Determination of volatile aroma compounds in beef using differences in steak thickness and cook surface temperature

A current review of U.S. beef flavor I: Measuring beef flavor

Historically, consumer acceptance of beef was determined by tenderness. Developments in genetics and management over the last couple of decades have improved tenderness to the point that it is secondary to other factors in beef's taste. Flavor, however, is an extraordinarily complex taste attribute dependent on biological sensors in the mouth, sinus cavity, and jaws. The culinary industry has recently focused on innovative ways to give consumers new products satisfying their curiosity about different foods, especially proteins. Competition from plant-based, cell-based, and even other animal-based proteins provides diversity in consumers' ability to select a protein that satisfies their desire to include unique products in their diet. Consequently, the beef industry has focused on flavor for the last 10 to 15 years to determine whether it can provide the guardrails for beef consumption in the future. The U.S. beef industry formed a Flavor Working Group in 2012 composed of the authors listed here to investigate new and innovative ways to manage and measure beef flavor. The results of this working group have resulted in dozens of papers, presentations, abstracts, and symposia. The objective of this manuscript is to summarize the research developed by this working group and by others worldwide that have investigated methodologies that measure beef flavor. This paper will describe the strengths of the research in beef flavor measurement and point out future needs that might be identified as technology advances.

A current review of U.S. beef flavor II: Managing beef flavor

Beef flavor continues to be one of the largest drivers of beef demand and a differentiation point of beef from other competing proteins. Tenderness has long been identified as the most important palatability trait for consumer satisfaction. However, as technological advancements and industry practices evolve and improve in response to tenderness management, flavor has emerged as a key driver of consumer satisfaction. In response, the beef industry has recently invested in research focused on beef flavor development, measurement, and management to better understand the factors impacting flavor and help beef maintain this advantage. The current review paper is the second of two such papers focused on summarizing the present knowledge and identifying knowledge gaps. While the other review focuses on current practices related to beef flavor measurement, this review will cover research findings related to beef flavor management. Numerous production and product management factors influence beef flavor. Pre-harvest factors including marbling level, animal genetics/cattle type, diet, and animal age, can influence beef flavor. Moreover, numerous post-harvest product management factors, including product type, aging length and conditions, cookery methods, product enhancement, muscle-specific factors, packaging, retail display factors, and antimicrobial interventions, have all been evaluated for their impact on beef flavor characteristics. Results from numerous studies evaluating many of these factors will be outlined within this review in order to present management and production chain factors that can influence beef flavor.

Changes provoked by altitudes and cooking methods in physicochemical properties, volatile profile, and sensory characteristics of yak meat

The present study aimed to shed light on the effects of altitudes and three cooking methods (boiling, steaming, and roasting) on the physicochemical quality, volatile profile, and sensorial characteristics of yak meat. Composite meat samples were prepared to represent each cooking method and altitude level from the longissimus thoracis et lumborum (LTL) muscle of nine yaks. The techniques employed were gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-nose) along with chemometrics analysis to study the changes occurring in yak volatile profile, and TBARS measurement in lipid oxidation during cooking. Among the cooking methods, boiling and steaming exhibited higher protein and fat content while lower volatile compound contents. Additionally, roasted yak meat received the highest sensory scores, along with decreased L*-values, while elevated a*- and b*-values, and tenderness. A total of 138 volatile compounds were detected, and among them, 36 odorants were identified as odor-active compounds in cooked yak meat. It is evidenced that low-altitude yak presented more complex and richer flavor profiles than high-altitude ones. Moreover, yak meat from low- and high-altitude was classified into two groups by an electronic nose (E-nose) owing to distinct flavor characteristics. Overall, roasted yak meat originating from low altitudes tends to be more popular from a sensory perspective.

