Effects of a compensatory growth strategy on sensory and physical properties of meat from young bulls

The objective of the present study was to investigate the sensory properties, with special emphasis on tenderness, of meat from strategically fed young bulls (13 months of age) slaughtered when a plateau in protein turnover was observed. Twelve Holstein Friesian young bulls were divided into two feeding strategies. One group of young bulls (n = 6) were fed ad libitum throughout the rearing period (AD) whereas the second group (n = 6) was subjected to a compensatory growth feeding strategy (CO). Sensory profiling of beef longissimus dorsi (LD), semimembranosus (SM) and supraspinatus (SS) was performed in addition to physical measurements (shear force) and content of intramuscular fat of LD. The data was analysed using a regression-based multivariate data analytical strategy. In relation to predictivity of the various shear force measurement constituents for sensory texture, it was determined that a number of the responses collected (e.g. max_mm), in addition to the commonly used max_(N) may be utilised to predict subtlety in the sensory texture differences of the samples (e.g. Crumbliness) with respect to compensatory feeding. Through profiling LD and SS were found to have enhanced texture and flavour properties when the young bulls were fed ad libitum during rearing. However, the SM samples were found to improve in characteristics regarding texture and appearance when the young bulls had been fed compensatorily. Thus, compensatory feeding as a texture improvement strategy proved to be highly dependant on muscle type. Of note, LD and SS were found to develop an off-flavour designated as ‘steer taint’ when derived from compensatory feeding. This was postulated as potentially not a problem for the consumer, in LD as the level was not significant, and in SS due to sensory masking when commonly prepared as a stew or casserole. Considering the different preparation methods used for meat from LD, SM and SS, compensatory feeding may be considered to have improved the texture and elevated the eating quality where it was most relevant, namely in SM roasts.     

Preference mapping of salmon–sauce combinations: The influence of temporal properties

Food–food combinations are complex stimuli where the dynamic nature of sensory interactions plays an important role for perception and acceptance. The aim of this study was to investigate if TDS provides additional insight about drivers of liking compared to DA in a preference mapping context. A trained sensory panel performed DA and TDS on six different samples (combinations of salmon and culinary sauces), and sixty-one consumers rated acceptance for the same samples. In addition to TDS SCORES, this study introduces the use of extracted parameters based on dominance information from TDS; the area of dominance based on the integrated area under the dominance curves and the number of dominant sensations and blends within a specified time period. Results from preference mappings showed that the TDS approaches generally provided similar but less detailed information regarding drivers of liking and disliking compared to DA. Moreover, with the use of the extracted TDS parameters, it was possible to identify the time of dominance of certain attributes and the number of perceived sensations and blends in specific time periods as potential drivers of liking and disliking. The results also showed that TDS has a potential to provide complementary information about the dynamic nature of sensory interactions in food–food combinations compared to DA.     

Separation of angiotensin I‐converting enzyme inhibitory peptides from bovine connective tissue and their stability towards temperature,pH and digestive enzymes

Bovine collagen was isolated from connective tissue, a by‐product in the meat processing industry and characterised by SDS‐PAGE. Alcalase and papain were employed to generate collagen hydrolysates with different degree of hydrolysis (DH). In vitro angiotensin I‐converting enzyme (ACE) inhibitory activities were evaluated and the two most potent hydrolysates from each enzyme were separated by two‐step purification. Both alcalase‐catalysed and papain‐catalysed hydrolysates exhibited strong ACE inhibitory capacities with IC₅₀ values of 0.17 and 0.35 mg mL^?1, respectively. Purification by ion‐exchange chromatography and gel filtration chromatography revealed higher ACE inhibitory activities in one fraction from each enzyme with IC₅₀ values of 3.95 and 7.29 μg mL^?1. These peptide fractions were characterised as 6‐12 amino acid residues by MALDI‐TOF/MS. The peptides retained their activity (>90%) after exposure to processing temperature and pH and in vitro simulated gastrointestinal digestion. The present results demonstrated that collagen peptides can be utilised for developing high value‐added ingredients, for example ACE inhibitory peptides.     

Effect of gender on meat quality in lamb from extensive and intensive grazing systems when slaughtered at the end of the growing season

In Norway, most lambs are slaughtered at the end of the grazing season in September. An increased demand for fresh meat during the off-season may change this pattern. Castration of male lambs is not permitted, and off-season slaughtering may affect the acceptability of the meat. The objective of this study was to determine the effect of gender and the interaction between gender and diet on meat quality from Norwegian White Sheep lambs slaughtered in September. In two different experiments, 22 and 29 males compared with 22 and 46 female lambs, respectively, were used. Loin samples of M. Longissimus dorsi were analysed for sensory profile and fatty acid composition. Meat from male lambs in Experiment 2 had higher scores for cloying and rancid flavour, and lower scores for sour and sweet taste compared to meat from female lambs. It is concluded that even at the normal slaughtering time in September, significant differences between genders may occur.     

