By Dr Jane Muir
Everyone was very disappointed when our rating for rice milk was red = high FODMAP!
We have had many requests to conduct further testing of rice milks from different countries. Our team has just completed testing rice milks from Australia, United Kingdom and the United States.
Remember that the analysis of all FODMAPs in food is a complex and time-consuming process undertaken by the laboratory team here at Monash. Some foods (particularly processed foods) present technical challenges. Rice milk is one of these challenging foods.
Currently, rice milk has been given a red rating in the app. This was due to the presence of very high level of oligosaccharides (Oligos) that our team detected in the rice milk samples. As we discussed in our last rice milk blog – this high level of Oligos are due to the enzymatic breakdown of the rice flour starch to release glucose (this is how rice milk is made). As you can see from the diagram below, rice starch is a large and complex carbohydrate - made up of chains of glucose (these can be very long - thousands of glucose units long). The enzymes used to make rice milk sometimes fail to completely break down the rice starch and as a result some small oligos are left behind. The key point here is that these types of starch-derived oligos are digestible, unlike the Oligos- fructans and GOS. So these are not really FODMAPs!
Our laboratory team has discovered that these starch-derived oligos get mixed up with the FODMAP - GOS-oligos during the laboratory analysis. This means it has been difficult to know how much of these oligos are starch-derived and therefore well tolerated, and how much is GOS, a FODMAP, poorly tolerated. The team has recently established a new technique to answer this question. As a result of their hard work, they have discovered that there is little GOS in rice milk and indeed these Oligos are probably starch-derived and therefore well tolerated. All rice milks have been re-tested using this new method.
We have now reviewed the rating for rice milk and will be modifying this accordingly. We have given a safe (low level green rating) for 200 ml of rice milk per sitting. The results for the Australian, UK and US will be in the app very soon. We apologize for any confusion this may have caused - but this is science in action! and part of the ongoing research and refinement of the Monash University Low FODMAP diet.
Be careful: There are still some fructans present in some rice milks and therefore we do not recommend very high quantities of rice milk in one sitting.
So will this problem of starch-derived Oligos affect other food ratings in the app? We have reviewed other foods in the app and we have not found any other foods which have been affected by this technical issue.