The Cultivation of Stevia, "Nature's Sweetener"

The Cultivation of Stevia, "Nature's Sweetener"

Introduction

The stevia plant (Stevia rebaudiana Bertoni), belongs to the Compositae (sunflower family of plants). Centuries ago, Natives of Paraguay used the leaves of this small, herbaceous, semi-bushy, perennial shrub to sweeten their bitter drinks. Originating in the South American wild, it could be found growing in semi-arid habitat ranging from grassland to scrub forest to mountain terrain. The plant made its way to Pacific Rim countries where in recent decades it became cultivated domestically, used in its raw leaf form and now is commercially processed into sweetener.

Similar soil and climatic conditions exist in Southern Ontario as that found where stevia originated. As a transplanted annual plant, stevia tends to grow well on a variety of soil types ranging from course textured sands to well drained loams but not clay or poorly drained sites. During the growing season, it seems to thrive in a temperature range of 15°C to 30°C provided all input resources and good management practices are incorporated. Stevia requires cultivation practices similar to those of other transplanted horticultural crops.

Stevia leaves have a long history of use as sweeteners, due to the presence of sweet crystalline glycosides called steviosides which are 200-300 times sweeter than sucrose. Stevioside is non-caloric, non-fermentable, non-discolouring, heat stable at 95°C and has a lengthy shelf life. The product can be added to cooked/baked goods or processed foods and beverages. In the Pacific Rim countries, China, Korea and Japan, stevia is regularly used in preparation of food and pharmaceutical products.