Comparative effects of beef heart, liver, and kidney inclusion on quality characteristics and consumer acceptability of ground beef patties

Abstract

Consumer demand for beef products is driven by eating quality, affordability, and versatility. Creating value-added formulations that enhance nutritional density without compromising acceptability is a crucial part of product development. Organ meats are nutrient-dense beef byproducts that remain underutilized in U.S. food systems. Edible beef by-products contribute substantially to carcass value through domestic and export markets. Incorporating beef organs into ground beef blends may provide a value-added opportunity to enhance whole-animal utilization. Objectives of this study were to evaluate the effects of beef heart, liver, or kidney at 15% inclusion on product quality and consumer acceptability of ground beef patties. Patties were formulated as control (no organ) or with heart, liver, or kidney and evaluated for cooking characteristics, instrumental color, objective tenderness, and consumer acceptance. Liver and kidney patties increased redness and chroma of raw and cooked patties (P < 0.0001). Moreover, liver and kidney patties reduced shear force and hardness compared to control and patties containing beef heart (P < 0.0001). Consumer panelists rated patties with kidney as juicier (P < 0.0001) and more tender (P = 0.0004). Sensory panelists scores report similar findings for control and heart patties for overall liking (P = 0.5208), appearance (P = 0.5823), aroma (P = 0.1756), and texture (P = 0.6387). A tendency (P = 0.0763) was observed for flavor with control and heart patties receiving higher flavor scores than the remaining treatments. Liver patties received the lowest scores for overall liking, flavor, and texture (P < 0.0001) compared to all other treatments. Results demonstrate that ground beef quality and consumer perception are influenced by organ type with beef heart maintaining characteristics like control patties. Among the organs evaluated, kidney inclusion provided the greatest improvements in juiciness and tenderness for beef patties but exhibited sensory challenges. Results indicate the need for further investigation to identify an optimal inclusion rate that maximizes eating quality and consumer acceptability. Formulation estimates suggest that replacing 15% of the beef trimmings with organ meat can reduce formulation cost while improving utilization of carcass components. Results suggest the potential for incorporating beef organs into ground beef as a value-added strategy to enhance sustainability and economic efficiency.

This study evaluated the effects of incorporating beef heart, liver, and kidney into ground beef on quality traits and consumer acceptance. Results identify organ specific differences that influence future product development.

Introduction

Growing interest in nutrient-dense foods, sustainable food systems and whole-animal utilization has renewed attention toward animal-derived products that are often underutilized in modern food systems (Beal et al. 2024). Organ meats including beef heart, liver, and kidney are concentrated sources of essential micronutrients such as iron, zinc, selenium, and vitamins A and B-complex (Latoch et al. 2024). Beef liver is particularly rich in vitamin A and iron, whereas heart contains high-quality protein and coenzyme Q10, and kidney provides substantial concentrations of iron, selenium, and B vitamins (Fuerniss et al. 2024; Latoch et al. 2024). These nutritional differences suggest that individual organ types may differentially influence the nutritional profile of reformulated beef products. Moreover, organ meats provide highly bioavailable nutrients and high-quality protein that contribute to nutritional adequacy (Beal and Ortenzi 2022; Latoch et al. 2024). Despite their nutrient density, organ meats are infrequently consumed by many consumers in the United States due to sensory perceptions, cultural preferences, and limited availability in mainstream retail channels all of which contribute to low utilization of these products (Bearth et al. 2021; Sabbagh et al. 2023). Consequently, a substantial proportion of edible beef organs is diverted to other uses such as international exports or pet food. This represents a missed opportunity to enhance both nutritional value, utilization efficiency within the United States beef supply chain as well as an opportunity to help mitigate increasing ground beef prices (Toldrá et al. 2021).

Ground beef represents a practical platform for incorporating nutrient-dense ingredients such as organ meats due to its widespread consumption, versatility, and familiarity among consumers (USDA ERS 2024). Retail purchasing behavior indicates that consumers are responsive to product information and perceived value which supports continued interest in reformulated products that can add nutritional value without compromising taste and quality (Li et al. 2023). Enhancing the nutritional profile of ground beef without affecting product quality may provide a value-added opportunity that aligns with both consumer demand and industry objectives (Flowers et al. 2019).

Interest in organ meats has recently become popular with an increase in dietary approaches that emphasize nutrient density and “nose-to-tail” eating (Latoch et al. 2024). Recent dietary movements have also emphasized the nutritional value of organ meats, further contributing to renewed interest in consumption (Latoch et al. 2024). Diet approaches such as the Wahls Protocol and the Biblio Diet highlight organ meats as concentrated sources of bioavailable micronutrients and functional compounds that may support metabolic and immune health (Wahls and Adamson 2014; Rubin and Axe 2025). This renewed attention matches the historical dietary practices in which organ meats were often consumed preferentially following harvest due to their recognized nutritional richness and perishability relative to skeletal muscle (Kuipers et al. 2010). Collectively, both historical dietary patterns and modern nutrition reinforce the relevance of organ meats in modern discussions of nutrient density, sustainability, and whole animal utilization.

Previous research evaluating organ meat inclusion is limited. However, some studies focus on single-organ incorporation or non-beef species with limited emphasis on quality and consumer acceptability. Differences in connective tissue content, flavor profiles, and nutrient composition among beef heart, liver, and kidney suggest that their inclusion may have distinct impacts on both nutritional and quality attributes (Fuerniss et al. 2024; Latoch et al. 2024). Comparative evaluation of beef organs within a ground beef product measuring physicochemical and consumer sensory outcomes remains limited.

Therefore, the objective of this study was to evaluate the effects of incorporating beef heart, beef liver, or beef kidney at a 15% inclusion level into ground beef patties on cooking characteristics and consumer acceptability. A 15% inclusion level was selected to represent a level that meaningfully incorporates organ meat while maintaining palatability of ground beef products based on prior research examining organ inclusion into ground beef products (Douglas et al. 2024). By comparing multiple organ types, results from this study provide insight into the feasibility of utilizing beef organs as value-added ingredients in ground beef products which offers potential benefits for consumers, processors, and sustainability of the beef industry.

