Foal meat volatile compounds: effect of vacuum ageing on semimembranosus muscle

Application of Omics in Donkey Meat Research: A Review

This review comprehensively examines the molecular basis of donkey meat characteristics and growth-associated genes, integrating findings from multiple omics approaches. This study examines the nutritional profile of donkey meat, which is rich in protein, essential amino acids, and unsaturated fatty acids. Through a systematic literature search across Web of Science, Google Scholar, PubMed, and Scopus databases (2000-2024), we collected and analyzed data from 400 research articles using predefined inclusion criteria focused on nutritional composition, omics approaches, and meat quality parameters in donkey populations. The study also evaluates various factors affecting meat quality, including breed differences, age, feeding management, and storage conditions. Advanced genomic and transcriptomic analyses have revealed numerous candidate genes, such as ACTN3, BMP7, NR6A1, Wnt7a, HOXC8, LCORL, TPM2, and TPM3, associated with growth traits and meat quality characteristics, providing valuable insights for genetic improvement programs. Furthermore, the review discusses various authentication methods for ensuring donkey meat quality and preventing adulteration, highlighting the integration of traditional and modern analytical approaches.

The Formation and Change of Volatile Flavor Compounds During the Cooking of Sheep Bone Soup

To investigate the formation of flavor compounds in sheep bone soup, E-nose, gas chromatograph (GC), and gas chromatography-mass spectrometry (GC-MS) were used to determine the changes in lipid oxidation, Maillard reaction, and volatile flavor compounds during the slow cooking process of 4 h. The thiobarbituric acid reactive substances (TBARS) value began to increase significantly (p < 0.05) after 2 h of cooking, reaching its peak in the third hour before significantly decreasing. The intensity of the Maillard reaction significantly increased after 2 h of cooking and subsequently stabilized. Thirty-nine flavor compounds were identified, primarily comprising aldehydes, ketones, alcohols, esters, aromatic compounds, and heterocyclic compounds. The formation of volatile flavor compounds in sheep bone soup was associated with lipid oxidation, particularly the oxidation of unsaturated fatty acids, and the Maillard reaction. Lipid oxidation produced a large number of volatile flavor compounds, such as aldehydes and ketones. The Maillard reaction gave sheep bone soup a certain flavor. Aldehydes were mostly influenced by cooking time, becoming the main flavor compounds in the bone soup after 2.5 h of cooking, accounting for more than half of the total volatile flavor compounds. The highest content and richest profile of volatile flavor compounds were obtained in the soup cooked for 2.5 h and 3 h. This study provides a theoretical basis for the flavor regulation of sheep bone soup.

Enhancement of culled ewes' meat quality: Effects of aging method and time

This study assesses the impact of wet and dry aging, over 35 days, on various physico-chemical, colorimetric, oxidative, volatolomic, and sensory attributes of meat from culled ewes. Water holding capacity of dry-aged (DA) meat increased from day 28 and was significantly higher than wet-aged (WA) meat. Cooking loss of DA meat decreased, and it was lower than that of WA meat. Warner Bratzler shear force increased in DA meat but decreased in WA meat during aging. Higher oxidation product concentration in DA meat likely results from oxygen exposure. Some aldehydes and ketones peaked at day 7 in DA meat, surpassing levels in WA meat. Overall liking scores favored DA meat at day 14 and 21 but declined from day 14 to 35, coinciding with increased pentanal content. Dry aging could improve the acceptability of culled ewes' meat more than wet aging, but in short aging time (14 days).

Hydrogen Gas-Grilling in Meat: Impact on Odor Profile and Contents of Polycyclic Aromatic Hydrocarbons and Volatile Organic Compounds

The effect of fuel (hydrogen vs. butane) on the formation of volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) was evaluated for grilled horse meat (very low-fat and low-fat) cooking vertically. Gas chromatography-mass spectrometry was used to analyze PAHs and VOCs. An electronic nose was used to evaluate the odor profile. Total high-molecular-weight PAHs ranged from 19.59 to 28.65 µg/kg with butane and from 1.83 to 1.61 µg/kg with hydrogen. Conversely, total low-molecular-weight PAHs went from 184.41 to 286.03 µg/kg with butane and from 36.88 to 41.63 µg/kg with hydrogen. Aldehydes and alkanes were the predominant family in a total of 59 VOCs. Hydrogen gas-grilling reduced significantly (p < 0.05) the generation of VOCs related to lipid oxidation. The odor profile was not modified significantly despite the change of PAHs and VOCs. The findings indicate that hydrogen is a viable alternative to butane for grilling horse meat. Hydrogen gas-grilling may be regarded as a safe cooking procedure of meat from a PAH contamination point and perhaps sustainable environmentally compared to a conventional technique. The present study provides the basis for the use of hydrogen gas in grilled meat.

