Cytological and compositional evaluation of white asparagus spears as a function of variety, thickness, portion and storage conditions

An evaluation was made of the degree of toughening of asparagus during its storage through a study of the morphological and cellular differences of th e xylem vascular bundles as a function of the variety, thickness and portio n of the asparagus spear. Light microscopic examinations were carried out t o determine the thickness of the cell wall to quantify the extent of the to ughening. At the same time a study was made of the fractions of dietary fib re of the asparagus spear by means of chemical extraction techniques. Stati stically significant differences were observed in both methods between vari eties, thicknesses and portions of the asparagus spear. Different factors s uch as variety, degree of maturing, portion of spear, moment of harvesting, and type and time of storage have an influence on the toughening of white asparagus that should be taken into account in order to standardise its qua lity. (C) 2000 Society of Chemical Industry.