In vitro digestibility and solubility of phosphorus of three plant-based meat analogues.

Interest in plant-based meat analogues has increased and can be expected to be applied to pet foods, which necessitates the understanding of the nutrient supply in those foods. Our primary aim was to advance our understanding of the digestive properties of sterilized plant-based meat analogues. The impact of the preparatory processing steps on the solubility of meat analogues was studied. Meat analogues were made by mixing water, salt, and wheat gluten with soy protein isolate, pea protein isolate, or faba bean concentrate. Mixed materials were processed into model meat analogues using shear cell technology. Products were canned in water or gravy and sterilized. An animal-based canned pet food was made as a reference. Products sampled at the processing steps (mixing, shearing, sterilization) were digested in vitro. Samples of digestate were taken at the gastric phase (0 and 120 min) and small intestinal phase (120, 200, 280, and 360 min) for analysis of protein hydrolysis. The extent digestion of nitrogen and dry matter was determined at the end of incubation. Total phosphorus, soluble phosphorus after acid treatment, and after acid and enzymatic treatment were determined. The degree of hydrolysis after gastric digestion was low but increased immediately in the small intestinal phase; products based on pea had the highest values (56%). Nitrogen digestibility was above 90% for all materials at each processing step, indicating that bioactive compounds were absent or inactivated in the protein isolates and concentrate. Phytate seemed to play a minor role in meat analogues, but phosphorus solubility was influenced by processing. Shearing decreased soluble phosphorus, but this effect was partly reversed by sterilization. Nutrient digestibility as well as phosphorus solubility in plant-based products was higher than or comparable with the reference pet food. These findings show that the digestive properties of the tested plant-based meat analogues do not limit the supply of amino acids and phosphorus.

Enhancing textural properties in plant-based meat alternatives: The impact of hydrocolloids and salts on soy protein-based products.

Consumer studies suggest that the meat-like texture of plant-based meat alternatives is crucial for the market success of these products. Many meat analogues contain wheat gluten, because it is cost-effective and give rise to nice fibrous structures. However, individuals with celiac disease cannot consume products containing wheat gluten producing a fibrous structure. To provide meat-like textures, different hydrocolloids with appropriate salt concentrations could be used. Therefore, this study investigated the influence of different hydrocolloids, including high acyl gellan gum, low acyl gellan gum, high methoxyl pectin, low methoxyl pectin, and xanthan at 2%, as well as two types of salts (CaCl2 and NaCl) at three concentrations (0%, 0.5%, and 1%) on the macrostructure, microstructure, and mechanical properties of plant-based meat alternatives containing only soy protein isolate and without wheat gluten. The addition of hydrocolloids and salts increased the cross-link bonds and structural compactness at the microscopic level and enhanced the fibrous structure at the microscopic level at different extent. These findings provide insight into how the addition of salts and hydrocolloids can effect plant-based meat alternatives without wheat gluten, which have practical implications for the food industry and are important for their success in the market.

Structure analysis of multi-component pastes - The effect of water distribution on the rheological properties.

Techno-functional properties of multi-component blends and ingredients are determined by the contribution of each ingredient and the water distribution between those ingredients in the blends. However, ingredients can consist of multiple components, which should be considered to better understand the properties of ingredients and blends thereof. Recently, empirical models were used to describe the viscosity of mildly refined ingredient blends. While many compositions were described well by the empirical models, blends with high fiber contents were not predicted sufficiently well. Therefore, in this research, the multi-component blends of commercial pea protein, pea starch, and pea fiber isolates were investigated on their rheological properties as a function of dry matter content. The same properties were then measured for blends of two of these isolates mixed in different ratios. From the rheological experiments, estimations of the water distribution were made with the polymer blending law. The results were compared with CLSM images. A quantitative analysis of the CLSM images mostly confirmed the model outcomes. The isolate ratio could describe the isolate blends sufficiently well, meaning that it was not necessary to know the exact compositions of the ingredients. It was concluded that changes in meso-structure of the blends, for example a phase transition at high fiber contents, caused the lower predictability by the recently published empirical viscosity models. This study demonstrates that the water distribution in multi-component blends plays a crucial role for their viscoelastic properties and the contribution of the individual isolates and components. Moreover, these polymer blending laws that include water distribution provide extra mechanical insights into the fraction behavior in multi-component blends.

The behaviour of sunflower oleosomes at the interfaces.

Oleosomes are particles equipped with a sophisticated membrane, comprising a continuous monolayer of phospholipids and hydrophobic proteins, which covers the triglyceride core and grants them extreme physical and chemical stability. The noteworthy qualities of oleosomes have attracted strong interest for their incorporation in emulsion formulations; however, little is known about their emulsifying properties and their behaviour on interfaces. For these reasons, oleosomes were isolated from sunflower seeds (96.2 wt% oil, 3.1 wt% protein) and used as an emulsifier for the stabilization of O/W and W/O interfaces. In both cases, oleosomes showed high interfacial and emulsifying activity. Individual oleosome particles had a broad size distribution from 0.4 to 10.0 µm and it was observed that the membrane of the larger oleosomes (>1-5 µm) was disrupted and its fractions participated in the newly formed interface. Oleosomes with a smaller diameter (<1 µm) seemed to have survived the applied mild emulsification step as a great number of them could be observed both in the bulk of the emulsions and on the interface of the emulsion droplets. This phenomenon was more pronounced for the W/O interface where oleosomes were absorbed intact in a manner similar to a Pickering mechanism. However, when the triglycerides were removed from the core of oleosomes in order to focus more on the effect of the membrane, the remaining material formed sub-micron spherical particles, which clearly acted as Pickering stabilisers. These findings showcase the intriguing behaviour of oleosomes upon emulsification, especially the crucial role of their membrane. The study demonstrates relevance for applications where immiscible liquid phases are present.