Volatile Profile of Dry and Wet Aged Beef Loin and Its Relationship with Consumer Flavour Liking

This study investigated the effect of ageing method and ageing time on the volatile profiles of grilled beef striploins (Longissimus thoracis et lumborum) and their relationship with consumer flavour liking. Volatiles were measured in grilled steaks subjected to 35 days of dry ageing, 35 days of wet ageing, 56 days of dry ageing or 56 days of wet ageing, using headspace-solid-phase microextraction followed by gas chromatography-mass spectrometry. Gas chromatography-olfactometry-mass spectrometry was also conducted on 35-day wet and dry aged samples to identify volatiles with high odour impact. The concentration of many odour impact volatiles, e.g., 3-hydroxy-2-butanone, 2-acetyl-2-thiazoline, and various alkyl-pyrazines, was significantly higher in dry aged beef compared to wet aged beef (p < 0.05). Several odour impact volatiles, e.g., 2-acetyl-1-pyrroline, and alkyl-pyrazines, decreased significantly with ageing time (p < 0.05), while volatile products of lipid oxidation and microbial metabolism increased with ageing time. Partial least-squares regression analysis showed that the higher consumer flavour liking for 35-day dry aged beef was associated with higher concentrations of desirable odour-active volatiles.

The influence of muscle, ageing and thermal treatment method on the quality of cooked beef

The study was undertaken to investigate the effect of muscle, thermal treatment, and ageing on the beef quality. The longissimus lumborum (LL) and semimembranosus (SM) muscles were taken from Holstein–Friesian young bull carcasses then subjected to steam-cooking and sous-vide after 9 and 14-d wet ageing. It was shown that characteristics of cooked beef were the most significantly affected by thermal treatment method. Using sous-vide provided beef with lower shear force and cooking loss values, darker, and more red colour and more beneficial sensory quality. LL and SM muscles showed a similar quality when subjected to the same thermal treatment method after the same ageing time. It is possible to obtain juicy and tender beef from Holstein–Friesian bulls after 9-d ageing and sous-vide treatment.

Physical Changes during Post-Mortem Ageing of High-Value Impala (Aepyceros Melampus) Steaks

Antelope meat production is rapidly growing, not only due to their adaptation to marginal land usage, but also because of its favorable nutritional properties and free-range production. However, limited information is available on the meat quality and processing potential of game meat for commercial consumption. The objective of this study was to determine the ageing period to achieve maximum tenderness of longissimus thoracis et lumborum (LTL) muscles of impala. The LTL muscles of 11 male and 11 female impala were harvested, and divided into eight portions. Each portion was randomly allocated to 1, 2, 4, 6, 8, 10, 12, or 14 days of wet-ageing (4 °C) in vacuum packaging. The meat pH, color, weep loss, cooking loss, and Warner–Bratzler shear force were measured throughout ageing. Initially the ageing profile differed depending on the sex of the animal from which the muscle was harvested; however, after 8 days of ageing, maximum tenderness was reached (13.5 ± 0.91 N) and no further sex differences were seen. Ageing improved the surface color of all meat until day 8, after which discoloration occurred. Therefore, it is recommended that impala LTL steaks should be wet-aged at 4 °C for eight days to achieve maximum tenderness and minimize sex variability.

Effects of Extended Aging on the Flavor Characteristics of Grass and Grain Fed Australian Beef Longissimus Thoracis

ObjectivesThe objective of this study was to investigate the effects of extended wet ageing on the flavor characteristics, of grass and grain fed Australian beef lumborum thoracis.Materials and MethodsCube rolls (HAM #2244) were collected from grass and grain fed cattle (n = 30) at a commercial abattoir near Brisbane, Australia. Cube rolls were vacuum packaged and shipped under refrigeration (0–2°C) to Texas Tech University. Each cube roll was cut into 2.5-cm steaks and labeled according to position from posterior to anterior end. Steaks were vacuumed packaged, stored through the appropriate postmortem ageing period (35, 45, 55, or 65 d postmortem), and then frozen until further analysis. One steak from each cube roll was used for trained descriptive flavor analysis with 8 trained panelists comprised of mostly graduate students from Texas Tech University. Flavor attributes of cooked steaks were scored using 100-point anchored line scales (0 = none, 50 = moderate, and 100 = strong).Data were analyzed used PROC GLIMMIX of SAS with diet, postmortem ageing, and their interaction as fixed effects and panelist as a random effect. Final temperature was tested as a covariate for all the flavor attributes.ResultsAn interaction was detected only for the bitter flavor and overall juiciness (P ≤ 0.03). Beef flavor ID, fat-like, metallic, umami, and sweet were not influenced by diet or postmortem ageing (P > 0.05). Ageing influenced bloody serumy flavor (P > 0.05) with 45 d samples having greater flavor than 55 d samples, but not differing (P > 0.05) from any other ageing period. Diet and ageing influenced rancid flavor (P > 0.05), with grass fed samples having a stronger rancid flavor than grain fed samples. Samples aged 65 d had a stronger rancid flavor than 45 or 55-d samples, and 35-d samples had the lowest rancid flavor. Diet and ageing influenced grassy flavor (P > 0.05), again being stronger in grass than grain fed samples. Samples aged 35 d had a weaker (P > 0.05) grassy flavor than any other ageing period, which did not differ (P > 0.05). Diet and ageing had an effect on liver-like flavor (P < 0.05) with stronger flavors in grain than grass fed samples and liver-like flavor increasing with postmortem ageing time. Sour flavor was affected by diet only (P < 0.05) with grass fed samples having stronger sour flavor than grain fed samples. Ageing had an effect on overall tenderness (P < 0.05); samples aged 35 d were least tender, and samples aged 45 d were more tender than 55 d samples but did not differ from 65 d samples.ConclusionThe results suggest that beef flavor as measured by beef flavor ID and umami were not impacted by extended ageing; however, some off-flavors grew stronger as ageing time extended. Flavor attributes such as rancid, grassy, sour were stronger in grass than grain fed samples, but grain fed has a stronger liver-like flavor. Ageing influenced both overall tenderness and juiciness, but typically not in a linear fashion.

