The effect of fibre orientation, measurement interval and muscle on lamb meat drip loss values

Characterization and antibacterial application of peppermint essential oil nanoemulsions in broiler

In order to mitigate the risk of antibiotic resistance in poultry, scientists nowadays consider plant secondary metabolites to be a major organic antibacterial substitute. This study aimed to characterize and investigate the in silico, in vitro, and in vivo antibacterial effects of peppermint essential oil (PEO) in the form of a nanoemulsion (NE), termed PEONE. Menthol as a major compound of PEO has been identified by gas chromatography and mass spectroscopy (GCMS) analysis as 32.3 %, while lower droplet size, polydispersity Index (PDI), and optimum zeta potential values depicted the stability of PEONE have been observed and validated by transmission electron microscopy (TEM) micrograph image. In silico antibacterial activity was studied by molecular docking of menthol and enrofloxacin with Topoisomerase IV protein (PDB: 1s16;) of Escherichia coli K12 MG1655 and this effect was validated by in vitro and in vivo analysis. In vitro analysis, sustained release of PEONE has been observed against Escherichia coli and Staphylococcus aureus. In this study for in vivo experiments (n = 90) day-old broiler chicks were distributed into 6 dietary treatments with 5 replicates of 3 birds per replication. Dietary treatments included 1) Negative control (basal diet), 2) Positive control (basal diet + 200 µl enrofloxacin), 3) 25 µl PEONE + basal diet, 4) 50 µl PEONE + basal diet, 5) 75 µl PEONE + basal diet, and 6) 100 µl PEONE + basal diet. Analyzed data by different statistical tools confirmed that PEONE significantly affected body weight gain (BWG) with an improved feed conversion ratio (FCR) compared to the control group. A significant increase in cecal Lactobacillus count and a decrease in total coliform was observed. Positive effects on physiological parameters, visceral organs, and meat quality characteristics have been observed. In conclusion, our experiments suggest that PEONE can be used in the broiler industry as a substitute for antibiotics to minimize bacterial resistance.

The carcass characteristics and quality of meat from lambs grazing perennial wheat with different companion legumes (clover, serradella, lucerne) or a mineral supplement

This study compared carcasses as well as the quality and mineral concentration of meat from lambs extensively grazing perennial wheat with clover (PW + C), serradella (PW + S), lucerne (PW + L), or a mineral salt supplement (PW + Min). A split-plot design was used, wherein 3 crossbred ewe lambs (n = 72 in total) (sub-plots) grazed each of 4 forage types (plots), that were replicated across 6 locations (blocks). The feeding study concluded after 96 d, when all the lambs were slaughtered. The left longissimus lumborum muscles (LL) were collected and wet aged for either 5 or 56 d post-mortem. Lambs grazing PW + Min were found to produce carcasses with lower dressing percentage values to those grazing the other forage types (P = 0.037). The LL of lambs grazing PW + L had the lowest crude protein values (P = 0.015). Forage type by ageing period interactions did not affect meat quality. The 56 d ageing period resulted in higher purge loss (P < 0.001) and TVB-N values (P < 0.001) and a decline in shear force (P < 0.001) compared to the 5 d ageing period. The other carcass and meat quality parameters were not affected by forage type; including hot carcass weight, pH decline parameters, eye muscle area, cooking loss, intramuscular fat, sarcomere length, colour stability, and concentrations of calcium, iron, magnesium, sodium, and zinc in the LL. These findings confirm that perennial cereal production systems, that include legume forages with contrasting protein, energy, and micronutrient profiles, can deliver comparable lamb carcasses and meat quality.

Characterization and discrimination of lamb with different breeds and muscle types using precursors and volatile compounds

The unique aromas of mutton stem from the chemical reactions between the characteristic precursors during cooking. This study aimed to establish the relationship of volatile compounds and aroma precursors (protein, fat, free amino acids and fatty acids) in lamb from different breeds and muscle types. Hong lamb was characterized by greater tenderness and water holding capacity, higher polyunsaturated fatty acids and higher essential/non-essential amino acids in comparison with Hu lamb. Aldehydes, such as heptanal, hexanal, octanal and nonanal were higher in Hong-ST compared with Hu-ST. Principal component analysis (PCA) showed that aroma precursors were closely related to volatile components of cooked lamb. Discriminant analysis results showed that precursors and volatile compounds could be used to identify the breeds and muscle types of lamb. These findings revealed the contributors of lamb aroma and might help understand the regulatory mechanism of aroma in lamb from different breeds and muscle types.