Characteristics of Purified Horse Oil by Supercritical Fluid Extraction with Different Deodorants Agents

This study investigated the impact of activated carbon, palm activated carbon, and zeolite on horse oil (HO) extracted from horse neck fat using supercritical fluid extraction with deodorant-untreated HO (CON) as a comparison. The yield and lipid oxidation of deodorant untreated HO (CON) were not significantly affected by the three deodorants. However, deodorant-treated HOs exhibited significantly elevated levels of α-linolenic acid (C18:3n3) and eicosenoic acid (C20:1n9) compared to CON (p<0.05), while other fatty acids remained consistent. Zeolite-purified HO demonstrated significantly lower levels of volatile organic compounds (VOCs) than other treatments (p<0.05). Remarkably, zeolite decreased the concentration of pentane, 2,3-dimethyl (gasoline odor), by over 90%, from 177.17 A.U. ×106 in CON to 15.91 A.U. ×106. Zeolite also effectively eliminates sec-butylamine (ammonia and fishy odor) as compared to other deodorant-treated HOs (p<0.05). Additionally, zeolite reduced VOCs associated with the fruity citrus flavor, such as nonanal, octanal, and D-limonene in HO (p<0.05). This study suggests that integrating zeolite in supercritical fluid extraction enhances HO purification by effectively eliminating undesirable VOCs, presenting a valuable approach for producing high-quality HO production in the cosmetic and functional food industries.

Physicochemical Features and Volatile Organic Compounds of Horse Loin Subjected to Sous-Vide Cooking

The purpose of this study was to evaluate the effect of temperature and time of sous-vide cooking method on the characteristics of Thoroughbred horse loin. Sliced portions (200 ± 50 g) were cooked by boiling (control) and sous-vide (65 and 70 °C for 12, 18, and 24 h). The samples were analyzed for proximate composition, pH, color, texture, microstructure, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), microbiology, volatile organic compounds (VOCs), nucleotide content, and fatty acids composition. The color analysis showed decreased redness at elevated temperatures. Improved tenderness, demonstrated by reduced shear force values (36.36 N at 65 °C for 24 h and 35.70 N at 70 °C for 24 h). The micrographs indicated dense fiber arrangements at 70 °C. The SDS-PAGE revealed muscle protein degradation with extended sous-vide cooking. The VOC analysis identified specific compounds, potentially distinctive markers for sous-vide cooking of horse meat including 1-octen-3-ol, decanal, n-caproic acid vinyl ester, cyclotetrasiloxane, octamethyl, and 3,3-dimethyl-1,2-epoxybutane. This study highlights the cooking time's primary role in sous vide-cooked horse meat tenderness and proposes specific VOCs as potential markers. Further research should explore the exclusivity of these VOCs to sous-vide cooking.

Aquafeed fermentation improves dietary nutritional quality and benefits feeding behavior, meat flavor, and intestinal microbiota of Chinese mitten crab (Eriocheir sinensis)

