Aroma development in high pressure treated beef and chicken meat compared to raw and heat treated

Unravelling the formation of characteristic aroma of traditional braised pork through untargeted and targeted flavoromics

Untargeted flavoromics and targeted quantitative analysis of key aroma compounds, and analysis of dynamic change of aroma precursors concentration were used to investigate the aroma evolution of traditional braised pork and the underlying mechanism. The results indicated that lipid oxidation dominated at early cooking stage (0th-45th min), resulting in an increased concentration of most aldehydes, alcohols, ketones, such as hexanal, heptanal, octanal, nonanal, (E)-2-octenal, benzaldehyde, 1-octen-3-ol, and 2,3-octanedione, accompanied with an enhanced unpleasant fatty odor. From 45th to 73rd min, the seasonings alleviated excessive oxidation of unsaturated fatty acids accompanied with decreased aldehydes. Moreover, the diffusion of glucose and amino acids from seasonings to lean meat promoted the consumption of endogenous ribose and amino acids in meat through Maillard reaction, and facilitated the formation of dimethyl trisulfide, dimethyl disulfide, methanethiol, and 2-furfural, which contributed to the meaty, sauce-like, and sweety aroma, thus formed the characteristic aroma of traditional braised pork.

Evaluation of the effect of dietary supplementation with Allium mongolicum regel bulb powder on the volatile compound and lipid profiles of the longissimus thoracis in Angus calves based on GC-IMS and lipidomic analysis

The effect of A. mongolicum Regel bulb powder (AMRP) supplementation on the flavour of beef from Angus calves has not been investigated thus far. We used GC-IMS and untargeted lipidomics techniques to examine the volatile compound and lipid metabolic profiles and reveal the effects of dietary AMRP supplementation on the flavour of beef. A total of 6 characteristic volatile compounds and 30 key lipid compounds were identified in the AMRP treatment group. AMRP promoted the release of triglycerides and phosphatidylinositols from beef and accelerated the production of volatile compounds such as ethyl acetate, 1-penten-3-one, and tetrahydrofurane, and the production of these three characteristic volatile compounds was significantly correlated with the UFAs in triglycerides according to correlation analysis. In summary, dietary AMRP supplementation had a positive effect on the flavour of beef, and these findings provide a theoretical basis for the development and utilisation of AMRP as a feed additive.

Fermented By-Products of Banana Wine Production Improve Slaughter Performance, Meat Quality, and Flavor Fingerprint of Domestic Chicken

This study aimed to compare the effects of incorporating fermented feed into daily diets on the slaughter performance, meat quality, and flavor compounds of 120 domestic chickens over a 140-day period. A total of five groups (n = 24), including the control group (CK) of the Guangxi Partridge chickens received a standard base diet. The other four groups were provided with pellets that had been added with 10% fermented banana peel (Pe-10), 20% fermented banana peel (Pe-20), 10% fermented banana pulp residue (Pu-10), and 20% fermented banana pulp residue (Pu-20). The flavor compounds in the meat samples of the chickens in these groups were determined using the gas chromatographic method. The results demonstrated that the chickens in the Pe-10, Pe-20, Pu-10, and Pu-20 groups exhibited pectoral muscle percentages, thigh muscle percentages, and total fatty acid content of chest meat that were higher than those observed in the CK group. The moisture content, meat color, carcass weight, total net weight, and abdominal fat percentage of the meat samples in these experimental groups exhibited no notable differences. The flavor compounds in the meat samples of the chickens fed with the two concentrations of fermented banana peel and banana residue were found to be significantly different from those in the control group, with p-values less than 0.05. As the quantity of fermented banana peel incorporated into the daily ration was increased from 10% to 20%, a notable alteration in the flavor compounds present in the chicken samples was observed. The chickens that were provided with fermented banana peels and pulps in their diets exhibited superior slaughter performance and meat quality, particularly in the case of the Pu-10 group, in comparison to the control chickens.

