I have been around many folks who have eaten food derived from GMO crops since they were introduced in the mid-1990s, including my family, and I have not heard anyone comment on their tasting bad. (Now, brussels sprouts (which are not technically GMOs but did result from quite a bit of genetic modification) are a different matter—lots of complaints there.)
From personal experience with eating a range of foods that are GMO (like Bt sweet corn right out of the field, virus-resistant papaya or even foods made with products that are no longer with us, like bruschetta with FlavrSavr tomato and fries made from Bt potatoes), I can vouch that they taste just like any other sweet corn, papaya, tomato or potato. Heck, I have even tasted beer brewed using Bt corn, and it also tasted just fine. And if you are talking about how tomatoes taste in the winter, I’m with you—they don’t taste too good. But none of the tomatoes currently on the market is GM, so you can’t pin that problem on GMOs.
But since you asked about the taste of GMOs, I can share with you some basic information on what we know about taste. First off, 80 percent of what is perceived as taste is actually dependent upon smell. So you could rephrase your question to ask about how GMOs smell. There are many components in food that give each particular food its distinctive taste. For some tastes, like sweet, it is the presence of sugars that elicits a specific taste. Others tastes, like savory, are determined by levels of the amino acid glutamate. But often it is a complex mixture of components that results in a particular distinctive flavor of a food or food ingredient. While chemical composition impacts how foods taste, significant variation in taste occurs from season to season, across varieties and, most notably, in how fresh the food is.
As part of the safety evaluation process, every GM product is analyzed extensively for the key compositional components (carbohydrates, fats, amino acids, minerals, bitter components that may be antinutrients) in the edible portions of the crop and compared with the composition of conventional lines grown in the same trials. There are many, many peer-reviewed articles that show that GM crops are compositionally equivalent to their conventional counterparts. Although not every component responsible for determining taste is evaluated in these studies, the components that determine nutritional value are assessed.
Because scientists tend to be curious, there has been the occasional study to look at the sensory properties (or taste) of some GMO crops, even when there was not a particular reason to believe that the introduced GM trait would have any impact on taste or quality. A sensory evaluation conducted relatively recently looked at GMO (Bt) sweet corn relative to similar hybrids grown in the same location. In these studies, trained assessors at the National Food Lab participated in a blind sensory analysis to evaluate Seminis Performance series sweet corn (see https://www.earlmay.com/bulk_seed__custom_packaging/seminis_performance_series_sweet_corn/). The evaluators found that the GMO sweet corn had the same, great taste and eating quality of its conventional counterparts. There are numerous blogs out there (for example, this one) that attest to the findings of the expert tasters.
Even one of the most widely grown GM crops, Roundup Ready soybeans, was put to the test early on to see how it performed in taste tests. Samples of soy oil and flour from the GM soy and a similar conventional variety were evaluated by USDA expert assessors to look for key flavor attributes. The assessors found the same range and intensity of flavors in the oils and flours from the GM and non-GM lines.
So next time you get some food that tastes “bad,” send it back to the kitchen, but don’t blame GMOs.