Normally, proper fermentation can be an efficient and widely used method to improve feed quality in animal rearing; however, the studies on crustaceans, especially Eriocheir sinensis, remain limited. This study aimed to investigate whether feed fermentation could meliorate dietary nutritional value and benefit E. sinensis rearing. First, non-fermented feed (NFD) and fermented feed (FD) were produced and assessed, respectively. Then, the "Y" maze feed choice behavior test (180 times; 30 times, 6 rounds) was conducted to assess the attractiveness of these 2 feeds for crabs. Finally, a total of 80 crabs (44.10 ± 0.80 g) were randomly assigned into 2 groups with 4 replicates, and fed the experimental diets for 8 weeks to evaluate the effects of each feed on growth, antioxidant capacity, meat flavor, and intestinal microbiota. In this study, FD showed higher levels of crude protein (P < 0.01), soluble protein (P < 0.01), amino acids (P < 0.05), lactic acid (P < 0.001), and lower levels of crude fiber (P < 0.05) and antinutritional factors (agglutinin, trypsin inhibitor, glycinin, and β-conglycinin) (P < 0.001) than NFD. Additionally, FD was more attractive to crabs than NFD (P < 0.01) and it stimulated the appetite of crabs more than NFD (P < 0.05). The growth performance, feed efficiency, and digestive enzyme activity of FD-fed crabs were significantly higher than those of NFD-fed crabs (P < 0.05). The electronic sensory measurements and free amino acid profiles revealed that the FD diet had positive impacts on the meat flavor of crabs, particularly in "sweet" and "umami" tastes. Moreover, the antioxidant capacity of FD-fed crabs was significantly higher than that of NFD-fed crabs (P < 0.05). Fermented feed also affected the diversity and composition of intestinal microflora. The functional prediction of microbial communities showed that crabs fed FD had a better microecological environment in the intestine. In conclusion, the fermentation of aquafeed could be an effective approach to enhance feed quality and therefore benefit E. sinensis rearing.

Evaluation of the Influence of Flavor Characteristics of Cooked Bacon with Different Sterilization Methods by GC-IMS Combined with HS-SPME-GC-MS and Electronic Nose

This study investigated the impact of high pressure and temperature (HTHP) and electron-beam irradiations (3, 5, 7, and 9 kGy) using differences in two sterilization methods on the volatile compounds and sensory characteristics of cooked bacon. It showed that 7 and 9 kGy of irradiation caused a significant reduction in species of volatile compounds and sensory features, but the concentration of total ketones, alcohols, aldehydes, acids and aromatic hydrocarbons significantly increased at 9 kGy. Samples treated with a dose of less than 5 kGy did not change volatile compounds and sensory properties. High-temperature-high-pressure conditions could greatly impact the concentrations of volatile compound species and sensory traits. The electronic nose effectively detected the flavor difference in different sterilization methods. Fingerprinting showed that HTHP and 9-kGy-treated groups were significantly different from other treatments. This study inferred that 5 kGy might be optimal for maintaining the original flavor and sensory properties of cooked bacon.

Effects of Ageing on Donkey Meat Chemical Composition, Fatty Acid Profile and Volatile Compounds

Donkey meat samples obtained from muscle Longissimus Thoracis Lumborum (LTL) taken from 14 entire donkey males slaughtered at 20 months and aged for 1, 8 and 15 days were analysed with the aim of determining the chemical composition, physical attributes, fatty acid profile and volatile compounds. Ageing did not significantly affect the chemical composition and colour parameters, while cooking loss was significantly (p < 0.05) higher at 8 and 15 days of ageing. Thiobarbituric acid reactive substances (TBARS) content significantly (p < 0.01) increased during ageing, while shear force values significantly (p < 0.01) decreased. Ageing significantly (p < 0.05) increased polyunsaturated fatty acids (PUFAs) determined both at 8 and 15 days after slaughter. Volatile compounds were analysed using solid-phase microextraction (SPME) and gas chromatography−mass spectrometry (GC−MS). Among 109 volatile compounds determined in donkey meat, hydrocarbons were the most common molecules detected. Ageing affected 21 of the detected volatile compounds; both total aldehydes and total ketones contents were significantly (p < 0.05) higher 15 days after slaughter. Total furans and total alcohols were significantly (p < 0.01) higher 15 days after slaughter, as well. Significant modifications of donkey meat volatile compounds can be attributed to ageing periods longer than 7 days.

Effects of Anthocyanin Supplementation and Ageing Time on the Volatile Organic Compounds and Sensory Attributes of Meat from Goat Kids

