Abstract
This research was concerned with the screening of fruit waste as a source of
pectin, isolation, physicochemical characterization, functional properties and
applicability of the extracted pectin. The process of pectin extraction from
jackfruit waste was standardized by evaluating three different techniques
(ammonium oxalate, acid, sodium hexametaphosphate), three different conditions
(pH, temperature and time) and four different drying techniques (freeze drying,
spray drying, vacuum drying and oven drying) to assess its potentiality as an
alternative source of commercial pectin. Among the extraction methods, the
highest yield of pectin (15.17%) was obtained by sodium
hexametaphosphate/HCI method containing higher amount of moisture and ash.
Ammonium oxalate and sulfuric acid extracted pectin showed similar rheological
and structural properties to commercial pectin though acid hydrolysis produces
significantly lower yield. Pectin recovery by acid hydrolysis was further
improved by optimization of extraction conditions by response surface
methodology. The optimum extraction conditions of pH, temperature and time
were found 1.5, 90 °C and 82 minutes respectively. At the optimum condition
yield, galacturonic acid (GalA) and degree of esterification (DE) of extracted
jackfruit waste pectin were 10.57, 67.0 and 66.17 respectively. Experimental data
of yield, GalA and DE agreed well with predicted value. Drying methods have
insignificant effect on the chemical composition but affected significantly the
functional properties of jackfruit waste pectin. The gelation of jackfruit waste
pectin was investigated and compared with analytical and commercial grade
pectins. Jackfruit waste pectin was found high in protein content (3.87-4.19%), ash
content (4.95-5.87%) and DE (63-78.33%) and low in molecular weight (38873-
39976 Da) than commercial and analytical grade pectin, respectively. Jackfruit
waste pectin (JWP) form weak gel at high temperature. Varying the different
parameters of gelation conditions such as sucrose concentration, pH and pectin
concentration have influenced the gelation properties of pectin. JWP was
investigated as an ingredient for preparing a drying aid for spray drying of
papaya juice. Pectin addition in liquid feed significantly (p<0.01) increased
powder particle size, moisture content, redness and lycopene but powder yield,
density and lightness were reduced significantly (p<0.01). Papaya powder was
compressed to check the compressible behavior. Maltodextrin added papaya (MP)
powder tablet was found more porous and less resistant to compress than pectin
added papaya (PP) powder tablet. The dissolution rate of MP was faster than PP
tablet which influenced by their compaction behavior, tensile strength and
powder solubility. Jackfruit waste could be potential source of pectin which could
fulfill the field of food and fermaceuticals.