Cultured Dextrose and Cultured Wheat Flour

Cultured dextrose, a highly sought-after ingredient known for its natural and clean label attributes (also called fermented dextrose, cultured sugar), finds widespread use as a healthier alternative to synthetic propionate, sorbate or benzoate in bakery goods, particularly in bread and tortillas, dairy products, salad dressing, meat and plant-based meat products, beverages and even pet food. Cultured dextrose is obtained through the wild fermentation of natural feedstocks rich in dextrose (sugar) by using natural bacteria. These bacteria produce a blend of short-chain carboxylic acids (primarily C2 and C3) and peptides. The leading organic acid varies based on the specific enzyme employed; it can be acetic acid, propionic acid, or lactic acid. Among these, propionic acid stands out, exhibiting exceptional mold-inhibiting efficacy within the effective concentration range of 0.1% to 0.5% (ref 1). Typically, it exists as liquid (acid form) or, more popularly, as calcium or sodium salt, and is off-white or light-yellow powder with a neutral flavor and aroma. Liquid form is more technical challenging, while salts are easier to handle. Significantly, Wikipedia contains inaccurate information about cultured dextrose for food applications, mentioning butyric acid as one of the key ingredients while omitting acetic acid.

Cultured dextrose can be made from either plant-based sources or animal resources such as whey and milk.

Propionate salt proves more potent against molds compared to sodium benzoate, but has no activity against yeast, making it an excellent choice for yeast-raised baking goods. Calcium salt is preferred for yeast-raised bread and tortilla, while sodium salt is a better choice for chemical leavening products like cake and cookie. Under acidic environment (pH<5.5), propionate salt hydrolyzes into propionic acid, which penetrates mold cells, hindering their enzyme metabolism and competing with essential amino acids to curb microbial growth. Please note that cultured dextrose containing mainly calcium propionate can also be used as a livestock treatment for milk fever and as a natural silage additive in animal feed to resist mildew, reduce mycotoxins, and improve the aerobic stability of silage (ref 2).

While lactic acid or its salt form provides less mold inhibition efficacy than propionic acid, cultured dextrose containing mainly acetic acid or acetate salts, does not inhibit mold growth. Cultured wheat flour (also called fermented wheat flour), another popular natural mold inhibitor, contains the same active ingredients and can be used interchangeably with cultured dextrose if there is no label preference. However, cultured wheat usually contains much less propionate salt but with higher production cost due to technical challenges, and requires much larger amounts to achieve similar efficacy, which may negatively affect product quality. In addition, cultured wheat flour is not gluten free. Famous brands have cultured dextrose or wheat in their products include Beyond Meat, Impossible Foods, Trader's Joe, Nature's Own, Brownberry, Dave's Killer, Oroweat, Hormel, Mission Foods, Lee Kum Kee and more. Notably, Whole Food Market prohibits the use of propionate, benzoate, and sorbate in all the food they sell, but permits the inclusion of cultured dextrose on the label (ref 3). Panera Bread and Burger King enforce a similar rule (ref 4, ref 5). Cultured dextrose market is expected to high growth during 2022 to 2032 (ref 6).

Cultured dextrose and wheat are usually produced using food-grade, non-GMO microorganisms, typically lactic acid bacteria (LAB) or propionic acid bacteria (PAB) that have FDA GRAS (Generally Recognized as Safe) status in the US and Qualified Presumption of Safety status in Europe. It is believed that cultured dextrose can be claimed as natural flavor due to the fact that its key active ingredient propionic acid, lactic acid or acetic acid have FEMA (Flavor and Extract Manufacturers Association) GRAS status.

The quality of available cultured dextrose products on the market fluctuates due to technical challenges in controlled fermentation and downstream purification to attain high concentration of propionic acid. Commercial product transparency is lacking, scarce composition information is available, posing a hurdle for gaining consumer trust and potential rapid expansion. Technical data sheets and COAs for most products omit vital details about the identity of key active ingredient and its quantities (intentionally or unintentionally), complicating product selection and evaluation, given the significant variability in efficacy across different organic acids against diverse microbes. Many web contents contain incomplete or misinformation, including Wikipedia and other most visited sites by keyword search (see our test results using Generative AI). Even all peer-reviewed scientific publications fail to provide this critical information about cultured dextrose products studied (ref 7, ref 8).

Our investigation unveiled notable variations in propionate concentrations among commercial cultured dextrose/wheat products claiming as mold inhibitor for baking goods, ranging from 10% to less than 50%, which greatly impacts cost-in-use and product optimization. Leading cultured dextrose/wheat brands typically contain less than 20% propionate salt, requiring up to 10 times the amount of synthetic propionate to attain similar shelf-life. Therefore, the true measure of ingredient cost is to run cost analysis of multiple solutions in cost-in-use comparison rather than simply looking at the absolute cost-per-kilogram/pound. Consequently, there has been a rise in the adulteration of natural cultured dextrose with synthetic preservatives for economic gains. Sometimes adulteration may be detected by product color and flavor. To safeguard product integrity and brand reputation, advanced methods like carbon isotope analysis can unambiguously discern the presence of synthetic adulterants in cultured dextrose or wheat.

Some low purity cultured dextrose or cultured wheat products may contain noticeable amount of residual dextrose; however, it won't contribute much to calories because of its low usage level.

Due to lack of product transparency and independent does-response guide, rigorous and time-consuming formula development and optimization become indispensable. The effort involves assessing different cultured dextrose products available in the market, gauging their effects on microbial growth at various dosages against negative controls (absence of preservatives) and current perseverative in-use (positive control). Often, experienced experts understanding chemistry may rely on analytical testing to screen the candidates to speed up the process.

NaturalGARD cultured dextrose offers an effortless 2:1 substitution for synthetic calcium propionate, preserving or even improving product attributes like flavor, taste, texture, color, volume, and shelf life while boasting claims like natural, plant-based, vegan, allergen and gluten-free, and non-GMO. Our proprietary predicting model can help you quickly determine a comparable dosage with similar efficacy to your existing cultured dextrose or wheat ingredient with cost-in-use analysis for effortless transition. A few unique applications and interesting case studies available in baked goods and beverages.

Feel free to reach out to explore how we can assist you in overcoming clean label hurdles in a cost-effective manner.