高植化素綠豆(Vigna radiata (L.) Wilczek)芽菜 栽培之研究

Abstract

本試驗以綠豆抗豆象品系VC6089A、其近同源但不抗豆象品系VC1973A及日正綠豆 (日正食品工業股份有限公司，南北坊綠豆) 為材料，探討於黑暗中栽培高植化素含量綠豆芽之最適環境條件。綠豆種子於20˚C、26˚C與32˚C浸水0、4、8及12小時，其乾重隨浸種時間延長而降低。以四種密度栽培綠豆芽，收穫指數 (harvest index) 以7 g·cm-2種子最佳，其下胚軸較長、總類黃酮 (total flavonoids) 含量較高；密度試驗中，綠豆芽總酚類含量與收穫指數之間 (r=0.74***) 、總酚類 (total phenolics) 含量及總類黃酮含量之間 (r=0.77***) 皆呈正相關。以壓重0、100、200、300、400 g·51.84 cm-2栽培綠豆芽，VC1973A及日正綠豆於400 g·51.84 cm-2處理下，其豆芽下胚軸較粗短，根長亦較短；壓重試驗中，綠豆芽總類黃酮含量與DPPH自由基清除能力[α,α-diphenyl-β-picrylhydrazyl radical scavenging activity]間，以及總類黃酮含量與FRAP鐵離子氧化還原能力 (ferric reducing antioxidant power, FRAP ) 間之相關係數r分別為0.82***與0.64***。繼以16 h/8 h為一週期，於26˚C/20˚C、26˚C/23˚C、26˚C/26˚C、29˚C/20˚C、29˚C/23˚C及29˚C/26˚C栽培綠豆芽，VC6089A在29˚C/23˚C 及26˚C/26˚C栽培之鮮重較佳，VC1973A與日正綠豆則分別於29˚C/23˚C與26˚C/26˚C之鮮重較佳；綠豆芽之可溶性固形物及可溶性蛋白質含量顯著受栽培溫度組合之影響；而VC1973A綠豆芽之總類黃酮及總酚類含量皆較其他兩綠豆芽高。相較於0、10、20與50 mM氯化鈉溶液，以15 mM氯化鈉溶液栽培綠豆芽時，其產量較高、總類黃酮及總酚類含量最高，且VC1973A綠豆芽之亞鐵離子螯合能力(Fe2+ chelating ability)較高；氯化鈉試驗中，綠豆芽鮮重分別與可溶性糖含量 (r=0.83***) 、總類黃酮含量 (r=0.84***) 、總酚類含量 (r=0.85***) 及DPPH自由基清除能力 (r=0.85***) 皆呈高度正相關，而總酚類與總類黃酮含量或可作為DPPH自由基清除能力及FRAP鐵離子氧化還原能力之參考指標。以0、10、25、50、75及100 mM葡萄糖溶液栽培綠豆芽，50 mM組之抗壞血酸及總類黃酮含量較高，100 mM組含有較多的可溶性固形物及可溶性蛋白質。綜之，VC1973A綠豆芽之鮮重、外觀及植化素含量皆優於以VC6089A及日正綠豆栽培之綠豆芽。故建議於全黑暗環境下，以種子密度7 g·cm-2、壓重400 g·51.84 cm-2、15 mM氯化鈉溶液及29˚C 16 h /23˚C 8 h，栽培VC1973A綠豆芽3天，可獲得總類黃酮 (0.38 mg·g-1DW) 及總酚類含量 (11.1 mg·g-1DW) 、亞鐵離子螯合能力 (84.8 % of 50 mg DW·mL-1) 、DPPH自由基清除能力 (54.1 % of 50 mg DW·mL-1)與FRAP鐵離子氧化還原能力 (150.9 µmol FeSO4·g-1DW) 最高、且產量 (54.5 g FW·51.84 cm-2) 亦佳之綠豆芽。

Two isogenic lines of mungbean, bruchid-resistant VC6089A and bruchid-susceptible VC1973A, and Sunright mungbean (Sunright Foods Co.) were used as experimental material to study the optimal environmental condition of cultivating mungbean sprout with high phytochemicals contents in the dark. Mungbean seeds were soaked at 20˚C, 26˚C and 32˚C for 0、4、8 and 12 h. Seed dry weight decreased as the soaking time extending to 12 h. Among 4 planting densities, 7 g·cm-2 treatment showed the highest harvest index, longer hypocotyl length and higher total flavonoids content in VC6089A and VC1973A sprouts. Total phenolics content in mungbean sprouts was highly positively related to harvest index (r=0.74***), so did the total phenolics content to total flavonoids content (r=0.77***). Among forcing pressures of 0, 100, 200, 300 and 400 g·51.84 cm-2, VC1973A mungbean sprout cultivated under 400 g·51.84 cm-2 showed shorter and thicker hypocotyl also shorter root. In forcing pressure experiment, correlation coefficient (r) of total flavonoids content to α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) were 0.82*** and 0.64***, respectively. Among 6 combinations of temperatures based on 16 h/8 h cycle, fresh weights of VC6089A sprouts were the highest at 29˚C/23˚C and 26˚C/26˚C, while Sunright and VC1973A sprouts at 26˚C/26˚C and 29˚C/23˚C, respectively. Soluble solids and soluble protein contents of mungbean sprouts were both affected by the cultivating temperature combinations. VC1973A sprouts has the highest content of total flavonoids and total phenolics than other 2 entries. Comparing to 0, 10 and 25 mM NaCl solution, sprouts cultivated in 15 mM NaCl solution exhibited higher fresh weight and total flavonoids and total phenolics contents than under 0, 10, 20 and 50 mM NaCl treatments. VC1973A sprouts also showed higher Fe2+ chelating ability in 15 mM NaCl treatment. In NaCl experiment, sprout fresh weight was positively related to soluble sugar content (r=0.83***), total flavonoids content (r=0.84***), total phenolics content (r=0.85***) and DPPH scavenging ability (r=0.85***) in NaCl experiment. Contents of total phenolics and flavonoids contents could be reference values of DPPH radical scavenging activity and FRAP. Cultivation sprouts with 0, 10, 25, 50, 75 and 100mM 5 glucose solution, 50 mM treatment could increase ascorbic acid and total flavonoids in mungbean sprouts. Sprouts grown in 100 mM glucose solution had more soluble solid and protein. In conclusion, VC1973A sprouts had higher fresh weight and phytochemicals contents than VC6089A and Sunright sprouts. The mungbean sprout would have higher total flavonoids (0.38 mg·g-1DW) and total phenolics (11.1 mg·g-1DW) contents and better Fe2+ chelating ability (84.8 % of 50 mg DW·mL-1), DPPH scavenging ability (54.1 % of 50 mg DW·mL-1), and FRAP (150.9 µmol FeSO4·g-1DW), and higher fresh weight (54.5 g FW·51.84 cm-2). VC1973A seeds are suggested to be cultivated with 7 g·cm-2 sowing density, 400 g·51.84 cm-2 forcing pressure, 15 mM NaCl solution at 29˚C 16 h/23˚C 8 h in the dark.