Grape pomace in ewes diet: Effects on meat quality and the fatty acid profile of their suckling lambs

Bioaccessibility of condensed tannins and their effect on the physico-chemical characteristics of lamb meat

The bioaccessibility of tannins as antioxidants in meat is essential to maximise their effectiveness in protecting the product. This property determines the amount of tannins available to interact with meat components, inhibiting lipid and protein oxidation and, consequently, prolonging shelf life and preserving the sensory quality of the product. The objective of this study was to evaluate the bioaccessibility of condensed tannins (CT) from Acacia mearnsii extract (AME) and their effect on the physico-chemical characteristics of fattened lamb meat. Thirty-six Dorset × Hampshire lambs (3 months old and 20.8 ± 3.3 kg live weight) were used. The lambs were distributed equally (n = 9) into four treatments: T1, T2, T3 and T4, which included a basal diet plus 0%, 0.25%, 0.5% and 0.75% of CT from AME, respectively. At the end of the fattening period, bioaccessibility was evaluated, the animals were slaughtered and a sample of the longissimus dorsi (LD) muscle was collected to assess colour, lipid oxidation, cooking weight loss and shear force on days 1, 4, 7 and 14 of shelf-life, in samples preserved at -20 °C. In addition, the long chain fatty acid profile was analysed. A completely randomised design was used, and the means were compared with Tukey's test (P < 0.05). The mean lightness (L*), yellowness (b*) and hue (H*) values were higher for T3 and T4. The addition of CT did not affect (P > 0.05) redness (a*), cooking weight loss (CWL) or shear force (SF). T4 decreased (P < 0.05) stearic acid and increased cis-9 trans-12 conjugated linoleic acid (CLA). Bioaccessibility was higher in the supplemented groups (T1 < T2, T3 and T4). In conclusion, supplementing CT from AME in the diet of lambs did not reduce lipid oxidation, but T3 or T4 improved some aspects of meat colour and CLA deposition.

The quality of meat in milk fed lambs is affected by the ewe diet: A review

Several scientific publications have highlighted the importance of feeding management practices in improving the nutritional properties of milk from dairy ewes. Meat production quality from suckling lambs is based on the use of milk as exclusive or near exclusive dietary component. There is considerable evidence that lamb meat contains many important nutrients and bioactive compounds that play an important role in consumer health. This paper examines the different quality characteristics of lamb meat from ewes fed different diets to improve milk quality. To conduct this research, we consulted different scientific databases and acquired relevant documents that studied the relationships between the dietary treatment of lactating ewes and the performance of their suckling lambs (growth and carcass traits) as well as the meat quality in terms of nutrient content (fat and protein in particular), bioactive compounds content (fatty acids, vitamins, and antioxidant molecules), color, odor and flavor. The extent of change in meat carcass traits and meat quality of suckling lambs due to different feeding strategies applied to ewes was evaluated and discussed. This overview of the knowledge on the relationship between the milk quality and suckling lamb quality can be useful for production and communication strategies development for the lamb meat industry.

Effects of Plant-Based Antioxidants in Animal Diets and Meat Products: A Review

The perceived level of risk associated with a food product can influence purchase and consumption decisions. Thus, current trends in food safety address an issue of general interest-the identification of healthy and economical alternatives to synthetic antioxidants that may have harmful effects on human health. Still, the processors' target is to increase the shelf life of food products using preserving substances. Natural antioxidants can be extracted and used in the food industry from different plants, such as blueberry, broccoli, chokeberry, cinnamon, ginger, olives, oregano, etc. The identification of the main natural antioxidant types that have been used in the food industry is very important in order to provide a comprehensive analysis of the researched topic. In this regard, the aim of this paper was to illustrate the positive aspects of using natural antioxidants with preservative roles in meat products, while, at the same time, highlighting the potential risks induced by these compounds. All of those aspects are correlated with the impact of sensorial attributes and the improvement of the nutritional value of meat products.