Canola meal as a supplement for grass-fed beef cattle: Effects on growth rates, carcase and meat quality, and consumer sensory evaluations

The current study examined the growth rates, carcase characteristics, meat quality, and consumer sensory evaluation of the longissimus lumborum muscle (striploin) from steers that were supplemented with either canola meal or grain-based pellets. Forty Angus and Hereford × Angus steers received one of these two supplements with ad libitum lucerne hay for 60 d prior to slaughter. Average daily weight gain was not affected by dietary treatment; however, hot standard carcase weight was significantly lower for steers offered canola meal compared with steers on the grain-based pellets. Dietary treatment did not affect the carcase characteristics, meat quality traits, and consumer sensory evaluation, irrespective of ageing periods. Therefore, canola meal can be used as an approved Pasturefed Cattle Assurance System (PCAS) supplement on moderate dry quality forages without negatively affecting carcase and meat quality traits.

Development of Plastic/Gelatin Bilayer Active Packaging Film with Antibacterial and Water-Absorbing Functions for Lamb Preservation

In order to extend the shelf life of refrigerating raw lamb by inhibiting the growth of microorganisms, preventing the oxidation of fat and protein, and absorbing the juice outflow of lamb during storage, an active packaging system based on plastic/gelatin bilayer film with essential oil was developed in this study. Three kinds of petroleum-derived plastic films, oriented polypropylene (OPP), polyethylene terephthalate, and polyethylene, were coated with gelatin to make bilayer films for lamb preservation. The results showed significant improvement in the mechanical properties, oxygen, moisture, and light barriers of the bilayer films compared to the gelatin film. The OPP/gelatin bilayer film was selected for further experiments because of its highest acceptance by panelists. If the amount of juice outflow was less than 350% of the mass of the gelatin layer, it was difficult for the gelatin film to separate from lamb. With the increase in essential oil concentration, the water absorption capacity decreased. The OPP/gelatin bilayer films with 20% mustard or 10% oregano essential oils inhibited the growth of bacteria in lamb and displayed better mechanical properties. Essential oil decreased the brightness and light transmittance of the bilayer films and made the film yellow. In conclusion, our results suggested that the active packaging system based on OPP/gelatin bilayer film was more suitable for raw lamb preservation than single-layer gelatin film or petroleum-derived plastic film, but need further study, including minimizing the amount of essential oil, enhancing the mechanical strength of the gelatin film after water absorption.

Comparison between Standardized and Modified EZ-DripLoss Determination Methods in Chicken Breast Meat

The EZ-DripLoss method is relatively new gravimetric method that is used for the determination of excessive drip in meat. The literature reports diversity regarding the use of EZ-DripLoss methodology. In the standardized EZ-DripLoss method, drip loss is calculated as the change in the container weight, whereas in the modified EZ-DripLoss method, it is calculated as the change in sample weight. This technical note aimed to research the relationship between these two methods on chicken breast meat (40 broilers from the line Ross 308) during the measurement interval of 24, 48, and 72 h. The results showed statistically a significant positive linear increase in drip loss values regardless of the used method during all of the investigated measurement intervals. At 24, 48, and 72 h of storage, the average drip loss in the weighed samples was 0.77, 1.40, and 2.23 percentage points greater than in the not weighed samples (p < 0.0001), respectively. A strong and positive estimate of correlation coefficients between the drip loss of weighed and not weighed samples was found after 24 h (r = 0.95), 48 h (r = 0.92), and 72 h (r = 0.86). This technical report indicates that the used EZ-DripLoss methodology highly influences the drip loss in chicken breast meat and the comparisons of the EZ-DripLoss results should be performed with great caution.

Effect of Supplementary Levels of Rumen-Protected Lysine and Methionine on Growth Performance, Carcass Traits, and Meat Quality in Feedlot Yaks (Bos grunniens)

Simple Summary

Yak is an indigenous ruminant on the Qinghai-Tibetan Plateau and its meat is known as the “beef crown”. Traditionally, yak graze on the rangeland all year round and without any supplementation, and weight loss would occur in the cold season, which leads to rather low productive performance. In recent years, the strategy of intensive feedlot fattening was introduced to the yak raising industry. However, the results were not as encouraging as in the cattle steers, a fact that can be attributed to yak malnutrition due to differences in feed varieties supply and nutrients requirement between yaks and cattle. Consequently, this study was conducted to examine the effect of the first two limiting amino acids on growth performance, carcass traits, and meat quality in feedlot yaks. The animals were offered total mixed ration with supplementary four levels of rumen-protected lysine and methionine throughout the whole experiment. The results showed that the average daily gain, feed to gain ratio, meat color, drip loss, and shear force were improved when yaks were supplemented with rumen-protected amino acid while the medium level was most promising. These results indicated that supplementary rumen-protected amino acid improved the growth performance and meat quality characteristics of fattening yaks in feedlot.

