Robin Jacob

Dr. Robin Jacob


Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 March 2021 in Foods
Verified
Journal Article
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MCMaddison Corlett
Maddison Corlett
DPDavid W. Pethick
David W. Pethick
Khama R KelmanKhama R Kelman
Khama R Kelman
RJRobin Jacob
Robin Jacob
GGGraham E. Gardner
Graham E. Gardner
Lamb (n = 79) meat colour was scored by 879 untrained consumers using a scale of 0 (brown) to 100 (red). This consumer colour score (CCS) was obtained on m. longissimus lumborum (loin) and m. semimembranosus (topside), stored for short (5–7 days), medium (33–35 days), and long periods (110–112 days) and a retail display time of up to 4 days. Consumers perceived topside to be less red initially and changed from red to brown more rapidly when stored for the long-storage period (p < 0.01). Whereas, the initial CCS of loin samples were similar across the storage periods (p > 0.05). CCS and the instrument measure oxy/met (reflectance of light at wavelengths 630 nm and 580 nm) had a low correlation coefficient of 0.33 (p < 0.01). The propensity for lamb growth and leanness indicated by sire breeding values for lamb weight, eye muscle depth, eye muscle fat depth, and loin intramuscular fat had varied and inconsistent effects on CCS. Therefore, even the selection on CCS.

1 April 2020 in Meat Science
Verified
Journal Article
Closed access
RJRobin Jacob
Robin Jacob

20 January 2009 in Animal Production Science
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Journal Article
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RJRobin Jacob
Robin Jacob
GGG. E. Gardner
G. E. Gardner
DPD. W. Pethick
D. W. Pethick
An experiment was conducted using 105 Merino hoggets to measure the change in tissue glycogen concentration over a 48-h period following an exercise regime. The exercise regime consisted of a 2-km run repeated four times with a 15-min break between each run. After exercise the hoggets were split into treatment groups and fed three different levels (fasting, maintenance and three times maintenance) of the same ration. A subset of each group of hoggets was killed at –24, 0, 12, 24 and 48 h from the time of exercise and samples taken from the liver, skin, rumen, duodenum, colon, kidney, M. semimembranosus, M. semitendinosus, M. longissimus thoracis et lumborum, M. psoas major, M. triceps brachii and M. subscapularis. Exercise caused a reduction in glycogen concentration in the liver and all muscles but not in the kidney, skin, duodenum, or colon tissues. After exercise the most significant changes in glycogen concentration were in the liver, muscle and skin. Metabolisable energy intake influenced the change in the liver and muscle tissue but not in the skin. It was concluded that glycogen concentration increased in liver before muscle and that this effect may contribute to the slower rate of glycogen concentration in muscle for ruminants compared with monogastric animals. Skin may also compete with muscle for glucose during the repletion phase in Merino sheep but the exact nature of this effect remains uncertain.

