Evaluation of Prickly Pear’s Pulp Powder (Opuntia stricta) on Physicochemical Properties of Raw and Cooked Analogue Burgers

There has been an increasing demand for functional analog meat products due to environmental, human health, and animal welfare concerns. Burger analogs are plant-based products that are designed to mimic the taste, texture, and appearance of meat burgers. They are typically made from a combination of plant-based ingredients such as textured vegetable protein, legumes, grains, and vegetables. The goal of burger analogs is to provide a meat-like experience without using animal-based products.These formulations aim to provide a healthier and sustainable alternative to conventional meat products. The organoleptic properties of burger analogs, including texture, taste, and aroma, are crucial for their acceptance by consumers.Prickly pear (Opuntia stricta) is a fruit from the Cactaceae family that contains various beneficial components, including natural pigments, proteins, fibers, and polysaccharides. Pectic polysaccharides and arabinogalactans are two types of polysaccharides found in prickly pear that have thickening properties and can improve the texture of food products. Moreover, Prickly pear is a nutritious and functional fruit that can provide various benefits when incorporated into the diet or used as an ingredient in food products. To date, no health benefit analog burgers incorporating Opuntia fruit have been developed.This study investigated the effects of adding Prickly pear pulp powder at levels of 0.5-2.5% on the physicochemical, sensory, and textural properties of analog burgers.

Analog burgers were formulated according to Iranian national standards using common ingredients (texturized soy protein, water, canola oil, garlic, dehydrated onion, soy sauce, and guar gum) as a control sample. Mature prickly pear fruits (Opuntia stricta) were collected from west of Mazandaran province in February. The  fruits were washed, peeled, and dried in a forced oven dryer at a temperature of 45 °C. The dried samples were then ground into a powder and stored at 4 °C until further physico-chemical parameters of the  including moisture, pH, ash, protein, lipid, color and total phenolic content. For developing new formulation of analog burgers, the roasted flour was substituted with prickly pear pulp powder at 0.5%, 1.5%, and 2.5% of the base recipe. The average moisture, ash, fat, carbohydrate content, pH, holding capacity, and color of each raw packed burger were measured. The hardness, springiness, cohesiveness, and chewiness of cooked analog burgers were evaluated using a texturometer instrument. Sensory analysis was performed by 10 panelists who judged discrimination scales of color, odor, taste, and texture characteristics. Analysis and sample treatments were repeated at least three times. Statistical analysis was performed using SPSS (version 19.0), and data were expressed as means ± standard deviation (SD).

The lowest and highest cooking losses were observed in analog burgers with 2.5% pulp powder (21.03 ±0.47%) and the control (22.2 ± 0.63%), respectively. However, moisture retention and juiciness did not show significant differences (p > 0.05) between analog burgers with prickly pear pulp powder and the control. The results indicated that increasing prickly pear pulp powder levels significantly decreased the redness (+a*) parameter and yellowness (+b*) of raw analog burgers. Moreover, a reduction in cooking loss and shrinkage were observed for cooked soy burger samples using prickly pear pulp powder. However, cooked analog burgers with added prickly pear pulp powder showed significantly higher juiciness. The elasticity of the produced analog burgers significantly decreased with an increasing percentage of pulp powder (p <0.05).

The incorporation of prickly pear pulp powder in analog burger formulation resulted in a significant decrease in cooking loss and shrinkage of the cooked burgers, while not significantly affecting moisture retention and juiciness. An increase in prickly pear pulp powder levels in analog burger formulation led to a significant decrease in the redness and yellowness of the raw analog burgers, as well as a decrease in their elasticity. Based on the sensory evaluation and consumers' overall tendency to consume burgers, it is recommended to use 1.5% prickly pear pulp powder in analog burger formulation.