چكيده لاتين :
PHYSICO-CHEMICAL ASSESSMENT OF NATURAL SWEETENERS STEVIOSIDES PRODUCED FROM STEVIA Rebudiana bertoni PLANTABSTRACT
Stevia plants are a good source of carbohydrates (61.93 % d.w.), protein
(11.41 % d.w.), crude fiber (15.52 % d.w.), minerals (K, 21.15; Ca, 17.7; Na, 14.93 &
Mg, 3.26 mg/100g d.w. and Cu, 0.73; Mn, 2.89; Fe, 5.89 & Zn, 1.26 mg/100g d.w.)
also essential amino acids were found in amounts higher than those recommended by
FAO and WHO for adults as well as non- essential amino acids. Stevioside was
extracted and purified from the dried Stevia leaves by three methods. The first one,
extraction by hot water (65 °C) at different ratios of leaves to water (1:15 to 1:75). The
optimum ratio was 1:35 in which the maximum stevioside content was obtained (7.53
%), recovery of stevioside was 80.21 % and purity related to depigmentation was
97.56 %. The second method, extraction by methanol at ratio 4:1 methanol/leaves
and purification, recovery of stevioside was 94.90 % and purity was 81.53 %. The
third method, extraction by mixture of methanol/water (4:1) and purification, recovery
of stevioside and purity were 92.34 and 79.81 %, respectively. Physical and chemical
characteristics of the extracted stevioside were studied. Stevioside extractions were
analyzed by HPLC in which the highest amount of stevioside (23.20 %) was obtained
in methanol extract. Physical, chemical and organolyptic characteristics of extractions
indicate that this sweetener has been applied as substitutes for sucrose in different
drinks and baking products.
Keywords: , , , , natural
sweeteners.
