Nutritional and environmental impact of plant-based burger prototypes

Abstract

The transition from animal-based to plant-based proteins is rapidly increasing because of different concerns about meat consumption, some being the nutritional and environmental effects of meat consumption. During this transition, there needs to be a holistic approach to assessing plant-based food. This master thesis is focused on investigating the nutritional and environmental impact of three plant-based burger prototypes made of pea protein isolate provided by the Frankfurt Institute. Furthermore, the results were compared to a commercial vegan burger and a beef burger. The nutritional assessment consisted of an analysis of protein content, total polyphenol content, phytate and estimation of the bioavailability of essential minerals, iron, zinc, and calcium. The environmental impact was evaluated through a life cycle assessment of the burger prototypes, commercial vegan, and beef burgers, from cradle to factory gate.

The nutritional assessment showed that the protein content is significantly higher in the beef burger, with 57.7 g/100g DM, compared to the plant-based burgers, with the range 26.5-33.9 g/100g DM. Polyphenol and phytate content were significantly higher in the plant-based burgers. The polyphenol content was for the beef burger 23.2 g/100g DM, while the plant-based burgers were in the range of 33.8-36.4 g/100g DM. Furthermore, the phytate content was for the beef burger 0.02 g/100g DM, while the plant-based burgers were in the range of 0.53-0.74 g/100g DM. The bioavailability estimations showed that with a higher amount of phytate in the plant-based burgers, the bioavailability of the minerals is lower when compared with a low phytate content in the beef burger.
The LCA results showed that prototype C (3.2 kg CO2-eq/1000 g) had the lowest impact, followed by prototype B (4.5 kg CO2-eq/1000 g) and then prototype A (8.1 kg CO2-eq/1000 g) with the highest impact. This could be due to the formulation and higher content of the ingredient HME (high moisture extruded product). The prototypes had a lower impact when compared to the beef burger (15.9 kg CO2-eq/1000 g) and higher to the vegan burger (1.66 kg CO2-eq/1000 g). The commercial vegan burger is expected to have a lower impact because it is produced at an industrial scale while the prototypes are at a lab scale. The smaller the equipment is, the more energy-consuming for a kg of product.
The results of the nutritional and environmental impact assessment will be very useful for the further development of the prototype burgers.

Popular Abstract

According to The Food and Agriculture Organization of the United Nations (FAO), two of the most significant problems in our lifetime are malnutrition and the impact of food on the environment and natural resources. To combat this issue, the transition from animal to plant-based proteins is beneficial because, generally, plant-based food is healthier and more environmentally friendly. This means that developing more plant-based alternatives is a way to combat the above-mentioned problems. In this development, it is vital to have a holistic approach to the scientific assessments, which includes nutritional and environmental assessments of the products.

In this report, the nutritional and environmental impact of three plant-based burger prototypes, one commercial vegan burger and one beef burger, were evaluated and compared. The nutritional assessment included protein, polyphenols and phytate content analysis; furthermore, the estimated mineral bioavailability of iron, zinc and calcium was calculated with molar ratios, phytate: mineral. For the environmental assessment, an LCA (life cycle assessment) was conducted from the cradle to the factory gate, where the process's individual stage's contribution to the total greenhouse gas emissions was assessed.

For the nutritional assessment, the protein content was lower in the plant-based burgers than in the beef burger, while the polyphenol and phytate content was higher in the plant-based burgers. A higher polyphenol content positively impacts health because of its antioxidant and anti-mutagenic properties. The estimated mineral bioavailability of iron, zinc and calcium was also higher in the beef burger than in the plant-based burgers. The fact that plant-based burgers have more phytate than beef burger explains why the mineral bioavailability is lower because phytate binds to the minerals impairing their absorption.

The LCA results showed that the prototypes' environmental impact, total GHG emissions were the highest for prototype A, then prototype B had the second highest and then prototype C had the lowest total GHG emissions. In comparing prototypes to the commercial burgers, the prototypes had a lower environmental impact than the beef burger but higher than the commercial vegan burger. The results can be used to investigate how the prototypes should further develop, particularly which process stages are necessary and which ingredients should be excluded.

• author: Ströhagen, Noemi
• supervisor: Claudia Lazarte; Nelly Garcia Gonzalez
• organization: Food Technology and Nutrition (M.Sc.)
• course: KLGM01 20231
• year: 2023
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: plant-based, LCA, phytate, phytic acid, polyphenol, protein, food technology
• language: English
• id: 9125400
• date added to LUP: 2023-06-19 11:57:25
• date last changed: 2023-06-19 11:57:25