Trained sensory descriptors and volatile aroma compounds of USDA Select steaks using five grill temperatures

Thirty-three USDA Select boneless top loins were selected from carcasses at a commercial major packing plant, vacuum-packaged, and aged for 14 d (4 °C). The loins were then divided into 10 portions (5 grill temperatures for each of trained sensory panel and Warner-Bratzler shear force). Flat-top electric grills were pre-heated to 1 of 5 different temperatures: 149 °C (149), 177 °C (177), 204 °C (204), 232 °C (232), or 260 °C (260). Steaks were placed on the grill, turned when the internal temperature reached 35 °C and removed when the internal temperature reached 71 °C. A trained sensory panel evaluated ten basic flavors and five texture attributes. Extra cubes from each sample were frozen in liquid nitrogen and stored at -80 °C for GC/MS volatile aroma compound analysis. Beef identity, brown, and roasted flavor descriptors increased linearly (P < 0.001) while bloody/serumy tended to decrease (P = 0.016) and sour flavor decreased (P = 0.006) linearly as grill temperature increased. Furthermore, burnt (deviation P = 0.008) and bitter (deviation P = 0.012) flavor descriptors were affected by effects other than linear or quadratic, while umami (P = 0.002) and overall sweet (P = 0.016) flavors increased quadratically from 149 to 232 then declined at 260 grill temperatures. Two alcohols, eight aldehydes, four alkanes, three furans, eight ketones, and twelve pyrazines were impacted by differences the grill temperature. Increasing grill temperature increases volatile compounds, primarily from the Maillard reaction, that improve positive beef flavor descriptors.

Predicting VOCs content and roasting methods of lamb shashliks using deep learning combined with chemometrics and sensory evaluation

A comparison was made between the traditional charcoal-grilled lamb shashliks (T) and four new methods, namely electric oven heating (D), electric grill heating (L), microwave heating (W), and air fryer treatment (K). Using E-nose, E-tongue, quantitative descriptive analysis (QDA), and HS-GC-IMS and HS-SPME-GC-MS, lamb shashliks prepared using various roasting methods were characterized. Results showed that QDA, E-nose, and E-tongue could differentiate lamb shashliks with different roasting methods. A total of 43 and 79 volatile organic compounds (VOCs) were identified by HS-GC-IMS and HS-SPME-GC-MS, respectively. Unsaturated aldehydes, ketones, and esters were more prevalent in samples treated with the K and L method. As a comparison to the RF, SVM, 5-layer DNN and XGBoost models, the CNN-SVM model performed best in predicting the VOC content of lamb shashliks (accuracy rate all over 0.95) and identifying various roasting methods (accuracy rate all over 0.92).

Descriptive beef flavor and texture attributes relationships with consumer acceptance of US light beef eaters

Consumer acceptance and overall liking has been shown to be related to beef instrumental and trained sensory attributes related to beef flavor, tenderness, and juiciness. Our objective was to understand the relationships between descriptive beef flavor and texture attributes, Warner-Bratzler shear force (WBSF), and consumer liking attributes for light US beef eaters. It is not known if light beef eaters have different drivers of overall liking. Treatments were created to differ in beef flavor and texture by utilizing different beef cuts (Choice top loin, high pH top loin, Select top sirloin, Choice tenderloin steaks, and Select and Choice bottom rounds roasts) cooked to 58 °C or 80 °C. Cooking methods included either a George Forman grill, food-service grill, or crock-pot. Cooking method, cut, and internal temperature impacted beef descriptive flavor and texture attributes, WBSF and consumer liking ratings (P ≤ 0.05) similarly. Descriptive juiciness and tenderness attributes were highly related to each other and with consumer juiciness and tenderness liking ratings. Consumer overall liking was closely related to descriptive fat-like, overall sweet, sweet and salty attributes. Musty/moldy, liver-like, and sour aromatic attributes were negatively associated with consumer liking. Overall flavor accounted for 85% of the variation in overall liking and tenderness liking contributed an additional 4%. While light beef eaters used different parts of the scale, they rated beef across treatments similarly. When beef flavor and texture descriptive attributes differed, consumer liking was impacted for light beef eaters.

Using untargeted metabolomics and volatile aroma compounds to predict expert sensory descriptors and consumer liking of beef loin steaks varying in quality grade, aging time, and degree of doneness