Dietary Grape Pomace Supplementation in Lambs Affects the Meat Fatty Acid Composition, Volatile Profiles and Oxidative Stability

The aim of this study was to evaluate the effects of supplementing grape pomace (GP) in lambs’ diets. A total of 30 lambs homogeneous for body weight (13.1 ± 2.1 kg) and age (25–30 days) were randomly allocated into two groups. The control group (CTR) received a standard diet for 45 days, while in the same period the experimental group (GP+) was fed with a diet containing 10% GP on a dry matter (DM) basis. The meat samples from the two groups showed no significant differences in drip loss, cooking loss, meat color and total lipid amount. However, the experimental feeding strategy influenced the meat fatty acid composition, with an increase in the relative percentages of stearic, vaccenic and rumenic acids. In particular, the increase in rumenic acids is associated with several health benefits attributed to its high bioactive properties. In cooked meat samples stored for 5 days at 4 °C, the dietary GP supplementation induced an increase in nonanal and 1-octen-3-ol and a significant reduction of hexanal, an indicator of oxidation; this improved resistance to oxidation in the GP+ samples and was also confirmed by the thiobarbituric acid reactive species (TBARS) test. In summary, the present study showed that the dietary GP supplementation was effective in improving the fatty acid composition and the oxidative stability of lamb meat. The use and valorization of the GP as a matrix of interest for zootechnical nutrition can, therefore, represent a suitable strategy for improving the qualitative aspects of animal production.

Effects of supplementing sweet sorghum with grapeseeds on carcass parameters, and meat quality, amino acid, and fatty acid composition of lambs

OBJECTIVE

Sweet sorghum is an important forage crop for ruminants, especially in low rainfall areas. Grapeseeds are an abundant by-product of wine-making and contain bioactive substances that can improve the antioxidant capacity of meat. We examined the effect of sweet sorghum forage with supplementary grapeseeds on carcass and meat quality in lambs.

METHODS

Twenty-eight Small-tailed Han lambs (body weight = 19.1±1.20 kg), aged 3 to 4 months, were penned, and fed individually. The lambs were divided into four groups (n = 7 each) and were offered one of four diets: i) sweet sorghum silage; ii) sweet sorghum silage + grapeseeds; iii) sweet sorghum hay; and iv) sweet sorghum hay + grapeseeds. The grapeseeds were added to the concentrate at 6% DM and the diets were fed for 100 d.

RESULTS

Sweet sorghum silage tended (p = 0.068) to increase hot carcass weight, while grapeseeds tended (p = 0.081) to decrease dressing percentage without affecting other carcass parameters. Lambs consuming supplementary grapeseeds increased (p<0.05) meat redness and tended to decrease (p = 0.075) concentration of methionine in meat. Lambs consuming sweet sorghum silage increased (p<0.001) water content of the meat and had a lower (p<0.05) concentration of n-6 polyunsaturated fatty acids (PUFA) and n-6:n-3 PUFA ratio than lambs consuming sweet sorghum hay. Saturated fatty acids content in meat was lowest (p<0.05) in lambs consuming sweet sorghum silage with grapeseeds. Lambs with supplementary grapeseeds tended (p<0.10) to increase eicosapentaenoic acid and docosahexaenoic acid and have a lower thrombogenic index than lambs not consuming grapeseeds.

CONCLUSION

It was concluded that sweet sorghum with supplementary grapeseeds fed to lambs; i) improved the color of the meat to be more appetizing to the consumer; ii) tended to improve the fatty acids composition of the meat; and iii) lowered thrombogenic index of the meat.

Meat quality, metabolic profile and antioxidant status of lambs fed on seedless grape pomace (Vitis vinifera L.)

This study was aiming to research the effect of the seedless grape pomace (GP) added to feed mixture on meat quality, metabolic profile, and antioxidant status of Merinolandschaf lambs. The 90 days old lambs in the control group (C, n=10) were fed feed mixture without GP while in experimental groups were fed with 10% (GP10, n=10) or 20% (GP20, n=10) of GP in feed mixture for 30 days. There was a significant increase in L*, a* values and hue angle as well as a decrease in b* values of lamb carcasses in GP10 and GP20 compared to C group. When lambs were fed GP glucose concentrations decreased, while non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) increased on the 30th day in GP10 and GP20 compared with C group. A significant increase in SOD activity on day 30 and GPx activity on day 15 in lambs’ blood of GP10 and GP20 compared with C group was determined. Also, an increase in DPPH in lamb GP10 and GP20 compared with C was determined. The obtained results of the meat quality, metabolic profile and antioxidant status parameters of lamb meat showed that the use of 10% GP in the diet is justified, while 20% of GP was questionable.