Materials and methods

Raw materials

255 kg of beef top rounds (USDA Institutional Meat Purchasing Specifications #169A), 84 kg of beef 50:50 trimmings (USDA Institutional Meat Purchasing Specifications #138), 13 kg beef heart (USDA Institutional Meat Purchasing Specifications #1723), 13 kg of beef liver (USDA Institutional Meat Purchasing Specifications #1724), and 13 kg of beef kidney (USDA Institutional Meat Purchasing Specifications #1728) were obtained from a commercial meat distributor (Capital Farms, Wickenburg, AZ, USA) and transported under refrigerated conditions to the Lambert-Powell Meats Laboratory (Auburn, AL, USA). Beef top rounds and beef 50:50 trimmings were procured to manufacture a 80% lean ground beef block prior to organ inclusion. A Pearson square calculation was used to determine the proportion of lean beef top round and 50:50 trimmings required to achieve the target formulation. This standardized base formulation allowed treatment differences to be attributed to organ inclusion rather than variation in fat composition.

Three 11.34-kg batches were manufactured for each treatment. Each batch was formulated, mixed, ground, and processed prior to patty formation. To produce an 80% lean and 20% fat coarse grind, 8.5 kg of beef top rounds were combined with 3.1 kg of 50:50 trimmings and coarse ground through a 9.525 mm plate (SPECO 400, Shiller Park, IL, USA) using a commercial grinder (Model AFMG-48, Biro Manufacturing Company, Marblehead, OH, USA). Beef organs were processed separately through a 9.525 mm plate prior to incorporation into the coarse ground beef. Following organ inclusion, each batch was mixed for 3 min and then ground once through a 3.18 mm plate (SPECO 400, Shiller Park, IL, USA) equipped with a bone eliminator (SPECO 400, Shiller Park, IL, USA). Ground beef mixtures were formed into patties weighing 151.1 g (n = 75 patties/batch/treatment) using an automated patty former (Super 54, Hollymatic Corporation, Countryside, IL, USA).

Patties were crust-frozen at −25°C (Model LEH0630, Larkin, Stone Mountain, GA, USA) for 30 min prior to packaging. Individual patties were packaged using a thermoforming packaging system (Optimus OL0924, Variovac, Zarrentin, Germany) using a forming film with an oxygen transmission rate of 0.4 cc/m²/24 h and a non-forming film with an oxygen transmission rate of 1.0 cc/m²/24 h (WINPAK Ltd., Winnipeg, MB, Canada). Packaged patties were stored in the absence of light, at −22.7°C (Artic Air AF49, Brioch Enterprises, Minneapolis, MN, USA) until laboratory analyses were completed (7 days).

Nutritional density analysis

A composite sample of 500 g (167 g per batch) from each treatment was vacuum packaged, boxed and transported using a commercial shipping company and an insulated shipping container to a commercial laboratory (Food Safety Net Services, San Antonio, TX, USA) to determine nutritional composition (Table 1). Samples were submitted in triplicate for a composite analysis. Nutritional composition was determined by the contract laboratory using AOAC Official Methods of Analysis. Moisture (AOAC 950.46), crude protein (AOAC 992.15), total fat and fatty acids (AOAC 996.06), and ash (AOAC 920.153) were quantified to determine proximate composition. Cholesterol concentration was measured using AOAC 994.10. Mineral concentrations including calcium, iron, potassium, and sodium were measured according to AOAC methods 985.01M. Total calories were calculated from analytical values provided by the laboratory.

Table 1.

Proximate analysis and nutritional composition of beef patties with organ inclusion.

	Treatment
	Control	Heart	Liver	Kidney
n a	1	1	1	1
Protein (%)	19.86	18.86	19.64	18.98
Moisture (%)	63.62	65.62	65.28	65.28
Total fat (g)	15.45	14.44	13.56	14.49
Ash (%)	1.29	1.75	2.27	1.60
Energy (kcal)	218.50	205.41	200.60	206.35
Cholesterol (mg/100 g)	64.01	68.89	93.36	101.78
Iron (mg/100 g)	2.65	2.68	2.84	3.08
Sodium (mg/100 g)	39.44	40.58	40.90	55.84
Potassium (mg/100 g)	304.15	308.63	302.16	296.54

Control, ground beef patty with no organ inclusion; Heart, ground beef patty formulated with 15% beef heart; Liver, ground beef patty formulated with 15% beef liver; Kidney, ground beef patty formulated with 15% beef kidney.

^a n, number of composite samples per treatment. Each composite sample (500 g) was prepared by combining multiple patties across all batches within a treatment.

Cooking time and cooking loss

Before cooking, patties (n = 15/batch/treatment) were thawed for 12 h at 2.0°C (±1.5°C) in a two-door, refrigerated case (Model 178GDC49HCB, Clark Associates Inc. DBA Avantco Equipment, Lancaster, PA, USA). After thawing, patties were removed from packaging and gently blotted dry using a paper towel. Individual patty weights were recorded using an analytical balance (Model MA2002P, Mettler-Toledo, Leicester, United Kingdom). A commercial oven (Vulcan, Baltimore, MD, USA) was preheated to 176.7°C and patties were cooked until an internal temperature of 71.1°C was reached. Internal temperature was monitored using a multi-channel temperature data logger (TCTemp X-Series, LogMaster, ThermoWorks, American Fork, UT, USA) with temperature measurements automatically logged at 30 second intervals. Cooking time was defined as the duration required for patties to reach the target internal temperature of 71.1°C (n = 15/batch/treatment). After cooking, patties were cooled to room temperature and were re-weighed to determine final cooked weight. Cooking loss percentage was calculated using the following equation: [(cooked weight − raw weight) ÷ cooked weight × 100].

