Researchers compared the mineral content and absorption of plant-based meat-free (vegan and vegetarian) burgers to beef burgers in a new study published in Nutrients.
Because plant-origin diets lessen the risk of obesity, cardiovascular disease, and type 2 diabetes, the globe is shifting away from animal-origin diets. Although vegetarians have low iron levels, the prevalence of anemia among vegetarians and vegans is not significantly different from that of non-vegetarians. As a result, a well-planned, diverse vegetarian diet might provide adequate iron nutrition. Plant-based diets also promote microbial balance and diversity in the gut microbiome.
However, there have been questions over whether plant-based diets can match omnivorous diets in terms of calcium, iron, zinc, n-3 fatty acids, vitamin D, and vitamin B12. Because these nutrients are prevalent in animal-based products, vegan and vegetarian diets require expert advice to avoid nutritional deficits.
Concerning the research
Researchers evaluated the mineral content and bioavailability of minerals in plant- and animal-based burgers in this study.
The burger samples were obtained from a supermarket in the United Kingdom (UK) and cooked using a grill or an oven. The burgers were then freeze-dried for 5.0 days before being ground into fine powders and kept at 5.0°C. The moisture content of the dry powders was determined by putting them in crucibles at 65°C for two days and reweighing the samples until a consistent weight was attained.
Following microwave digestion, the mineral content (calcium, copper, iron, magnesium, manganese, and zinc) was measured using inductively coupled plasma-optical emission spectrometry (ICP-OES). The scientists studied mineral bioavailability in vitro using gastrointestinal simulations of food digestion, and mineral absorption was tested by exposing the human colorectal adenocarcinoma (Caco-2) cell line to the burger samples.
Furthermore, the protein content of Caco-2 cell lysate was measured using bovine serum albumin as a standard. The data were reported as means, and the one-way analysis of variance (ANOVA) test was used to compare them. Furthermore, using beef as the control, posthoc analyses were performed for multiple comparisons. If the p-value obtained was less than 0.05, the data was considered statistically significant.
The mineral composition of the burgers varied greatly. Pumpkin, beetroot, mycoprotein, red cabbage, jackfruit, potato, and soy were the key ingredients in the plant burgers. Raw burgers had moisture contents ranging from 51% to 78%, whereas cooked burgers had moisture contents ranging from 48% to 75%. The vegetarian/vegan burgers had higher levels of calcium, magnesium, copper, and manganese than the animal burgers.
The zinc and iron content of beef burgers was much higher than that of plant burgers. Furthermore, iron bioaccessibility was much higher in beef burgers than in most plant-origin replacements; yet, iron bioavailability was comparable in both types of burgers. Similarly, zinc bioaccessibility and bioavailability were much higher in the anima-based burgers, with only the mycoprotein-based plant burger exhibiting comparable zinc bioavailability, according to earlier research.
Plant-origin burgers including beetroot and pumpkin contained equivalent quantities of iron to beef burgers, however, burgers containing soy protein contained four times more iron (15 mg of iron per 100 g) than beef burgers. Iron bioavailability in beetroot burgers, on the other hand, was much lower than in beef burgers.
The discovery of higher calcium content in plant-based burgers than beef burgers mirrored the findings of the National Diet and Nutrition Survey (NDNS) and might be attributed to the integration of calcium chloride (CaCl2) in plant-based burgers to increase firmness and calcium fortification of wheat flour. The findings suggest that plant-based alternatives might be crucial calcium sources for people who don’t eat dairy, fish, or meat.
Iron incorporation inside large-sized peptide complexes during digestion in vitro reduces iron bioaccessibility. Nonetheless, sufficient doses of soy fortification with vitamin C may be able to offset the effects of soy on iron bioaccessibility. Furthermore, the baking processes used during burger preparation may partially overcome iron suppression caused by soy protein. The equivalent levels of iron bioavailability in plant-based and beef burgers might be attributed to the extra dietary elements integrated into the patties.
Overall, the study found that beef was a superior source of physiologically accessible iron and zinc than most plant-origin alternatives, although vegetarian/vegan burgers were higher in calcium, copper, magnesium, and manganese than beef burgers. The quantity of physiologically available and absorbable iron in the plant-origin burgers varied significantly.
The meat substitutes may supply adequate amounts of zinc and iron to people who consume them as part of a variety of diets. As a result, guiding health decisions would be determined by the variety of vegetable components and the nutritional quality of iron in the various burgers. However, because the content does not exactly measure bioavailability, the overall quantity of minerals may not be proportionate to their bioavailability and bioaccessibility.