Antioxidant, physicochemical, and sensory properties of buffalo meat patties incorporated with roselle (Hibiscus sabdariffa L.), wolfberry (Lycium barbarum L.), and beetroot (Beta vulgaris L.) purées

The present work evaluated the antioxidant, physicochemical, and sensory properties of buffalo meat patties incorporated with 2% roselle (Hibiscus sabdariffa L.), wolfberry (Lycium barbarum L.), or beetroot (Beta vulgaris L.), and chill-stored (4°C) for 11 days. 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, 2-thiobarbituric acid reactive substances (TBARS), shrinkage, cooking yield, water holding capacity, pH, colour, textural properties, and sensory evaluation of the patties were examined. Patties incorporated with roselle, wolfberry, and beetroot had increased scavenging activity, thus decreasing oxidative activity in the patties during storage. Cooking yield was improved in all treatments with significant decrease in pH in both cooked and uncooked roselle-incorporated patties. No changes were observed for the texture of all samples, while roselle-incorporated patties maintained the redness after the 11th day of storage. Sensory attributes of the modified patties were acceptable to all panellists. In conclusion, the incorporation of roselle in buffalo meat patties showed more beneficial effects than the other purées tested in improving the quality of the patties while maintaining their sensory properties.

Inclusion of Grape Pomace in Finishing Cattle Diets: Carcass Traits, Meat Quality and Fatty Acid Composition

Because of its high content of polyphenolic compounds, dietary inclusion of grape pomace (GP) in finishing cattle diet could possibly enhance product quality and the health value of beef lipids. Therefore, the aim of this study was to evaluate the effects of feeding a high amount of grape pomace in finishing cattle diets on carcass traits, product quality, and fatty acid (FA) composition of beef. Jersey × Holstein crosses (n = 24) were fed either a typical finishing diet (CON) or a finishing diet containing 58% grape pomace (DM basis; HGP). Following the feeding period, animals were harvested, and carcass traits measured. Longissimus lumborum (LL) and semimembranosus (SM) muscle were then collected from each carcass for sensory quality evaluation and FA profile analysis. Hot carcass weight, backfat thickness, and preliminary and final yield grades were greater (p ≤ 0.04) for CON than HGP steers. However, there was no diet effect on rib eye area (REA), kidney, pelvic, and heart (KPH) fat, and marbling. Feeding the HGP compared to CON diet reduced lipid oxidation of LL and SM steaks over time; the malondialdehyde (MDA) concentration, which did not differ on d 0 and 2 of 8-d simulated retail display, was lower on d 4, 6 and 8 for HGP than CON steers (treatment × day of simulated display interaction; p < 0.01). Brightness (L* values) and redness (b*) were greater for LL steaks from HGP than CON steers on most days of simulated display (treatment × day of simulated display interaction; p < 0.01). In addition, the LL and SM muscle content of several FA linked to positive health outcomes in humans including 18:2 n-6, 18:2 c9t11, total conjugated linoleic acid (CLA) and total polyunsaturated fatty acid (PUFA) was also greater (p ≤ 0.02) for steers fed the HGP compared to the CON diet. In summary, current findings suggest that although it could possibly limit growth performance, feeding a high amount of grape pomace to finishing cattle could enhance both the sensory quality and the health value of beef lipids, which are key in increasing consumer acceptability of beef.