Precursors to flavor are important to its development, yet little is known about the intrinsic products of metabolism that influence flavor. Our objective was to use untargeted metabolomics and volatile aroma compounds to predict expert and consumer sensory traits. USDA Select and upper 2/3 Choice beef strip loins were wet aged for 10 or 20 d and then cut into steaks, vacuum-packaged, and frozen. Steaks were cooked to 63 °C, 71 °C, or 80 °C end-point internal steak temperature. USDA Choice steaks had more intense beef flavor identity, brown, roasted, fat-like, salty, sweet, sour, umami, buttery, and overall sweet flavors compared to USDA Select steaks (P < 0.05). Steaks cooked to 80 °C had more intense beef identity, brown, roasted, and umami flavors than steaks cooked to a lower degree of doneness. Steaks cooked to either 63 °C or 71 °C had more intense bloody, metallic, and sour flavors and were juicier, more tender, and had less connective tissue than steaks cooked to a higher degree of doneness. Volatile aroma compounds increased (P < 0.05) in Choice steaks aged for 20 d, while cooking steaks to 80 increased aldehydes, ketones, and pyrazines. Raw steaks had 69 small-molecule metabolomic compounds shared across all four quality grade x aging combinations, and discriminant analysis correctly categorized (P < 0.05) these metabolites. Metabolites and volatiles can be used to predict (r2 > 0.85) expert and consumer sensory panel descriptors and liking.

Effect of Fat to Lean Meat Ratios on the Formation of Volatile Compounds in Mutton Shashliks

This study aimed to investigate the release of volatile compounds in mutton shashliks (named as F_xL_y, x-fat cubes: 0-4; y-lean cubes: 4-0) with different fat-lean ratios before and during consumption, respectively. In total, 67 volatile compounds were identified in shashliks using gas chromatography/mass spectrometry. Aldehyde, alcohol, and ketone were the major volatile substances, accounting for more than 75% of the total volatile compounds. There were significant differences in the volatile compounds of mutton shashliks with different fat-lean ratios. With the increase of the fat content, the types and content of volatile substances released also increase. However, when the percentage of fat exceeded 50%, the number of furans and pyrazine, which were characteristic of the volatile compounds of roasted meat, was decreased. The release of volatiles during the consumption of mutton shashliks was measured using the exhaled breath test and the results showed that adding an appropriate amount of fat (<50%) helps to enrich the volatile compound components in the mouth. However, shashliks with higher fat-lean ratios (>2:2) shorten the mastication duration and weaken the breakdown of bolus particles in the consumption process, which is not conducive to the release potential of volatile substances. Therefore, setting the fat to lean ratio to 2:2 is the best choice for making mutton shashliks, as it (F₂L₂) can provide rich flavor substances for mutton shashliks before and during consumption.

A South African beef quality survey

In this study a survey of various meat quality characteristics of beef loin cuts was conducted in the City of Tshwane Metropolitan Municipality (Gauteng Province of South Africa) to determine the variation and consistency of beef quality of products purchased over time. Four hundred and twenty beef loin samples were collected on 20 occasions over 308 days from 13 outlets of 2 supplier types (butcher and supermarket). Packaging type, label information and price were considered for the evaluation of meat tenderness, colour, cooking loss, tissue composition and steak thickness. The results demonstrate that large variation in characteristics relevant to consumers' choice and satisfaction among and within different products sold as porterhouse steak in South Africa. In particular, muscle tenderness varied (P < 0.0001) across the 20 products and also showed significant inconsistency over the 20 purchasing events for certain products.

Influence of Dietary Algae Meal on Lipid Oxidation and Volatile Profile of Meat from Lambs with Competent Reticular Groove Reflex

Dietary lipid sources influence intramuscular fatty acid composition, which in turn may affect the volatile profile of meat. The aim of this work was to investigate the effects of marine algae supplementation (Aurantiochytrium limacinum) on volatile compounds of cooked lamb meat. Forty-eight lambs with 42 days of age were divided into three groups: lambs fed a conventional diet without algae meal supplementation (NOALG), lambs with competent reticular groove reflex (RGR) fed the same diet supplemented with 2.5% marine algae meal mixed in the concentrate (ALGCON), and lambs with competent RGR, receiving the same diet and fed with 2.5% marine algae meal in a milk replacer to bypass the rumen (ALGMILK). Lipid and protein oxidation in raw meat was assessed and volatile compounds in grilled meat were determined. The highest and lowest lipid oxidations were observed in the ALGMILK and NOALG groups, respectively. Protein oxidation was unaffected. Out of 56 identified compounds, 12 volatiles significantly increased in both algae groups and 6 of them exclusively in the ALGCON treatment. Algae meal supplementation and its form of administration, either protected or not from rumen degradation, are important factors to consider in lipid oxidation and the aromatic profile of lamb meat.

