A recent study by Spanish, English and Argentine researchers (Labrador et al., 2022) investigates the sweetening intensity and flavor of a new prebiotic sweetener based on galactooligosaccharides and mogrosides of natural origin, from monk fruit, modified with enzymes. (1)
The research - funded by Optibiotix Health Plc (York, UK) and the Spanish government (Ministry of Science, Innovation and Universities), with an indirect contribution from Horizon (EU) - offers interesting insights for the development of a replacement for 'microbiota-friendly', calorie-free sugar. (2)
1) Introduction. Galactooligosaccharides (GOS)
Galactooligosaccharides (GOS) - non-digestible carbohydrates obtained by enzymatic synthesis from lactose - are widely used as prebiotics. In fact, they promote the growth of beneficial microorganisms, such as lactobacilli and bifidobacteria. Which in turn can induce competition in the gut microbiota and outweigh the 'non-beneficial' microbial population.
The GOS they are low energy prebiotics and are reported for the ability to promote satiety and reduce food intake. In addition to having various clinical applications, including:
- the treatment of constipation and irritable bowel syndrome (irritable bowels syndrome, IBS),
- the prevention of atopic disease and gastrointestinal infections,
- modulation of mood and stress response. (1)
2) Target sweeteners of natural origin
The growing awareness of disease risks - type 2 diabetes (in primis) - related to obesity and overweight stimulates the demand for sweeteners of natural origin with low and / or no energy intake. Such as steviol glucosides and allulose, (3,4) both useful in reducing the intake of added sugars, in line with EFSA's recommendations. (5)
The sweetening capacity of GOS is however not sufficient to use galactooligosaccharides as sugar substitutes (sucrose). The authors of the study in question therefore considered the hypothesis of integrating galactooligosaccharides with an intensive sweetener of natural origin, extracted from the fruit. luo han guo, The monk fruit (Siraitia grosvenorii).
3) Monk fruit, mogrosids
The natural extract of the monk fruit (Siraitia grosvenorii), made up of cucurbit-like triterpenoid saponins known as mogrosides, is used in traditional Chinese medicine for its antioxidant, hepatoprotective, hypoglycemic, immunological and anti-inflammatory properties.
The sweetening power of mogrosides is 200-300 times higher than sucrose and yet concurs with a bitter taste and metallic aftertaste. Enzymatic glycosylation improves the flavor of these terpenoids which however - like steviol glycosides (6) - need a bulking agent (or bulk sweeteners) to improve their functional properties.
4) Probiotic sweetener, the study
A systematic review (Labrador et al., 2022) was based on the hypothesis of producing a prebiotic sweetener, mMV-GOS, composed of galactooligosaccharides and enzymatically modified mogrosides through a technology 'one pot'patented. With the aim of verifying its prebiotic effects and consumer acceptability:
- the prebiotic effects were measured by in vitro fermentation of human fecal microbiota collected from 4 healthy donors, with real-time PCR analysis to quantify the bacterial population and identify the types of bacteria,
- the sensory analysis was entrusted to a panel of 10 experts (at the Sensory Science Center, Department of Food and Nutritional Sciences, University of Reading, UK). They considered the intensity of the sweetness of the probiotic sweetener similar to that of sucrose.
5) Innovation awaiting authorization novel food
The results show the effective ability of the probiotic sweetener to stimulate the significant growth in the gut microbiota of 'health allies' microorganisms such as Bifidobacterium, Clostidrium coccoides, Lactobacillus. In addition to the formation of metabolites, such as propionate and butyrate, which are involved in the regulation of appetite, the integrity of the tight cell junctions and the anti-inflammatory properties of relevance in mitigating the inflammatory processes of type II diabetes.
Researchers suggest that the simultaneous synthesis of mogrosides and GOS can perform both a calorie-free sweetening function and that of a prebiotic. On this promising basis - also taking into account that EFSA (2019) has not yet defined an Acceptable Daily Intake (ADI) for mogroside V (7) - further studies, including in vivo, can be conducted to better assess human exposure. In view of a possible authorization such as novel food, pursuant to reg. EU 2015/2283.
Dario Dongo and Isis Consuelo Sanlucar Chirinos
(1) Ana Munoz Labrador et al. (2022). Prebiotic Potential of a New Sweetener Based on Galactooligosaccharides and Modified Mogrosides. J. Agric. Food chem. 2022, 70, 9048−9056. https://doi.org/10.1021/acs.jafc.2c01363
(2) Dario Dongo (2020). Prebiotics and probiotics, microbiome and immune system. GIFT (Great Italian Food Trade). 28.4.20
(3) Dario Dongo. Stevia and steviol glycosides, from Guaraní to GMO sweeteners. Distant worlds. GIFT (Great Italian Food Trade). 30.1.22
(4) Marta Strinati. Allulose, a natural sweetener candidate novel food in the EU and UK. GIFT (Great Italian Food Trade). 8.12.21
(5) Marta Strinati. The harmful role of sugars in the diet, EFSA opinion. GIFT (Great Italian Food Trade). 1.3.22
(6) Dario Dongo. Stevia, a sweet superfood with a biotech risk. GIFT (Great Italian Food Trade). 2.4.18
(7) Gabriele Aquilina, Laurence Castle, Karl ‐ Heinz Engel, Paul Fowler, Maria Jose Frutos Fernandez, Peter Fürst, Rainer Gürtler, Ursula Gundert ‐ Remy, Trine Husøy, Wim Mennes, Peter Moldeus, Agneta Oskarsson, Romina Shah, Ine Waalkens ‐Berendsen, Detlef Wölfle and Maged Youne. Safety of Use of Monk Fruit Extract as a Food Additive in Different Food Categories. EFSAJournal 2019, 17, No. e05921. https://doi.org/10.2903/j.efsa.2019.5921