Flavoromics Analysis of Passion Fruit-Roasted Chicken

Currently, research on the flavor components and their dynamic changes in roasted chicken with a special flavor is rare. In this study, a passion fruit-roasted chicken was prepared, its characteristic flavor components were profiled by flavoromics, and their evolution patterns and precursors were determined. The results showed that the characteristic flavor component with the highest contribution rate was ethyl butyrate (50.44%). In particular, some unique flavor compounds were identified compared with other roasted chicken products available. The main volatile flavor components in all stages of processing were alcohols, esters, and hydrocarbons, 15 to 30 min of roasting is an important stage for establishing the aroma system, and at the end, hydrocarbons were the main volatile compounds. During the 30-day storage period, the characteristic flavor components included ethyl butyrate, ethyl maltol, β-caryophyllene, and guaiacene. In conclusion, passion fruit-roasted chicken contained many characteristic flavor components, which were mainly formed within 15 to 30 min of roasting and were basically stable during the 30-day storage period. In a word, this work prepared a novel roasted chicken and revealed its mechanism of flavor formation at different baking stages and storage periods, which provided references for industrial production.

Comparison of Odorants in Beef and Chicken Broth-Focus on Thiazoles and Thiazolines

The shift in consumer landscape towards vegan, vegetarian and flexitarian diets has created an unprecedented challenge in creating meat aroma from plant-based alternatives. The search for potential vegan solutions has thus led to a renewed interest in authentic meat flavour profiles. To gain a better understanding of the qualitative odour differences between boiled beef and boiled chicken, aroma extracts were isolated using Likens-Nickerson simultaneous distillation-extraction (SDE), selected expressly because the in-situ heating of the sample facilitates the capture of aroma intermediates during the cooking process, thereby mimicking the cooking of meat in stocks and stews. The extracts were then analysed by Gas Chromatography-Mass Spectrometry (GC-MS) and GC-Olfactometry (GC-O). Most of the volatiles identified in this study were sulfur-containing compounds, such as sulfides, thiols, mercaptoaldehydes and mercaptoketones, which are derived from the Maillard reaction. Meanwhile, lipid oxidation results in the formation of unsaturated aldehydes, such as alkenals and alkadienals. Families of thiazoles and 3-thiazolines were found in the extracts. Two novel 3-thiazolines (5-ethyl-2,4-dimethyl-3-thiazoline and 2-ethyl-4,5-dimethyl-3-thiazoline) which may also contribute to the meaty aroma were identified in this work and synthesised from their respective aldehyde and mercaptoketone precursors.

Competitive Detection of Volatile Compounds from Food Degradation by a Zinc Oxide Sensor

During the phenomenon of food degradation, several volatile organic compounds are generally released. In particular, due to lipid oxidation in stored and packed meat, hexanal is formed as a typical decomposition product. Therefore, its detection can provide an important indication of the quality and conservation of meat. Unfortunately, the simultaneous release of other compounds, such as 1-pentanol and 1-octen-3-ol, during the first phase of the degradation process can have an undesirable effect on the detection of hexanal. In this work, a metal oxide (MOX) sensor based on zinc oxide (ZnO) was prepared and tested for possible use in the monitoring of low concentrations of hexanal. The sensor was expected to detect the target volatile with minimum interference from all the others, when released all at the same time. For this purpose, the ZnO sensor was exposed to both pure and different mixtures of vapors of the main competing organic compounds. Comparing the results of the mixtures to the response relating to pure hexanal, it was highlighted that the presence of 1-pentanol and 1-octen-3-ol decreases the response of the sensor to hexanal in terms of the eR/R0 ratio, especially at low concentrations (5–10 ppm), while at 50 ppm, the sensor response was comparable with the hexanal quantity, proving that its detection was less affected at higher concentrations.

