Meat quality, fatty acids, volatile compounds, and antioxidant properties of lambs fed pasture versus mixed diet

Effects of Feeding Systems on the Growth Performance, Carcass Characteristics, and Meat Quality in Sheep: A Meta-Analysis

Meat quality is important in the meat-production chain. Conflicting reports of the effects of feeding systems on sheep growth performance and meat quality exist. By way of meta-analysis, we reviewed the literature on the growth and slaughter performance, and meat quality of lambs that grazed solely on pasture, those that grazed on pasture but received a dietary supplement, and those were exclusively fed indoors. The relevant literature comprised 28 papers, from which response variables of interest were obtained. Compared with stall-fed sheep, pasture-grazing led to significantly (p < 0.05) lower average daily gain, slaughter live weight, hot carcass weight, cold carcass weight, and similar dressing percentage, but pasture-grazed sheep fed a supplement had similar (p > 0.05) values for each of these attributes to stall-fed sheep. The quality of the longissimus muscle from lambs that grazed either exclusively on pasture or pasture with a supplement had significantly (p < 0.05) lower lightness and intramuscular fat content, and significantly (p < 0.05) higher yellowness, Warner-Bratzler shear force, and protein content than meat from stall-fed sheep. We conclude that sheep that have fed exclusively on pasture have lower carcass yield and meat edibility, but improved meat quality, and that pasture-fed sheep that received a supplement had comparable carcass attributes, but greater meat color and health quality than stall-fed sheep.

Soybean oil, linoleic acid source, in lamb diets: carcass traits and meat quality

We developed a study to determine the ideal level of inclusion of soybean oil (SBOil) in the diet without affecting the quantitative and qualitative parameters of the carcass and meat of lambs in a feedlot system; therefore, determining the ideal level of inclusion. Forty male lambs (Santa Inês breed) were used. The initial body weight and age averaged 34.88 ± 3.19 kg and 5 months, respectively. Experimental units (lambs) were randomly distributed in 5 different diets: inclusion levels of SBOil: 0, 30, 60, 90, and 120 g/kg of dry matter (DM). The SOil inclusion reduced the DM intake (P < 0.001), Total digestible nutrients (P = 0.004), and crude protein (P < 0.001). Total weight gain (P < 0.001) decreased with the SBOil inclusion and subcutaneous fat thickness (P = 0.017) showed the same behaviour. The final body weight decreased by 42.9 g/kgDM until the inclusion level of 30 g/kgDM; from this level it was reduced by 145 g/kgDM. The hot and cold carcass weights (P = 0.013) decreased by 36.6 g/kgDM after including 30 g/kgDM of SBOil. Meat physicochemical composition was not altered (P > 0.05). Lower meat tenderness values ​​were obtained at the levels of 60 and 90 g/kgDM. The inclusion above 30 g/kgDM decreased meat tenderness. It is concluded that soybean oil should be included up to 30 g/kgDM in diets. It is important to note that with diets with 60% concentrate, SBOil levels greater than 30 g/kgDM promote yield losses.

Effects of yeast cultures on meat quality, flavor composition and rumen microbiota in lambs

Since the banning of antibiotics, the use of feed additives to improve meat quality to satisfy people's pursuit of high quality has become a research hotspot. Yeast culture (YC) is rich in proteins, mannan oligosaccharides, peptides, and yeast cell metabolites, etc., and its use as a feed additive has a positive impact on improving meat quality. So the study aimed to provide a theoretical basis for YC improving mutton flavor and quality by detecting and analyzing the effects of YC on muscle physicochemical properties, amino acids, fatty acids, flavor composition, expression of related genes, and rumen microbiota of lambs. A total of 20 crossbred F1 weaned lambs (Australian white sheep♂ × Hu sheep♀; average 23.38 ± 1.17 kg) were randomly assigned to 2 groups, the control group (CON) and the 1.0% YC supplemented group (YC) (n = 10), and were reared in separate pens. The experiment had a pre-feeding period of 10 d and a treatment period of 60 d. After the experiment, 6 lambs in each group were randomly selected for slaughtering. The results showed that dietary YC supplementation increased rumen total VFA and acetate concentrations (p < 0.05), and muscle carcass fat (GR), a∗ value, intramuscular fat (IMF), lysine (Lys), arginine (Arg), nonessential amino acid (NEAA), oleic acid (C18:1n9c), and eicosanoic acid (C20:1) contents were significantly increased (p < 0.05), while cooking loss and γ-linolenic acid (C18: 3n6) were decreased (p < 0.05). Furthermore, we found that dietary YC improved the types of flavor compounds, and the key flavor substances such as hexanal, nonanal, styrene, benzaldehyde, p-xylene, and 1-octen-3-ol contents were changed (p < 0.05). Additionally, the expression of fat metabolism related genes PPARγ, FASN, and FABP4 were increased. Adding 1% YC to lamb diets increased profits by 47.70 CNY per sheep after 60 d of fattening. All of which indicated that YC could improve meat quality, especially flavor, which may be related to the regulation of the relative abundance of rumen microorganisms Bacteroidota, Prevotella_7, Succiniclasticum and Lachnospiraceae_NK3A20_group.

New evidence for gut-muscle axis: Lactic acid bacteria-induced gut microbiota regulates duck meat flavor

The interaction between gut microbiota and muscles through the gut-muscle axis has received increasing attention. This study attempted to address existing research gaps by investigating the effects of gut microbiota on meat flavor. Specifically, lactic acid bacteria were administered to ducks, and the results of e-nose and e-tongue showed significantly enhanced meat flavor in the treatment group. Further analyses using GC-MS revealed an increase in 6 characteristic volatile flavor compounds, including pentanal, hexanal, heptanal, 1-octen-3-ol, 2,3-octanedione, and 2-pentylfuran. Linoleic acid was identified as the key fatty acid that influences meat flavor. Metagenomic and transcriptomic results further confirmed that cecal microbiota affects the duck meat flavor by regulating the metabolic pathways of fatty acids and amino acids, especially ACACB was related to fatty acid biosynthesis and ACAT2, ALDH1A1 with fatty acid degradation. This study sheds light on a novel approach to improving the flavor of animal-derived food.

Statistical approaches for assessing meat quality and heifer rumen histology based on dietary forage

Introduction

Feeding local forages to ruminants is a promising strategy for enhancing metabolic processes, promoting sustainable farming, and improving product quality. However, studies comparing the effects of different forages on rumen histology and meat attributes of heifers are limited and variable.

Material and methods

This study evaluated the benefits of incorporating local forages into heifer diets by comparing barley straw (BS) and oat hay (OH) on heifer attributes focusing on meat quality (MQ) and rumen status (RS). Sixteen crossbred (Charolais x Limousin) female heifers (7 months of age, 263 ± 10.50 kg) were randomly assigned to two dietary treatments (BS or OH) over 120 days.

Results and discussion

Heifers fed OH showed enhanced RS (p < 0.05), characterized by improved intestinal epithelial integrity and a lower percentage of hyperpigmented cells, suggesting a potential reduction in inflammatory processes compared to BS, which may indicate a lower risk of metabolic diseases. Despite this, no significant differences (p > 0.05) were found in animal performance, chemical composition, and technological properties of the meat between the dietary groups, while lower levels (p < 0.05) of certain saturated fatty acids (C12:0, C15:0, and C22:0) were found in the meat from heifers fed OH. Principal component analysis (PCA) reduced the variables and demonstrated that all variables assessed can be condensed into four new variables explaining 75.06% of the variability. Moreover, biplot analysis reveals that the OH diet could be discriminated from BS. Our findings suggest that OH is a valuable fiber source, positively influencing certain heifer attributes, and supporting sustainable animal agriculture practices.