The aim of this study was to assess the effects of dietary anthocyanin addition on volatile compounds of meat from goat kids during ageing. For this work, 60 male and female kids were divided into two groups: red orange and lemon extract (RLE group; n = 30), which received an RLE extract (90 mg/kg of live weight); and control (CON group; n = 30). The phytoextract in dry powder form was rich in bioflavonoids such as flavanones (about 16%) and anthocyanins (about 3%). After slaughtering, the longissimus thoracis et lumborum muscle was aged at 4 °C. The volatile organic compound (VOC) and sensorial analyses were carried out at 1, 3 and 7 days. A total of 10 chemical families were identified during the ageing process. Aldehydes were the most abundant VOC, followed by ketones and alcohols. Their contents increased during the process, showing after 7 days of ageing mean values of 20,498, 2193 and 1879 ng/g of meat, respectively. Regarding dietary effects, carboxylic acids, hydrocarbons and thiols presented significant differences between treatments, with higher carboxylic acid contents observed in RLE samples (437 vs. 467 ng/g of meat for CON and RLE batches, respectively; p < 0.05). On the contrary, hydrocarbons (436 vs. 254 ng/g of meat for CON and RLE batches, respectively) and thiols (160 vs. 103 ng/g of meat for CON and RLE batches, respectively) displayed significantly (p < 0.01) higher amounts in CON compared to the RLE group. Regarding ageing time, the tenderness, juiciness, odour and overall assessment parameters showed significantly higher scores at the end of the whole process (p < 0.05). On the other hand, only odour displayed significant differences between treatments, reaching higher scores in CON samples (p < 0.05). Therefore, ageing time improved the sensorial properties (tenderness, juiciness, odour and overall assessment) and the VOC content, whereas the inclusion of anthocyanins in the kids' diet did not have a great impact on the properties of aged meat.

Study on the influences of ultrasound on the flavor profile of unsmoked bacon and its underlying metabolic mechanism by using HS-GC-IMS

For exploring the influence of ultrasound on the flavor characteristic of unsmoked bacon, sensory evaluation combined with E-nose and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) were performed to analyze the overall flavor profile and specific volatile flavor compounds (VFCs), respectively. Furthermore, the metabolic pathway of VFCs affected by ultrasound was also investigated. Results demonstrated that ultrasound improved the flavor characteristic of unsmoked bacon by raising the levels of nonanal, heptanal, octanal, 3-methylbutanal n-hexyl acetate and n-propyl acetate. Enzymatic oxidation was found to be an important metabolic pathway responsible for the development of flavor characteristic after ultrasound treatment, which could be attributed to the increased activities of lipases and lipoxygenase and the higher concentration of polyunsaturated free fatty acids. The increased level of lipid oxidation after ultrasound treatment was also confirmed by thiobarbituric acid reactive substances. Consequently, ultrasound is an effective approach to enhance the flavor characteristic of unsmoked bacon.

Fatty Acid Composition and Volatile Profile of longissimus thoracis&nbsp;et&nbsp;lumborum Muscle from Burguete and Jaca Navarra Foals Fattened with Different Finishing Diets

The present study evaluated the effect of breed, Jaca Navarra (JN) vs. Burguete (BU), and finishing diet, conventional concentrate—diet 1 (D1) vs. silage and organic feed—diet 2 (D2), on the fatty acid composition and volatile profile of longissimus thoracis et lumborum muscle from forty-six foals. For this, foals were reared under a semi-extensive system and slaughtered at about 21 months of age. The outcomes showed that breed and finishing regime had a significant (p < 0.05) effect on the lipid and volatile profile of foal meat. In particular, JN foals reported higher polyunsaturated fatty acid contents and better nutritional indices in line with the health guidelines; whereas, BU and D1 groups generated higher amounts of total volatile compounds. However, it was the diet to occupy a central role in this study. Indeed, diet 2, due to its “ingredients” and composition, not only ameliorated the lipid profile of foal meat, but also reduced the generation of volatile compounds associated with lipid oxidation and minimized off-flavors. Thus, this diet could give an added value to the aromatic perception of meat and improve its sensorial acceptability.

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.

Influence of the Production System (Intensive vs. Extensive) at Farm Level on Proximate Composition and Volatile Compounds of Portuguese Lamb Meat