A Rapid Gas-Chromatography/Mass-Spectrometry Technique for Determining Odour Activity Values of Volatile Compounds in Plant Proteins: Soy, and Allergen-Free Pea and Brown Rice Protein

Plant-based protein sources have a characteristic aroma that limits their usage in various meat-alternative formulations. Despite being the most popular plant-based protein, the allergenicity of soy protein severely restricts the potential adoption of soy protein as an animal substitute. Thereby, allergen-free plant-protein sources need to be characterized. Herein, we demonstrate a rapid solid-phase-microextraction gas-chromatography/mass-spectrometry (SPME-GC/MS) technique for comparing the volatile aroma profile concentration of two different allergen-free plant-protein sources (brown rice and pea) and comparing them with soy protein. The extraction procedure consisted of making a 1:7 w/v aqueous plant protein slurry, and then absorbing the volatile compounds on an SPME fibre under agitation for 10 min at 40 °C, which was subsequently injected onto a GC column coupled to an MS system. Observed volatile concentrations were used in conjunction with odour threshold values to generate a Total Volatile Aroma Score for each protein sample. A total of 76 volatile compounds were identified. Aldehydes and furans were determined to be the most dominant volatiles present in the plant proteins. Both brown rice protein and pea protein contained 64% aldehydes and 18% furans, with minor contents of alcohols, ketones and other compounds. On the other hand, soy protein consisted of fewer aldehydes (46%), but a more significant proportion of furans (42%). However, in terms of total concentration, brown rice protein contained the highest intensity and number of volatile compounds. Based on the calculated odour activity values of the detected compounds, our study concludes that pea proteins could be used as a suitable alternative to soy proteins in applications for allergen-free vegan protein products without interfering with the taste or flavour of the product.

Determining the presence of undeclared animal species using Real-time PCR in canned and ready-to-eat meat products in South Africa

DNA based PCR is the most widely used technique for the detection of animal species in processed meat products. However, the detection of animal species in highly processed meat products, specifically, canned meat, has been reported to be challenging due to the presence of highly degraded DNA and/or the inability to extract sufficient amount of amplifiable DNA. The aim of this study was to evaluate the use of Real-time PCR to detect animal species in ready-to-eat meat products which represent highly processed complex food matrices. DNA was extracted from a total of 44 ready-to-eat meat products purchased from supermarkets in South Africa. The extracted DNA was screened for the presence of commonly reported undeclared animal species using Real-time PCR. Real-time PCR successfully detected the animal species declared on the product label, thus demonstrating its suitability for highly processed complex food matrices. Undeclared animal species was detected in 27% of the meat products tested in this study. Surprisingly, four products marketed with a specific "no-pork" claim tested positive for pork. An additional eight products tested positive for undeclared chicken, beef and/or sheep. The presence of undeclared animal species indicates a need for food authenticity monitoring. In cases where it may not be practically feasible to prevent the adventitious presence of unintended animal species despite adhering to the highest standards of production, it may be advisable for manufacturers to implement precautionary labelling. The use of precautionary labelling for animal species in processed meat products is a new concept that requires further consideration.

Comparisons of Chemical Composition, Flavor and Bioactive Substances between Korean and Imported Velvet Antler Extracts

The aim of this study was to compare the antioxidant activity, chemical composition, flavor and bioactive compounds between Korean and imported velvet antlers (VAs)-derived extracts. The Korean (KVA), Russian (RVA) and New Zealand (NZVA) VAs (n=24 each, dry form) purchased from a local supplier were used in the investigation. After extracting with water (750 g VA with 6,000 mL water) for 20 h at 95°C, the VA extracts (VAE) were then used for analysis of antioxidant activity, amino acids (AAs), flavor and bioactive compounds. Compared to the RVA and NZVA, the KVA extract showed significantly higher 2,2-diphenyl 1 picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radicals scavenging activities (p<0.05). Significantly higher Fe content was found in the KVA while, higher Mn, Zn and Ca contents were found in the RVA (p<0.05). Twenty AAs were detected in all three VAEs and some of them (e.g., glycine and alanine) were higher in the KVA (p<0.05). A higher diversity (quality and quantity) of flavor compounds was found in the KVA extract compared to the imported VAs-derived extracts. Over six hundred metabolic compounds were identified in the VAEs. Among them, 412 compounds were commonly found in all the VAE types while, 109, 107, and 84 biomarker compounds were only found in the KVA, NZVA, and RVA extracts, respectively. Based on the results obtained in this study, it may be concluded that the country of origin partly affected the antioxidant activity, chemical composition, flavor and bioactive compounds of the VAEs.