Effect of dawri-damaa (Pentas schimperiana) leaf meal supplementation on performances, carcass characteristics, and economic feasibility of sheep fed native grass hay

With a growing export and local market, sheep farming is critical to the economy of smallholder farmers; however, indigenous sheep breeds usually exhibit low carcass output and live weight due to nutritional constraints. The study aimed to investigate the impact of supplementing local sheep with dawri-damaa leaf meal (DDLM) on their performance, carcass characteristics, and profitability when fed native grass hay. The research used a randomized complete block design (RCBD) to administer four feeding treatments (T1, T2, T3, and T4 at 0%, 30%, 50%, and 70% DDLM, respectively) to 20 local uncastrated male lambs having an average 23.72 ± 0.73 kg body weight and average age of 11.72 ± 0.74 months. Greater doses of DDLM in the diet resulted in greater average daily gain (ADG) of 51.4-83.8 g/day and feed conversion efficiency (FCE) of 0.066-0.089 in lambs, compared to 15.0 g/day ADG and 0.025 FCE in lambs under control diet (T1). Additionally, the lambs had increased slaughter body weight (SBW), empty body weight (EBW), and hot carcass weight (HCW) in T4 and T3 compared to other treatments (p < .05). There were no significant differences in dressing percentages (DPs) across any treatment group. The study also discussed the economic viability of supplementing with DDLM, suggesting that feeding 70% daily dry matter of DDLM at 2.5% live weight might be beneficial depending on availability, access, and cost factors. In conclusion, feeding DDLM up to 70% has improved the performance of sheep and is economically feasible. Further research might be required to discover whether such levels of inclusion are harmful and apply different processing methods for feeding animals.

Effect of Lactobacillus helveticus IMAUJBH1 on fat and volatile flavor substances in fermented mutton sausages

The decomposition and oxidation of fat is essential for the formation and quality of the unique flavor of sausage. To explore the effect of lactic acid bacteria on fat decomposition and oxidation in fermented sausage, free fatty acids and volatile flavor compounds were determined by gas chromatography (GC) and headspace solid-phase microextraction (HS-SPME)-GC-MS, respectively. The results showed that the addition of Lactobacillus helveticus IMAUJBH1 inhibited fat peroxidation and relatively increased the proportion of monounsaturated fatty acids. A total of 47 volatile flavor compounds were detected, including aldehydes, esters, alcohols, and ketones. The content of substances such as hexanal, heptanal, nonanal and 1-octene-3-ol related to lipid oxidation was significantly reduced. The results obtained in this study show that the strain can further affect the flavor of the product by inhibiting the formation of lipid oxidation or peroxide flavor substances to a certain extent.

Unraveling proteome changes of Sunit lamb meat in different feeding regimes and its relationship to flavor analyzed by TMT-labeled quantitative proteomic

In order to explore the molecular mechanism of the effect of feeding regimes on lamb flavor, biceps femoris muscle samples from pasture-fed groups (PF) and concentrate-fed groups (CF) were chosen, and tandem mass tag (TMT) labeling combined with mass spectrometry (MS) was performed to find associations between flavor indicators and proteome profiles. The content and composition of amino acids and volatile flavor substances were better in the PF compared to the CF, with higher levels of some beneficial flavor components such as Arg, Pro Pentanal, Heptanal, Octanal, 1-octen-3-ol and 2,3-Octanedione. About 82 differentially abundant proteins (DAPs) were identified. The Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis indicated that the pathways that may be associated with lamb flavor are focused on amino acid anabolism. These results provide a basis for further understanding of the molecular mechanisms of proteins in meat flavor regulation.

Improved muscle fatty acid composition and oxidative stability in lambs grazing on sainfoin pasture

As a mode of animal management, grazing on pasture has the potential to improve animal performance and provide healthy meat. However, there is little information about the effects of lamb meat quality grazed on sainfoin pasture. Therefore, the present study was conducted to compare the fatty acid composition and oxidative stability of growing lambs. The twenty-four lambs were randomly divided into grazing on sainfoin pasture (GS) or feeding indoors pelleted total mixed ration (FI). The results show that GS had the higher polyunsaturated fatty acids (PUFA), especially n-3 PUFA (P = 0.002), and beneficial for nutritional index of fatty acid. Corresponding that GS had lower the Thiobarbituric acid reactive substance (TBARS) in raw (P = 0.005) and cooked meat (P = 0.008). The GS had higher total phenols (P = 0.021), ferric reducing antioxidant power (FRAP) (P = 0.048) and α-Tocopherol of meat (P = 0.004). In conclusion, grazing on sainfoin pasture in lambs can improve muscle fatty acid composition and oxidative stability than feeding indoors.

Green tea catechin prevents oxidative stress-regulated autophagy and apoptosis signaling, and inhibits tenderness in postmortem bovine longissimus thoracis et lumborum muscle

Although green tea catechin has been reported to be an antioxidant and preservative in meat, the extent to which it affects the tenderization of bovine muscle remains largely unknown. This study seeks to evaluate the effect of catechin on the interplay between apoptosis and autophagy, and subsequently, the development of bovine muscle tenderness. The results indicate that catechin significantly alleviated oxidative stress. A concomitant reduction of autophagic markers LC3-II/LC3-I ratio, Beclin-1, and Atg7 levels were caused by catechin. Besides, aforementioned autophagy inhibition was further augmented by PI3K/Akt/mTOR activation. Additionally, catechin protected against mitochondrial dysfunction and inhibited mitochondria-dependent caspase apoptosis pathway. Furthermore, there was a reciprocal inhibition between autophagy and apoptosis. Ultimately, tenderness at 24 and 120 h, an increase in the gap between muscle fiber bundles, and disintegration of myofibrillar architectures were all inhibited by catechin. Therefore, despite alleviating oxidative stress, catechin may hamper tenderization pattern of postmortem bovine muscle.

Effect of dietary arginine supplementation on protein synthesis, meat quality and flavor in growing lambs

This study aimed to assess the effect of dietary arginine supplementation on protein synthesis, meat quality and flavor in lambs. Eighteen Dorper (♂) × Small Tailed Han sheep (♀) crossed ewe lambs of similar weight (27.29 ± 2.02 kg; aged 3 months) were assigned to two groups, the control group was fed the basal diet (Con group), and the arginine group (Arg group) was supplemented with 1% l-arginine based on the Con group for 90 d. The results suggested that dietary arginine significantly increased final body weight, loin eye muscle area, muscle fiber diameter, cross-sectional area (P < 0.050), and decreased shear force value and cooking loss (P < 0.050), as well as altered the composition and contents of volatile flavor compounds in lambs. Importantly, the total protein (TP) content, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP) activities in serum, branched-chain aminotransferase (BCAT), AST, ALT activities and neuronal nitric oxide synthase (nNOS) gene expression and content were elevated (P < 0.050), while content of urea nitrogen (BUN) in serum and 3-methylhistidine (3-MH) were decreased in arginine fed lambs (P < 0.050). In addition, arginine triggered muscle protein synthesis through protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway, while minimized protein degradation by regulating gene expression of myogenin (MyoG), myostatin (MSTN), muscle atrophy F-box (MAFbx) and forkhead box O3 family (FoxO3) (P < 0.050). Taken together, this study suggested that arginine can be used to improve protein deposition and meat quality in lamb production.

