• Food Science of Animal Resources
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• v.38 no.5
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• pp.959-969
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• 2018

This study investigated the effects of deep freezing and storage temperature ($-50^{\circ}C$, $-60^{\circ}C$, and $-80^{\circ}C$) on the quality and freshness of lamb. To compare the qualities of deep frozen and stored lamb, fresh control and normal freezing conditions ($-18^{\circ}C$) were adopted. As quality and freshness parameters, drip loss (thawing loss and cooking loss), water-holding capacity (WHC), texture profile analysis (TPA), thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVBN) were evaluated during 5 months of storage. Temperature influenced the drip loss and WHC, and deep freezing minimized the moisture loss during frozen storage compared to the normal freezing condition. Lamb frozen and stored at deep freezing temperature showed better tenderness than that stored in normal freezing conditions. In particular, lamb frozen at lower than $-60^{\circ}C$ exhibited fresh lamb-like tenderness. Regardless of temperature, evidence of lipid oxidation was not found in any frozen lamb after 5 months, while TVBN was dependent on the applied temperature. Therefore, this study demonstrated that deep freezing could potentially be used to maintain freshness of lamb for 5 months. From the quality and economic aspects, the freezing and storage condition of $-60^{\circ}C$ is estimated as the optimum condition for frozen lamb.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.3
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• pp.224-230
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• 2007

This work is aimed to explore a possibility of using the generalized Lamb waves for nondestructive evaluation of the bonding quality of layered substrates. For this purpose, we prepared two sets of specimens with imperfect bonding at their interfaces; 1) TiN-coated specimens with various wear conditions, and 2) CVD diamond specimens with various cleaning conditions. A dispersion simulation performed for layered substrates with imperfect interfaces are carried out to get the characteristics of dispersion curves that can be used for bonding quality evaluation. Then the characteristics of dispersion curves of the fabricated specimens are experimentally determined by use of an ultrasonic backward radiation measurement technique. The results obtained in the present study show that the lowest velocity mode (Rayleigh-like) of the generalized Lamb waves are sensitively affected by the bonding quality. Therefore, the generalized Lamb waves can be applied for nondestructive evaluation of imperfect bonding quality in various layered substrates.

• Food Science of Animal Resources
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• v.41 no.5
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• pp.802-815
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• 2021

To investigate the effect of postmortem phases on lamb meat quality, the physicochemical quality, microstructure and water mobility of oyster cut, short loin, knuckle and silverside muscles from Small-Tail Han sheep were evaluated in the pre-rigor, rigor mortis and post-rigor phases. Pre-rigor lamb meat had higher pH and water holding capacity (WHC), whereas lower CIE L^*, b^*, hue angle values than rigor mortis and post-rigor meat (p<0.05). The Warner-Bratzler shear force (WBSF) values were higher in rigor mortis short loin and silverside than their pre-rigor and post-rigor counterparts, pre-rigor short loin had lower WBSF value than its post-rigor counterpart (p<0.05). Muscle fibers shrank laterally and longitudinally during the onset of rigor mortis. Rigor mortis and postrigor lamb meat exhibited wide I-bands, dark A-bands, short sarcomeres and large inter-myofibrillar spaces. The shift of immobilized water to free water and repulsion from the intra-myofibrillar space to the extracellular space result in the increase of water loss in rigor mortis and post-rigor lamb meat. The results of the principal component analysis (PCA) indicated that rigor mortis and post-rigor lamb meat had similar quality properties but different from pre-rigor lamb meat. In conclusion, the lamb meat in the pre-rigor phase had good tenderness, color and WHC. The results of this research could provide some theoretical references for lamb meat production and processing.

• Journal of Nutrition and Health
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• v.24 no.1
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• pp.20-29
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• 1991

This study was carried out to compare the protein quality of lamb and beef meat. by feeding to growing rats. Sixty weanling rats, 30 males and 30 females, were blocked into 12 groups(6 gruops of males and 6 groups of females). They were fed casein. beef, or lamb as a protein source at two levels, 6 and 15%, for 5 weeks. The amount of food intake. food efficiency ratio, protein efficiency ratio. body weight gain. and the weights of skeletal muscles and liver were measured. Nitrogen retention, protein content in the liver and skeletal muscles, and the levels of protein and cholesterol in the serum were also assayed. Summarzing the results, there were no significant differences between lamb and beef on the growth and nitrogen utilization in the rats fed same percentage of protein diet. However. rats fed 15% protein diet showed significantly higher growth rate than those fed 6%. Therefore, it can be concluded that lamb is as good a protein food as beef in terms of protein quality.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.292-299
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• 2000

Forty-four Javanese thin-tail ewes were used to study the effect of superovulation prior to mating and of ration quality on lamb birth weight at parturition. Twenty-two ewes weaning at least one lamb were used to measure lamb preweaning growth. Prior to mating, the experimental ewes were injected twice with prostaglandin, with an 11 d interval between injections to synchronize the estrous cycle. At the last prostaglandin injection, 24 ewes were also injected with 700 IU of pregnant mare serum gonadotropin (PMSG) to stimulate superovulation and the remainder were injected with saline as control. During pregnancy and lactation, the experimental ewes were fed either on a low (12% CP and 65% TDN) or a high (15% CP and 75% TDN) quality ration. During lactation, the milk was collected twice a day and was refed to the lambs by bottle feeding immediately after collection. Superovulation or ration quality as a main factor did not significantly affect lamb birth weight. Litter size significantly affected lamb birth weight (p<0.05), and there was an interaction of superovulation and litter size. Nonsuperovulated ewes giving birth to multiple lambs had significantly lower average lamb birth weight (1.34 kg) as compared to those giving birth to a single lamb (1.97 kg) (p<0.05). However, superovulated ewes giving birth to multiple lambs had no significant difference in average lamb birth weight (1.68 kg) as compared to those giving birth to a single lamb (1.91 kg) (p>0.05). Superovulation of ewes prior to mating resulted in a significant improvement in lamb birth weight in the multiple litter size, without significant effect on average preweaning daily gain (p=0.07). Superovulation had a promising use in improving animal production through improvement of prenatal growth during pregnancy and milk production during lactation.

