Rebaudioside-A — Reb-A (Stevia Diterpene Glycoside · Premium Sweetener · GRAS E960)

Compound	Rebaudioside-A (Reb-A; Rebiana)
Chemical class	Terpenoid — Diterpene Glycoside (Ent-kaurane steviol glycoside; sophoroside)
CAS	58543-16-1
Primary source	Stevia rebaudiana (stevia leaves, 2–4% of dry weight)
Key applications	Premium non-caloric sweetener (200–400× sweeter than sucrose); cleaner taste than stevioside; GRAS/E960; antidiabetic
Claim strength	High (sweetener); Moderate (antidiabetic)
Typical form	Stevia extract standardised to ≥97% rebaudioside-A; branded “Reb-A” ingredients
Buy from Herbuno	Stevia Extract Powder (95%) → Organic Stevia Leaf (Stevia rebaudiana) Powder →

Name origin: From Stevia rebaudiana — the species name honours Bertoni’s description, combined with “reba-” from the genus, and “-oside” for glycoside. Rebaudioside-A (Reb-A) is the second most abundant steviol glycoside in stevia leaves after stevioside, and shares the same ent-kaurane steviol aglycone. The structural difference: Reb-A has three glucose units on the steviol 13-position (a sophorose + glucose chain) versus stevioside’s two glucose units — this additional glucose unit significantly alters the organoleptic profile. Commercial significance: Reb-A is the preferred commercial form for most food and beverage applications due to its superior taste compared to stevioside. The first FDA GRAS notification for steviol glycosides (2008, Cargill/Truvia® and PureCircle) specifically covered high-purity rebaudioside-A (≥97%), establishing it as the regulatory anchor for the commercial stevia sweetener market. Major stevia brands (Truvia®, PureVia®, Enliten®) are primarily Reb-A based. Pharmacology: Shares stevioside’s antidiabetic mechanisms (KATP channel closure in β-cells, insulin sensitisation) with comparable potency. Metabolised by gut bacteria to steviol (the aglycone), which is then absorbed and excreted — the systemic exposure is the same metabolic pathway as stevioside. Commercial source: Stevia Extract Powder (95%) and organic stevia leaf powder, both delivering Reb-A as the primary sweetener is available from Herbuno.

---

Evidence for Rebaudioside-A Applications

Non-caloric sweetener — glycaemic neutrality: Multiple RCTs confirm Reb-A produces no blood glucose or insulin response in healthy subjects or T2DM patients. Direct comparison studies (Anton et al., 2010, Appetite) show Reb-A-sweetened meals result in lower postprandial glucose and insulin than sucrose-sweetened meals AND lower energy intake at subsequent meals (suggesting appetite regulation, not just caloric replacement). Claim strength: High.

Antidiabetic pharmacology: Reb-A at pharmacological doses (in addition to sweetener use) stimulates insulin secretion via pancreatic β-cell KATP channel closure and improves glucose tolerance in animal models. This mirrors stevioside’s direct antidiabetic pharmacology — both yield the same metabolite (steviol) in vivo, making their pharmacological profiles essentially identical. Claim strength: Moderate (human data primarily via stevioside RCTs; shared metabolite pharmacology).

Taste advantage over stevioside: Reb-A has approximately 300–400× the sweetness of sucrose (versus stevioside’s 200–300×) and a significantly lower bitter/liquorice aftertaste threshold. In sensory panel studies, Reb-A at ≥97% purity closely resembles sucrose in taste profile at low concentrations, with detectable aftertaste only above ~0.05% w/v. This is why Reb-A (≥97% purity) is the dominant commercial stevia sweetener form in most developed markets. Claim strength: High (established sensory science).

---

Frequently Asked Questions — Rebaudioside-A

Is Reb-A different from stevia in pharmacological terms?
Reb-A and stevioside are closely related steviol glycosides that differ only in the number of glucose units attached to the steviol aglycone. In the gut, both are deglycosylated by bacteria to yield steviol, which is then absorbed and excreted. The systemic pharmacological effects (antidiabetic, antihypertensive) are therefore attributable to steviol equivalents derived from both glycosides. Most clinical pharmacology data use stevioside — but since Reb-A is metabolised to the same aglycone at equivalent doses, its pharmacological effects should be comparable.

Why does Reb-A taste cleaner than stevioside?
The additional glucose unit in Reb-A’s sophorose moiety sterically shields the steviol aglycone more effectively than stevioside’s smaller glycoside chain. Steviol itself has bitter properties — the more complete glycosylation in Reb-A reduces the exposure of the bitter steviol scaffold to taste receptors, producing a cleaner sweetness profile. Higher-purity Reb-A (≥97%) with less stevioside contamination has a notably superior taste compared to lower-purity stevia extracts containing significant stevioside fractions.

What are rebaudiosides D and M and how do they compare to Reb-A?
Rebaudiosides D and M are minor steviol glycosides with 4–5 glucose units on the C-13 and C-19 positions, providing even greater steric shielding of the steviol aglycone. Sensory panels consistently rate Reb-D and Reb-M as having the most sucrose-like taste profile with minimal aftertaste — essentially the “ideal” steviol glycosides. However, they occur at only 0.01–0.05% of dry leaf weight (versus Reb-A at 2–4%), making extraction-based supply extremely expensive. Fermentative biotechnology (engineering yeast to produce Reb-D/M from sucrose — as done by Evolva) is being developed to enable commercial-scale production.

Is Reb-A safe during pregnancy?
JECFA’s ADI of 4 mg steviol equivalents/kg/day applies to all steviol glycosides including Reb-A. Multigenerational reproductive studies have not identified adverse effects on fertility, foetal development, or offspring health at the ADI. EFSA, FDA, and JECFA have concluded Reb-A is safe for all population groups including pregnant women at normal consumption levels. There is no specific clinical trial data on Reb-A in pregnancy (an ethical constraint on trial design), but the available toxicological and epidemiological evidence supports safety at normal sweetener use levels.

Related compounds: Stevioside, Glycyrrhizin, Mogrosides, Aspartame

---

Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.

← HerbIQ Compound Index · HerbIQ P02: Extraction · HerbIQ P03: Delivery