Measuring the Phytochemical Richness of Meat: Effects of Grass/Grain Finishing Systems and Grapeseed Extract Supplementation on the Fatty Acid and Phytochemical Content of Beef

Grass-finished beef (GFB) can provide beneficial bioactive compounds to healthy diets, including omega-3 polyunsaturated fatty acids (n-3 PUFAs), conjugated linoleic acid (CLA), and secondary bioactive compounds, such as phytochemicals. The objective of this study was to compare fatty acids (FAs), micronutrients, and phytochemicals of beef fed a biodiverse pasture (GRASS), a total mixed ration (GRAIN), or a total mixed ration with 5% grapeseed extract (GRAPE). This was a two-year study involving fifty-four Red Angus steers (n = 54). GFB contained higher levels of n-3 PUFAs, vitamin E, iron, zinc, stachydrine, hippuric acid, citric acid, and succinic acid than beef from GRAIN and GRAPE (p < 0.001 for all). No differences were observed in quantified phytochemicals between beef from GRAIN and GRAPE (p > 0.05). Random forest analysis indicated that phytochemical and FA composition of meat can predict cattle diets with a degree of certainty, especially for GFB (5.6% class error). In conclusion, these results indicate that GFB contains higher levels of potentially beneficial bioactive compounds, such as n-3 PUFAs, micronutrients, and phytochemicals, compared to grain-finished beef. Additionally, the n-6:n-3 ratio was the most crucial factor capable of separating beef based on finishing diets.

Review of Feeding Systems Affecting Production, Carcass Attributes, and Meat Quality of Ovine and Caprine Species

Growth rate, carcass attributes, and meat quality traits of small ruminants (i.e., sheep and goats) depend on various factors, among which the feeding system is one of the most important factors. However, how feeding systems affect these parameters differ between sheep and goats. Therefore, this review aimed to evaluate the differences in how different feeding systems affect the growth performance, carcass characteristics, and meat quality of sheep and goats. It also explored the effects of a new finishing strategy-time-limited grazing with supplements on these traits. Compared with stalled feeding, finishing lambs/kids on pasture-only feed reduced the average daily gain (ADG) and carcass yield, while supplemented-grazing lambs/kids had near-equivalent or higher ADG and carcass attributes. Pasture-grazing increased the meat flavor intensity and healthy fatty acid content (HFAC) of lamb/kid meat. Supplemental grazing lambs had comparable or superior meat sensory attributes and increased meat protein and HFAC compared to stall-fed ones. In contrast, supplemental grazing only improved the meat color of kids but had little effect on other meat qualities. Moreover, time-limited grazing with supplemental concentrates increased the carcass yield and meat quality in lamb meat. Overall, the effects of different feeding systems on growth performance and carcass traits were comparable between sheep and goats but differed in terms of the meat quality.

Study on the formation pathways of characteristic volatiles in preserved egg yolk caused by lipid species during pickling

The formation of volatiles in high-fat foods is strongly influenced by the composition and structure of lipids. The relationship between key variable lipid species and characteristic volatiles were performed by lipidomics and flavoromics to resolve the pathways of volatiles in preserved egg yolk (PEY) during pickling. The results showed that the formation of nonanal and benzaldehyde at early stage possibly derived from oleic acid sited at Sn-1 in TG(18:1_18:2_20:4), Sn-2 in PE(22:6_18:1), and linoleic acid bonded at Sn-2 in TG(18:1_18:2_20:4), respectively. 1-octen-3-ol may be formed from linoleic acid located at Sn-2 in TG(18:1_18:2_20:4) and arachidonic acid sited at Sn-3 in TG(18:1_18:2_20:4). Indole was formed through TGs(16:0_16:1_20:1;16:1_18:1_22:1;23:0_18:1_18:1) at the later stage, and acetophenone through TGs(14:0_20:0_20:4;14:0_15:0_18:1; 16:0_16:0_22:6), PCs(24:0_18:1;O-18:1_18:2), PEs(P-18:1_20:4;P-18:1_22:6) and SPH(d18:0) during whole process of pickling. Our study provides a deep and precise insight for the formation pathways of characteristic volatiles in PEY through lipids degradation during pickling at the molecular level.

Molecular insights into quality and authentication of sheep meat from proteomics and metabolomics

Sheep meat (encompassing lamb, hogget and mutton) is an important source of animal protein in many countries, with a unique flavour and sensory profile compared to other red meats. Flavour, colour and texture are the key quality attributes contributing to consumer liking of sheep meat. Over the last decades, various factors from 'farm to fork', including production system (e.g., age, breed, feeding regimes, sex, pre-slaughter stress, and carcass suspension), post-mortem manipulation and processing (e.g., electrical stimulation, ageing, packaging types, and chilled and frozen storage) have been identified as influencing different aspects of sheep meat quality. However conventional meat-quality assessment tools are not able to elucidate the underlying mechanisms and pathways for quality variations. Advances in broad-based analytical techniques have offered opportunities to obtain deeper insights into the molecular changes of sheep meat which may become biomarkers for specific variations in quality traits and meat authenticity. This review provides an overview on how omics techniques, especially proteomics (including peptidomics) and metabolomics (including lipidomics and volatilomics) are applied to elucidate the variations in sheep meat quality, mainly in loin muscles, focusing on colour, texture and flavour, and as tools for authentication. SIGNIFICANCE: From this review, we observed that attempts have been made to utilise proteomics and metabolomics techniques on sheep meat products for elucidating pathways of quality variations due to various factors. For instance, the improvement of colour stability and tenderness could be associated with the changes to glycolysis, energy metabolism and endogenous antioxidant capacity. Several studies identify proteolysis as being important, but potentially conflicting for quality as the enhanced proteolysis improves tenderness and flavour, while reducing colour stability. The use of multiple analytical methods e.g., lipidomics, metabolomics, and volatilomics, detects a wider range of flavour precursors (including both water and lipid soluble compounds) that underlie the possible pathways for sheep meat flavour evolution. The technological advancement in omics (e.g., direct analysis-mass spectrometry) could make analysis of the proteins, lipids and metabolites in sheep meat routine, as well as enhance the confidence in quality determination and molecular-based assurance of meat authenticity.

Comparing the aromatic profile of seven unheated edible insect species

Insects and insect-based products have gained increasing interest as human food because of their many technological, nutritional and environmental advantages, but they are still rejected by many Western consumers. Analytical knowledge of flavour compounds could contribute to enhancing product attractiveness to consumers. Therefore, the goal of this study was to examine the volatile compound profiles of 7 unheated insects: Zophobas morio (ZM), Tenebrio molitor (TM), Locusta migratoria (LM), Galleria mellonella (GM), Blaptica dubia (BD), Alphitobius diaperinus (ALD) and Acheta domesticus (ACD). A total of 67 compounds were identified. Carboxylic acids were predominant in ALD, BD, GM, TM and ZM, while ketones were the major family in ACD and linear hydrocarbons in LM. ZM contained the highest number of unpleasant odour compounds, including indole, also present in BD and GM, which is characterised by a low detection threshold.