Sainfoin in the Dams' Diet as a Source of Proanthocyanidins: Effect on the Growth, Carcass and Meat Quality of Their Suckling Lambs

Sainfoin (Onobrychis viciifolia) is a forage legume with a medium content of proanthocyanidins (PAC), which may affect animal performance and product quality. The objective of the present study was to assess the effect of PAC from sainfoin fed to dams, using polyethylene glycol (PEG) as a blocking agent, on the performance and carcass and meat quality of their suckling male lambs. After lambing, twenty lactating dams were fed fresh sainfoin ad libitum plus 200 g per day of barley; ten were orally dosed with water (Sainfoin), and ten were dosed orally with a water dilution of 100 g PEG (Sainfoin + PEG). Their lambs (4.1 ± 0.64 kg at birth) suckled ad libitum until they reached the target slaughter weight of 10-12 kg. The presence of PAC in the dams' diet did not affect the growth, blood metabolites and carcass weight and fatness of the suckling lambs but decreased the lightness of caudal fat (p < 0.05) and increased the weight of the digestive compartments (p < 0.05). Regarding the meat characteristics, PAC only decreased polyphenols content (p < 0.05). In conclusion, the presence of PAC in the dams' diet had not significant effects on the performance and product quality of their suckling lambs.

Effects of grape pomace supplementation on the diet of lactating ewes as compared to vitamin E on the meat shelf life of suckling lambs

Forty-eight Churra ewes and their suckling lambs were assigned to four dietary treatments: control (CTRL), VIT-E (500 mg kg-1 TMR vitamin E), GP-5 (5% grape pomace) and GP-10 (10% grape pomace). After slaughter (11.5 kg live weight), longissimus muscle of lambs was sliced, packaged under modified atmosphere (80,20%/O 2:CO 2) and stored in retail conditions. At each sampling point (0, 3, 7, 10, 14 days), microbiological, physicochemical and sensory characteristics were analysed. Vitamin E and GP-5 were found to be effective (p < 0.05) at preventing enterobacteria growth as of day 10. After day 10, vitamin E and grape pomace in the ewe's supplementation reduced metmyoglobin (p < 0.05) lipid oxidation (p < 0.05) and sensory spoilage throughout the storage period. An effect of the grape pomace dosage was observed, with the supplementation at 5% being more effective. Therefore, we can conclude that grape pomace was just as effective as vitamin E in preventing spoilage during retail storage.

Plant Feed Additives as Natural Alternatives to the Use of Synthetic Antioxidant Vitamins on Livestock Mammals' Performances, Health, and Oxidative Status: A Review of the Literature in the Last 20 Years

In the last two decades, the interest in natural plant feed additives (PFA) as alternatives to synthetic vitamins in livestock nutrition has increased. After a systematic review, a total of 19 peer-reviewed papers published between 2000 and 2020 were retained to evaluate the antioxidant effects of PFA compared to synthetic antioxidant vitamins (mainly vitamin E; VitE) in livestock nutrition. These studies demonstrated that PFAs could be as efficient as VitE in counteracting oxidative stress in pigs, rabbits, and ruminants. However, PFAs only positively affected animals’ growth performance and feed efficiency in some monogastric studies. The PFA can affect antioxidant enzyme activity in a dose- and method of administration-dependent manner. The antioxidant capacity of both PFA and VitE were depressed in cows fed with diets rich in polyunsaturated fatty acids. Variability among studies could be related to species differences. Despite the interest of the feed industry sector in PFA, there are still very few studies evaluating their antioxidant effect in species other than poultry.

Plant Feed Additives as Natural Alternatives to the Use of Synthetic Antioxidant Vitamins in Livestock Animal Products Yield, Quality, and Oxidative Status: A Review

The interest for safe and natural foods of animal origin is currently increasing the use of plant feed additives (PFA) as antioxidants in animal nutrition. However, studies with livestock animals dealing with PFA as antioxidants are scarce. The aim of the present review was to evaluate the antioxidant impact of PFA compared with synthetic vitamins on animal food product yield and quality. For this purpose, peer-reviewed studies published between 2000 and 2020 were collected. Most papers were carried out on ruminants (n = 13), but PFA were also tested in swine (n = 6) and rabbits (n = 2). The inclusion of PFA in the diets of pigs, rabbits, and ruminants improved the products’ quality (including organoleptic characteristics and fatty acids profile), oxidative stability, and shelf life, with some impacts also on their yields. The effects of PFA are diverse but often comparable to those of the synthetic antioxidant vitamin E, suggesting their potential as an alternative to this vitamin within the diet.

