Nutritional composition, protein digestibility and mineral bioaccessibility of plant-based burgers compared with a beef burger

Gamez Fernandez, Marta Maria (2021) Nutritional composition, protein digestibility and mineral bioaccessibility of plant-based burgers compared with a beef burger. MRes thesis, University of Nottingham.

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Background. Food production is the largest cause of global environmental change with animal protein being the dietary group with the strongest impact, especially ruminant meat. In contrast, plant-based foods cause fewer adverse environmental effects, but they typically contain anti-nutritional factors that reduce protein digestibility and mineral bioaccesibility. Food processing in general, and cooking in particular, can reduce anti-nutritional factors’ activity, and this could improve the nutritional adequacy of plant-based meat alternatives (PBMAs). Hence, whether plant-based meat alternatives are a meat-equivalent source of these nutrients remains unknown.

Aims. The first objective was to examine the nutritional composition and the effect of cooking on it, in comparison with a beef burger. The second objective was to analyse the content of antinutritional factors (ANFs) such as phenolics and phytic acid in beef and plant-based burgers. Finally, the third objective was to investigate the bioaccessibility of iron and zinc and the protein digestibility in beef and plant-based burgers.

Methods. A total of 8 plant-based burgers (Vivera 1 and 2, The Meatless Farm, Quorn and 4 Sainsbury’s burgers (mushroom and jackfruit, mixed vegetable, onion and parsley, and quinoa) along with a beef burger (Birds Eye Beef) were acquired. Both cooked and raw burgers were subjected to energy, protein and mineral content determination. Cooked burgers were subjected to analysis of phytic acid and total phenolics as well as to determination of the bioaccesibility of iron and zinc and the digestibility of proteins.

Results. Plant-based burgers composed of highly concentrated plant proteins (Vivera 1 and 2, The Meatless Farm, Quorn, and Sainsbury’s onion and parsley) had slightly less energy and similar or even more protein compared to the beef burger. In addition, plant-based burgers were richer in minerals than the beef burger, but they also had higher levels of sodium. Cooking tended to increase the concentration of minerals, protein and energy. Plant-based burgers had higher levels of total phenolics and phytic acid than the beef burger, for which protein digestibility was greater. Iron solubility was similar between the beef burger and the plant-based burgers containing plant protein concentrates. However, zinc solubility was greater for the beef burger than for the plant-based burgers. A burger fortified with iron and zinc (The Meatless Farm) had higher soluble iron and similar soluble zinc than the beef burger, but it also had higher amounts of non-soluble iron and zinc, as fortified minerals might be bounded by ANFs. In conclusion, PBMAs are not nutritionally identical replacements of meat products, with the concentration of ANFs along with the solubility of iron and zinc being key differences. Also, the impact of ANFs on mineral absorption may depend on other factors such as food processing, interactions with microbiota, and mineral status and hence their impact on PBMAs nutritional adequacy needs further investigation.

Item Type: Thesis (University of Nottingham only) (MRes)
Supervisors: Salter, Andrew
Brameld, John
Keywords: Plant-based meat alternatives, Sustainability, Protein digestibility, Mineral bioaccessibility, In vitro
Subjects: Q Science > QP Physiology
Faculties/Schools: UK Campuses > Faculty of Science > School of Biosciences
Item ID: 64904
Depositing User: Gamez Fernandez, Marta
Date Deposited: 04 Aug 2021 04:41
Last Modified: 04 Aug 2021 04:41

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