Intake, growth performance, carcass traits, and meat quality of feedlot lambs fed novel anthocyanin-rich corn cobs

Feeding anthocyanin- and antioxidant-rich forages to sheep and dairy cows can improve performance and product quality. The objective of this study was to evaluate the impact of feeding anthocyanin-rich (Hi-A) corn cobs on the growth performance and meat quality of lambs. A total of 30 eight-month-old Rambouillet ewe lambs (body weight 30.7 ± 1.2 kg) were fed for 63 days with three diets consisting of 80% concentrate and 20% roughage: Hi-A corn cobs (Hi-A), regular corn cobs (Low-A), and bermudagrass hay (BGH). A completely randomized design trial with 10 lambs per treatment was used. Data were collected on dry matter intake (DMI), body weight (BW), average daily gain (ADG), gain:feed ratio (G:F), carcass traits, meat color, fatty acid (FA) profile, volatile aroma compounds, and sensory panels. After feeding for 63 days, lambs were harvested, and the carcasses were evaluated. Boneless lamb loin chops were fabricated and submitted to FA, aroma, and sensory analysis. The corn cob diets did not affect BW, ADG, or G:F of the lambs compared to BGH diet, but DMI (P < 0.01) was decreased. The dressing percentage was greater (P < 0.05) in lambs fed BGH than in those fed Hi-A, while lambs fed Low-A did not differ from the other two diets. Loin chop instrumental color characteristics were not influenced by diets, except the hue angle, which was greater (P < 0.05) in lambs fed Hi-A than Low-A, while BGH did not differ from lambs fed either cob diet. There was no significant difference in the meat fatty acid profile. Five volatile compounds were affected by diets. The 2-butanone (P = 0.07) and 2,3-butanedione (P = 0.05) were greater in chops from lambs fed BGH relative to lambs fed Hi-A and neither differed (P > 0.05) from lambs fed Low-A diet. The 2-propanone was greater (P = 0.01) in chops from lambs fed BGH than in those fed either the Low-A or Hi-A diets. Both 3-methyl-butanal and methyl benzene were lower (P = 0.01 and P = 0.02, respectively) in chops from lambs fed the Hi-A diet than in those fed either the BGH or Low-A diet. Replacing 20% bermudagrass hay with corn cobs in the diets of feedlot lambs did not affect sheep growth performance, meat fatty acid profile, sensory traits, and most carcass characteristics and meat color parameters. Hi-A corn diet improved aroma in cooked boneless loin chops, but sensory traits were not affected. This study showed the Hi-A corn cobs can be safely used for roughage and feed for lambs and for improving meat aroma in cooked boneless loin chops.

Effect of Feeding System on Muscle Fiber Composition, Antioxidant Capacity, and Nutritional and Organoleptic Traits of Goat Meat

The objective of this study was to evaluate the effect of feeding system on muscle fiber composition, antioxidant capacity, and nutritional and organoleptic traits of goat meat. Goats that grazed on flatland (whole area with about 0% inclination, FG group) and mountain range (whole area with about 40% inclination, MG group) were selected for the analysis. The results showed that grazing on flatland increased oxidized-twitch fiber percentage, the expression of the MyHC IIa gene (p < 0.001), the activity of glutathione peroxidase (GSH-Px) (p < 0.05), total antioxidant capacity (T-AOC) (p = 0.001), and radical scavenging ability (RSA) (p < 0.05); meanwhile, the MyHC IIb gene expression (p < 0.01) and malondialdehyde (MDA) content (p = 0.001) were decreased. Feeding system affected nutritional and organoleptic traits of goat meat, and grazing on flatland increased protein content, total content of monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), pH45min, a* value, and variety of volatile flavor compounds but decreased the content of saturated fatty acid (SFA), shear force, and b* value. In addition, the key flavor substances were screened using relative odor activity value (ROAV), including hexanal, heptanal, (E)-2-octenal, octanal, nonanal, decanal, (E)-2-nonenal, and 1-octen-3-ol. Among them, 1-octen-3-ol and (E)-2-nonenal were the most contributing flavor compounds in the FG and MG groups, respectively, providing distinctive odor to goat meat.

Dietary linseed supplementation improves meat quality and flavor of sheep by altering muscle fiber characteristics and antioxidant capacity

Linseed as a common oil crop that has been implicated in regulating the meat quality of animals. The aim of this investigation was to establish the effects of dietary linseed supplementation on carcass traits, meat quality, muscle fiber characteristics, volatile compounds and antioxidant capacity of sheep. Twenty-four Sunit sheep were distributed into 2 groups with different diet: control (CO) fed a standard diet and linseed (LS, 8% of extruded linseed). The results showed that linseed not only increased M. longissimus thoracis (LT) increased the loin-eye area but also decreased pH24h, L* and shear force. Meanwhile, linseed increased mRNA expression of MyHCI and MyHCIIx and decreased in cross-sectional area (CSA) and muscle fiber diameter. In addition, linseed altered the composition of meat volatile flavor compounds, such as Z-10-Pentadecen-1-ol, pentanal, 2-Octenal, (E)-, decanal, butane, and 2-heptanone. Moreover, linseed increased total antioxidative capacity (T-AOC) activity, the mRNA expression of glutathione peroxidase (GSH-Px) and catalase (CAT), decreased malondialdehyde (MDA) content. Overall, the results suggest that linseed is an effective feed additive in improving meat quality and flavor. The underlying mechanisms for its effectiveness may be partly due to a change in muscle fiber characteristics and antioxidant capacity.

Effects of nomadic grazing system and indoor concentrate feeding systems on performance, behavior, blood parameters, and meat quality of finishing lambs

The objective of the study was to evaluate the effects of three production systems on growth performance, behavior, blood parameters, carcass characteristics, and meat quality. A total of 30 lambs (n = 10 lambs/treatment) were randomly assigned to three production systems that included rotational grazing (NG) and two different levels of concentrate (CON), one with medium (roughage/concentrate ratio 50:50% based on DM, MC) and one with high concentrate (roughage/concentrate ratio 30:70% based on DM, HC) during the 90-day fattening period. At the start of the experiment, all lambs averaged 90 ± 4 days of age (mean ± SD) and were slaughtered at an average of 180 ± 3 days (mean ± SD). CON-fed lambs had higher average daily gain and loin thickness than NG-fed lambs. The NG lambs spent more time eating, drinking, and standing, but less time resting and rumination than the CON-fed lambs. In addition, plasma lipid, β-hydroxybutyrate, and urea levels were higher, while phosphorus levels were lower in NG-fed lambs than in CON-fed lambs. CON-fed lambs had better carcass yield, but gastrointestinal tract and rumen weights were lower than NG lambs. CON-fed lambs had higher pH values 0 h post mortem than the NG lambs; however, there was no effect of treatment on pH 24 h post mortem. The post-mortem color of the LD muscle of NG lambs had a higher lightness and yellowness index and a lower redness index than that of the LD muscle of CON-fed lambs. The results of this study showed that lambs fed CON had better carcass yield than lambs fed NG, although feed intake, feed conversion ratio (FCR), growth performance, carcass yield, and meat quality of lambs fed MC and HC were similar.