Physicochemical Characteristics, Fatty Acid Profile, Alpha-Tocopherol Content, and Lipid Oxidation of Meat from Ewes Fed Different Levels of Distilled Myrtle Residues

The aim of this work was to study the sheep meat physicochemical traits as affected by distilled myrtle residues (MR) supplementation. For this, 27 culled ewes were divided into three groups receiving a ration composed by concentrate and hay for the Control group, concentrate and MR as a total substitute to hay for the Myrt-H group, or hay, less concentrate, and MR as a partial substitute to concentrate for the Myrt-C group. The meat chemical composition, pH, and color parameters were not affected by the MR intake. However, this animal’s dietary treatment resulted in higher meat polyphenol and α-tocopherol content for both MR groups (9.38 and 8.05 vs. 3.04 μg g⁻¹ DM for Myrt-H, Myrt-C, and Control, respectively). In addition, since day 3 of meat storage, the lipid oxidation was improved by MR intake being lower for both MR groups than the Control (0.51 vs. 1.11 mg MDA/kg of meat). The total polyunsaturated fatty acid (PUFA) and saturated fatty acid (SFA) were similar among groups. However, the meat of Myrt-H had the highest C18:2n-6 and total PUFAn-6. In conclusion, the MR intake could be useful given it increases the meat content of vitamin E and improves its oxidative status without negative effects on the FA profile.

1H NMR-based metabolomics study of breast meat from Pekin and Linwu duck of different ages and relation to meat quality

This study investigated the effects of breed and age on meat quality, and metabolite profiles of duck breast meat, and the relationship between changes in metabolite profiles and the meat quality. The meat quality and 1H nuclear magnetic resonance (NMR)-based metabolomics of breast meat from Pekin and Linwu ducks at 2 different ages (42 and 72d) was analyzed. The results showed that age exerted a greater effect on the observed meat quality traits of breast meat than breed, and its interaction (breed × age) effect on pH values and yellowness (b*) of duck breast meat was significant. Total of 32 metabolites were detected in breast meat of Pekin and Linwu duck. The difference of metabolite profiles in breast meat between Pekin and Linwu duck at 72 d was greater than that at 42 d, while the effects of age on metabolites of duck meat from both breeds were similar. Anserine, aspartate, and carnosine were the most relevant metabolites of duck breast meat quality, and nicotinamide in duck breast meat was negatively correlated with cooking loss. These results provide an overall perspective for bridging the gap between the breed and age on duck meat quality and metabolome, and improve the understanding of the relationship between metabolites and duck meat quality.

Influence of Grape Pomace Intake on Nutritional Value, Lipid Oxidation and Volatile Profile of Poultry Meat

Grape pomace (GP) represents the main solid by-product deriving from grape processing. The aim of this study was to evaluate the effect of dietary GP intake on nutritional quality, lipid oxidation and volatile profile of chicken meat. A total of 112 Ross 508 broilers were randomly divided into 4 groups and fed for 21 days with a standard diet. For the remaining 28 days of the trial, the control group (CG) continued to receive a standard diet, while the experimental groups (EGs) were fed with diets containing different GP concentrations: 2.5% (EG1), 5% (EG2) and 7% (EG3). Following the slaughtering, samples of breast meat were collected from each group. No significant differences were observed for pH, cooking loss and meat brightness, whereas the GP intake showed effectiveness in inducing variations in drip loss, meat yellowness and redness. The experimental feeding strategy also induced changes in the fatty acid profile, with an overall increase in polyunsaturated fatty acids (PUFA), mainly due to the increase in concentration of linoleic acid. The dietary supplementation also induced a decrease in lipid oxidation in meat, a finding also confirmed by the reduction in volatile aldehydes in 7 days stored raw meat. The feeding strategy based on the use of GP did not induce detrimental effects on the quality of broiler meat and showed the potential to lengthen the shelf-life as a direct consequence of the improvement in the oxidative stability. Overall, the present study showed a viable way for the recovery and the valorization of an agro-industrial by-product, with potential benefits also from an environmental point of view.