Abstract

Yak, a unique bovine species on the Qinghai-Tibetan Plateau, has provided pastoralists with the basic materials of production and life for thousands of years. Existing literature showed that yak meat is of high nutritional value for humans whereas the growth performance is relatively low. As it has been demonstrated, lysine and methionine are the two key limiting amino acids in ruminants. Therefore, this study was conducted to investigate the effect of supplementary levels of rumen-protected lysine (RPL) and methionine (RPM) on growth performance, carcass traits, and meat quality in feedlot yaks. Thirty-two male yaks, with initial body weight (IBW) of 237.5 ± 13.99 kg were randomly assigned to four dietary treatments (n = 8), including control group (CON; basal diet without adding rumen-protected amino acid (RPAA)), low RPAA supplementation group (Group Low; basal diet supplemented with RPL (30.0 g/animal/day) and RPM (7.5 g/animal/day)), medium RPAA supplementation group (Group Medium; basal diet supplemented with RPL (50.0 g/animal/day) and RPM (12.5 g/animal/day)), and high RPAA supplementation group (Group High; basal diet supplemented with RPL (70.0 g/animal/day) and RPM (17.5 g/animal/day)). The average daily gain was increased linearly (p < 0.001) and quadratically (p < 0.01) while feed to gain ratio was decreased linearly (p < 0.001) and quadratically (p < 0.001) with the increasing RPAA supplementation, and the average daily gain was higher while feed to gain ratio was lower in RPAA than CON (p < 0.001). Meat color L* values and b* were decreased linearly (p < 0.01) with the increase of RPAA supplementation, and b* was lower in RPAA than CON (p < 0.05). Meat color a* value was increased linearly (p < 0.05) with the increasing RPAA supplementation, and a* was higher in RPAA than CON (p < 0.05). The 24 h drip loss and shear force were decreased quadratically (p < 0.01) with the increasing RPAA supplementation, and drip loss and shear force values were lower in RPAA than CON (p < 0.05). The glycine concentration in longissimus dorsi (LD) increased linearly (p < 0.05) with the increasing RPAA supplementation. These results demonstrated that both the growth performance and meat quality characteristics were improved in feedlot yaks as an effect of the dietary supplementation with RPL and RPM, and the medium supplementary level is recommended, since it showed the most promising results.

Effects of dietary supplementation with breadfruit leaf powder on growth performance, meat quality, and antioxidative activity in Japanese quail

Background and Aim:

In an era of increasing concerns about food availability globally, poultry meat is being increasingly consumed rather than red meat given its quality in terms of pH, color, and tenderness, conferring consumer satisfaction. The choice of feed is a crucial factor in poultry production. This study investigated the effect of dietary supplementation with breadfruit leaf powder on growth performance, meat quality, and antioxidative activity in Japanese quail.

Materials and Methods:

A total of 120 day-old quail were used in this study and assigned equally into four treatment groups: Group C fed a basal diet and three treatment groups fed a basal diet supplemented with 2.5% (T1), 5% (T2), or 10% (T3) breadfruit leaf powder. The concentrations of breadfruit leaf powder were 2.5, 5, and 10 g/kg in the basal diet. Quail body weight and feed intake (FI) were evaluated at 1, 21, and 35 days of age at 7 a.m. Pectoral muscle was collected to determine pH, meat color, drip loss, cooking loss, water-holding capacity (WHC), tenderness, and antioxidant levels. All variables were analyzed statistically using ANOVA followed by Duncan’s post hoc test (significance set at p<0.05).

Results:

T3 showed increased body weight gain of quails at1-21 and 21-35 days (p<0.05). Feeding in the T3 group improved the feed conversion ratio compared with those in the C and T1 groups at the starter phase (p<0.05). Dietary treatment did not affect FI (p>0.05). In the present study, meat redness and WHC were improved in the T3 group (p<0.05). Meanwhile, drip loss, cooking loss, and meat tenderness were improved in the T2 group (p<0.05). The pH_{45 min}, pH_{24 h}, lightness, and yellowness were not influenced by the treatments (p>0.05). The antioxidative activities of superoxide dismutase and malondialdehyde decreased in the T3 group (p<0.05), while no significant difference in glutathione peroxidase level (p>0.05) was identified.