Differences in meat quality between Angus cattle and Xinjiang brown cattle in association with gut microbiota and its lipid metabolism

Gut microbiota plays important roles in mediating fat metabolic events in humans and animals. However, the differences of meat quality traits related to the lipid metabolism (MQT-LM) in association with gut microbiota involving in lipid metabolism have not been well explored between Angus cattle (AG) and Xinjiang brown cattle (BC). Ten heads of 18-month-old uncastrated male AG and BC (5 in each group) raised under the identical conditions were selected to test MQT-LM, i.e., the backfat thickness (BFT), the intramuscular fat (IMF) content, the intramuscular adipocyte areas (IAA), the eye muscle area (EMA), the muscle fiber sectional area (MFSA) and the muscle shear force after sacrifice. The gut microbiota composition and structure with its metabolic function were analyzed by means of metagenomics and metabolomics with rectal feces. The correlation of MQT-LM with the gut microbiota and its metabolites was analyzed. In comparison with AG, BC had significant lower EMA, IMF content and IAA but higher BFT and MFSA. Chao1 and ACE indexes of α-diversity were lower. β-diversity between AG and BC were significantly different. The relative abundance of Bacteroidetes, Prevotella and Blautia and Prevotella copri, Blautia wexlerae, and Ruminococcus gnavus was lower. The lipid metabolism related metabolites, i.e., succinate, oxoglutaric acid, L-aspartic acid and L-glutamic acid were lower, while GABA, L-asparagine and fumaric acid were higher. IMF was positively correlated with Prevotella copri, Blautia wexlerae and Ruminococcus gnavus, and the metabolites succinate, oxoglutaric acid, L-aspartic acid and L-glutamic acid, while negatively with GABA, L-asparagine and fumaric acid. BFT was negatively correlated with Blautia wexlerae and the metabolites succinate, L-aspartic acid and L-glutamic acid, while positively with GABA, L-asparagine and fumaric acid. Prevotella Copri, Blautia wexlerae, and Ruminococcus gnavus was all positively correlated with succinate, oxoglutaric acid, while negatively with L-asparagine and fumaric acid. In conclusion, Prevotella copri, Prevotella intermedia, Blautia wexlerae, and Ruminococcus gnavus may serve as the potential differentiated bacterial species in association with MQT-LM via their metabolites of oxoglutaric acid, succinate, fumaric acid, L-aspartic acid, L-asparagine, L-glutamic acid and GABA between BC and AG.

Effects of Fermentation on the Physicochemical Properties and Aroma of Lamb Liver Paste

The probiotic fermentation of lamb liver paste is a new method with which to utilize sheep by-products and address the issue of waste. In this study, a pH meter, chromaticity meter, texture analyzer, and gas chromatograph–mass spectrometer (GC–MS) were used to determine various indicators. The objective was to investigate the effect of fermentation on the physical properties and aroma of lamb liver paste. The results showed that the L* (brightness), a* (redness), and b* (yellowness) of the samples were significantly higher in the starter fermentation group than in the other two groups after storage for 0, 1, 7, 14, 21, and 28 days (p < 0.05). In addition, cohesiveness, adhesion, and chewiness were lower in the starter fermentation group after 7 days (p < 0.05). TVB-N and fat were lower in the starter fermentation group compared to the sterilization group at 28 days. pH was significantly lower in the starter fermentation group at the beginning of storage, and lactic acid bacteria numbers were significantly higher than in the sterilization groups (p < 0.05). Important aroma compounds, such as 2-undecenal, 1-octen-3-ol, and anethole, were significantly higher in the starter fermentation group than in the sterilization group (p < 0.05). Fermented lamb liver paste is a new by-product that exhibits a high degree of freshness and a low degree of fat oxidation during storage. This study provides a theoretical basis for future industrial production.

Effects of Feeding Regimes and Postmortem Aging on Meat Quality, Fatty Acid Composition, and Volatile Flavor of Longissimus Thoracis Muscle in Sunit Sheep

The effects of different feeding regimes on antioxidant activity, meat quality, fatty acid composition, lipid oxidation, and volatile matter production in the longissimus thoracis (LT) of Sunit sheep at 0, 24, 48, 72, and 96 h postmortem were investigated. The results showed that the activity of antioxidant enzymes, tenderness, water retention, and percentage of unsaturated fatty acids were significantly higher in the pasture-fed sheep (PF) than in the concentrate-fed sheep (CF) (p < 0.05). During postmortem aging, antioxidant activity, water retention, and the proportion of unsaturated fatty acids decreased in the PF and CF (p < 0.05), while malondialdehyde (MDA) content, the proportion of saturated fatty acids, and the content of flavor substances resulting from fat oxidation increased. After 24 h of LT muscle aging, the pH and shear force of the meat started to increase and the color stabilized. The differences between shear force values and lipid volatile flavor substance content of sheep meat under different feeding regimes disappeared with increasing aging time. PF had better oxidative stability and fatty acid composition. Postmortem aging changed the oxidative stability of sheep meat, thus affecting meat quality and fatty acid composition and consequently meat flavor composition, while aging also eliminated to some extent the differences caused by feeding regimes.

Formation and Analysis of Volatile and Odor Compounds in Meat-A Review

The volatile composition and odor of meat and meat products is based on the precursors present in the raw meat. These are influenced by various pre-slaughter factors (species, breed, sex, age, feed, muscle type). Furthermore, post-mortem conditions (chiller aging, cooking conditions, curing, fermentation, etc.) determine the development of meat volatile organic compounds (VOCs). In this review, the main reactions leading to the development of meat VOCs such as the Maillard reaction; Strecker degradation; lipid oxidation; and thiamine, carbohydrate, and nucleotide degradation are described. The important pre-slaughter factors and post-mortem conditions influencing meat VOCs are discussed. Finally, the pros, cons, and future perspectives of the most commonly used sample preparation techniques (solid-phase microextraction, stir bar sorptive extraction, dynamic headspace extraction) and analytical methods (gas chromatography mass spectrometry and olfactometry, as well as electronic noses) for the analysis of meat VOCs are discussed, and the continued importance of sensorial analysis is pinpointed.

Impact of Feeding Probiotics on Blood Parameters, Tail Fat Metabolites, and Volatile Flavor Components of Sunit Sheep

Sheep crude tail fat has unique nutritional values and is used as a raw material for high-quality natural oil. The purpose of this study was to investigate the effects of probiotics on the metabolites and flavor of sheep crude tail fat. In this study, 12 Sunit sheep were randomly divided into an experimental group (LTF, basal feed + Lactiplantibacillusplantarum powder) and a control group (CTF, basal feed). The results of sheep crude tail fat analysis showed that blood lipid parameters were significantly lower and the expression of fatty acid synthase and stearoyl-CoA desaturase genes higher in the LTF group than in the CTF group (p < 0.05). Metabolomic analysis via liquid chromatography−mass spectrometry showed that the contents of metabolites such as eicosapentaenoic acid, 16-hydroxypalmitic acid, and L-citrulline were higher in the LTF group (p < 0.01). Gas chromatography−mass spectrometry detection of volatile flavor compounds in the tail fat showed that nonanal, decanal, and 1-hexanol were more abundant in the LTF group (p < 0.05). Therefore, Lactiplantibacillus plantarum feeding affected blood lipid parameters, expression of lipid metabolism-related genes, tail fat metabolites, and volatile flavor compounds in Sunit sheep. In this study, probiotics feeding was demonstrated to support high-value sheep crude tail fat production.