Characterization of Volatile Profiles and Correlated Contributing Compounds in Pan-Fried Steaks from Different Chinese Yellow Cattle Breeds through GC-Q-Orbitrap, E-Nose, and Sensory Evaluation

This study focused on characterizing the volatile profiles and contributing compounds in pan-fried steaks from different Chinese yellow cattle breeds. The volatile organic compounds (VOCs) of six Chinese yellow cattle breeds (bohai, jiaxian, yiling, wenshan, xinjiang, and pingliang) were analyzed by GC-Q-Orbitrap spectrometry and electronic nose (E-nose). Multivariate statistical analysis was performed to identify the differences in VOCs profiles among breeds. The relationship between odor-active volatiles and sensory evaluation was analyzed by partial least square regression (PLSR) to identify contributing volatiles in pan-fried steaks of Chinese yellow cattle. The results showed that samples were divided into two groups, and 18 VOCs were selected as potential markers for the differentiation of the two groups by GC-Q-Orbitrap combined multivariate statistical analysis. YL and WS were in one group comprising mainly aliphatic compounds, while the rest were in the other group with more cyclic compounds. Steaks from different breeds were better differentiated by GC-Q-Orbitrap in combination with chemometrics than by E-nose. Six highly predictive compounds were selected, including 3-methyl-butanal, benzeneacetaldehyde, 2-ethyl-6-methyl-pyrazine, 2-acetylpyrrole, 2-acetylthiazole, and 2-acetyl-2-thiazoline. Sensory recombination difference and preference testing revealed that the addition of highly predictive compounds induced a perceptible difference to panelists. This study provides valuable data to characterize and discriminate the flavor profiles in pan-fried steaks of Chinese yellow cattle.

Production of Hydroxy Fatty Acids, Precursors of γ-Hexalactone, Contributes to the Characteristic Sweet Aroma of Beef

Aroma is an essential factor for meat quality. The meat of Japanese Black cattle exhibits fine marbling and a rich and sweet aroma with a characteristic lactone composition. The mechanism of lactone formation associated with beef aroma has not been elucidated. In this study, we examined the precursors of γ-hexalactone, an indicator of the sweet aroma of beef and identified the mechanism underlying γ-hexalactone production. A low-temperature vacuum system was used to prepare beef tallow from Japanese Black cattle and Holstein cattle. The odor components were identified using headspace–gas chromatography. The analysis revealed that γ-hexalactone, γ-dodecalactone, δ-tetradecalactone, and δ-hexadecalactone were present as sweet aroma components of beef tallow prepared from marbling and muscle. Since we previously reported that γ-hexalactone formation correlates with linoleic acid content in beef, we analyzed ten oxidized fatty acids derived from linoleic acid by liquid chromatography–triple quadrupole mass spectrometry and detected two hydroxy-octadecadienoic acids (9S-HODE and 13S-HODE) in beef tallow. Significant differences in arachidonic acid 15-lipoxygenase and cyclooxygenase protein expression levels among subcutaneous fat, intramuscular fat, and muscle tissue were observed. Our results suggest that the combination of linoleic acid and the expression of lipid oxidase derived from beef muscle and intramuscular fat produce hydroxy fatty acids that result in a sweet aroma.

Cooking Surface Temperatures, Steak Thickness, and Quality Grade Effects on Volatile Aroma Compounds

Volatile aroma compounds were evaluated in USDA Top Choice and Select beef top loin steaks cut 1.3 cm (THIN) or 3.8 cm (THICK) and cooked on a commercial flat top grill at 177°C (LOW) or 232°C (HIGH) grill surface temperature. Gas chromatography/mass spectrophotometry was used to evaluate volatile aroma compounds. USDA Select steaks had more 2-octene and less trimethyl pyrazine in (P &lt; 0.05) THIN steaks than THICK steaks, whereas Choice was unaffected by steak thickness (P &gt; 0.05). Benzene acetaldehyde was higher and 4-hydroxybenzoic acid was higher in Select LOW grill temperatures compared with Select HIGH grill temperatures, whereas 5-methyl-2-furan carboxaldehyde was only present in Choice HIGH grill temperatures (P &lt; 0.05). Two acids, 3 alcohols, 1 aldehyde, 1 alkane, and 1 ketone volatile aroma compound were higher (P &lt; 0.05) for LOW compared with HIGH. Conversely, 5 alcohols, 2 aldehydes, 2 alkanes, all 4 furans, 6 ketones, 4 pyrazines, along with 1H-indole, 2 pyrroles, 2 pyridines, and 1 benzene aroma compound were higher (P &lt; 0.05) in HIGH compared with LOW. Additionally, 1 alcohol, 2 aldehydes, 1 ketone, 1 sulfur-containing, and 6 other volatile compounds were lower, whereas 1 acid, 1 alcohol, 1 aldehyde, 2 furans, 1 ketone, 3 pyrazines, 1 sulfur-containing, and 1 other volatile compound were higher in the THIN compared with THICK. Some aroma compounds such as 2-butanone, 4-methyl-2-pentanone, 1-ethyl-1H-pyrrole, 1-methyl-1H-pyrrole, and 2-methyl-pyridine were only present in THICK cooked HIGH (P &lt; 0.05). Steak thickness and grill temperature are important factors to consider in the development of positive Maillard reaction products. Key findings are that high grill temperatures and/or thick steaks with longer grilling times are required for the development of key Maillard reaction products and many Maillard reaction products were only found in the most severe high-temperature, long-time grilling scenarios.

