RESUMEN
A new form of plant-based meat, known as 'high-moisture meat analogs' (HMMAs), is captivating the market because of its ability to mimic fresh, animal muscle meat. Utilizing pea protein in the formulation of HMMAs provides unique labeling opportunities, as peas are both "non-GMO" and low allergen. However, many of the commercial pea protein isolate (PPI) types differ in functionality, causing variation in product quality. Additionally, PPI inclusion has a major impact on final product texture. To understand the collective impact of these variables, two studies were completed. The first study compared four PPI types while the second study assessed differences in PPI inclusion amount (30-60%). Both studies were performed on a Wenger TX-52 extruder, equipped with a long-barrel cooling die. Rapid-visco analysis (RVA) and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated differences in protein solubility among the different PPI types. In general, lower protein solubility led to better product quality, based on visual evaluation. Cutting strength and texture profile analysis showed increasing PPI inclusion from 30-60% led to significantly higher product hardness (14,160-16,885 g) and toughness (36,690-46,195 g. s). PPI4 led to lower product toughness (26,110 and 33,725 g. s), compared to the other PPIs (44,620-60,965 g. s). Heat gelling capacity of PPI4 was also highest among PPI types, by way of least gelation concentration (LGC) and RVA. When compared against animal meat, using more PPI (50-60%) better mimicked the overall texture and firmness of beef steak and pork chops, while less PPI better represented a softer product like chicken breast. In summary, protein content and also functionality such as cold water solubility and heat gelation dictated texturization and final product quality. High cold water solubility and poor heat gelation properties led to excessive protein cross linking and thicker yet less laminated shell or surface layer. This led to lower cutting firmness and toughness, and less than desirable product texture as compared to animal meat benchmarks. On the other hand, pea proteins with less cold water solubility and higher propensity for heat gelation led to products with more laminated surface layer, and higher cutting test and texture profile analysis response. These relationships will be useful for plant-based meat manufacturers to better tailor their products and choice of ingredients.
RESUMEN
A growing demand for alternative sources of texturized vegetable protein (TVP) has resulted from various factors including plant allergies, perceived health risks associated with genetically modified organisms (GMO), animal welfare beliefs, and lifestyle choices. Soy and wheat have been the primary ingredients in TVP over the past few decades, but desires for clean label ingredients (especially non-GMO and nonallergenic) have led to demand for alternative plant protein ingredients such as pea protein. To understand the capabilities of pea protein to create meat-like texture with additions of another protein source that also contributes starch, this study focused on extruding pea protein with increasing amounts of chickpea flour (CPF). Six treatments, with inclusions of CPF ranging from 0 to 50%, were processed on a twin-screw extruder to determine the optimal ratio of pea protein isolate to CPF. Bulk density was the greatest with 20% CPF (272 g/L) and resulted in the lowest water holding capacity (55.5%). Texture profile analysis (TPA) hardness, springiness, and chewiness showed optimum results for the 10 and 20% CPF (674 to 1024 g, 72.1 to 80.7%, 400 to 439, respectively). With no CPF addition, protein interactions created a strong network exhibiting extreme springiness (91.3%). Addition of CPF greater than 20% resulted in a detrimental decrease in hardness by 38 to 84% and chewiness by 73 to 92%. Phase transition analysis and specific mechanical energy data provided a greater understanding of the degree of texturization during extrusion. Inclusion of CPF between 10 and 20% led to the optimum protein to starch ratio, allowing adequate protein texturization and creating product characteristics that could potentially mimic meat. PRACTICAL APPLICATION: Pea protein was mixed with increasing levels of chickpea flour to produce a textured plant protein product using extrusion technology. The ratio of protein to starch can be optimized to target specific textural attributes of textured pea protein to closely mimic different meat products like fish, chicken, or beef. The 10 and 20% chickpea flour treatments produced the highest quality products according to textural attributes.