Effect of dietary probiotics supplementation on meat quality, volatile flavor compounds, muscle fiber characteristics, and antioxidant capacity in lambs

This study investigated the effects of probiotics on growth performance, meat quality, muscle fiber characteristics, volatile compounds, and antioxidant capacity in lambs. A total of 24 Sunit lambs were randomly allocated into two groups, each consisting of three replicates of four lambs. Throughout the experiment period, the lambs were fed with based diet (CON) and 10 g probiotics/d supplemented diet (PRO). Compared with the CON group, the number of lactic acid bacteria in fecal samples of PRO group was significantly increased (p < .05) and the coliforms were significantly decreased (p < .05). Dietary probiotics supplementation decreased pH24h, L*, and shear force (p < .05). The muscle fibers were switched from type IIB to type I, with a decrease in the mean cross-sectional area (CSA) (p < .05) of longissimus thoracis (LT) muscle. Also, probiotics altered the composition of meat volatile flavor compounds, such as nonanal, undecanal, 1-pentanol, 1-hexanol, and 2,3-octanedione. In addition, probiotics increased the total antioxidative capacity (T-AOC) and catalase (CAT) activity of LT muscle, while it decreased superoxide dismutase (SOD) activity (p < .05). Overall, these results indicated that probiotics could be used as an effective feed additive by improving meat tenderness and flavor.

A selected population study reveals the biochemical mechanism of intramuscular fat deposition in chicken meat

BACKGROUND

Increasing intramuscular fat (IMF) is an important strategy to improve meat quality, but the regulation mechanism of IMF deposition needs to be systematically clarified.

RESULTS

A total of 520 chickens from a selected line with improved IMF content and a control line were used to investigate the biochemical mechanism of IMF deposition in chickens. The results showed that the increased IMF would improve the flavor and tenderness quality of chicken meat. IMF content was mainly determined both by measuring triglyceride (TG) and phospholipid (PLIP) in muscle tissue, but only TG content was found to be decisive for IMF deposition. Furthermore, the increase in major fatty acid (FA) components in IMF is mainly derived from TGs (including C16:0, C16:1, C18:1n9c, and C18:2n6c, etc.), and the inhibition of certain very-long-chain FAs would help to IMF/TG deposition.

CONCLUSIONS

Our study elucidated the underlying biochemical mechanism of IMF deposition in chicken: Prevalent accumulation of long-chain FAs and inhibitions of medium-chain FAs and very long chain FA would jointly result in the increase of TGs with the FA biosynthesis and cellular uptake ways. Our findings will guide the production of high-quality chicken meat.

Effects of oxidative stability variation on lamb meat quality and flavor during postmortem aging

This study evaluated the effects of oxidative stability variation on meat quality and flavor in biceps femoris (BF) and longissimus dorsi (LD) muscles of lambs during postmortem aging. The samples were stored at 4±1℃; the meat quality, flavor and muscle oxidative stability were measured on day 0, 1, 2, 3, and 4 of postmortem aging. The results showed that malondialdehyde (MDA) content increased in both muscle types; superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities decreased, as did total antioxidative capacity (T-AOC). LD muscle showed lower MDA content and antioxidative activity than BF muscle. Meat quality analyses indicated that aging increased the lightness (L*), redness (a*), and yellowness (b*) values of meat while improving its tenderness. Gas chromatography-mass spectrometry results showed that volatile flavor compounds were more abundant in LD muscle than in BF muscle. As the aging time extended, relative contents of aldehyde and alcohol increased in both muscles. The key flavor compounds during postmortem aging including heptanal, octanal, nonanal, and decanal were screened by relative odor activity value (ROAV), and the content of key flavor compounds showed the trend of increasing, which were usually associated with fresh green grass, nutty, and fat descriptors. In conclusion, the oxidative muscles displayed better antioxidative capacity, and postmortem aging altered the oxidative stability of lamb muscle, which affected the meat quality and flavor. PRACTICAL APPLICATION: Meat aging is an important strategy to improve the quality of various meat traits (including flavor). The results of this work could be of interest to meat professionals who will be able to apply in actual production by choosing the best aging time based on flavor and meat quality for different muscle parts.

The SLC27A1 Gene and Its Enriched PPAR Pathway Are Involved in the Regulation of Flavor Compound Hexanal Content in Chinese Native Chickens

The role of hexanal in flavor as an indicator of the degree of oxidation of meat products is undeniable. However, the genes and pathways of hexanal formation have not been characterized in detail. In this study, we performed differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) on groups of Tiannong partridge chickens with different relative hexanal content in order to find the genes involved in the formation of hexanal and the specific pathways of hexanal formation. Then we confirmed the relationship of these candidate genes with hexanal using Jingxing Yellow chicken and Wenchang chicken. In this study, WGCNA revealed a module of co-expressed genes that were highly associated with the volatile organic compound hexanal. We also compared transcriptome gene expression data of samples from chicken groups with high and low relative contents of hexanal and identified a total of 651 differentially expressed genes (DEGs). Among them, 356 genes were up regulated, and 295 genes were downregulated. The different biological functions associated with the DEGs, hub genes and hexanal were identified by functional analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations. Among all the hub genes in the significant module identified by WGCNA, more were enriched in the PPAR signaling pathway, the proteasome pathway, etc. Additionally, we found that DEGs and hub genes, including SLC27A1, ACOX3, NR4A1, VEGFA, JUN, EGR1, CACNB1, GADD45A and DUSP1, were co-enriched in the peroxisome proliferator-activated receptor (PPAR) signaling pathway, p53 signaling pathway and mitogen-activated protein kinases (MAPK) signaling pathway, etc. Transcriptome results of the Jingxing Yellow chicken population showed that the SLC27A1 gene was significantly associated with hexanal and enriched in the PPAR pathway. Our study provides a comprehensive insight into the key genes related to hexanal content, and can be further explored by functional and molecular studies.

Characterization of the Flavor Precursors and Flavor Fingerprints in Grazing Lambs by Foodomics

Tan sheep are greatly preferred by consumers in China because of their nutritional value and unique flavor. However, the meat quality of Tan sheep has decreased due to the change in feeding systems from grazing to indoor. Studies investigating the mechanisms for the decrease in meat quality are limited. A total of 28 Tan sheep were randomly allocated to two treatments, receiving a concentrated diet, or pasture. Flavor precursors and volatile compounds were analyzed with foodomics. E-nose and E-tongue analyses suggested that the aroma and taste profiles differed between the feeding systems. The grazing lambs had higher levels of linoleic acid and n-3 polyunsaturated fatty acids (p < 0.01). Metabolomics indicated that 25 hydrophilic metabolites active in glycolipid and amino acid metabolisms were changed by the feeding system. Among the 57 volatile compounds identified, methional, γ-butyrolactone, benzaldehyde, and ethyl acetate were at concentrations significantly higher in the grazing lambs than the indoor-fed lambs (p < 0.01). These results reveal key changes in flavor precursors and flavor profiles affected by the feeding system, which may provide an initial view of the reason for consumer preference for the grazing Tan sheep.

Effect of Pre-Slaughter Practises and Early Post-Mortem Interventions on Sheep Meat Tenderness and Its Impact on Microbial Status

Tenderness, together with flavour, is the main quality trait that defines consumer acceptance of sheep meat. The factors affecting tenderness can be grouped as those influenced before slaughter, in the early post-mortem intervention and, finally, during the aging period. These factors have been extensively studied with respect to tenderness, but the impact of early post-mortem interventions and subsequent aging on the microbial quality of the final products has not been broadly reviewed to date. In this review, the authors summarize the most recent knowledge on lamb meat tenderness management and how such practices may impact the final meat quality, especially its microbial status. The impacts of pre-slaughter factors (age, sex, diet, genotype and transport) and post-mortem interventions (chilling regime, electrical stimulation, or hanging method), are described and comprehensively discussed.