The role of cooking in consumers' quality formation: An exploratory study of beef steaks

The role of cooking on pre- and post-consumption quality expectations and its impact on satisfaction during the eating experience is under-researched. To address this gap, a 'task and talk' focus group study involving participants preparing and eating a beef steak as part of a meal was designed to explore the role of cooking on consumers' evaluation of beef quality. The results from six focus groups (n = 36 participants) identified that 'perceived cooking quality' of beef is an important criterion impacting pre-purchase evaluation. Cooking is a process of adaptation to personal tastes and is influenced by cooking self-efficacy. This personal confidence in steak preparation mediates a willingness to directly complain about a disappointing eating experience. Direct complaints generally occurred in relation to intrinsic quality cues prior to cooking where the locus of quality control was external to the participant. Poor eating quality of beef was generally attributed to a deficiency in cooking skills, an internal attribution of quality failure that minimised the likelihood of direct complaints. A lack of confidence in cooking skills may explain a delay in repeat purchasing following a negative eating experience.

Effect of ageing time on the volatile compounds from cooked horse meat

Volatile compounds from cooked and aged (0, 7, 14, 21 days) Hispano-Bretón horse meat (loin) were analyzed by solid-phase microextraction coupled to gas chromatography-mass spectrometry. A total of 77 volatile compounds were found, from which aldehydes were the predominant family. Most of the identified compounds had their origin in the degradation of lipids, with a negligible contribution of Maillard derived products. Odour impact ratios were calculated and used as indicators of the contribution of each compound to the total aroma and aldehydes were, in general, the major contributors to cooked horse meat aroma. Results revealed that ageing affected 15 of the volatile compounds detected. From them, hexadecanal and 2- and 3-methylbutanal significantly increased during ageing, presumably affecting the cooked meat odour as these have considerable odorant impact. Under the present study conditions, periods longer than 14 days would be necessary for significant changes in the volatile profile of cooked horse meat.

Elucidating the combined effect of sample preparation and solid-phase microextraction conditions on the volatile composition of cooked meat analyzed by capillary gas chromatography coupled with mass spectrometry

Solid-phase microextraction coupled to gas chromatography-mass spectrometry is a common approach to analyze the volatile profile of cooked meat. The present study aims to investigate the combined effect of sample preparation, including meat presentation (minced and steak) and cooking method (stewed and grilled), and extraction temperature (30, 60 and 80 °C) and time (30 and 50 min) on the volatile composition of cooked deer meat. The statistical results indicated that extraction temperature was the most relevant factor affecting the meat volatile profile of cooked meat followed by the extraction time. Higher extraction temperatures improved the detection of heavy volatile compounds, while sample preparation had little influence on the meat volatile profile, probably due to the accurate control of the parameters used for meat presentation and cooking methods. The results of this work can assist in the standardization of analytical procedures for the characterization of volatile compounds in cooked meat.