Instrumental color

To assess raw surface color, patties (n = 15/batch/treatment) were removed from their individual packaging and allowed to bloom for 20 min prior to color measurement allowing adequate exposure to atmospheric oxygen for color stabilization. Patties were cooked using the previously described cooking methods, allowed to cool to room temperature and sliced horizontally through the geometric center to record internal cooked color. Beef patty color was measured using a HunterLab MiniScan EZ colorimeter (Model 45/0 LAV, Hunter Associates Laboratory Inc., Reston, WV, USA). Prior to data collection, the colorimeter was calibrated using a black and white tile per the manufacturer specifications. Instrumental color values were obtained as the average of three readings per patty using illuminant A, an aperture of 31.8 mm, and a 10° observer to measure the lightness (L*), redness (a*) and yellowness (b*). Hue angle was calculated as: tan^{− 1} (b* ÷ a*) with increasing values indicative of the surface color shifting from red to yellow. Chroma (C*) was calculated as: √a*² + b*² where higher values reflect a more vivid color. In addition, reflectance values within the spectral range of 400 to 700 nm were used to capture the change in internal cooked color from red to brown by calculating the ratio of 630 nm ÷ 580 nm (King et al. 2023).

Texture analysis

Objective tenderness was determined using a 5-blade Allo–Kramer shear force attachment (AKSF) with a texture analyzer (Model TA.XT.Plus 10°C, Texture Technologies Corp., New York, NY, USA). Cooked and room temperature (23.3°C) patties (n = 15/batch/treatment) were cut into a 6 × 9 cm² cube. Shear force measurements were recorded using a 490.5 N load cell and a crosshead speed of 3 mm/s with each sample sheared once. Maximum peak force generated during shearing was recorded and reported as Allo-Kramer shear force (N).

Texture profile analysis (TPA) was conducted on patties (n = 15/batch/treatment) at room temperature using a texture analyzer (Model TA.XT.Plus 10°C, Texture Technologies Corp., New York, NY, USA). From each patty, three samples measuring 1 × 1 cm² were removed and subjected to a two-cycle compression test using a 490.5 N load cell. Samples were compressed to 50% of their original height using a cylindrical probe in 50 mm diameter (TA-25A) at a crosshead speed of 6.0 cm/min. Texture attributes were calculated following established procedures (AMSA 2016; Tobin et al. 2012) and included hardness (kg), defined as the force required to compress the sample; cohesiveness, defined as the degree of structural integrity prior to fracture; springiness, defined as the ability of the sample to recover its original height after deformation; and chewiness (kg × cm), calculated as the product of hardness, cohesiveness, and springiness and representing the energy required to masticate the sample prior to swallowing.

Consumer panel

Consumer panelists 18 years or older who reported consuming ground beef at least three to four times per month were recruited to participate (n = 92; Table 2). Study protocol was reviewed and approved as exempt by the Auburn University Institutional Review Board (Exempt Protocol STUDY00000959). Sample order was generated using RedJade sensory software (version 6.1, Pleasant Hill, CA, USA) to ensure randomized serving sequences with samples identified using randomly assigned three-digit blinding codes. Ground beef patties (n = 25/treatment) were cooked to an internal temperature of 71.1°C and cut into triangular portions (n = 4/patty) in accordance with American Meat Science Association guidelines (AMSA 2016). Prepared samples were served in a randomized order to panelists in individual sensory booths under red color-masked lighting conditions. Panelists were instructed to cleanse their palate between samples using room-temperature water and unsalted saltine crackers (Great Value Unsalted Tops, Walmart Inc., Bentonville, AR, USA). Consumers evaluated samples for overall liking, appearance, aroma, flavor, and texture using a 9-point hedonic scale (1 = dislike extremely; 9 = like extremely). Additionally, perceived intensity of juiciness, tenderness, and beef flavor was assessed using 9-point intensity scales, where juiciness ranged from 1 = extremely dry to 9 = extremely juicy; tenderness from 1 = extremely tough to 9 = extremely tender; and beef flavor intensity from 1 = none to 9 = extremely intense. Panelists were provided a list of descriptive sensory attributes. Panelists were asked to select which attributes they felt applied to each sample including beefy, liver-like, metallic, bland, fatty, juicy, dry, tender and an open-ended ‘other’ category.

Table 2.

Consumer panel demographics and purchasing characteristics.

	Respondents, %
n a	92
Sex
Male	57.61
Female	42.39
Age
18 to 20 years	3.27
21 to 29 years	57.63
30 to 39 years	26.03
40 to 49 years	8.71
50 to 59 years	1.10
60 to 69 years	3.27
Ethnicity
Caucasian	59.78
Latino/Hispanic	15.22
African American	13.04
Native American	0
Asian or Pacific Islander	9.78
Other	2.18
Income
Less than $30,000	65.21
$30,000 to $49,999	14.13
$50,000 to $79,999	11.96
Greater than $80,000	8.70
Consumes Ground Beef
Once a day	4.35
More than 3 times per week	11.96
2–3 times per week	47.83
Once a week	20.65
2–3 times per month	15.21
Purchase Ground Beef
Once a week	22.83
Once every 2 or 3 weeks	54.35
Once a month	9.78
Once every 2 or 3 months	11.96
Once every 4 to 6 months	0
Once or twice a year	0
Less than once a year	1.08

^a n, total number of consumers who completed the testing. Values are expressed as percentage of respondents.

Statistical analysis

Data was analyzed using the GLIMMIX procedure of SAS (version 9.4; SAS Institute Inc., Cary, NC, USA). Patties produced within each batch served as experimental unit for each analysis, while batch represented the independent manufacturing replicate included as a random effect in the statistical model. For physicochemical and instrumental measurements (cook loss, cook time, raw and cooked color, Allo–Kramer shear force, and texture profile analysis), treatment was included as a fixed effect and batch served as a random blocking factor. Consumer sensory ratings were analyzed using a mixed model with treatment as a fixed effect and panelist as random effect. For descriptive sensory attribute selection frequencies, each sensory descriptor was analyzed as a binary response (selected or not selected). Data was analyzed using the GLIMMIX procedure with a binomial distribution and logit link function with treatment included as a fixed effect and panelist as a random effect. Pairwise comparisons among treatments were performed using the LINES option. Significance was declared at (P ≤ 0.05) with tendencies discussed at 0.05 ≤ P ≤ 0.10. Least square means were separated using pairwise comparisons generated with the PDIFF option. Orthogonal contrasts comparing organ inclusion versus control were also evaluated.

