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Nov 05, 2024

Low-glycemic dog foods may benefit from lentil by-products | PetfoodIndustry

Red lentil pasta by-products may be a healthy carbohydrate source for dog foods and may prove useful in the formulation of dog foods with low glycemic indexes that help dogs maintain healthy blood

Red lentil pasta by-products may be a healthy carbohydrate source for dog foods and may prove useful in the formulation of dog foods with low glycemic indexes that help dogs maintain healthy blood sugar levels.

As pet owners’ fears about DCM have died down, lentils no longer face potential stigma when incorporated into pet foods. However, one of the factors that allowed the DCM controversy remains. Not much research has been done on lentils in dog diets, so there was little empirical evidence to support the ingredient's safety when called into question. A group of researchers set out to address that gap while also finding a potential use for a by-product of human food production. That by-product, a leftover from red lentil pasta, may serve as a healthy carbohydrate source for dog foods and may prove useful in the formulation of dog foods with low glycemic indexes that help dogs maintain healthy blood sugar levels.

“Research interest in the use of pulses in the pet food industry is growing fast, but data on the extrusion processing and kibble formation of dog food containing this ingredient is scarce, and no studies have been performed to date with respect to lentils,” the researchers wrote in the journal Frontiers in Veterinary Science. “Despite this lack of scientific knowledge, commercial dry pet food formulations containing legumes or tubers instead of cereals as the main carbohydrate source in food (i.e., the grain-free diets) are becoming increasingly popular, with the pet food industry claiming superior health and functional properties of these formulations.”

The study tested five different dog food formulations with forty adult, clinically healthy, beagle dogs divided into five groups.

1. A control diet based on rice and poultry by-product meal.

2-4. Experimental diets where lentil paste (LP) replaced rice at levels of 33%, 66% or 100% (LP33, LP66, and LP100).

5. A specialized diet containing 70% of the control diet plus 30% LP, intended to assess LP's digestibility.

When preparing the diets, the researchers found that as LP content increased, kibble production parameters, such as extruder pressure, hardness and bulk density, showed a linear rise. Starch gelatinization, a factor influencing kibble quality, remained unaffected by LP inclusion, suggesting LP can be integrated without compromising textural properties.

The digestibility analysis revealed that replacing rice with LP up to 66% did not negatively impact the apparent total tract digestibility coefficient, with some inclusion levels even improving digestibility relative to the control diet. Nitrogen balance, a marker for protein utilization, remained stable across diets, affirming that LP substitution did not impair protein absorption.

However, higher LP levels led to increased fecal production and moisture content, as well as a slight decrease in fecal pH. A significant finding was the linear increase in fecal short-chain fatty acids, including acetate and propionate, as well as branched-chain fatty acids and lactate, which are indicators of beneficial fermentation in the gut. Despite these changes, fecal scores and ammonia levels remained stable, suggesting that LP inclusion may enhance gut health without adversely affecting stool consistency.

Red lentil by-products, rich in dietary fiber, provided substrates for beneficial fermentation by the gut microbiota. The increase in fecal SCFAs, such as acetate and spermidine, is associated with improved gut health, indicating that LP may support a more favorable gut microbiome in dogs. Higher concentrations of fermentation by-products, including cadaverine, tyramine, and histamine, were noted with greater LP levels, potentially influencing gut microbial activity and nutrient absorption.

Notably, dogs consuming the LP100 diet exhibited lower post-prandial glucose and insulin levels compared to the control diet, indicating a possible benefit for managing blood sugar. This suggests that LP could be a valuable ingredient for formulating low-glycemic dog foods, potentially benefiting dogs with specific dietary needs related to blood sugar management.

“A dog's glycemic and insulinemic response to a carbohydrate source is of great importance, especially in those requiring a low, prolonged response. Indeed, obesity and insulin resistance are a significant problem in the canine population,” the researchers wrote. “Starch is generally considered the dog food nutrient influencing postprandial glycemic and insulinemic the most.”

Palatability tests showed that LP100 performed exceptionally well, with dogs preferring it both in initial choice and consumption rate. This preference highlights the potential of LP as a consumer-friendly ingredient in canine diets, combining sustainability with an appealing taste profile.

“The substitution did not reduce the apparent digestibility or metabolizable energy of nutrients at the 33 or 66% inclusion levels, and it increased the level of fermentation by-products in the feces (VFA and biogenic amines), indicating the potential benefits of LP on intestinal health due to its high content of fermentable fiber,” the researchers wrote. “The higher TDF content of LP with respect to rice and its higher protein and relatively lower starch content might explain the lower post-prandial glucose and insulin responses in dogs, features which would make it particular interesting for use in diets designed to produce a low glycemic response. Finally, palatability was enhanced in the formulation containing the red lentil pasta by-product, further supporting its use as a suitable ingredient in dog food.”

The study underscores the promise of red lentil pasta by-products in sustainable pet food formulations. The ingredient’s compatibility with extrusion processes, positive effects on nutrient digestibility, potential to support gut health, and ability to maintain a low glycemic response make it a viable option for the pet food industry. The favorable palatability further enhances LP's market potential, presenting a compelling opportunity for brands to offer environmentally conscious products that meet both nutritional and sensory expectations.

As the industry continues to seek ways to reduce its environmental impact, red lentil pasta by-products offer an innovative approach to sustainable pet food production, combining resource efficiency with potential health benefits for pets.