Exploring the Characteristic Aroma of Beef from Japanese Black Cattle (Japanese Wagyu) via Sensory Evaluation and Gas Chromatography-Olfactometry

Beef from Japanese Black cattle (Japanese Wagyu) is renowned for its flavor characteristics. To clarify the key metabolites contributing to this rich and sweet aroma of beef, an omics analysis combined with GC-olfactometry (GC-O) and metabolomics analysis with gas chromatography-mass spectrometry (GC-MS) were applied. GC-O analysis identified 39 odor-active odorants from the volatile fraction of boiled beef distilled by solvent-assisted flavor evaporation. Eight odorants predicted to contribute to Wagyu beef aroma were compared between Japanese Black cattle and Holstein cattle using a stable isotope dilution assay with GC-tandem quadrupole mass spectrometry. By correlating the sensory evaluation values of retronasal aroma, γ-hexalactone, γ-d2ecalactone, and γ-undecalactone showed a high correlation with the Wagyu beef aroma. Metabolomics data revealed a high correlation between the amounts of odorants and multiple metabolites, such as glutamine, decanoic acid, lactic acid, and phosphoric acid. These results provide useful information for assessing the aroma and quality of beef.

Characterization of the Key Aroma Compounds in Dog Foods by Gas Chromatography-Mass Spectrometry, Acceptance Test, and Preference Test

Gas chromatography-mass spectrometry (GC-MS) coupled with the acceptance test, partial least-squares regression (PLSR) analysis, validation experiment, and preference test was used to identify the key aroma compounds in dog foods (DFs). Six DFs were evaluated by spraying six palatability enhancers onto a basal DF. The differently flavored palatability enhancers were prepared by the Maillard reaction using different protein sources and reaction conditions. The intake ratios of the six DFs were tested by six adult beagle dogs and were classified into high, medium, and low levels. A total of 55 volatile compounds were identified using headspace solid-phase microextraction (HS-SPME) GC-MS. Correlation analysis of the volatile compounds associated with intake ratios using partial least-squares regression (PLSR) found nine significantly positive and three significantly negative compounds that made a significant contribution to the palatability of DFs. Validation tests undertaken by adding three significantly positive compounds, one significantly negative compound, and one nonsignificant compound into the odorless matrix successfully verified the accuracy prediction of the PLSR model. The nine significantly positive compounds were heptanal, nonanal, octanal, (E)-2-hexenal, (E,E)-2,4-decadienal, 2-pentylfuran, 4-methyl-5-thiazoleethanol, 2-furfurylthiol, and (E)-2-decenal. The contributions of nine key aroma compounds were further analyzed by the preference test. (E)-2-decenal, 2-furfurylthiol, and 4-methyl-5-thiazoleethanol showed higher first choice, consumption ratio, and unit contribution rate and were vital to the overall preferred aroma of DFs.

Contribution of the retronasal odor of soy sauce to salt reduction

The characteristic odor of soy sauce has been reported to enhance saltiness. However, soy sauce is used not only as a sauce that is added directly to food, but also as a seasoning. In addition, some of the aromatic compounds that contribute to the soy sauce odor change during cooking or heating. In the present study, the effects of the retronasal odor of uncooked and cooked soy sauce on the enhancement of saltiness and palatability of a low-salt solution were sensory evaluated. A probit analysis indicated that the saltiness-enhancing effect of the odor of 15% uncooked soy sauce was lost by heating. The odors of soy sauce boiled for 10 min (cooked SS) and the residue of soy sauce heated at 200 °C for 1 min improved the palatability of the low-salt solution. Gas chromatography (GC) analyses, namely, GC-olfactometry and GC-mass spectrometry, showed that one active candidate aromatic component of soy sauce contributing to saltiness enhancement was 3-methyl-1-butanol (3-Me-BuOH). The saltiness-enhancing effects of cooked SS could be restored by adding 3-Me-BuOH, as assessed by the sensory evaluation. These data demonstrated that 3-Me-BuOH contributes to saltiness enhancement. PRACTICAL APPLICATION: We found that the odor of cooked soy sauce could improve the palatability of low-salt food. Although the saltiness-enhancing effect provided by the odor of uncooked soy sauce was lost, the saltiness-enhancing effect of the odor of cooked soy sauce can be partially restored by adding 3-methyl butanol. Thus, not only the odor of unheated soy sauce but also the odor of heated soy sauce following addition of 3-methyl butanol may be useful for developing palatable salt-reduced food.

