# Chemical and Sensory Properties of Corn Extrudates Enriched with Tomato Powder and Ascorbic Acid
###### Abstract  
The chemical and sensory properties of corn extrudates enriched with spray-dried tomato powder (TP) in 4, 6 and 8% ratios were researched. Two extrusion temperature regimes were used: 135/170/170 \({}^{\circ}\)C (E1) and 100/150 \({}^{\circ}\)C (E2). Ascorbic acid (AA) at levels of 0.5 and 1% was also added to the raw mixtures in order to prevent the undesirable oxidation of the constituents, primarily carotenoids. AA was especially efficient in the case of the lutein content and 1% AA, but lutein originating from TP was more sensitive to the extrusion conditions than corn lutein, and zexaanthin was more sensitive than lutein. Lycopene, \(\alpha\)-carotene, 13-_cis_-\(\beta\) caroten and 9-_cis_-\(\beta\) caroten degraded completely in all the samples, at both extrusion regimes. The proposed models for the color of the extrudates showed the significant influence of TP and AA. Extrudates obtained at the E1 temperature regime containing 4% TP and pure corn extrudate with 1% AA were the best-rated samples by the sensory panel.  
tomato powder; extrusion; carotenoids; ascorbic acid; sensory analysis 2024 14 7968 2024 14 7  
Tomato is among the most consumed crops worldwide, with a variety of products. Consequently, there is a high amount of waste like peels and seeds, which could be effectively transformed into useful raw material for new products [1]. It is well known that high nutritional value is primarily due to high levels of lycopene with antioxidant, anticarcinogen and immunomodulatory properties. Therefore, the addition of tomato in different forms to extruded products has been previously studied. Some of these studies focused on the physical properties of extruded products [9; 10], and some included an analysis of lycopene [1; 11; 12]. However, it is important to highlight that although lycopene is the predominant carotenoid in tomato, it is not the only one. The authors of [13] showed that lutein, \(\alpha\)-carotene and \(\beta\)-carotene originating from tomato also exhibit strong antioxidant activity. An especially important finding was that tomato carotenoids showed the strongest antioxidant potential in a mixture due to the synergistic effect. To the best of our knowledge, there has not been research on the extrusion influence on other tomato carotenoids besides lycopene. The influence of extrusion cooking on carotenoids from other sources like grains, sweet potatoes, pumpkin and carrots has been previously studied [14; 15; 16; 17; 18], but their stability depended on the food matrix that they originated from or were combined with. The authors of [19] reviewed current findings on the carotenoid stability during extrusion processing. They concluded that the processing conditions and extruded material are interrelated in a complex manner, so it is crucial to optimize the parameters with improved extruders and process control. There is also an idea to protect carotenoids by encapsulation, which gave good results in the protection of pumpkin peel carotenoids [20], but so far, we have not found research regarding tomato carotenoids.  
The aim of this study was to check the stability of the tomato carotenoids lycopene, lutein, \(\alpha\)-carotene and \(\beta\)-carotene in combination with corn carotenoids, primarily lutein and zeaxanthin. The objective was to obtain an extruded product with increased nutritional value and satisfactory sensory characteristics by adding tomato powder (TP). Ascorbic acid (AA) was also added to the mixture as a potential protector of the carotenoids, which are strongly vulnerable to oxidation.