Effect of dietary buriti oil on the quality, fatty acid profile and sensorial attributes of lamb meat

Forty crossbred (Santa Ines × Dorper) male lambs were used to investigate the effect of dietary buriti oil (BOIL) intake on meat quality, fatty acid (FA) composition and sensory attributes. A completely randomized design with five BOIL intake levels (0, 12, 24, 36 and 48 g/kg DM) was used. Increasing dietary BOIL intake linearly reduced the DMI, slaughter weight, cooking loss, shear force, yellowness, 16:0, c9-18:1 FA concentrations, and the delta-9-desaturase activity index computed using c9-16:1 and 16:0 as product and substrate pair, cis-MUFA and ƩMUFA/ƩSFA ratio of lamb meat (P ≤ 0.05); however, increasing dietary BOIL intake quadratically increased the energy intake, lipid content and linearly increased the total FA intake, chroma, collagen, total BI, 18:0, 20:3n-6 concentration and sensory attributes of lamb meat (P ≤ 0.05), without affecting health indexes regarding fat consumption. BOIL addition at levels above 24 g/kg DM in lamb diet reduces growth, however, improves tenderness, flavor and "goat" aroma intensity and slightly changes meat FA levels, promoting better acceptance by panelists.

Maillard reaction of food-derived peptides as a potential route to generate meat flavor compounds: A review

Plant-based meat analogues (PBMA) are promising foods to address the global imbalance between the supply and demand for meat products caused by the increasing environmental pressures and growing human population. Given that the flavor of PBMA plays a crucial role in consumer acceptance, imparting meat-like flavor is of great significance. As a natural approach to generate meat-like flavor, the Maillard reaction involving food-derived peptides could contribute to the required flavor compounds, which has promising applications in PBMA formulations. In this review, the precursors of meat-like flavor are summarized followed by a discussion of the reactions and mechanisms responsible for generation of the flavor compounds. The preparation and analysis techniques for food-derived Maillard reacted peptides (MRPs) as well as their taste and aroma properties are discussed. In addition, the MRPs as meat flavor precursors and their potential application in the formulation of PBMA are also discussed. The present review provides a fundamental scientific information useful for the production and application of MRPs as meat flavor precursors in PBMA.

Changes in Proximate Chemical and Mineral Compositions of Different Sex Categories of Mutton during the Dry-Curing Process

The aim of this research was to determine the effect of sex, castration, and processing on the chemical properties of mutton in the production of kaštradina-a traditional Dalmatian dry-cured meat product. Therefore, the carcasses of 20 ewes (E), 20 rams (R), and 20 wethers (W) of the Dalmatian pramenka breed were processed by dry-curing. On the 1st, 35th, and 60th days of processing, the samples from the scapulae were taken, then the proximate chemical, NaCl, and mineral analyses were performed, and significant differences between most of the parameters were found. Unlike W, the R samples contained significantly more proteins (p < 0.01), NaCl (p < 0.05), and potassium (p < 0.05) and less fat (p < 0.05). Furthermore, compared to the W and R categories, the E category of kaštradina contained significantly more calcium (p < 0.05). The higher contents of intramuscular fat, potassium, and calcium and lower content of NaCl could positively affect the sensory (marbling, flavor, juiciness, and tenderness) and chemical (fatty acid profile) properties of kaštradina. These findings suggest that the W and E raw mutton could be a better-quality raw material for production of kaštradina than could the R, but further research is needed for a more comprehensive picture of its quality.

Purple Corn Anthocyanin Affects Lipid Mechanism, Flavor Compound Profiles, and Related Gene Expression of Longissimus Thoracis et Lumborum Muscle in Goats

Simple Summary

Natural flavor compounds can stimulate people’s senses of smell and taste; as indicators of food sensory quality, such compounds influence the acceptance by consumers. In addition, natural antioxidants are becoming popular among consumers because they are safe and have no adverse side effects. Purple corn anthocyanins are polyphenolic compounds with natural antioxidant properties that exist widely in nature. Research has shown that anthocyanins can provide extra electrons to the free radicals, preventing lipid oxidation and improving muscle volatile components. However, no information is available concerning the effect of feeding anthocyanin on goat meat volatile compounds. This was the first study to investigate the effects of dietary anthocyanins from purple corn supplementation on lipid mechanism, body composition, volatile compound profiles, and related gene expression in the longissimus thoracis et lumborum muscle of goats. The current study indicates that the consumption of purple corn anthocyanin by growing goats improves mutton flavor by decreasing plasma lipid metabolism parameters and by modulating the abundance of several flavor-related genes in the longissimus thoracis et lumborum muscle. The results will help to understand the mechanism of action of anthocyanins on the flavor compounds, providing the rationale for anthocyanins regulating mutton flavor through related signaling pathways of ruminants in future studies.

Abstract

The current study aimed to investigate the effect of anthocyanins on muscle flavor compound profiles in goats. Goats in three groups were fed a basic diet or a diet supplemented with 0.5 g/d or 1 g/d anthocyanin-rich purple corn pigment (PCP). Compared to the control group, plasma total cholesterol was significantly decreased (p < 0.05) in the anthocyanin groups. The feeding of anthocyanin increased (p < 0.05) flavor compound types and total alcohol level, whereas it decreased (p < 0.05) total hydrocarbons, aromatics, esters, and miscellaneous compounds in the longissimusthoracis et lumborum muscle (LTL). Adding PCP to the diet enriched (p < 0.05) vegetal, herbaceous, grease, and fruity flavors compared to the control group. The 0.5 g/d PCP group had increased (p < 0.05) abundance of peroxisome proliferator-activated receptor gamma, but there was a decreased (p < 0.05) level of lipoprotein lipase in LTL. Collectively, this study indicated that anthocyanin can improve mutton flavor by decreasing plasma lipid parameters and by modulating the abundance of several flavor-related genes of goats.

Reis M, Silcock P, Johnson PL, Realini CE. Relationships among Consumer Liking, Lipid and Volatile Compounds from New Zealand Commercial Lamb Loins

Loin sections (m. Longissimus lumborum) were collected at slaughter from forty-eight lamb carcasses to evaluate consumer-liking scores of six types of typical New Zealand commercial lamb and to understand the possible underlying reasons for those ratings. A consumer panel (n = 160) evaluated tenderness, juiciness, flavor liking, and overall liking of the different types of lamb loins. Consumer scores differed among the types of lamb meat for all the evaluated attributes (p < 0.05). Further segmentation based on overall liking scores showed two consumer clusters with distinct ratings. Correlation and external preference map analyses indicated that one consumer cluster (n = 75) liked lamb types that had lower total lipid content, a lower proportion of branched-chain fatty acids, oleic and heptadecanoic acids; and a higher proportion of polyunsaturated fatty acids and volatile compounds (green and fruity descriptors). Consumer liking of the other segment (n = 85) was less influenced by fatty acids and volatiles, except hexanoic, heptanoic and octanoic acids (rancid, fatty, and sweaty descriptors). Thus, the fatty acid profile and the volatile compounds derived from their oxidation upon cooking seem to be a stronger driver of consumer liking of lamb for some consumers than others.