Temperature-time combination effects on aged beef volatile profiles and their relationship to sensory attributes

Beef ageing (in vacuo) for tenderisation and flavour development may be accelerated by favourable temperature-time combinations (TTCs), however the effect of such manipulations on volatile organic compounds (VOCs) that are generated during cooking, is unknown. We compared VOCs from grilled beef longissimus lumborum muscle samples which had been subjected to different TTCs. The TTCs consisted of combinations of temperatures (~ 3, 5, or 7 °C) and ageing time periods (6, 8, 10 or 12 d); as well as control samples, which were held at 0-2 °C for a total of 14 d. Sensory quality attributes of these same samples were measured by untrained consumer panellists. Generally, it was found that TTCs had negligible effects on grilled beef VOCs and were comparable to controls. Furthermore, many VOCs were significantly related to flavour intensity, flavour liking and overall liking. These findings support the use of TTCs as a viable means to accelerate the rate of beef ageing without compromising quality.

Cytotoxicity and degradation product identification of thermally treated ceftiofur

Ceftiofur (CEF) is a cephalosporin antibiotic and is a commonly used drug in animal food production. As a heat-labile compound, the residual CEF toxicity after thermal treatment has rarely been reported. This study was to investigate the potential toxicity of thermally treated CEF and determine the toxic components. By cytotoxicity tests and liquid chromatography-mass spectrometry (LC-MS) assays, the cytotoxicity of the thermally treated CEF (TTC) and the components of TTC was identified, respectively. Our results showed that TTC exhibited significantly increased toxicity compared with CEF towards LO2 cells by inducing apoptosis. Through LC-MS assays, we identified that the toxic compound of TTC was CEF-aldehyde (CEF-1). The IC₅₀ value of CEF-1 on LO2 cells treated for 24 h was 573.1 μg mL⁻¹, approximately 5.3 times lower than CEF (3052.0 μg mL⁻¹) and 3.4 times lower than TTC (1967.0 μg mL⁻¹). Moreover, we found that CEF-1 was also present in thermally treated desfuroylceftiofur (DFC), the primary metabolite of CEF, indicating that residual CEF or DFC could produce CEF-1 during the heating process. These findings suggest that CEF-1 is a newly identified toxic compound, and CEF-1 may pose a potential threat to food safety or public health.

Ceftiofur (CEF) is a cephalosporin antibiotic and is a commonly used drug in animal food production. This study investigated the cytotoxicity of thermally treated CEF.

Steak Thickness, Cook Surface Temperature and Quality Grade Affected Top Loin Steak Consumer and Descriptive Sensory Attributes

Beef flavor attributes of USDA Top Choice and Select beef top loin steaks were evaluated that differed in thickness (1.3 or 3.8 cm) and grill surface temperature (177 or 232°C) when cooked on a commercial flat top grill. A trained descriptive attribute panel and consumer sensory panels were used to evaluate steak flavor and texture. As thickness and temperature increased, beef identity and brown/roasted flavor aromatics increased (P < 0.05). Steaks cooked at 232°C and cut 3.8-cm thick had the highest (P < 0.05) levels of burnt flavor and bitter basic tastes. Thicker steaks cooked at 177°C had more intense umami basic taste and beef identity (P < 0.05). Steaks cut 1.3 cm had lower levels of beef identity and brown/roasted flavor aromatics and the thin cut steaks cooked at 177°C had more sour basic taste (P < 0.05). Consumers rated 232°C, 3.8 cm steaks lowest (P < 0.05) for overall, beef flavor, overall flavor, and grilled flavor liking; whereas, the 177°C, 3.8 cm steaks were highest (P < 0.05) in beef flavor liking. Beef identity, brown/roasted, bloody/serumy, fat-like, umami, sweet, salty, overall sweet, overall tenderness, and muscle fiber tenderness were positive attributes, and metallic, bitter, and burnt were negative attributes in predicting consumer overall liking. Thick steaks cooked at low temperatures or thin steaks cooked at high temperatures resulted in more positive sensory panel traits and consumer liking scores.

Survey of Quality Attributes of Beef from Farmers Market Vendors

Farmers Market steaks (n = 39 ribeyes, n = 39 top loins, and n = 38 top sirloins) were procured to establish a baseline for palatability characteristics and to compare consumer acceptance of retail steaks (n = 20 ribeyes, n = 20 top loins, and n = 20 top sirloins) to beef sold in niche markets. Palatability was evaluated using Warner–Bratzler shear force (WBS) and consumer sensory panels. No differences (P>0.05) were identified among Farmers Market steaks for WBS values nor between cuts for sensory panel ratings for Farmers Market or retail products. Overall liking and tenderness liking sensory panel ratings were lower (P=0.0493 and P=0.0058, respectively) for steaks from Farmers Markets when compared to retail. Farmers Market ribeyes and top loins were thicker (P=0.0107) than top sirloins. These results will help niche producers understand how their products compare to beef from traditional supermarkets and allow them to identify areas for improvement.