Flavor and Metabolite Profiles of Meat, Meat Substitutes, and Traditional Plant-Based High-Protein Food Products Available in Australia

Demand for plant-based proteins and plant-based food products is increasing globally. This trend is driven mainly by global population growth and a consumer shift towards more sustainable and healthier diets. Existing plant-based protein foods and meat mimetics often possess undesirable flavor and sensory properties and there is a need to better understand the formation of desirable meat-like flavors from plant precursors to improve acceptance of novel high-protein plant foods. This study aimed to comprehensively characterize the non-volatile flavor metabolites and the volatiles generated in grilled meat (beef, chicken, and pork) and compare these to commercially available meat substitutes and traditional high-protein plant-based foods (natto, tempeh, and tofu). Solid phase microextraction with gas-chromatography mass-spectrometry was used for elucidation of the flavor volatilome. Untargeted characterization of the non-volatile metabolome was conducted using Orbitrap mass spectrometry and Compound Discoverer^TM datamining software. The study revealed greater diversity and higher concentrations of flavor volatiles in plant-based foods in comparison to grilled meat, although the odor activity of specific volatiles was not considered. On average, the total amount of volatiles in plant-based products were higher than in meat. A range of concentrations of free amino acids, dipeptide, tripeptides, tetrapeptides, nucleotides, flavonoids, and other metabolites was identified in meat and plant-based foods.

Rapid Profiling of the Volatilome of Cooked Meat by PTR-ToF-MS: Characterization of Chicken, Turkey, Pork, Veal and Beef Meat

This study aimed to compare the volatile organic compound (VOC) profiles of cooked meat from different species. Four burgers were prepared and cooked from each of 100 meat samples obtained from 100 animals of five species/categories (chicken, turkey, pork, veal and beef) sourced from five supermarkets and five local butchers. Two burgers were cooked in a water bath and two were grilled. Direct proton-transfer-reaction time-of-flight mass-spectrometry (PTR-ToF-MS) analysis of the sample headspace yielded 129 mass peaks, 64 of which were tentatively identified. The results showed that turkey and chicken had the largest and the smallest total concentrations of all VOCs, respectively. Of the mammalian meats, veal and beef had greater total VOC concentrations than pork. The proportions of the amounts of all the individual VOCs differed significantly according to species. Additionally, 14 of 17 independent latent explanatory factors (LEFs) identified by multivariate analysis exhibited significant differences between meat species/categories, and therefore helped to characterize them. PTR-ToF-MS has been used for the first time for the rapid and non-invasive profiling of cooked meat of different species/categories. Knowledge of specific VOC profiles paves new avenues for research aimed at characterizing species through sensory description, at authenticating species or at identifying abnormalities or fraud.

Rapid Profiling of the Volatilome of Cooked Meat by PTR-ToF-MS: Underlying Latent Explanatory Factors

Volatile organic compounds (VOCs) are important contributors to meat aroma and are variably correlated with each other. To study the sources of variation and the correlations among meat VOCs, meat cuts from five animal species/categories (chicken, turkey, pork, veal, and beef; two animals/species/retailer: 100 meat cuts) were obtained by 10 retailers. Each cut was processed into four burgers, two of which were grilled and two were cooked in a water bath (400 meat burgers). VOCs were detected by Proton-Transfer-Reaction Time-of-Flight Mass-Spectrometry (PTR-ToF-MS). From these, 129 peaks were selected, of which 72 were tentatively identified as relevant VOCs. Pearson correlations revealed a large number of positive and negative relationships among the VOCs. A multivariate statistical analysis revealed that 87% of the matrix covariance was explained by 17 independent Latent Explanatory Factors (LEFs), which have been described and characterized. LEFs identified may be valuable tools for reducing the dimensionality of results from VOC analyses and can be useful for better understanding and interpreting the variation in the meat aroma profile, although further study is required to characterize their sensory meaning.

