THE EFFECT OF DIFFERENT SUBSTRATES AND PROCESSING CONDITIONS ON THE TEXTURAL CHARACTERISTICS OF BACTERIAL CELLULOSE (NATA) PRODUCED BY ACETOBACTER XYLINUM

摘要

Bacterial cellulose (nata) produced by Acetobacter xylinum on differentnsubstrates like tomato juice, pineapple juice, pineapple wastes, tender coconutnwater and microbial undefined media was compared for textural properties.nDifferent processing conditions typical to the manufacture of nata were alsonstudied using three instrumental texture analyses, viz., puncture test, measurementnof shear and texture profile analysis (TPA). Different processing conditionsnsignificantly (P < 0.05) influenced the water holding capacity of nata,nwhile no effect of substrates was indicated. The moisture content was neithernaffected by processing conditions nor by various substrates. In the puncturentest, significant effect of both substrates and processing conditions on all thenpuncture test parameters was seen at 3 mm probe penetration depths, whilenprocessing conditions did not significantly influence any of the studied puncturenparameters at 1 and 2 mm penetration depths. Shearing stress and shearingnenergy (area under the curve) were affected only as a function of differentnsubstrates and not of processing conditions. TPA indicated significant effect ofnboth the substrates and the processing conditions on all the textural attributesnstudied.