Grilling temperature effects on tenderness, juiciness, flavor and volatile aroma compounds of aged ribeye, strip loin, and top sirloin steaks

Ribeye, top loin, and top sirloin steaks were assigned a grilling temperature setting (177°C, 205°C, or 232°C) and consumer panel, Warner-Bratzler shear force, trained sensory panel, and GC/MS - olfactory analyses were performed. No differences (P > 0.05) in consumer overall, tenderness, juiciness, appearance, and flavor liking were detected among steak type or grill temperature. Grill surface temperature had no effect (P > 0.05) on trained panel tenderness scores. Of the volatiles present during an aroma event, pyrazine compounds were most influenced by grill surface temperature. The tenderness and juiciness of steaks grilled at differing temperatures were not perceived to be different by consumers; however, grilling temperature impacted the flavor of the final product by generating more pyrazine compounds. Steaks in this study likely were too tender to have a grilling effect on tenderness, but selecting different grilling temperatures can be used to vary the amount of browning of steaks and/or to modify aroma volatile compounds.

Rust and Thinning Management Effect on Cup Quality and Plant Performance for Two Cultivars of Coffea arabica L

Beverage quality is a complex attribute of coffee ( Coffea arabica L.). Genotype (G), environment (E), management (M), postharvest processing, and roasting are all involved. However, little is known about how G × M interactions influence beverage quality. We investigated how yield and coffee leaf rust (CLR) disease (caused by Hemileia vastatrix Berk. et Br.) management affect cup quality and plant performance, in two coffee cultivars. Sensory and chemical analyses revealed that 10 of 70 attributes and 18 of 154 chemical volatile compounds were significantly affected by G and M. Remarkably, acetaminophen was found for the first time in roasted coffee and in higher concentrations under more stressful conditions. A principal component analysis described 87% of the variation in quality and plant overall performance. This study is a first step in understanding the complexity of the physiological, metabolic, and molecular changes in coffee production, which will be useful for the improvement of coffee cultivars.

Palatability and Biochemical Factors of Beef from Mature Cattle Finished on a Concentrate Diet Prior to Harvest

The objective of this study was to investigate the influence of grain-finishing on mature beef palatability. Beef strip loins (n = 15 per treatment) from 2 marbling score groups [Slight (SL) and Traces/Practically Devoid (TR/PD)] and 3 carcass types [young fed (YF), mature fed (MF), and mature unfed (MU)] were collected. Young fed and MF cattle were grain-finished prior to harvest, whereas, beef from MU cattle were not identified as being grain-finished prior to harvest. Consumer and trained sensory panels evaluated steaks for palatability characteristics. Additionally, Warner-Bratzler shear force (WBSF), collagen solubility, sarcomere length, and volatile compounds were evaluated. Consumer ratings were not influenced (P > 0.05) by an interaction of main effects. Slight samples were greater (P < 0.05) than TR/PD samples for tenderness, juiciness, flavor, and overall like. Trained panelists rated SL samples more tender (P < 0.01) than TR/PD samples. Additionally, YF and MU steaks were the most and least tender (P < 0.01), respectively. No differences (P > 0.05) were observed among SL samples for beef flavor, beef flavor intensity, or off-flavor intensity due to carcass type. However, TR/PD-MF and MU steaks had more intense (P < 0.01) off-flavors. Steaks from YF and MF carcasses had lower (P < 0.01) WBSF values than steaks from MU carcasses. Percentage of heat soluble collagen was greatest (P < 0.01) in YF carcasses. Among SL treatments, sarcomere length was not affected (P > 0.05) by carcass type; however, MF and MU carcasses with TR/PD marbling scores had shorter (P < 0.05) sarcomeres than YF carcasses. Various volatile compounds were influenced (P < 0.05) by treatment and showed relationships with sensory ratings. Improvements in palatability were observed due to grain-finishing mature cattle, suggesting an adequate degree of marbling could offset negative palatability traits typically associated with beef from mature cattle.