High-pressure processing of meat: Molecular impacts and industrial applications

High-pressure processing (HPP) has been the most adopted nonthermal processing technology in the food industry with a current ever-growing implementation, and meat products represent about a quarter of the HPP foods. The intensive research conducted in the last decades has described the molecular impacts of HPP on microorganisms and endogenous meat components such as structural proteins, enzyme activities, myoglobin and meat color chemistry, and lipids, resulting in the characterization of the mechanisms responsible for most of the texture, color, and oxidative changes observed when meat is submitted to HPP. These molecular mechanisms with major effect on the safety and quality of muscle foods are comprehensively reviewed. The understanding of the high pressure-induced molecular impacts has permitted a directed use of the HPP technology, and nowadays, HPP is applied as a cold pasteurization method to inactive vegetative spoilage and pathogenic microorganisms in ready-to-eat cold cuts and to extend shelf life, allowing the reduction of food waste and the gain of market boundaries in a globalized economy. Yet, other applications of HPP have been explored in detail, namely, its use for meat tenderization and for structure formation in the manufacturing of processed meats, though these two practices have scarcely been taken up by industry. This review condenses the most pertinent-related knowledge that can unlock the utilization of these two mainstream transformation processes of meat and facilitate the development of healthier clean label processed meats and a rapid method for achieving sous vide tenderness. Finally, scientific and technological challenges still to be overcome are discussed in order to leverage the development of innovative applications using HPP technology for the future meat industry.

Storage of pasteurized milk in clear PET bottles combined with light exposure on a retail display case: A possible strategy to define the shelf life and support a recyclable packaging

The stability of whole pasteurized milk packaged in clear PET bottles was studied throughout 13-days storage in the dark, but including, at specific times, light exposure of 6, 12 or 18 h to simulate conditions potentially occurring in refrigerated display counters. The aim was to investigate the effects of light exposure when overlapping the unavoidable endogenous modifications in pasteurized milk during storage. Dissolved oxygen, riboflavin and other flavins, proteolysis products, volatile compounds, and sensory characteristics were evaluated. Besides the expected progress of proteolysis occurring during storage, light negatively affected milk flavour especially after longer exposure times. The development of "mushroom" flavor related to the increase of volatile 2,3 octanedione was the most characterizing modification. Gathered data were considered in view of providing the background knowledge for the control of light exposure conditions on a retail display, thus supporting the shelf life extension of pasteurized milk in a fully recyclable packaging.

Application of sensory evaluation, GC-ToF-MS, and E-nose to discriminate the flavor differences among five distinct parts of the Chinese blanched chicken

Blanched chicken, boiling the whole chicken without removing head and butt parts during process, is a traditional poultry product in China. In this manuscript, the flavor differences of five parts (skin, breast, thigh, head and butt) of the Chinese blanched chicken (CBC) were studied using sensory evaluation and instrumental analysis. Check-all-that-apply (CATA), rate-all-that-apply (RATA), and 9-point hedonic preference were used to collect consumers' sensory results. Gas chromatograph-time of flight mass spectrometer (GC-ToF-MS) and electronic nose (E-nose) were used to discriminate flavor variances. CATA perceptions showed different parts of CBC stimulated consumers' odor and emotion feelings differently. GC-ToF-MS and E-nose data elaborated that the flavor of breast with chicken-like flavor was better than the other parts. Consumers preferred the chicken breast part the most. This analysis of different parts of CBC could provide advice to cater consumers' preference and predict the quality change might induce.

The effects of dietary quercetin supplementation on the meat quality and volatile profile of rabbit meat during chilled storage

Thirty-four New Zealand White rabbits of both sexes were fed a control or supplemented (2 g/kg quercetin dihydrate) diet from weaning until slaughter (13 weeks). After post-mortem chilling, excised and minced Longissimus thoracis et lumborum muscles were stored at 3.2 °C under oxygen-permeable wrapping for 1, 3 or 5 days. Colour, pH, lipid oxidation (TBARS), antioxidant capacity (FRAP), volatile profile (day 1 and 5) and microbial count (day 5) were determined. Quercetin reduced alkane (day 5) and hexanal (day 1) concentrations, but otherwise had minimal antioxidant effect, and did not benefit microbial quality, and thus did not substantially improve the shelf-life. The sex effect was similarly limited. Overall, the pH increased and FRAP decreased during storage, but TBARS did not change and discolouration seemed delayed. The volatile profile was dominated by esters, alcohols and heterocyclic compounds, and while it changed during storage, lipid oxidation products did not increase as expected, suggesting that rabbit meat may have relatively active reducing mechanisms.