通过地质导向提高产量

为了延长老油田的寿命,油气公司需要将通常很难勘探和开采的储量作为开发目标。新的定向深探测随钻测井技术有助于地学专家实时确定高阻层边界和流体接触面的位置。采用这些信息优化井眼轨迹,使作业者能够通过提高产量、减少侧钻以及减少井眼失稳问题来获得更大的经济效益。     

Building safety and human behaviour in fire: A literature review

The most crucial aspect of a building's safety in the face of fire is the possibility of safe escape. An important precondition is that its fire safety facilities enable independent and adequate fire response performances by the building's occupants. In practice, it appears that the measures currently required by law do not always provide the support that people in burning buildings need. Consequently, understanding how individuals behave in the case of fire and fire evacuation is essential if we are to bring fire safety measures into line with occupants’ needs during an incident. This paper contains a review of the available literature on human behaviour in a fire so far as building safety is concerned. The findings are presented as an overview of the critical factors which determine occupants’ fire response performances, namely the characteristics of fire, human beings and buildings. The study highlights that some of the assumptions about the existing paradigm of fire safety in buildings are not consistent with the knowledge set out in the literature. The key observation is that psychonomics appear to have significant influence on occupants’ fire response performances. Accordingly, the traditional approach to fire safety will have to be supplemented by scientific knowledge from this field. Hence, there is a need for a new approach to fire safety design in buildings, which is set out herein.     

User involvement in system design: An empirical test of alternative approaches

User involvement in the development of information systems is often assumed to be key to successful implementation. However, few empirical studies have clearly demonstrated a relationship between user involvement and two key indicators of system success: system usage and user information satisfaction. The authors test the general hypothesis that user involvement is a more complex concept than previous research would indicate; there are different types of involvement and different stages in the system development life cycle in which users may become involved. In a study of 83 users in 23 companies, they found that only the activity of user sign-offs on project phases had a significant correlation with both user information satisfaction and satisfaction with the information systems group. The authors conclude that there is a complex relationship between the type and degree of user involvement and other organizational and individual factors; this relationship affects both user satisfaction with and usage of the resulting systems. Some suggestions for further research taking this complexity into account are given.     

Role of the physico-chemical factors in the purification process of water from surface-active matter by biosorption

Activated carbon adsorption with attached microorganisms (biosorption) has been studied. The approaches available do not account for an efficient role of activated carbon under a steady state of purification, considering it (carbon) as a carrier of biofilm only. This paper considers the role of physico-chemical factors in order to clear up and assess a contribution of both physical adsorption and biodegradation (influencing effectiveness of the biosorption process) into the cumulative effect of the biosorption. The nonionic and anionic surfactants as well as phenol were used as sorbates. The impact of such essential physico-chemical factors of the adsorption process as the change in the Gibbs free energy (−ΔG_a⁰) and the porous structure of the activated carbon on the effectiveness of the biosorption process has been established. The lower the contribution of the biological degradation into the biosorption process, the higher the −ΔG_a⁰. As a result of the biodegradation process, products differing in their −ΔG_a⁰ are generated on the active carbon. Separation of the biodegradation products characterized by different −ΔG_a⁰ in the biosorption column filled by active carbon results in redistribution of contributions of physical adsorption and biodegradation into a cumulative effect. The micropores of the active carbon in the course of the biosorption/bioregeneration process are occupied by adsorbed molecules and are not subjected to biological regeneration.     

Some physico-chemical properties of nine commercial or semi-commercial whey protein concentrates, isolates and fractions

Summary The physico-chemical properties are reported for a group of whey protein powders prepared on a commercial or semi-commercial scale by three companies and chemically characterized as described elsewhere (Holt et al ., 1999). The dependence of the apparent β-lactoglobulin % on the recovered % showed that the nine samples could be placed in three distinct groups with β-lactoglobulin weight % of 70.9 ± 1.1 (Group 1), 62.0 ± 3.4 (Group 2) and 39.5 ± 4.9 (Group 3). Measurements by ¹H-NMR spectroscopy, on 3 of the samples confirmed that the native fold still predominated in the β-lactoglobulin. β-lactoglobulin could be crystallized from all the powders and the normal space group and cell dimensions were determined for the 8 samples that gave crystals of good enough quality for X-ray studies. Differential scanning microcalorimetry of samples dispersed in a phosphate buffer showed a clear difference between Goups 1 and 2 with a more prominent peak due to α-lactalbumin in the Group 2 samples. Light scattering and size exclusion chromatography showed that two types of aggregates were present to a variable extent in all the samples and after a heat treatment, the larger aggregates tended to predominate in Group 2. The rheology measurements, also made in the phosphate buffer, showed a difference of gel stiffness during heat treatment between the Group 1 and Group 2 samples with the exception of the BORCwpc+ sample. Within each group, gel stiffness increased with the degree of lactoslylation of the β-lactoglobulin. Interfacial measurements on samples dispersed in water presented a more complex pattern of behaviour although surface tension measurements at the air water interface of the Group 2 samples showed a two-step pattern of surface tension decrease with time, compared to a single step pattern in the Group 1 samples.