Microleakage of Aesthetic Restorations Following Functional Simulation and Immersion in Saudi-Traditional Mouth Rinses

AIM: The study is aimed to assess the effect of 3 Saudi-traditional types of mouth rinses (Karadah, Myrrh, salted water) on the microleakage of composite and glass-ionomer restorations subjected to thermal cycling and cyclic loading. MATERIAL AND METHODS: Class V cavities in both buccal and lingual surfaces of eighty extracted premolars were restored with both nano-filled composite and glass-ionomer restoratives. Half the number of restored teeth (group 1, n = 40) were subjected to further thermal cycling and cyclic loading to mimic the in-service functional stresses. The rest of the teeth were left as control with no functional simulation (group 2, n = 40). Teeth of each group were then stored wet for one month in 4 subgroups (n = 10) according to the storage media (distilled water, salted water, Myrrh and Karadah extracts). Following wet ageing, all teeth were immersed in methylene blue solution for 24 hrs, followed by sectioning in Bucco-lingual direction. The microleakage was inspected using stereomicroscope and rated from 0-4 according to its penetration depth. The collected non-parametrical data was then analysed statistically using Kruskal-Wallis One-way ANOVA at α = 0.05. RESULTS: There was no statistically significant difference observed in microleakage between specimens treated with any of the mouthwashes for both glass ionomer and composite restorations in the presence and absence of thermal cycling and cyclic loading (p = 0.889). CONCLUSION: Given the results of the present study, the Saudi-traditional types of mouth rinses are not contributory to microleakage in aesthetic-based composite and glass-ionomer restorations.

Quality and Acceptability of Fresh and Long-Term Frozen In-Bag Dry-Aged Lean Bull Beef

In-bag dry-aged lean beef was produced using a stepwise ageing process. Lean bull beef striploins were dry-aged at 2°C, 75% RH under three different air velocities: 0.5, 1.5, and 2.5 m·s−1 for 7 days followed by wet-ageing for 14 days. The quality and acceptability of the dry-aged beef were compared with equivalent beef dry-aged for 21 days at 0.5 m·s−1 which served as a control. Two portions of the dry-aged beef (7/21 days) were randomly selected and held frozen at −18°C for 12 months. Shear force, drip, and cook loss decreased significantly (p<0.05) with dry-ageing time. Increased air velocities accelerated dehydration process with no negative impact on the meat quality, microbiological safety, and consumer acceptability compared to the control (p>0.05). Frozen storage for 12 months had little or no effect on the quality and acceptability of the dry-aged lean beef (p>0.05). Dry-aged lean beef of equivalent quality and palatability, with a lower level of surface microorganisms and higher yield compared to the control, could be produced using the stepwise ageing process.

Methods of beef ageing from the health safety standpoint

Beef ageing is a technique used by meat technologists, retailers, and restaurateurs to intensify flavor and improve tenderness due to the natural enzymatic processes occurring in meat postmortem. There is a widespread consensus that meat should age to achieve desirable palatability and tenderness. However, taking into account obvious advantages and disadvantages it is questionable which technique of meat ageing is to be selected. The paper presents two techniques of beef ageing (dry and wet) and their effect on the final sensory quality of meat, weight losses, and microbiological status. On the one hand, dry ageing primarily augments the flavor of meat. On the other hand, wet ageing notably increases the meat tenderness. Unfortunately, dry ageing of unpacked beef (or beef cuts) is a process which requires specific temperatures, relative humidity, airflow, and high standards of hygienic conditions. In contrast, wet ageing of meat in a vacuum bag does not require such circumstances (with the exception of temperature). Moreover, wet ageing can further amplify the effect of dry ageing, thus creating an additional benefit. The main advantages of this combination are the constrained weight loss of beef and a substantial reduction in the risk of contamination. Although the dry beef ageing process is extremely time-consuming, requires particular attention and professional knowledge, it turns out that a narrow group of consumers is prepared to pay a premium for the properly manufactured final productthat stands out in terms of a unique taste profile. Furthermore, such a product is nutritious and completely safe from the health point of view (the lack of pathogenic microorganisms and mycotoxins as well as relatively low level of biogenic amines) when good hygienic and manufacturing practices (temperature, humidity, air-flow, careful treatment) are respected.

Protection of Flax/PLLA Biocomposites from Seawater Ageing by External Layers of PLLA

Biocomposites are sensitive to water, and previous work on flax reinforced PLLA showed a large drop in mechanical properties after immersion (Le Duigou et al. 2009). Unreinforced PLLA was much less sensitive. This paper presents a strategy to reduce the influence of wet ageing by adding extra layers of PLLA on the biocomposite surface. Weight gain measurements show that a PLLA coating 350 m thick reduces weight gain by half, and biocomposite stiffness and strength after ageing are improved by 100% compared to uncoated composite behaviour. Thermal analysis and microscopic examination are used to show damage mechanisms with and without protection. Property changes are shown to be quasilinearly related to weight gain.