Elemental Analysis, Separation Science, And Metallography News By LECO

Perfect and easy analysis for solid and liquid products.

Protein is one of the most significant nutrient components in milk products. The accurate and precise determination of protein not only plays a role in the characterization of nutritional or dietary value of milk products but is also the key to determining the economic value of these materials. Protein in milk products is most commonly calculated using the measured total nitrogen content in the sample and a multiplier or conversion factor (typically 6.38). Nitrogen determination is performed using either the classical wet chemical method (Kjeldahl), or a combustion method (Dumas).

While plant-based proteins have been part of humanity's diet for centuries, it wasn't until the advent of the original textured vegetable protein (TVP) in the 1960s that it started becoming a viable replacement for animal-based protein sources in more mainstream diets. The first commercially available plant-based proteins would not be mistaken for animal-based protein sources and were largely of interest only to vegans, vegetarians, and pescatarians. 

Pet ownership has increased over the last few years, when an explosive boom during the COVID-19 lockdowns showing no signs of stopping. Over 70% of American households have at least one pet, with most of those homes having at least one cat or dog. As pet ownership continues to rise, so too does the demand for pet food.

A Small Overview and Comparison

The protein content in food and feeds is one of the parameters that are commonly analysed within most routine control samples in a food laboratory. Generally, the two most used reference methods/technologies are the wet chemistry method after Kjeldahl and the combustion method after Dumas.

The Dumas method has several advantages over the Kjeldahl method: it is much faster, with much lower operating costs, no real safety issues, and no toxic waste produced. However, there is a debate over which of the two main approaches to the Dumas method is better: a vertical or a horizontal combustion furnace. Determined to settle the question on which method is more precise and offers the most advantages, LECO chemists analyzed many sample types in both an FP828 and an FP928.