Today’s society demands healthy meat with a special emphasis on integrated animal husbandry combined with the concern for animal welfare. In this sense, the raising of lambs in an extensive system has been one of the most common practices, which results in meats with high nutritional value. However, both the production system and the diet play a fundamental role in the chemical composition of the meat, which has a direct impact on the content of volatile compounds. Thus, the aim of this study was to determine the effect of two production systems (intensive and extensive) on the chemical composition and volatile profile of lamb meat. Twenty-eight lambs of the Bordaleira-de-Entre-Douro-e-Minho (BEDM) sheep breed were raised for meat production under the intensive or extensive system and were fed with concentrate and pasture, respectively. All animals were carried out in the muscle longissimus thoracis et lumborum. Results evidenced that all the composition parameters were affected by the production system. Extensively-reared lambs produced meat with the highest fat and protein contents, while these animals had the lowest percentages of moisture and ash. Similarly, the total content of volatile compounds was affected (p < 0.05) by the production system and were higher in the meat of lambs reared extensively. Furthermore, the content of total acids, alcohols, aldehydes, esters, ethers, furans and sulfur compounds as well as most of the individual compounds were also affected (p < 0.05) by the production system, whereas total hydrocarbons and ketones were not affected (p > 0.05). As a general conclusion, the production system had very high influence not only in proximate composition but also in the volatile compounds.

Dry-Aged Beef Steaks: Effect of Dietary Supplementation with Pinus taeda Hydrolyzed Lignin on Sensory Profile, Colorimetric and Oxidative Stability

Flavor is one of the main factors involved in consumer meat-purchasing decision and use of natural antioxidants in animal feeding had a great appeal for consumers. The aim of this trial is to evaluate the effect of Pinus taeda hydrolyzed lignin (PTHL) feed addition on oxidative stability, volatile compounds characteristics, and sensory attributes of 35 days dry-aged beef steaks. Forty steer six months old were randomly divided into a control group (CON; n = 20) and an experimental group (PTHL; n = 20). Both groups were fed ad libitum for 120 days with the same TMR and only the PTHL group received PTHL supplement. Samples of LT muscle were removed from carcasses and dry aged for 35 days at 2 °C, 82% of humidity, and 0.4 m/s of ventilation and then analyzed. Meat of CON group showed lower yellowness (p < 0.01) and higher TBARS (p < 0.01) values. Moreover, CON meat showed higher volatile aldehydes and lower sulfur compounds (p < 0.01), with higher unpleasant odor (p < 0.05) and meaty odor (p < 0.01) score revealed by sensory assessors. PTHL inclusion in beef diet delayed the oxidative mechanisms in 35 days dry-aged steaks, resulting in an improved colorimetric, volatolomic, and sensory profile.

Evaluation of volatile flavor compounds in bacon made by different pig breeds during storage time

The oxidation and volatile constituents of bacon (which made of white pig (Duroc × Landrace × Yorkshire) and black pig (Beijing Black × Yorkshire)) during refrigerated storage were analyzed by thiobarbituric acid reactive substances (TBARS), total thiol groups, gas chromatography-mass spectrometry (GC-MS) and gas chromatography coupling with ion mobility spectrometry (GC-IMS). The TBARS value of tested samples increased while the total thiol groups decreased during 60 days storage (P < 0.05). Volatile fingerprint results were obtained by GC-MS and GC-IMS detector, the classes and contents of volatile compounds detected in WP bacon were much abundant than BP bacon. Higher phenols and acids concentrations were observed in WP bacon, while alcohols, ketones, and nitrogen-containing compounds were more determined in BP bacon. Besides, WP bacon was more notably affected by storage rather than BP bacon, and the difference of raw material is the main reason for the flavor in WP and BP bacon comparing with the storage process.

Effect of Different Aging Methods on the Formation of Aroma Volatiles in Beef Strip Loins

This study investigated the effects of different aging methods on the changes in the concentrations of aroma volatiles of beef. One half (n = 15) of the beef strip loins were dry-aged, and the other half were wet-aged, and both aging processes continued for 28 days. The aroma volatiles from dry- and wet-aged samples were analyzed at seven-day intervals (n = 3 for each aging period). As the aging period increased, dry-aged beef showed higher concentrations of volatile compounds than those in wet-aged beef (p < 0.05). Most changes in the concentrations of aroma volatiles of dry-aged beef were associated with propanal, 2-methylbutanal, 2-methylpropanal, 1-butanamine, trimethylamine, 2-methyl-2-propanethiol, and ethyl propanoate, which were mainly produced by lipid oxidation and/or microbial activity (e.g., proteolysis and lipolysis) during the dry aging period. Therefore, we suggest that the differences in aroma between dry- and wet-aged beef could result from increased lipid oxidation and microbial activity in dry-aged beef possibly owing to its ambient exposure to oxygen.

