MSc

Bitter gourd occupies a prominent position among the vegetables grown in
India. The importance of bitter gourd has long been recognized due to its nutritive
value and medicinal properties. It contains a unique phytoconstituent namely
charantin that has been confirmed to have hypoglycemic effect. There is also an
insulin like compound known as polypeptide P which has been recommended as an
insulin replacer in diabetic patients. The present study entitled “Development and
quality evaluation of bitter gourd (Momordica charantia L.) based low calorie dietetic
beverages” was aimed to standardise low calorie bitter gourd based dietetic beverages
and to evaluate the chemical, nutritional, organoleptic and shelf life qualities of the
products.
Standardisation of RTS beverages from bitter gourd and its blend with ash
gourd was carried out in 18 treatments. Sugar, low calorie sweetener and salt based
beverages were tried. For flavouring, cardamom and ginger drops were used. Based
on organoleptic evaluation, the most acceptable beverages ie., two each from sugar
based, low calorie sweetener based and salt based were selected for storage study.
Thus, twelve beverages were selected.
The selected beverages were prepared and stored for three months at ambient
and refrigerated conditions. Organoleptic qualities, chemical constituents and shelf
life qualities were evaluated initially and monthly intervals for a period of three
months.
The β carotene and total phenol content in RTS beverages showed a
significant difference during ambient and refrigerated storage whereas the variation
observed in total soluble solids (TSS), total sugar, reducing sugar and vitamin C
content was statistically insignificant. The acidity of RTS beverages increased during
storage at ambient condition, but a decreasing trend was noticed under refrigerated
condition. The loss of ascorbic acid was more in beverages stored under ambient
condition, compared to RTS beverages stored in refrigerated condition. The phenol
content was found to be low in RTS beverages prepared by blending bitter gourd and
ash gourd juice. The duration and conditions of storage had no influence on the
mineral constituents of the beverages.
The beverage prepared with equal quantity of bitter gourd and ash gourd juice
with salt and one drop of cardamom was found to be nutritionally superior when
stored under refrigerated condition. A gradual decrease in organoleptic qualities of
the beverages like appearance, colour, flavour, taste and overall acceptability was
noticed during storage. The RTS beverage prepared using bitter gourd and sugar
attained maximum mean scores followed by beverages prepared with bitter gourd
juice + low calorie sweetener and bitter gourd juice + sugar and flavoured with
cardamom drops. The same trend was observed under both storage conditions.
The bitter gourd based dietetic RTS beverages were evaluated initially and at
monthly intervals for bacteria, yeast and fungi for a period of three months. Yeast and
fungi were not detected in any of the beverages throughout the storage period. At the
end of third month of storage the presence of bacteria was observed in all the
treatments stored under ambient and refrigerated conditions, but they have not
exceeded the permissible threshold levels of microbial population.
The RTS prepared with bitter gourd and sugar was found to be the best in
organoleptic evaluation and consumer acceptance studies. Blending of bitter gourd
juice with ash gourd juice and flavouring with spice drops improved the nutritional as
well as organoleptic qualities of RTS beverages. To increase the consumption of
bitter gourd as an anti diabetic vegetable, production of RTS beverage is a viable
technology and it has ample scope for commercial exploitation.