Results and discussion

Nutritional composition

Nutritional values are presented in Table 1. Results indicate that organ inclusion modified the nutrient profile of the ground beef patties. Liver and kidney treatments exhibited greater iron concentrations than the control, which is consistent with previous reports describing these organs as concentrated sources of bioavailable iron and essential micronutrients (Fuerniss et al. 2024; Latoch et al. 2024). Additionally, replacement of skeletal muscle and fat trim with organ meats reduced fat content across treatments while contributing nutrients such as B vitamins, selenium, and vitamin A, particularly in liver and kidney tissues (Fuerniss et al. 2024). Beef heart has been recognized as a nutrient-dense ingredient, providing high-quality protein and essential micronutrients while maintaining a composition more similar to conventional skeletal muscle (Douglas et al. 2024). Overall, these observations support the potential for edible beef organs to enhance the nutritional density of ground beef products.

Cooking characteristics

Cooking characteristics of meat products can often be influenced by formulation of a product. Variations in moisture, fat, and protein alter the extent of denaturation, rendering and moisture retention (Tornberg 2005; Hughes et al. 2014). These factors ultimately determine cook loss and product quality (Zielbauer et al. 2016; Bhat et al. 2021). In ground beef, muscle fiber structure is altered through grinding. Therefore, the importance of protein and water interaction increases to maintain product quality through cooking (Abdul et al. 2025). Cooking characteristics for each treatment are presented in Table 3.

Table 3.

Cook loss and cook time of ground beef patties with 15% inclusion of organ meats.

	Treatment
	Control	Heart	Liver	Kidney	SEM*	P-value	Contrasta
n b	45	45	45	45
Cook loss (%)	26.92c	25.78d	20.50e	23.85f	0.320	<0.0001	<0.0001
Cook time (sec)	943.32	858.65	841.96	943.34	63.23	0.4844	0.3625

^aOrthogonal contrast: beef organ vs. control; Control, ground beef patty with no organ inclusion; Heart, ground beef patty formulated with 15% beef heart; Liver, ground beef patty formulated with 15% beef liver; Kidney, ground beef patty formulated with 15% beef kidney.

^b n, number of samples per treatment (15 per batch; 45 total per treatment).

^c–fMean values within a row lacking common superscripts differ (P < 0.05).

^*SEM, standard error of the mean.

A main effect of treatment was observed for cook loss (P < 0.0001) with liver patties exhibiting the least amount of cook loss followed by kidney, heart, and control patties with all treatments differing. Orthogonal contrast further indicated that patties containing organ meats differed from control patties (P < 0.0001) as control patties exhibited the greatest amount of cook loss. These results suggest that inclusion of organ meats improved moisture and fat retention during cooking. Reduced cook loss is likely driven by differences in protein composition and structural organization between organ tissues and skeletal muscle, particularly reduced myofibrillar protein integrity and altered connective tissue characteristics, which enhance water-binding capacity during thermal processing (Pereira and Vicente 2013). During cooking, protein denaturation occurs which alters the interaction between protein and water resulting in moisture loss. Additionally, the decrease in cook loss observed in patties containing liver and kidney is likely due to compositional differences between organ tissues and skeletal muscle (Tornberg 2005). Results indicate improved water-holding capacity with organ meat inclusion compared to control patties. Similar trends have been reported in ground beef products where formulation changes improved water-holding capacity and reduced cooking loss. Incorporation of non-meat ingredients such as plant proteins, fibers, and extenders has been shown to enhance moisture retention by increasing the ability of the protein matrix to bind water during cooking (Kassama et al. 2003; Bhat et al. 2021). These findings indicate that formulation changes can influence moisture retention properties in ground beef.

Despite differences in cook loss, cooking time did not differ among treatments (P = 0.4844) indicating that organ inclusion at 15% did not alter the time required to reach an internal cooked temperature of 71.1°C. Orthogonal contrast suggests organ inclusion did not alter cooking time when compared to control (P = 0.3625). Similar observations have been reported in ground beef patties where formulation changes influenced cooking yield without affecting cooking time when patty size, heat application, and endpoint temperature were controlled (Ball et al. 2021; Douglas et al. 2024). Overall, these findings indicate that incorporating beef organ meats, particularly liver and kidney can improve cooking yield through reduced cooking losses without negatively altering cooking performance for consumers or foodservice.

Instrumental color analysis

Raw red meat color is a primary factor influencing consumer purchasing decisions and is regulated by myoglobin state and concentration (Pujol et al. 2023; Malheiros et al. 2025). Instrumental raw surface color values are presented in Table 4. A main effect of treatment was observed for all raw color attributes, including lightness (P < 0.0001), redness (P < 0.0001), yellowness (P < 0.0001), hue angle (P < 0.0001) and chroma (P < 0.0001). Lightness values differed in patties containing liver exhibiting lower L* values, resulting in a darker raw surface color compared to other treatments. Patties containing beef liver and beef kidney exhibited the greatest redness values (P < 0.0001) which were both greater than patties containing beef heart and control. Increased redness observed in patties containing liver and kidney may be attributed to greater concentrations of heme pigments and iron-containing compounds that are often found in visceral tissues (Valenzuela et al. 2009; Pereira and Vicente 2013). In addition, chroma values were greatest for patties containing liver and kidney, followed by control and patties containing beef heart. Higher chroma values indicate an increase in color saturation suggesting that organ inclusion, particularly liver and kidney result in a more vivid red appearance (King et al. 2023). Furthermore, orthogonal contrast indicated that patties containing beef organs differed from control patties with an increase in redness, yellowness, hue angle and chroma (P < 0.0001), while lightness was not affected by organ inclusion (P = 0.2373). These results indicate that organ inclusion increased both the intensity and saturation of red color, likely due to elevated heme pigment concentrations inherent to organ tissues. Increased color intensity and saturation has the potential to positively influence consumer purchasing (King et al. 2023; Lybarger et al. 2023).

