Plant-based meat analogues: molecular assessment of protein quality and digestibility

Nowadays, there is a high concern about food sustainability and animal welfare. In particular, there is an increasing number of consumers who approach plant-based diets for environmental or for ethical reasons. Furthermore, there is a general awareness about the need of producing more environmentally sustainable food. Alongside this is the already existing awareness that diets based on highly processed red meat can have negative health effects. Therefore, the need to lean towards diets based on vegetable products is becoming evident and this lifestyle is already adopted by a good segment of the population. In any case, there are cultural (i.e., gastronomic tradition) and sensory (i.e., appearance, bite, mouthfeel, juiciness, taste) factors that act as a brake on replacing animal products with vegetable ones. From this point of view, plant-based meat analogues, which have been developed in order to replicate its sensory qualities such as appearance, bite, mouthfeel, and taste , are becoming more popular on the market and they have become part of the diet of different groups of consumers. The technological features of these products, the ingredients and the processes used to produce them are widely studied and described. Instead, a good knowledge of their nutritional characteristics appears to be lacking in the literature, so far. In this scenario, this thesis work stands as the first study intended to make a molecular assessment of the protein quality and digestibility of different plant-based meat analogue products. The study starts with an overview of the nutritional quality of the plant-based meat analogues sold on the Italian market, passing through the molecular characterisation and investigation of protein quality and digestibility of three principal categories of commercial meat analogue products (plant-based burgers, steaks, and cured meats), to finally performing the assessment of the molecular characterisation and protein quality and digestibility of specially formulated plant-based burgers. To better indicate the potential for these products to replace meat, appropriate meat controls were fully used as a comparison for each part of the study. The first study of the products on the market allowed us both to evaluate the variety of these products and to select the most interesting ones to be analysed in detail. The studies conducted on selected commercial products allowed us to evaluate the similarity level of the plant-based products examined – in terms of macronutrient composition, protein quality, and protein digestibility – with the meat products they intend to resemble. The study performed on new formulations of plant-based burgers allowed us to understand if and how the treatment carried out on protein and the addition of ingredients can affect the protein quality and digestibility of the final products. The study leads to conclude that some plant-based meat analogues can substitute meat, at least in terms of protein quality and digestibility. Anyway, being the supply on the market wide and vast and the composition of these products very heterogeneous, there is the need for careful choice by the consumer in order to select products with high quality. Furthermore, there is the need of more awareness that not all of these products have enough protein quality to meet the needs of all population groups. The consumption of some of these products to vulnerable segments of the population (such as children) could lead to replacing meat with a product of lower protein quality.