How Volatile Compounds, Oxidative Profile and Sensory Evaluation Can Change with Vacuum Aging in Donkey Meat

Simple Summary

Aging in donkey meat was never investigated. It represents an important process, because it leads the muscle to become meat. There are many ways to age meat, and vacuum aging is one of these. The present paper characterised donkey meat Volatile Organic Compounds (VOCs) production during 14 vacuum aging days, its oxidative status and the consequent sensory evaluation. Lipid oxidative processes are delayed, but some protein oxidative processes happen, influencing VOCs production and sensory evaluation.

Abstract

This study aims to improve knowledge on donkey meat and the vacuum aging effect on the Volatile Organic Compounds (VOCs), oxidative profile and status and the sensory characteristics. Ten 18-month old Martina Franca donkeys’ male foals were involved in the trial. Longissimus thoracis (LT) muscle was extracted from each left half carcass, between the fourth and the ninth rib. Each muscle was divided into five sections, vacuum packaged, stored at 2 °C, and randomly assigned to one of the different aging time (1, 3, 6, 9, and 14 days of aging). Volatile compounds, oxidation parameters, and antioxidant enzymes were analysed, and a sensory test was performed. A nested one-way analysis of variance (ANOVA) was performed for aging time as an independent variable. Significance was set at p < 0.05. Aldehydes are the most produced VOCs, but no changes were observed during vacuum aging (p > 0.05). Nitrogen compounds increased during aging (p < 0.01). TBARs and hydroperoxides did not change during the storage, whereas the protein carbonyls increased (p < 0.05). Vacuum aging slowed down lipid oxidation and put in evidence the presence of protein oxidation and degradation, influencing the VOCs productions and sensory evaluation.

Volatile Organic Compounds, Oxidative and Sensory Patterns of Vacuum Aged Foal Meat

The study aimed to evaluate the effect of 14-day vacuum aging on the volatile compounds (VOC) profile, oxidative profile, antioxidant enzymes activity, and sensory evaluation in the Longissimusthoracis muscle of foal meat under vacuum aging. Longissimusthoracis (LT) was sampled in 20 mm thick slices, vacuum packed, and stored at 4 °C. Samples were randomly assigned to different aging times (1, 6, 9, 14 days after slaughtering). VOCs, thiobarbituric acid reactive substances (TBARs), hydroperoxides, carbonyl proteins, superoxide dismutase, catalase, and glutathione peroxidase were analyzed, and a sensory test was performed. A nested one-way analysis of variance (ANOVA) was performed for aging time as an independent variable. Significance was set at p < 0.05. The main VOCs originating from cooked steaks were aldehydes, (from 47.18% to 58.81% of the total volatile compounds), followed by hydrocarbons (from 9.32% and 31.99%). TBARs and hydroperoxides did not show variations due to aging (p > 0.05), instead, protein carbonyls showed higher values at the 14th day (p < 0.01). Catalase, superoxide dismutase, and glutathione peroxidase showed increasing values during aging time (p < 0.01). Vacuum aging slowed down lipid oxidation, and protein oxidation was shown to be present. However, the best vacuum aging duration is in the range of 6-9 days from slaughtering, with an improvement of sensory evaluation.

Turmeric (Curcuma longa L.) extract on oxidative stability, physicochemical and sensory properties of fresh lamb sausage with fat replacement by tiger nut (Cyperus esculentus L.) oil

This study aimed to evaluate the effect of turmeric extract as natural antioxidant on modified atmosphere-packaged fresh lamb sausages with fat replacement during storage (2 °C). Five treatments were prepared: control without antioxidant (CONT); with 500 mg/kg sodium erythorbate (E500); and three batches with 250, 500 or 750 mg/kg turmeric extract (T250, T500 and T750), respectively. The proximate composition, pH, color, texture, oxidative stability, sensorial analysis, free fatty acids and volatile compounds of sausages were analyzed. Turmeric extract improved the antioxidant capacity of lamb sausages and also slowed lipid oxidation and the generation of related volatile compounds. Moreover, physic-chemical parameters of lamb sausages were not greatly influenced by turmeric addition and concentration, except for yellow color. All samples were considered acceptable by consumers. These findings showed that turmeric extract is effective against lipid oxidation and could be a good strategy to enhance the shelf life of lamb sausage.