A predictive model for the evaluation of flavor attributes of raw and cooked beef based on sensor array analyses

There are currently no standardized objective measures to evaluate beef flavor attributes, especially the comparison between raw beef and cooked beef. Beef flavor attribute is one of the most significant parameters for consumers. This study described a predictive model using a 12-ion-sensor array and sensory properties to evaluate beef flavor attributes based on potential. Then the number of sensors was reduced to six via variance of analysis, and these six sensors were reserved with the saturated calomel reference electrode to constitute a new sensor array. Sensitive flavors of each sensor were selected through multiple comparative analysis. Results showed that the accuracy rate of classifying five basic flavors (acidity, sweetness, bitterness, saltiness, freshness) using the new sensor array was 100%. The processing methods used were based on multivariate statistical methods done with the cluster analysis (CA). Results were compared to sensory evaluation using genetic algorithm (GA). From GA, the accuracy rates of raw and cooked beef were 85.0% and 90.0%, which was consistent with the sensory analysis results. Moreover, reducing the number of sensors could decrease the data dimensionality and detection time. Also raw beef instead of cooked beef could be used in flavor attributes evaluation. This model could become an important method for evaluating beef flavor attributes repeatedly and objectively.

Comparison of aroma-active compounds in broiler broth and native chicken broth by aroma extract dilution analysis (AEDA), odor activity value (OAV) and omission experiment

Two types of chicken broth, broiler broth (BB) and native chicken broth (NCB), were used to analyse their differences in aroma by gas chromatography-olfactometry/mass spectrometry (GC-O/MS). NCB contained more complex volatiles and exhibited a richer aromatic profile compared with BB. Results from aroma extract dilution analysis showed that (E,E)-2,4-decadienal was the odorant with highest flavour dilution (FD) factor in both broths. The FD factors of 10 odorants in NCB were greater than those in BB, and 13 odorants with almond, citrus, vegetable, cucumber and sweet smells were only found in NCB. Moreover, 16 aroma compounds had average odor activity values (OAVs) greater than 1, among which (E,Z)-2,4-decadienal (OAV_BB = 181, OAV_NCB = 1067), (E,E)-2,4-decadienal (OAV_BB = 175, OAV_NCB = 1065), (E,E)-2,4-nonadienal (OAV_BB = 28, OAV_NCB = 169), and (E)-2-nonenal (OAV_BB = 39, OAV_NCB = 120) exhibited the highest values. Omission tests corroborated the importance of dienals to the overall aroma of chicken broth; nevertheless, omitting either (E,E)-2,4-decadienal or (E,E)-2,4-nonadienal individually did not result in significant aroma change.

Ageing and retail display time in raw beef odour according to the degree of lipid oxidation

This study aims to assess the changes in beef aroma over time when steaks from pre-aged knuckles are stored in retail display under high oxygen conditions for 15 or 22days in vacuum conditions. Odorous volatile compounds were analysed by solid-phase microextraction/gas chromatography-mass spectrometry. Results were grouped as low, medium and high oxidative groups according to thiobarbituric acid reactive substances values after 9days of display. The intensity of off-odours in the raw meat increased with ageing and display time and oxidative groups. Based on correlations between the variables and regressions of the compounds through display, eight compounds were proposed as odour shelf-life markers. Among them, five were most sensitive and precise in all oxidative groups: 1-hexanol in meat aged for 15days, ethyl- octanoate and 2-pentylfuran in meat aged for 22days, and pentanoic and hexanoic acids in the two studied ageing times.