Synthesis of fructooligosaccharides in banana 'prata' and its relation to invertase activity and sucrose accumulation.
Levels of sucrose and total fructooligosaccharides (FOS) were quantified in different phases of banana 'Prata' ripening during storage at ambient (approximately 19 degrees C) and low (approximately 10 degrees C) temperature. Total FOS levels were detected in the first days after harvest, whereas 1-kestose remained undetectable until the sucrose levels reached approximately 200 mg/g (dry weight) in both groups. Sucrose levels increased slowly but constantly at low temperature, but they elevated rapidly when the temperature was raised to 19 degrees C. Total FOS and sucrose levels were higher in bananas stored at low temperature than in the control group. In both samples, total FOS levels were higher than those of 1-kestose. The carbohydrate profiles obtained by HPLC and TLC suggest the presence of neokestose, 6-kestose, and bifurcose. The enzymes putatively involved in banana fructosyltransferase activity were also evaluated. Results obtained indicate that the banana enzyme responsible for the synthesis of FOS by transfructosylation is an invertase rather than a sucrose-sucrosyl transferase-like enzyme.
Departamento de Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes 580, Butanta, São Paulo (SP), Brazil CEP 05508-000.
Roberta Ghedini
RG
Der Agopian
Eduardo
E
Purgatto
Beatriz Rosana
BR
Cordenunsi
Franco Maria
FM
Lajolo
D002851:Chromatography, High Pressure Liquid; D005519:Food Preservation / Q000379:methods; D005638:Fruit / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D028521:Musa / Q000378:metabolism*; D009844:Oligosaccharides / Q000032:analysis / Q000096:biosynthesis*; D013395:Sucrose / Q000032:analysis / Q000378:metabolism*; D013696:Temperature; D043324:beta-Fructofuranosidase / Q000378:metabolism*
D009844:Oligosaccharides; C116580:fructooligosaccharide; D013395:Sucrose; D043324:beta-Fructofuranosidase