Mealworms: low ash content with an interesting mineral profile for pet food recipes

Health & nutrition
February 29, 2024

More than ever, consumers expect transparency and quality around the food they feed their animals. Pet diets remain under scrutiny as recipes boast premium ingredients and reduced unwanted additives. Many look to the ash content in a meal as a marker of protein-quality as it provides a measure of the inorganic matter of a feed material, that comes from bone, cartilage, tendons. The lower the ash level, the better quality of food. Ash levels are often a limiting factor of high-protein inclusion in pet food recipes. Full of a valuable mix of minerals that fit nutritional needs, Sprÿng’s mealworm-based ingredients are particularly attractive because they combine high protein levels with a low ash content.


Ash, a limiting factor of high-protein inclusion in pet food recipes 

Crude ash provides a measure of the inorganic matter or total mineral content of a feed material, such as phosphorous, calcium, zinc and iron1. It depicts a rough estimate of the amount of mineral present in a diet while being less complex and expensive to measure than individual minerals. Indeed, the ash content is calculated based on the remaining percentage of food left after combustion.

Ash can originate from mineral additives added to the product, but oftentimes, it comes from animal and fish bones, cartilage, tendons and the like that have been ground into the meat meal. As such, high ash contents are often perceived as a measure of these low-value materials with low digestibility. Many look to ash as the key to understanding if a higher quality protein is being used in the making of a dog or cat food. 

Pet food producers take great consideration in the ash content of their ingredients and end-products. While official recommendations advocate diets with less than 10% of ash, the average ash content of most commercial dog foods appears to be about 5-8 percent, with higher meat recipes averaging ash levels closer to 10%2. Dry pet foods, especially those that contain higher protein concentrations and more meat meals in the ingredient list, are usually higher in ash than canned foods3. The ash content is often a limiting factor of high-protein inclusion in pet food recipes but also tends to be used as a marker of protein-quality. Sprÿng ingredients are particularly attractive because of their high protein content associated with low ash levels, less than 5%. 

Pet food needs to include minimal ash as minerals are necessary for pet health

Despite its link to low-value materials, don’t write off ash just yet. Essential minerals play an important role in pet health. Dogs and cats actually require roughly about 2% ash in their diet to meet their mineral needs.

Essential minerals are found in all food ingredients. In commercial pet food, they can be supplemented via specialized ingredients to provide a complete and balanced nutritional profile. For dogs and cats, these essential minerals can be divided into two separate categories: macrominerals needed in large amounts and trace minerals in very small quantities4. Both support a range of body functions that help pets remain healthy, active and strong. For instance, they promote bone development, nerve and muscle function, balancing of fluid in cells, thyroid function, skin and coat maintenance and red blood cell production.  

Pet food products should contain a healthy amount of minerals to avoid medical concerns. It is important to have a balanced intake of minerals. Minerals need to be included in the right quantities - specified by the nutrient profiles and intake guidelines from public pet food organizations like the AAFCO or the FEDIAF - in the diet of cats and dogs to promote health and wellbeing of animals. The AAFCO specifications indirectly restrict ash by setting limits on calcium and phosphorus levels and their ratio.


The interesting mineral profile of mealworms


Sprÿng mealworm products are particularly attractive because they have a high protein concentration, combined with the sought-after low in ash content that meets the nutritional needs of both dogs and cats. Compared to equivalently qualitative animal protein sources, like fish or poultry, mealworms contain 3 to 5 times less ash. Our dry protein concentrate made of ground up mealworms, Protein70 only contains 3.6% ash for a protein concentration of 72.6%. This makes mealworm proteins similar to vegetal protein sources and far more interesting that animal proteins. Indeed, mealworms are a significant source of essential minerals.

Sprÿng products don’t contain a lot of ash, but the ash they do contain has an interesting mineral profile that contributes to good health and nutrition. For instance, a 20% inclusion of Protein70, supplies more than a third of the required mineral for phosphorus (P), potassium (K), and Sodium (Na). More importantly Protein70 will provide 90% of magnesium (Mg) intake, 72.2% copper (Cu) intake, 50.8% iron (Fe) intake, 57.6% manganese (Mn) intake and 64.2% zinc (Zn) intake recommended for an adult dog. Similarly, it will provide 157.5% of Mg intake, 104% Cu intake, 66.8% Mn intake and 61.6% Zn intake recommended for an adult cat.

For information, magnesium is involved in hundreds of reactions in the body and supports electrolyte balance inside cells, bone structure integrity and heart cell function. Iron is important in energy metabolism, supporting notably the synthesis of red blood cells and muscle cells. Zinc is linked to skin integrity. Manganese is essential to energy metabolism and healthy bones. And finally copper helps with coat quality.  

As for minerals in which there is a maximum level of inclusion, not a single macromineral or trace-element is added in excess when including 10 to 30% of our Protein70 in kibble recipes.

Added to pet food recipes, our mealworm-based products help pet food product meet the nutritional recommendations set by the AAFCO and the FEDIAF, with a balanced, rich, high-quality ingredient. Ash is an important part of pet food formulation. With our Sprÿng products, the pressure of including a premium protein source, without adding too much ash to the final product is vastly alleviated. Mealworms could be the one-size-fit-all solution to premium, high-protein pet food diets, full of interesting minerals.  


Lorena Sanchez, PhD, Scientific Project Manager, Sprÿng Powered by Ynsect, France


1. Thiex N, Novotny L, Crawford A. Determination of ash in animal feed: AOAC official method 942.05 revisited. J AOAC Int. 2012Sep-Oct;95(5):1392-7. doi: 10.5740/jaoacint.12-129. PMID: 23175971.

2. What is Crude Ash and why is it in my dogs dinner? – Bone Idol

3. All About Ash – Clinical Nutrition Service at Cummings School (

4. BrownS., Taylor B., “See Spot Live Longer”, 2007 Creekobear Press, Eugene, OR USA, p55

Mealworms for premium quality, nutrient rich and sustainable pet food
Mealworms for premium quality, nutrient rich and sustainable pet food
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