• Animal Bioscience
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• v.36 no.6
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• pp.840-850
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• 2023

Objective: This study aimed to investigate the polymorphisms of the dopa decarboxylase (DDC) gene and association analysis with lamb quality and expression quantification of the DDC gene in phenotypically divergent Indonesian sheep. Methods: The totals of 189 rams with an average body weight of 24.12 kg at 10 to 12 months were used to identify DDC gene polymorphism using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Among 189 rams, several rams representing various sheep genotypes were used for an association study between genotypes and phenotypic traits with proc general linear model (GLM) analysis. In addition, the gene expression analysis of the DDC mRNA in the phenotypically divergent sheep population was analyzed using quantitative reverse-transcription PCR. Results: The DDC gene (g. 5377439 G>A) showed polymorphisms that indicated three genotypes: AA, AG, and GG. The DDC gene polymorphism was significantly associated (p≤0.05) with carcass characteristics including carcass percentage, carcass length, hot and cold carcass; physical properties of lamb quality including pH value; retail cut carcass; fatty acid composition such as fat content, pentadecanoic acid (C15:0), tricosylic acid (C23:0), lignoceric acid (C24:0), oleic acid (C18:1n9c), elaidic acid (C18:1n9t), nervonic acid (C24:1), linoleic acid (C18:2n6c), arachidonic acid (C20:4n6), cervonic acid (C22:6n3); and mineral content including potassium (K). The GG genotype of the DDC gene had the best association with lamb quality traits. The DDC gene expression analysis mRNA showed no significant difference (p≥0.05) between lamb quality traits. Conclusion: The DDC gene could be used as a potential candidate gene to improve lamb quality.

• Food Science of Animal Resources
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• v.42 no.5
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• pp.816-832
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• 2022

To evaluate the effects of early postmortem vacuum packaging (VP) on meat quality during postmortem chilled storage, hot-boned lamb was vacuum-packaged at 1, 6, 12, 24, and 48 h postmortem and stored around 2℃ until 168 h postmortem, with lamb packaged in plastic wrap as the control (aerobic packaging). Intramuscular pH decline was delayed when lamb was vacuum packaged at 1, 6, and 12 h postmortem (p<0.05). The lamb vacuum-packaged at 1 h postmortem (VP-1h group) had significantly lower shear force values and purge losses accompanied by lower free thiol group values than other treatments during postmortem storage and was also higher in extractable calpain-1 activity by 6 h postmortem (p<0.05). Free thiol group concentrations were significantly higher after VP at 6 and 12 h postmortem (p<0.05). Packaging lamb under vacuum very early postmortem produced the lowest shear force and purge loss, likely by slowing heat loss and muscle temperature decline, implying that lamb quality is improved by VP when applied very early postmortem. This was at the expense of protein oxidation, which was unrelated to other meat quality measurements, most likely because potential contracture during hot boning confounded its impact. Further research is required to understand the implications of the interaction between protein oxidation, VP, and hot boning on the acceptability of lamb.

• Food Science of Animal Resources
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• v.38 no.4
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• pp.653-663
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• 2018

Lamb has long been considered a traditional meal within Australia; however as consumer preferences have changed since the 1950's, consumption of lamb has decreased from the 1980's. This is the result of changing societal roles, particularly for females, decreasing household sizes and increasing awareness of the impact of food choices on human health. Since the 1980's improvement of farm practices and increases in genetic gains has addressed part of this decline by increasing the amount of lean meat and decreasing fat in lamb retail cuts. Yet, this has created a challenge for the industry to utilise the larger carcases now being produced. Thus, a whole value chain approach to increasing consumption has been undertaken through several research programs to create cuts which suit the modern consumer, examine nutritional and eating quality and increase adoption of value added cuts. Therefore, this paper outlines this history of changing consumer patterns and the consequent research to address these changes.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.1128-1149
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• 2023

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.

• Proceedings of the Korean Reliability Society Conference
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• 2002.06a
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• pp.227-233
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• 2002

Suspension system is one of the most important components indespensible for stability and reliability of automobiles. The demands to more safe and durable suspension system have been increased as the automobiles get popular and improve in quality. The crack in the coil spring of the suspension system produced during manufacturing may grow under a fatigue load and cause a severe safety problems which lead to a catastrophic damage to the passengers. Many conventional NDT techniques including ET, RT, and UT are less sensitive or hard to apply to detect the surface breaking crack in the suspension coils partly because the techniques are point-to-point measurement methods, thus take too long time to inspect the coil spring longer than 1m. Contrary to this, Lamb wave technique is full-field measurement method that make it possible to examine the whole coil spring in real time. In this paper, the Lamb wave is applied to the coil spring to investigate the possibility to detect the cracks on the surface of the coil spring.