Influence of the Inclusion of Chestnut (Castanea sativa Miller) in the Finishing Diet and Cooking Technique on the Physicochemical Parameters and Volatile Profile of Biceps femoris Muscle

The aim of this study was to evaluate the influence of the diet (chestnut vs. commercial feed) and cooking techniques (roasting, grilling, frying and microwaving) on the quality of the Biceps femoris muscle of the Celta pig breed. Chemical composition, physicochemical parameters, oxidative stability and volatile profile were analysed. Overall, the inclusion of chestnuts did not affect the chemical composition, except for intramuscular fat content, which was higher in chestnut-fed pigs. The colour and shear force of cooked Biceps femoris were not affected by the finishing diet. However, a significant increase in cooking losses and thiobarbituric acid reactive substances (TBARS) value was found with the chestnuts included in the diet. In addition, the inclusion of chestnuts also modified some volatile compound that could be associated with the diet, such as furan, 2-pentyl. On the other hand, the cooking method significantly affected chemical composition (moisture, fat, protein and ash content), colour parameters, cooking loss, TBARS and volatile profile, whereas the shear force was not affected. Concretely, fried and microwave were the techniques that led to a greater presence of intramuscular fat. In addition, the frying method also showed the highest a* value, whereas the microwaved technique displayed the highest cooking loss. Regarding lipid oxidation, the fried method displayed the lower TBARS and hexanal content. On the other hand, the major volatile compounds were aldehydes in all cooking methods except for the frying technique in chestnut samples. Finally, method-frying displayed the lowest amount of total volatiles compounds, unlike grilling.

A Comprehensive Review on Lipid Oxidation in Meat and Meat Products

Meat and meat products are a fundamental part of the human diet. The protein and vitamin content, as well as essential fatty acids, gives them an appropriate composition to complete the nutritional requirements. However, meat constituents are susceptible to degradation processes. Among them, the most important, after microbial deterioration, are oxidative processes, which affect lipids, pigments, proteins and vitamins. During these reactions a sensory degradation of the product occurs, causing consumer rejection. In addition, there is a nutritional loss that leads to the formation of toxic substances, so the control of oxidative processes is of vital importance for the meat industry. Nonetheless, despite lipid oxidation being widely investigated for decades, the complex reactions involved in the process, as well as the different pathways and factors that influenced them, make that lipid oxidation mechanisms have not yet been completely understood. Thus, this article reviews the fundamental mechanisms of lipid oxidation, the most important oxidative reactions, the main factors that influence lipid oxidation, and the routine methods to measure compounds derived from lipid oxidation in meat.

Effect of guarana (Paullinia cupana) seed and pitanga (Eugenia uniflora L.) leaf extracts on lamb burgers with fat replacement by chia oil emulsion during shelf life storage at 2 °C

The effects of guarana seed and pitanga leaf extracts on the physical-chemical and sensory characteristics, and oxidative stability of modified atmosphere-packaged lamb patties with fat replacement during storage (2 °C) were investigated. Four treatments were prepared: control (without antioxidant); with BHT (10 mg/kg); with 250 mg/kg guarana extract (G250); with 250 mg/kg pitanga extract (P250). Analysis included the proximate composition (moisture, protein, fat, and ash) and sensory acceptance (day 0); pH, color (L*, a*, b*), TBARs, carbonyl content, DPPH, and visual sensory assessment (0, 6, 12, and 18 days); fatty acid profile and volatile compounds (0 and 18 days). G250 and P250 did not alter the centesimal composition and the acceptance of the lamb burgers on day 0. The extracts also delayed discoloration of the burgers, endowed the reddest intensity, and retarded lipid and protein oxidation throughout storage time, particularly P250, which presented the lowest TBARs levels (6.92 mg MDA/kg) and carbonyl values (5.59 nmol carbonyl/mg), and the highest antioxidant activity (249.48 μg Trolox/g), at day 18. The MUFA, SFA, and PUFA levels, AI, TI, and h/H ratio were comparable between treatments; only the n-6/n-3 ratio was higher in P250 treatment but within the recommended levels. More volatile compounds were derived from lipid oxidation in the control and BHT treatments than G250 and P250 treatments. As a result, both G250 and P250 groups are effective against color deterioration, and lipid and protein oxidation, without impairing the sensorial characteristics, representing a promising alternative to replace synthetic antioxidants by natural products in lamb burger.