1. Stevia: A Natural Non-nutritive Sweetener and its Potential
Application in Food Products
Som Nath Khanal1 and Yakindra Prasad Timilsena2*
1SouthDakota State University, Brookings, SD, 57007, USA.
2Department of Food Technology and Quality Control, Babarmahal, Kathmandu, Nepal
Email: yakendra.timilsena@gmail.com
Abstract Composition and Processing Aspects
Stevia rebaudiana is a small, perennial, semi-humid, and
subtropical plant containing several sweetening compounds.
Originated from Paraguay, Stevia has been used since ancient
times for various purposes including as a sweetener. As the
leaves of Stevia plants contain Stevioside, the sweet
component 150 to 300 times sweeter than sucrose, but with
no calorific value, they have functional and sensory properties
superior to those of many other high-potency sweeteners. Fatty acid composition
This is the reason, Stevia has been considered as a major
source of high-potency sweetener for the growing natural Fatty acids contents
(g/100g)
food market. In this presentation, different scientific and Palmitic acid (C16) 27.51
technological aspects of Stevia plant and Stevia derived Palmitoleic acid (C16-1) 1.27
sweeteners are described. This presentation tends to touch Stearic acid (C18) 1.18
Stevia agriculture; Oleic acid (C18-1) 4.36
however, extraction, purification, processing, and application Linoleic acid (C18-2) 12.40
of the stevia derived sweeteners are given major focus. Linolenic acid (C18-3) 21.59
(Savita et al., 2004)
(Tadhani and Subhash, 2006)
Objective
Sweet components
• Explore the agricultural and processing technologies
• Describe the chemical and biological properties of • Two main glycosides, Stevioside (St) and Rebaudioside A (R-A)
stevia components and their food safety concerns are sweet
• Stevioside makes up the majority of the sweetener (60 – 70% of
• Highlight its potential application as non-nutritive
the total), 110 – 270 times sweeter than sugar, licorice like slight
natural sweetener after taste.
• Rebaudioside A is usually present as 30 – 40% of total
Introduction sweetener,;180 – 400 times sweeter than sugar with no after-
taste.
Origin • The ratio R-A/St is the measure of sweetness quality – the more
R-A the better.
• Dr M.S. Bertoni discovered • The minor glycosides are considered to be less sweet, 30 – 80
Stevia rebaudiana in Paraguay in 1888. times sweeter than sugar
• The plant was named in 1905 in honour
of Paraguayan chemist Dr. Rebaudi.
• 150 Stevia species have been identified but Stevia rebaudiana
is the sweetest of all. Processing
The Stevia Farming
The native habitat-
• latitude of 25° S in a subtropical
region of northeastern Paraguay Two sweet products of stevia exist
• between 500–1,500 m above sea level, • dried stevia leaf or powder
• soil having a low phosphate content • Purified stevia glycoside powder (commercialized)
• annual average temperature of 75°F,
• average rainfall of about 55 in. per year Processing involves four basic steps:
• Seedlings are transplanted in April or May (on the basis of • Dissolving the sweetener in boiling water or other solvent
study in Japan) (Methanol)
• Requires frequent irrigation • Ion-exchange, membrane technology for purification and
• is a poor competitor with weeds, concentration
• warm temperatures with minimal frost, and high light • Filtration with precipitation/coagulation
intensities are required. • Crystallisation and drying.
• Acidic soil pH (pH 4–5) favors rapid growth (80 cm).
• Can be harvested in Summer and Autumn. Conclusion
• Non-nutritive natural sweetener with high sweetness
Use of Stevia products and medicinal value
• Japan is the biggest user. • No food safety concern, appropriate for diabetes
• Approved by USFDA as a food additive • Developed processing techniques
• Can be used in most of the foods.
• Preferably used in drinks
• Potential high value cash crop for Nepalese agri-sector.