyeongsang National University, Jinju 52828, Republic of Korea.
authors.forename: Young-Eun
authors.initials: YE
authors.lastname: Yoon
authors.affiliation: Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
authors.forename: Saranya
authors.initials: S
authors.lastname: Kuppusamy
authors.affiliation: Department of Food Science, Gyeongnam National University of Science and Technology, Jinju 52828, Republic of Korea.
authors.forename: Kye Man
authors.initials: KM
authors.lastname: Cho
authors.affiliation: Division of Applied Life Science (BK21 Plus), Gyeongsang National University, Jinju 52828, Republic of Korea; Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
authors.forename: Pil Joo
authors.initials: PJ
authors.lastname: Kim
authors.affiliation: Namhae Sub-Station, National Institute of Horticultural and Herbal Science, Rural Development Administration (RDA), Namhae 52430, Republic of Korea.
authors.forename: Yong-Bum
authors.initials: YB
authors.lastname: Kwack
authors.affiliation: Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea. Electronic address: yblee@gnu.ac.kr.
authors.forename: Yong Bok
authors.initials: YB
authors.lastname: Lee
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D001205:Ascorbic Acid / Q000032:analysis*; D003080:Cold Temperature; D009753:Nutritive Value; D018724:Spinacia oleracea / Q000737:chemistry* / Q000254:growth & development / Q000502:physiology*; D013312:Stress, Physiological; D014815:Vitamins / Q000032:analysis; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
chemical_list: D000596:Amino Acids; D014815:Vitamins; D005680:gamma-Aminobutyric Acid; D001205:Ascorbic Acid
keywords: Cold stress; GABA; Spinach; Sugars; Vitamins