Conclusion:

Ten grams/kilogram of breadfruit leaf powder, as administered in the T3 group, can be applied as a dietary supplement for Japanese quail to improve growth performance, meat quality, and antioxidative activity during the starter and grower periods.

The quality and mineral composition of the longissimus lumborum and semimembranosus muscles from lambs fed perennial or annual wheat forage with or without lucerne

This study compared the effect of a novel perennial wheat forage and a conventional annual wheat forage, fed to lambs with or without lucerne, on the quality and mineral profile of the longissimus lumborum and semimembranosus muscles. This involved 48 Poll Dorset × Merino ewe lambs, 12 per treatment, managed for 28 days within individual pens. Consumer sensory panel scores showed 'good eating quality' for all samples irrespective of diet, a conclusion supported by the shear force, cooking loss, particle size, and intramuscular fat results. Drip loss was affected by a significant interaction between diet and muscle. The ultimate pH of meat from lambs fed annual wheat was highest. Comparable colour stability and purge results suggested that diet did not impact on lamb retail-potential. Sodium, sulphur and zinc concentrations were higher in the meat from lambs fed annual wheat, compared to perennial wheat. Overall, these outcomes support the use of perennial wheat as a forage for lamb production.

EZ-DripLoss Assessment in Chicken Breast Meat Using Different Sample Areas, Fiber Orientation, and Measurement Intervals

Although the EZ-DripLoss method has been performed in numerous studies, there is a deficiency in our knowledge of the EZ-DripLoss method's suitability for poultry meat analysis. This study aimed to research the effect of different sample areas (10, 20, and 30 mm; n = 240), and fiber orientations (vertical vs. horizontal) on the EZ-DripLoss in chicken breast meat measured across a period of five days. The influence of sample area on the EZ-DripLoss of chicken breast meat with respect to the fiber orientation and across the five-day measurement interval was significant between 10 and 30 mm samples, and between 20 and 30 mm samples (p < 0.001). The estimated regression coefficient showed that EZ-DripLoss for the samples with horizontal and vertical fiber direction of 10 and 20 mm, significantly increased by 0.04% per hour, while for the samples with vertical fiber direction whose diameter was 30 mm, it significantly increased by 0.06% per hour, and for the horizontal fiber direction, it significantly increased by 0.07% per hour. The samples with vertical fiber orientation had 0.50% greater EZ-DripLoss compared to the samples with horizontal fiber orientation. EZ-DripLoss evaluation in chicken breast should be performed with a sample core diameter of 20 mm, a vertical fiber orientation, and over the course of longer measurement intervals.

Drip loss assessment by EZ and bag methods and their relationship with pH value and color in mutton

Drip loss, pH value, and color are among the important traits that determine meat quality. Contrary to pH and color, the method associated with drip loss is not yet standardized, and literature data are difficult to compare. Besides, to our knowledge, there is no research comparing drip loss methods and their relation with pH and color in mutton. This study aimed to assess drip loss measurements in mutton taken by different methods (EZ and bag – BM) and their relationship with pH values and color. Mutton samples (Musculus longissimus thoracis et lumborum) originating from 20 ewes of Istrian sheep were used to examine the effect of the method on drip loss after 24 h (EZ24 vs. BM24) and 48 h (EZ48 vs. BM48). Furthermore, correlations between drip loss, pH value, and color were analyzed. The statistical analysis was conducted in R programming environment by using different packages. Within the EZ method there was no significant difference (p>0.05) between ventral and dorsal sample cores used for the assessment of EZ drip loss. Drip loss measured with the same method at two different points of time (24 and 48 h) differed significantly (p<0.001). There was also a significant difference in drip loss determined by different methods (EZ vs. BM) at the same point of time. There were significant (p<0.05) correlations between pH45min and all color parameters (L*4, a*, b*). The L*, a*, and b* parameters were highly correlated (p<0.001). The strongest correlation occurred between a* and b* parameter (r=0.93). Correlations between drip loss by EZ method and other meat quality attributes were low and not significant. The b* parameter correlated with BM24 (r=0.46) and BM48 (r=0.58), while a* correlated only with BM48 (r=0.50). The correlations between the EZ24 and BM24 as well as between the EZ48 and BM48 were both non-significant (p>0.05). Drip loss cannot be predicted with sufficient accuracy by using pH and color. EZ and BM method in mutton do not provide equivalent results for measuring drip loss. Comparisons of the results obtained with different methods should be avoided or at least performed with great precaution.