Grape Pomace as a Promising Antimicrobial Alternative in Feed: A Critical Review

Antimicrobial resistance is among the most urgent global challenges facing sustainable animal production systems. The use of antibiotics as growth promoters and for infectious disease prevention in intensive animal-farming practices has translated into the selection and spread of antimicrobial resistance genes in an unprecedented fashion. Several multi-resistant bacterial strains have been isolated from food-producing animals, thus constituting an alarming food-safety issue. Many industrial byproducts with potential antimicrobial properties are currently being investigated to identify empirical and affordable solutions/alternatives that can potentially be used in feed for animals. Grape pomace is among such byproducts that gained the attention as a result of its low cost, abundance, and, most importantly, its bioactive and antibacterial properties. This review discusses the recently reported studies with regard to exploring the use of grape pomace (and its extracts) in animal production to control pathogens, along with the promotion of beneficial bacterial species in the gut to ultimately alleviate antibacterial resistance. The review further summarizes realistic expectations connected with grape pomace usage and lists the still-to-be-addressed concerns about its application in animal agriculture.

Dietary Supplementation of Dried Grape Pomace Increases the Amount of Linoleic Acid in Beef, Reduces the Lipid Oxidation and Modifies the Volatile Profile

Simple Summary

The grape pomace is the main solid by-product of the oenological industry, and represents a rich source of potent bioactive compounds. In this study we demonstrated that its inclusion in bovine diet resulted in a significant increase of linoleic acid concentration in meat, a condition which led to a positive increase in the polyunsaturated fatty acid:saturated fatty acids (PUFA:SFA) ratio. Despite the greater predisposition of PUFA to oxidation, an interesting improvement in the oxidative stability of meat was evidenced, presumably as an effect of the antioxidant activity performed by the bioactive compounds of which the grape pomace is rich in. This finding was also confirmed by the analysis of volatile compounds which highlighted a reduction of hexanal in meat samples obtained from animals fed the dietary grape pomace supplementation. Overall, the present study showed a viable way for the recovery and the valorization of the main by-product of the oenological industry.

Abstract

The aim of this study was to evaluate the effect of dietary supplementation with dried grape pomace on beef quality. Ten Friesian calves were divided into two groups, a control group that received a standard diet, and an experimental group that was administered the dietary supplementation. At the end of the 75 days of the trial, animals were slaughtered, and meat samples analyzed for physical and chemical properties, fatty acids composition, lipid oxidation, volatile compounds, and biogenic amines. The fatty acid profile resulted affected by dietary supplementation, since an increase in concentration of linoleic acid was observed. Furthermore, a reduction of lipid oxidation was found in the same samples. With reference to volatile compounds a reduction of hexanal and an increase of 2-3 octanedione was evidenced, while no effects were induced by diets on the synthesis of biogenic amines. The grape pomace exploitation as a dietary supplement in bovine diet did not have negative effects on the quality of beef and showed the potential to extend shelf life due to marked improvement in oxidative stability. Overall, the present study showed a viable way for the recovery and the valorization of the main by-product of the oenological industry.

Citrus and Winery Wastes: Promising Dietary Supplements for Sustainable Ruminant Animal Nutrition, Health, Production, and Meat Quality

Citrus and grapes are the most widely grown fruits globally, with one-third of total production used for juice and wine making. The juice and winemaking processes generate large quantities of solid organic wastes including citrus pulp and grape pomace. These fruit wastes pose serious economic, environmental, and social challenges, especially in low-to-middle-income countries due to financial, technological, and infrastructural limitations. They are, however, rich in valuable compounds which can be utilized in the ruminant livestock industry as novel, economical, and natural sources of cellulose, polyunsaturated fatty acids, and phytochemicals, which have nutritional, anthelmintic, antioxidant, and antimicrobial properties. Despite citrus and grape fruit wastes having such potential, they remain underexploited by the livestock industry in low-to-middle-income countries owing to lack of finance, skills, technology, and infrastructure. Inclusion of these fruit wastes in ruminant diets could combine the desirable effects of enhancing animal nutrition, health, welfare, production, and meat quality attributes with the prevention of challenges associated with their disposal into the environment. The current review explores the valorization potential of citrus and winery wastes as dietary supplements to sustainably enhance ruminant animal nutrition, health, welfare, production, and meat quality.