Health-Promoting Phytonutrients Are Higher in Grass-Fed Meat and Milk

While commission reports and nutritional guidelines raise concerns about the effects of consuming red meat on human health, the impacts of how livestock are raised and finished on consumer health are generally ignored. Meat and milk, irrespective of rearing practices, provide many essential nutrients including bioavailable protein, zinc, iron, selenium, calcium, and/or B12. Emerging data indicate that when livestock are eating a diverse array of plants on pasture, additional health-promoting phytonutrients—terpenoids, phenols, carotenoids, and anti-oxidants—become concentrated in their meat and milk. Several phytochemicals found in grass-fed meat and milk are in quantities comparable to those found in plant foods known to have anti-inflammatory, anti-carcinogenic, and cardioprotective effects. As meat and milk are often not considered as sources of phytochemicals, their presence has remained largely underappreciated in discussions of nutritional differences between feedlot-fed (grain-fed) and pasture-finished (grass-fed) meat and dairy, which have predominantly centered around the ω-3 fatty acids and conjugated linoleic acid. Grazing livestock on plant-species diverse pastures concentrates a wider variety and higher amounts of phytochemicals in meat and milk compared to grazing monoculture pastures, while phytochemicals are further reduced or absent in meat and milk of grain-fed animals. The co-evolution of plants and herbivores has led to plants/crops being more productive when grazed in accordance with agroecological principles. The increased phytochemical richness of productive vegetation has potential to improve the health of animals and upscale these nutrients to also benefit human health. Several studies have found increased anti-oxidant activity in meat and milk of grass-fed vs. grain-fed animals. Only a handful of studies have investigated the effects of grass-fed meat and dairy consumption on human health and show potential for anti-inflammatory effects and improved lipoprotein profiles. However, current knowledge does not allow for direct linking of livestock production practices to human health. Future research should systematically assess linkages between the phytochemical richness of livestock diets, the nutrient density of animal foods, and subsequent effects on human metabolic health. This is important given current societal concerns about red meat consumption and human health. Addressing this research gap will require greater collaborative efforts from the fields of agriculture and medicine.

Polyunsaturated fatty acid, volatile and sensory profiles of beef from steers fed citrus pulp or grape pomace

The present study compared the effects of feeding dried grape pomace (DGP) or citrus pulp (DCP) at 150 g/kg dry matter compared to a control diet on major polyunsaturated fatty acids (PUFA), volatile and sensory profiles of beef. Feeding DGP or DCP diets to Angus steers for 90 d increased the proportions of C18:2n-6, C20:4n-6, C18:3n-3, total conjugated linoleic acid (CLA), n-3 and n-6 PUFA in muscle. Control-fed beef had greater concentrations of C18:1n-9, total aldehydes, ketones, and alcohols compared to DCP and DGP. Feeding DGP and DCP diets produced less tender beef than control. Overall, finishing steers on diets containing DGP or DCP compared to control increased proportions of total CLA, n-3 and n-6 PUFA, and reduced concentrations of aldehydes, ketones, and alcohols, but did not affect beef sensory attributes except for a slight reduction in tenderness.

Influence of maintenance technology in arid conditions on efficiency of marbled beef production

In recent years, Russia has been developing domestic single-purpose meat cattle breeding. Some livestock farms have focused on the production of high-quality grades of raw meat, i.e. ‘marbled’ beef. Meat of that kind is in great demand in the premium meat market. At the same time, production of beef without using steroids and hormonal drugs increases the competitiveness of this product on the world market in countries of the West and the Middle East. Within the framework of our study, an experiment was conducted on Kalmyk cattle in the arid conditions of OAO Kirovskij in the Republic of Kalmykia. Standardized methods of analysis were used. For the experiment, 10-month-old steers were selected and divided into two groups (Control and Test), 30 heads each. They were kept and fed according to different technologies until the age of 19 months. The Test group steers were kept tied up and fed with a diet developed by the Volga Region Research Institute of Manufacture and Processing of Meat-and-Milk Production; the Control group steers were kept according to conventional beef cattle production technology. The wide expansion range and popularity of this cattle breed are caused by the high productivity of steers whether kept tied up or allowed to graze free. The compared qualities of beef obtained from Kalmyk steers proved that keeping them tied up allows increased production efficiency of raw meat which is an important factor for meat production, being intensified in an unstable situation in agriculture

Effects of Diets Containing Finger Millet Straw and Corn Straw on Growth Performance, Plasma Metabolites, Immune Capacity, and Carcass Traits in Fattening Lambs

As the byproduct of finger millet, millet straw is a new forage resource of ruminants. The effect of the combined utilization of millet straw with corn straw on fattening lamb production is seldom reported. The purpose of this study was to investigate the effect of different proportions of millet straw instead of corn straw on the growth performance, blood metabolites, immune response, meat yield, and quality of fattening lamb. Sixty-three-month-old healthy Small-Tailed Han sheep crossbred rams with an average initial weight of 19.28 ± 2.95 kg were randomly divided into four groups, with three replicates in each group and five lambs in each replicate. The replacement ratio of millet straw of each group (Group I, II, III, IV) was 0%, 25%, 35%, 50% at the first stage (the first two months) and 0%, 20%, 28%, 40% in the second period (final two months), respectively. The experiment lasted 4 months 10 days of the pre-feeding period. The results indicated that the body weight gain and average daily gain of group Ⅱ were significantly higher than those of group Ⅰ and group Ⅳ (p < 0.05). The concentration of total protein in group Ⅳ was significantly increased compared to those of the other three groups at the second stage (p < 0.05), which proved that the protein synthesis metabolism capacity was improved with the addition of millet straw. The concentration of the plasma glutamic-oxalacetic transaminase and lactic dehydrogenase of lambs was significantly decreased in group Ⅱ (p < 0.05). The combination of millet straw and corn straw had no impact on the glucose, total cholesterol, and triglycerides metabolism (p > 0.05). There was no significant difference in the pre-slaughter weight, carcass weight, dressing percentage, loin-eye area, and GR value among the four groups (p > 0.05). Furthermore, the immune response and meat quality were not impacted by the different proportions of millet and corn forage diets. The results showed that the combined utilization of millet straw with corn straw could improve the blood biochemistry metabolism capability of fattening lambs. The replacement of 50% of corn straw with millet straw could improve the growth performance and be an application in fattening lamb production.

Influence of Electrostatic Field on the Quality Attributes and Volatile Flavor Compounds of Dry-Cured Beef during Chill Storage

The purpose was to investigate the quality characteristics of dry-cured beef with different storage times under a high-voltage electrostatic field (HVEF) condition. The pH, moisture content, meat color, and volatile compounds of dry-cured beef samples treated with HVEF (3 kV) were compared with those of a common refrigerator (CON) at days 0, 3, 7, 10, and 14. The results showed that, compared with CON group, the decline rates of the pH and moisture content of beef and ∆E values were lower under HVEF storage condition. From the fingerprints, the 42 volatile compounds identified were mainly aldehydes, alcohols, ketones, and esters. The benzaldehyde, trimethyl pyrazine, and maltol contents in the HVEF group exhibited a dramatic increase after 10 days of storage. Principal component analysis revealed clustering of compound classes, distributed in a separate time. Based on the above findings, we concluded that HVEF treatment could promote color stability and enhance characteristic flavor during the storage of dry-cured beef. These results suggested that HVEF might be applicable for dry-cured meat storage techniques.