Table 4.

Raw surface color of ground beef patties with 15% inclusion of organ meats.

	Treatment
	Control	Heart	Liver	Kidney	SEM*	P-value	Contrasta
n b	45	45	45	45
Lightness (L*)c	46.36d	46.58d	45.36e	46.40d	0.263	<0.0001	0.2373
Redness (a*)g	19.85f	23.57e	25.27d	25.47d	0.389	<0.0001	<0.0001
Yellowness (b*)h	17.23e	19.27d	19.78d	19.84d	0.279	<0.0001	<0.0001
Hue Angle (°)i	41.15d	39.32e	38.07f	37.95f	0.203	<0.0001	<0.0001
Chromaj	26.31f	30.45e	32.10d	32.29d	0.468	<0.0001	<0.0001

^*SEM, standard error of the mean.

^aOrthogonal contrast: beef organ vs. control.

^b n, number of samples per treatment (15 per batch; 45 total per treatment).

^cLightness (L*) – values are a measure of darkness to lightness (a larger value indicates a lighter color).

^d,e,fMean values within a row lacking common superscripts differ (P < 0.05).

^gRedness (a*) – values are a measure of redness (a larger value indicates a redder color); and.

^hYellowness (b*) – values are a measure of yellowness (a larger value indicates a more yellow color).

ⁱHue angle (°) represents the change in color from the true red axis (a larger number indicates a greater shift from red to yellow).

^jC* (Chroma) is a measure of total color (a larger number indicates a more vivid color). Control, ground beef patty with no organ inclusion; Heart, ground beef patty formulated with 15% beef heart; Liver, ground beef patty formulated with 15% beef liver; Kidney, ground beef patty formulated with 15% beef kidney.

Cooked color values are presented in Table 5. A main effect of treatment was observed for all cooked color attributes, including lightness, redness, yellowness, hue angle, chroma, and red-to-brown ratio (P < 0.0001). Liver patties exhibited the greatest lightness, redness, yellowness, and chroma values (P < 0.05), followed by kidney, heart, and control patties. Control and heart patties consistently exhibited the lowest redness and chroma values, indicating a less intense cooked color. Kidney patties were intermediate for most color attributes but remained greater than control and heart treatments. Hue angle differed among treatments (P < 0.0001), with control patties exhibiting the greatest values, followed by heart, kidney, and liver patties. Lower hue angle values indicate a shift toward a redder color, further supporting that liver and kidney treatments maintained a more intense red color following cooking. Red-to-brown ratio followed a similar trend, with liver patties exhibiting the greatest values followed by patties containing kidney while control and patties containing heart were lowest (P < 0.05). Increased red-to-brown ratios indicate greater retention of red color relative to brown pigment formation. During cooking, myoglobin denatures and forms brown pigments. However, greater initial pigment concentrations can result in persistent redness following thermal processing (Tornberg 2005; Suman et al. 2014). An increase in redness, chroma, and red-to-brown ratios observed in liver and kidney treatments suggest that pigment concentration exceeded the threshold for complete visual browning, resulting in a darker and redder cooked appearance (Trout 1989; Suman et al. 2014). Additionally, differences in biochemical properties of organ tissues, including pH and protein composition, may influence pigment stability and denaturation kinetics during cooking (Tornberg 2005). Increased pigment stability may delay the transition from red to brown pigments, contributing to the persistent red color observed in liver and kidney treatments. Similar effects have been reported in ground beef systems where formulation changes altered pigment concentration and resulted in cooked color that does not align with traditional expectations of doneness (Hollenbeck et al. 2019). Orthogonal contrasts indicated that patties containing organ meats differed from control patties for all cooked color attributes (P < 0.0001), confirming that organ inclusion significantly altered cooked color characteristics relative to traditional ground beef.

Table 5.

Internal cooked color of ground beef patties with inclusion of organ meats.

	Treatment
	Control	Heart	Liver	Kidney	SEM*	P-value	Contrasta
n b	45	45	45	45
Lightness (L*)c	57.77d	59.11e	60.84f	57.71d	0.273	<0.0001	<0.0001
Redness (a*)h	14.79g	15.90d	19.40f	17.10e	0.283	<0.0001	<0.0001
Yellowness (b*)i	16.56d	17.46e	19.51f	17.85e	0.169	<0.0001	<0.0001
Hue Angle (°)j	48.43f	47.76f	45.24d	46.76f	0.272	<0.0001	<0.0001
Chromak	22.21g	23.63d	27.52f	24.74e	0.312	<0.0001	<0.0001
Red-to-Brownl	1.83d	1.88d	2.09f	1.99e	0.022	<0.0001	<0.0001

^aOrthogonal contrast: beef organ vs. control;.

^b n, number of samples per treatment (15 per batch; 45 total per treatment).

^cLightness (L*) – values are a measure of darkness to lightness (a larger value indicates a lighter color).

^d–gMean values within a row lacking common superscripts differ (P < 0.05). * SEM, standard error of the mean.

^hRedness (a*) – values are a measure of redness (a larger value indicates a redder color); and.

ⁱYellowness (b*) – values are a measure of yellowness (a larger value indicates a more yellow color).

^jHue angle (°) represents the change in color from the true red axis (a larger number indicates a greater shift from red to yellow).

^kC* (Chroma) is a measure of total color (a larger number indicates a more vivid color).

^lRed to brown is the reflectance ratio of 630 nm ÷ 580 nm and represents a change in color from red to brown (a larger value indicates a redder color). Control, ground beef patty with no organ inclusion; Heart, ground beef patty formulated with 15% beef heart; Liver, ground beef patty formulated with 15% beef liver; Kidney, ground beef patty formulated with 15% beef kidney.

Increased redness and persistent red color in cooked patties may influence consumer perception of doneness, as consumers often associate brown color with fully cooked meat (USDA ERS 2024). Therefore, organ inclusion may result in products that appear undercooked despite reaching a safe internal temperature.

