Abstract:
Value addition of inedible parts of Jackfruit such as rind and core using
efficient and environment friendly methods would reduce wastage, and its disposal
problem and also fetch additional profit to farmers. Pectin, a secondary food
ingredient used as gelling, stabilizing and emulsifying agent in food products is
such a valuable by-product having nutritional as well as health benefits.
Conventional extraction method includes direct boiling using acidified water,
which is time consuming and degrades quality pectin. Application of combined
novel technologies might help in conquering the inadequacies of conventional
methods.
In this study, a pulsed electric field and microwave assisted extraction system
for extracting pectin from Jackfruit rind and core was developed. To evaluate the
developed system towards pectin extraction, the effect of process parameters
influencing pectin yield and energy consumption such as PEF strength (5, 10 and
15 kV/cm); PEF treatment time (2, 4 and 6 min); microwave power density (450,
550 and 650 W/g) and time of exposure (5, 10 and 15 min) were studied. The
physicochemical and quality parameters of extracted pectin such as moisture
content, ash content, protein content, viscosity, solubility, colour, equivalent
weight, methoxyl percentage, galacturonic acid and degree of esterification of the
pectin were analyzed and compared with that obtained through conventional
extraction.
A PEF strength of 11.98 kV/cm, PEF treatment time of 5.46 min, microwave
power density of 647.55 W/g and time of exposure of 5 min were found to be the
optimized process variables of the combined treatment. High methoxyl pectin of
good quality was obtained through the combined process. The moisture content,
viscosity, ash content, protein content, equivalent weight, methoxyl percentage,
galacturonic acid and degree of esterification of the combined PEF and microwave
treated samples were 8.95 %, 39.78 cP, 6.78 %, 3.283 %, 557.473 g/mol, 8.37 %,
69.44 % and 68.43 % respectively with light brown colour whereas that of
conventional extracted pectin were respectively 10.04 %, 38.14 cP, 7.27 %, 9.98 %466.905 g/mol, 9.376 %, 67.85 % and 78.45 % with dark drown colour pectin.
Scanning Electron Micrographs of jackfruit rind and core powder samples before
and after combined treatment and conventional extraction revealed an increase in
rupture and severing of parenchymal cells of the combined treated samples
indicating better extraction efficiency. It was concluded that combined pulsed
electric field and microwave treatment resulted in increased extraction of high
quality pectin from Jackfruit rind and core.
