It is fair to say that in the past decade, health awareness has escalated and changed consumers’ perception of food and beverages. A product is no longer judged by its appearance and taste, and with the growing concern over nutritional claims, factors, such as natural and organic, have come into prominence regardless of whether they have sufficient scientific data to back them up.
One critical concern of the modern population is obesity. It is generally accepted that sugar intake has a direct link to the condition, which the American Medical Association has recently voted to classify as a disease. This ensues a great debate over the benefits and risks of using sugar and artificial sweeteners.
Recent studies have suggested that low-calorie artificial sweeteners can have an impact on health, even at low dosage. A recent research by the Washington University School of Medicine has found that the sweetener sucralose can modify how the body handles sugar. Other similar studies have shown that consumption of artificial sugar may cause the taker to consumer more calories than those eating natural sugar.
In the middle of the two extremes, another product category has emerged—the natural sweeteners. Besides acting as competent replacements for sugar, natural sweeteners often come with additional health benefits that are inherited from the source they are extracted from.
According to Research and Markets’ The Future of Innovation in Sweeteners report, “rather than simply substituting synthetic sweeteners, natural sweeteners are increasingly marketed as products that can replace 20-30 percent of the sugar in a product without affecting the taste.
Currently, the most popular natural sweetener is Stevia, which was the fifth bestselling non-caloric sweetener in the world in 2012. However, as the report noted, 2013 is set to be the year that the monk fruit, also known as luo han guo, hits the mainstream.
The Monk Fruit
Fresh monk fruit is comprised of about 30 percent triacylglycerols, primarily linoleic, oleic and palmitic acids, and 25 percent protein. So far, 18 amino acids have been identified, most prevalently aspartic acid, serine, proline and glutamic acid. The fruit is also high in vitamin C, containing around 340-488 mg/100g. Saccharide and polyol contents are about two percent, and the mogrosides content, the sweet component of the fruit, is about two percent.
“What makes monk fruit unique is that it tastes better than stevia as it does not have the bitter flavour,” said Chris Tower, president of Layn USA, which manufactures both stevia and monk fruit sweeteners.
Monk fruit can be formulated as a standalone sweetener, as he is seeing in the US, and in combination with stevia. “Monk fruit and stevia are the only natural, high intensity, zero calorie, as well as diabetic suitable sweeteners that are available in the market at the moment,” he added.
Known scientifically as siraitia grosvenorii, monk fruit is an herbaceous perennial vine of the Cucurbitacease (gourd) family that is native to southern China and northern Thailand. The Guilin, China, regions account for over 95 percent of the world’s commercial monk fruit cultivation.
The fruit has been traditionally used as a Chinese herb in the treatment of ailments, such as sore throat, cough and bronchial relief, due to its ‘cooling’ effect. It is commonly taken in the form of herbal tea.
Ingredient supplier Tate & Lyle stated that monk fruit extract is roughly 200 times sweeter than cane sugar and provides calorie-free sweetness. The extraction process involves four steps:
Fresh monk fruit is crushed to release the natural juices.
Crushed monk fruit is infused with water to release its sweet components.
The monk fruit infusion is refined, concentrating the sweet components into a fruit extract.
The monk fruit extract is spray-dried to facilitate its use in a wide range of food and beverage applications.
The US Food and Drug Administration (FDA) has recognised monk fruit extract as generally recognized as safe (GRAS) by issuing a ‘no question’ letter. Around the world, the extract is approved for broad use in China, Japan and South Korea.
Great Functional Potential
A summary report by Kyung Hee University’s Institute of Oriental Medicine, monk fruit extracts and purified mogrosides are shown to exhibit anti-diabetic, anti-carcinogenic, antioxidant and anti-allergic effects.
In a research by the biochemical laboratory of Saraya, a company based in Osaka, Japan, monk fruit extract is found to exhibit an antidiabetic effect on spontaneous type 2 diabetic Goto-Kakizaki rat specimens. It caused an improvement in the insulin response in the oral glucose tolerance test, an accumulation of insulin in the pancreas in the fasting state, amelioration of kidney function and enhancement of antioxidative properties in the liver and plasma.
Mogroside V and 11-oxo-mogroside V isolated from monk fruit exhibited strong inhibitory effects in antitumor primary screening test. The activity was indicated by the induction of Epstein-Barr virus early antigen by the tumour promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), which is known to be a primary screening test for antitumor promoters.
The results from a study by the College of Food Science & Technology of the Huazhong Agriculture University in Wuhan, China, showed that sweet glycosides extracted from the fruit (mogroside V and 11-oxo-mogroside V) have significant inhibitory effects on reactive oxygen species (O2-H2O2 and –OH) and DNA oxidative damage.
The Faculty of Pharmaceutical Sciences of the Okayama University studied the effect of the monk fruit on histamine-induced nasal rubbing and compound 48/80-induced skin scratching behaviour in ICR mice. An extract and glycoside of the fruit were found to have significant effect after repeated administration in inhibiting nasal rubbing and skin scratching behaviours.
Anti-Fatigue & Anti-Obesity
In addition to these properties, two separate reach studies have found that monk fruit extracts may have potential anti-fatigue and anti-obesity effects.
In a study by the Physical Education Institute of Jilin Normal University, 144 mice were randomly divided into four groups: control, low-dose, middle dose and high dose, to test the effects of monk fruit extracts on physical fatigue.
The mice outside the control group received a fixed amount of oral extract administration once a day for a period of 28 days. After which, the mice went through a forced swimming test and biochemical parameters relating to fatigue, including blood lactic acid, serum urea nitrogen, liver glycogen and muscle glycogen were measured.
The data showed that the extract can extend the swimming time of the mice, as well as increase the glycogen content in the liver and muscles. In addition, it decreased the level of blood lactic acid and serum urea nitrogen. The results indicated that the extract has significant anti-fatigue effects which are dose-dependent.
In another study by the College of Agriculture and Biotechnology of Chungnam National University, total mogrosides, as well as mogrosides V and IV, extracted from the monk fruit were tested for their effects on pancreatic lipase.
The body weight and food intake, abdominal and epididymal fats weight and hepatic triacylglycerol (TG) and total cholesterol (TC) contents were evaluated using male C57BL/6 mice fed with a high fat diet with or without different concentrations of total mogrosides for 11 weeks.
The results showed that all three extracts have good inhibitory effects on pancreatic lipase activity. Total mogrosides were able to suppress the increase in body weight, abdominal and epididymal fats weight, and TG and TC content in the mice’s livers. The rats fed with total mogrosides also displayed higher TG level in their faeces, which the study believed was due to decreased dietary fat absorption in the intestines.