Objective texture analysis

Instrumental texture properties were evaluated using Allo-Kramer shear force (AKSF) and texture profile analysis (TPA). These methods provide objective measurements on tenderness and texture characteristics of cooked meat products (Table 6). A main effect of treatment was observed for Allo–Kramer shear force (P < 0.0001), hardness (P < 0.0001), cohesiveness (P < 0.0001), chewiness (P < 0.0001), and resilience (P = 0.0010), while springiness was not affected by treatment (P = 0.4250). Patties containing beef kidney and liver exhibited lower shear force values than control and patties containing beef heart (P < 0.0001). Meanwhile, shear force values for control and beef heart patties were similar and did not differ from each other (P = 0.9591). These results indicate that inclusion of liver and kidney improved objective tenderness relative to traditional ground beef formulations. Similarly, hardness values were greatest for heart patties followed by control, kidney and liver with all treatments differing (P < 0.05). This aligns with AKSF results, indicating that liver and kidney treatments required less force to compress and shear. Chewiness followed a similar pattern with control and patties containing heart exhibiting greater values than patties containing liver and kidney. It is plausible these differences were due to changes in protein composition and increased moisture retention from the liver and kidney as formulation can alter texture and water-holding capacity (Hughes et al. 2014). Previous literature reports an increased water-holding capacity and reduced cooking loss have been linked to improved tenderness in ground meat products (Hughes et al. 2014). Moreover, cohesiveness differed among treatments (P < 0.0001), with heart patties exhibiting the greatest values, while control, liver, and kidney treatments had lower values and were similar. Increased cohesiveness in heart patties suggests greater structural integrity during compression, which may contribute to the higher hardness and shear force observed for this treatment. Resilience was also affected by treatment (P = 0.0010), with heart patties exhibiting greater resilience compared to control, liver and kidney treatments. This indicates that patties containing heart were better able to recover following deformation which reflects a firmer and more elastic structure. Springiness was not affected by treatment (P = 0.4250), indicating that organ inclusion did not influence the ability of the sample to return to its original height after compression. Orthogonal contrasts indicated that patties containing organ meats differed from control patties for AKSF (P < 0.0001), hardness (P < 0.0001), cohesiveness (P = 0.0483), and chewiness (P < 0.0001), while no differences were observed for springiness (P = 0.9178) or resilience (P = 0.9865). Observed improvements in tenderness for liver and kidney treatments may be attributed to differences in tissue structure and moisture retention. Organ tissues possess less organized muscle fiber structure and altered connective tissue composition compared to skeletal muscle, which reduces resistance to mechanical shear (Tornberg 2005). Additionally, reduced cook loss observed in these treatments suggests improved water-holding capacity, which contributes to a softer product by reducing internal resistance within the protein matrix (Hughes et al. 2014). These findings are consistent with previous studies where ground beef formulation changes can increase moisture retention resulting in decreased shear force, hardness, and chewiness values (Bhat et al. 2021). These findings further support that compositional differences of a product influence both structural and textural properties of ground beef patties.

Table 6.

Objective tenderness values of ground beef patties with 15% organ inclusion.

	Treatment
	Control	Heart	Liver	Kidney	SEM*	P-value	Contrasta
n b	45	45	45	45
AKSF (N)	301.08c	300.79c	196.65d	225.37e	4.360	<0.0001	<0.0001
Hardness (kg)	2994.12e	3128.59c	1823.25f	2174.98d	75.037	<0.0001	<0.0001
Springinessg	0.83	0.79	0.88	0.80	0.044	0.4250	0.9178
Cohesivenessh	0.42e	0.50c	0.42e	0.43e	0.012	<0.0001	0.0483
Chewinessi	1271.55c	1245.15c	713.42e	767.86e	65.523	<0.0001	<0.0001
Resiliencej	0.16e	0.18c	0.16e	0.15e	0.006	0.0010	0.9865

^aOrthogonal contrast: beef organ vs. control.

^b n, number of samples per treatment (15 per batch; 45 total per treatment).

^c–fMean values within a row lacking common superscripts differ (P < 0.05). *SEM, standard error of the mean.

^gSpringiness—ratio of the time duration of force input during the second compression to that during the first compression or length 2 ÷ length 1;.

^hCohesiveness—ratio of the positive force area during the second compression to that during the first compression or area 2 ÷ area 1;.

ⁱChewiness—hardness × cohesiveness × springiness;.

^jResilience—ratio of the time duration of force input during the first compression or area 5 ÷ area 4. Control, ground beef patty with no organ inclusion; Heart, ground beef patty formulated with 15% beef heart; Liver, ground beef patty formulated with 15% beef liver; Kidney, ground beef patty formulated with 15% beef kidney.

Consumer sensory analysis

Consumer panelists evaluation of sensory attributes was conducted to highlight the consumer acceptability of beef patties formulated with various beef organs. It is important to note a limitation of the present study. Consumer panelists were predominantly young and Caucasian. Consumer acceptance of organ meats may vary according to age, cultural background, prior exposure and attitudes toward nose-to-tail eating. Therefore, the findings of this study may not be fully representative of the broader U.S. consumer population. Future research should evaluate acceptance of organ-enhanced beef products across more diverse demographic groups to better understand potential market opportunities and consumer preferences. Ratings for overall liking are presented in Table 7. A main effect of treatment was observed for overall liking (P < 0.0001), appearance (P = 0.0430), aroma (P < 0.0001), flavor (P < 0.0001), and texture (P = 0.0010). Patties containing beef liver received the lowest ratings for overall liking (P = 0.0003), aroma (P = 0.5208), flavor (P = 0.0004), and texture (P = 0.0023) compared with control and heart patties, while kidney patties were intermediate for overall liking and appearance. Reduced liking for liver containing patties may be associated with the “liver-like” flavor compounds that differ from traditional beef flavor profiles which can negatively influence consumer acceptance. Control and heart patties received similar ratings for overall liking (P = 0.5208), appearance (P = 0.5823), aroma (P = 0.1756), and texture (P = 0.6387) with a tendency for a difference in flavor scores (P = 0.0763). Previous research evaluating beef heart inclusion suggests similar results in flavor ratings for control and samples containing beef heart (Douglas et al. 2024). Orthogonal contrast analysis indicated that patties containing beef organs received lower ratings than control patties for overall liking (P = 0.0002), overall aroma (P = 0.0001), and overall flavor (P < 0.0001). Furthermore, patties containing organs tended to receive lower ratings for overall appearance (P = 0.0714) and overall texture (P = 0.0794) than control patties.

Table 7.

Consumer panelists’ overall sensory ratings.

	Treatment
Sensory Anchora	Control	Heart	Liver	Kidney	SEM*	P-value	Contrastb
Overall Liking	6.51c	6.36cd	4.98e	5.90d	0.199	<0.0001	0.0002
Overall Appearance	6.63c	6.52c	6.10d	6.39cd	0.165	0.0430	0.0714
Overall Aroma	6.89c	6.60c	5.88d	6.12d	0.175	<0.0001	0.0001
Overall Flavor	6.83c	6.36c	4.58e	5.52d	0.211	<0.0001	<0.0001
Overall Texture	6.26c	6.15c	5.38d	6.18c	0.204	0.0010	0.0794

^*SEM, standard error of the mean.

^aSensory anchor—consumer panelist ratings represent the use of a 9-point hedonic scale (1 = dislike extremely to 9 = like extremely);.

^bOrthogonal contrast—beef organ vs. control. Control, ground beef patty with no organ inclusion; Heart, ground beef patty formulated with 15% beef heart; Liver, ground beef patty formulated with 15% beef liver; Kidney, ground beef patty formulated with 15% beef kidney.

^c–eMean values within a row lacking common superscripts differ (P < 0.05).

Consumer sensory intensity ratings are presented in Table 8. A main effect of treatment was observed for juiciness (P < 0.0001), tenderness (P < 0.0001), and beef flavor intensity (P = 0.0301). Kidney patties exhibited greater juiciness ratings followed by patties containing liver, control and patties containing heart. Moreover, patties containing liver and kidney exhibited increased tenderness ratings compared with control and patties containing heart. Greater juiciness and tenderness ratings for kidney containing patties are consistent with reduced cook loss and lower instrumental shear force observed for this treatment suggesting improved moisture retention which contributes to an increase in palatability. Literature reports that kidneys often contain the most amount of moisture in comparison to liver and heart which would explain the increased juiciness and tenderness in the current study (Park et al. 1991). Orthogonal contrast indicates that patties containing beef organs differed from control patties for juiciness (P = 0.0284) and tenderness (P = 0.0004), whereas beef flavor intensity was not affected by organ inclusion (P = 0.3904). Orthogonal contrast results support the idea of other results in this study that inclusion of organ meats provides a juicier and more tender product due to the water-holding capacity and moisture retention.

Table 8.

Consumer panelists’ intensity ratings for ground beef samples with 15% organ inclusion.

	Treatment
Sensory Anchora	Control	Heart	Liver	Kidney	SEM*	P-value	Contrastb
Juiciness	5.15cd	5.04d	5.61c	6.20e	0.200	<0.0001	0.0284
Tenderness	6.14c	6.23c	6.79e	7.06e	0.153	<0.0001	0.0004
Beef Flavor Intensity	6.09ce	5.72c	5.76c	6.31e	0.185	0.0301	0.3904

^*SEM, standard error of the mean.

^aSensory anchor—consumer panelist ratings represent the use of a 9-point hedonic scale for juiciness (1 = extremely dry to 9 = extremely juicy); tenderness (1 = extremely tough to 9 = extremely tender); and beef flavor intensity (1 = none to 9 = extremely intense).

^bOrthogonal contrast—beef organ vs. control. Control, ground beef patty with no organ inclusion; Heart, ground beef patty formulated with 15% beef heart; Liver, ground beef patty formulated with 15% beef liver; Kidney, ground beef patty formulated with 15% beef kidney.

^c–eMean values within a row lacking common superscripts differ (P < 0.05).

Descriptive sensory attributes are presented in Table 9. A main effect of treatment was observed for beefy (P = 0.0013), liver-like (P < 0.0001), metallic (P = 0.0441), juicy (P = 0.0056), dry (P < 0.0001), and tender attributes (P < 0.0001). Patties containing liver were most frequently described as liver-like (P < 0.0093) compared to all other treatments. Additionally, patties containing liver were described as more metallic (P = 0.0102) compared to control. Kidney patties were more often characterized as juicy (P = 0.0026) and tender (P = 0.0013), while control and heart patties were most frequently described as dry (P = 0.0095) compared with liver and kidney. Similar sensory trends have been reported in previous work evaluating meat products formulated with liver, where samples containing liver received lower sensory scores than control treatments and panelists identified bitterness and burnt flavor notes in meatloaves containing liver (Devatkal et al. 2004). Orthogonal contrast analysis indicated that patties containing beef organs differed from control patties for beefy (P = 0.0008), liver-like (P = 0.0004), dry (P < 0.0001), and tender (P = 0.0056) attributes. Whereas a trend was identified for an increase in metallic flavor (P = 0.0565) selection with organ meat inclusion. Collectively, these descriptive outcomes align with overall liking responses, indicating that organ-specific flavor and texture characteristics contributed to differences in consumer acceptance among treatments.

Table 9.

Percentage of consumers selecting sensory descriptors for ground beef samples with organ inclusion.

	Treatment
Sensory Descriptors	Control	Heart	Liver	Kidney	SEM*	P-value	Contrasta
Beefy	70.18b	57.20bc	48.77d	40.37cd	0.248	0.0013	0.0008
Liver-Like	3.96d	5.98d	47.82b	28.54c	0.360	<0.0001	0.0004
Metallic	5.36c	8.58bc	18.32b	12.90bc	0.358	0.0441	0.0565
Bland	21.04	34.84	26.69	28.99	0.264	0.2407	0.1028
Juicy	28.15c	25.97c	21.62c	44.54b	0.237	0.0056	0.7511
Dry	44.53b	42.34b	7.52c	2.16d	0.279	<0.0001	<0.0001
Tender	32.02c	40.35c	66.86c	41.56b	0.252	<0.0001	0.0056
Fatty	12.01	11.01	12.01	15.07	0.348	0.8437	0.8772
Other	3.19	3.19	2.13	3.19	0.657	0.9538	0.8408

Percentages represent the percentage of panelists selecting each sensory descriptor.

^*SEM, standard error of the mean.

^aOrthogonal contrast—beef organ vs. control. Percentage values are relative to the number of participants (n = 92). Control, ground beef patty with no organ inclusion; Heart, ground beef patty formulated with 15% beef heart; Liver, ground beef patty formulated with 15% beef liver; Kidney, ground beef patty formulated with 15% beef kidney.

^b–dMeans within a row lacking common superscripts differ (P < 0.05) based on pairwise comparisons.

An important consideration for commercial implementation is that products containing edible beef organs do not meet the current USDA standard of identity for “ground beef” and would therefore require an alternative product name and labeling that accurately reflects their composition. Consequently, the products evaluated in the present study should be considered novel beef-based formulations rather than traditional ground beef products. Although consumer acceptance of certain formulations, particularly those containing beef heart, was comparable to control patties, regulatory labeling requirements and consumer perceptions toward organ meat inclusion may influence market adoption. Future research should investigate consumer willingness to purchase and preferences for appropriately labeled organ-enhanced beef products.

Formulation cost comparison

To provide practical industry context, an ingredient cost comparison was conducted to estimate differences in formulation costs among treatments using current market prices. This comparison was intended to illustrate the potential effect of substituting skeletal muscle with organ meats and does not represent a comprehensive economic analysis. Market price differentials between skeletal muscle and organ meats are well documented, with organ meats typically marketed at lower values due to reduced consumer demand (USDA ERS 2024; Ramanathan et al. 2022). Ingredient prices used in this analysis were based on current market estimates, with liver, kidney, and heart priced at $3.31/kg, $4.96/kg, and $8.27/kg, respectively (Table 10). Replacing 15% of ground beef with organ meats reduced formulation cost across all treatments. Liver inclusion resulted in the greatest cost reduction, followed by kidney and heart. Formulation cost decreased from $10.76/kg for the control to $9.66/kg for liver, $9.99/kg for kidney and $10.38 for heart. This represents an estimated reduction in ingredient cost of $1.10/kg for liver, $0.77/kg for kidney and $0.38/kg for heart relative to control. Organ inclusion reduced cost per patty from $1.63 to $1.46–$1.57, resulting in a savings of $0.06 to $0.17 per patty.

Table 10.

Estimated formulation cost of ground beef patties with 15% organ inclusion.

Treatment	Cost ($/kg)	Cost reduction ($/kg)	Percent reduction (%)
Control	$10.76	$0.00	0
Heart	$10.38	$0.38	3.53
Liver	$9.66	$1.10	10.22
Kidney	$9.99	$0.77	7.16

Values represent estimated formulation cost based on average market prices. Cost estimates are based on ingredient substitution and do not account for processing, labor, or distribution costs. Control, ground beef patty with no organ inclusion; Heart, ground beef patty formulated with 15% beef heart; Liver, ground beef patty formulated with 15% beef liver; Kidney, ground beef patty formulated with 15% beef kidney.

In addition to ingredient cost savings, treatments containing organ meats exhibited lower cook loss (P < 0.0001) resulting in greater cooking yields than control patties. Although improved cooking yield may contribute to product value by increasing retained product weight, the economic impact of these yield differences was not quantified in the present study. Calculated yield increased from $73.08 in the control to 74.22% for heart, 76.15% for kidney and 79.50% for patties containing liver. Improved water-holding capacity and reduced cooking losses have been associated with increased economic return in ground meat systems (Hughes et al. 2014). Meat quality attributes such as moisture loss, color, and texture have also been shown to directly influence economic outcomes through impacts on product yield and consumer acceptance (Ramanathan et al. 2022). A comprehensive economic evaluation incorporating processing costs, labor, retail pricing, consumer acceptance, and market demand could be beneficial to determine the commercial feasibility of organ-enhanced ground beef.

Conclusion

Incorporating beef organs at a 15% inclusion level significantly influenced physicochemical quality characteristics and consumer sensory perception of ground beef patties. Liver and kidney inclusion reduced cook loss and instrumental shear force, corresponding with increased perceived juiciness and tenderness among consumers. However, liver inclusion negatively impacted overall liking and was associated with increased detection of liver-like and metallic flavor attributes, indicating limitations in consumer acceptance at the evaluated inclusion level. In contrast, beef heart maintained instrumental texture, color stability, and sensory characteristics most comparable to control patties, suggesting minimal deviation from traditional ground beef quality.

From an application standpoint, organ inclusion improved cooking yield and reduced formulation cost, demonstrating potential economic benefits alongside enhanced carcass utilization. Among the organs evaluated, kidney inclusion provided improvements in palatability attributes such as juiciness and tenderness but presented moderate sensory challenges, whereas heart inclusion offered the most favorable balance between product quality and consumer acceptability.

Collectively, these findings demonstrate that organ type is a primary determinant of product quality and consumer perception in organ-enhanced ground beef systems. Results support the feasibility of incorporating select beef organs, particularly heart and kidney, into value-added beef patty formulations, although future commercialization would require product labeling that accurately reflects organ inclusion and complies with current USDA standards of identity. Future research should evaluate varying inclusion levels and processing strategies to optimize formulation approaches that balance nutritional enhancement, economic efficiency, and consumer acceptance.

Funding

This project was funded in part by the Alabama Cattlemen’s Association, Agricultural Research Service, U.S. Department of Agriculture under Agreement No. 58–6010-1–005, the National Institute of Food and Agriculture, U.S. Department of Agriculture under Agreement No. 2023–67018-39182, and AAES Professional Enhancement for Emerging Researchers (PEER) Grant Program.

Glossary

List of abbreviations

AMSA

American Meat Science Association

AKSF

Allo-Kramer shear force

SEM

Standard error of the mean

TPA

Texture profile analysis

USDA ERS

United States Department of Agriculture Economic Research Service

Conflicts of interest

None declared.