1 June 2017 in Journal of Animal Science
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Journal Article
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SMSuzanne Mortimer
Suzanne Mortimer
SHS. Hatcher
S. Hatcher
NFN. M. Fogarty
N. M. Fogarty
JWJulius Van der werf
Julius Van der werf
DBD. J. Brown
D. J. Brown
DPD. W. Pethick
D. W. Pethick
Genetic correlations between 29 wool production and quality traits and 14 whole carcass measures and carcass component traits were estimated from the Information Nucleus of 8 flocks managed across a range of Australian sheep production environments and genetically linked. Wool data were from over 5,000 Merino progeny born over 5 yr, whereas carcass data were from over 1,200 wether progeny of over 176 sires, slaughtered at about 21 kg carcass weight, on average. Wool traits included yearling and adult records for wool weight, fiber diameter, fiber diameter variation, staple strength, scoured color, and visual scores for breech and body wrinkle. Whole carcass measures included HCW, dressing percentage (DP), and various measures of fat depth and eye muscle dimensions. Carcass components were obtained by dissection, and lean meat yield (LMY) was predicted. Heritability estimates for whole carcass measures ranged from 0.12 ± 0.08 to 0.35 ± 0.10 and ranged from 0.17 ± 0.10 to 0.46 ± 0.10 for carcass dissection traits, with no evidence of important genotype × environment interactions. Genetic correlations indicated that selection for increased clean wool weight will result in reduced carcass fat (−0.17 to −0.34) and DP (−0.48 ± 0.15), with little effect on carcass muscle. Selection for lower fiber diameter will reduce HCW (−0.48 ± 0.15) as well as carcass fat (0.14 to 0.27) and muscle (0.21 to 0.50). There were high genetic correlations between live animal measures of fat and muscle depth and the carcass traits (generally greater than 0.5 in size). Selection to increase HCW (and DP) will result in sheep with fewer wrinkles on the body (−0.57 ± 0.10) and barer breeches (−0.74 ± 0.12, favorable), with minor deterioration in scoured wool color (reduced brightness and increased yellowness). Selection for reduced fat will also result in sheep with fewer body wrinkles (−0.42 to −0.79). Increasing LMY in Merinos through selection would result in a large reduction in carcass fat and DP (−0.66 to −0.84), with a smaller increase in carcass muscle and some increase in wool weight and wrinkles. Although no major antagonisms are apparent between the wool and carcass traits, developing selection indexes for dual-purpose wool and meat breeding objectives will require accurate estimates of genetic parameters to ensure that unfavorable relationships are suitably considered. The findings will aid development of dual-purpose wool and meat breeding objectives.

5 January 2021 in Foods
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Journal Article
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MHMelindee Hastie
Melindee Hastie
HAHollis Ashman
Hollis Ashman
DLDale Lyman
Dale Lyman
LLLeonie Lockstone-Binney
Leonie Lockstone-Binney
RJRobin Jacob
Robin Jacob
Robyn Dorothy WarnerRobyn Dorothy Warner
Robyn Dorothy Warner
The global sheepmeat industry aspires to increase consumer liking for cull ewe meat and thereby increase its value; dry ageing application can increase the consumer appeal of this meat. In order to develop novel consumer-liked dry aged sheepmeat products, an innovation process aligned with design thinking principles was initiated. The objective was to understand optimal dry aged sheepmeat product formats from chef, butcher, producer and consumer perspectives, and use these findings to develop “highly liked” and “premium” dry aged cull ewe meat dishes. The methodology used and the results of stakeholder engagement, perceptual mapping, and quantitative consumer assessments are reported. Stakeholder engagement showed the importance of how novel products are introduced to the consumer and to the chef. Perceptual mapping highlighted that chef-perceived product “premiumness” was driven by eating quality and complexity of the dish. Consumer assessment validated these findings with increases in dish liking associated with increased premiumness and complexity in dish presentation. Overall, the described approach was successful; eight highly liked dry aged cull ewe meat dishes were developed (all scored > 7.69 on a 9-point hedonic scale for liking), and four of the eight dishes were rated “at the level of a very premium food”.

23 June 2020 in Animal Production Science
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RJRobin Jacob
Robin Jacob
KRKatja Rosenvold
Katja Rosenvold
MNMichael North
Michael North
RKRobert Kemp
Robert Kemp
Robyn Dorothy WarnerRobyn Dorothy Warner
Robyn Dorothy Warner
Context: Very fast chilling (VFC) involves cooling meat to approximately –1°C before the onset of rigor, and offers potential benefits compared with conventional chilling that include accelerated tenderisation, improved shelf life and reduced inventory costs. However, the practical difficulties of achieving the required temperature profile prevents adoption of VFC commercially. Aims: The objective of this study was to determine if electrical stimulation could be a way of making VFC easier to achieve for lamb meat. The hypothesis tested was that electrical stimulation would reduce the rate of chilling required with very fast chilling by accelerating the rate of pH decline post-mortem. Methods: The experiment was a 2 × 3 factorial design whereby 54 loins from 27 lambs were allocated to one of six different treatments: no electrical stimulation and electrical stimulation, and chilling rates to reach −1°C at 1 h (Fast), 1.5 h (Moderate) and 2.5 h (Slow) post-mortem respectively. Key results: Without electrical stimulation, shear forces were lowest for the Moderate chilling rate; but with electrical stimulation, consistently low shear force values were obtained with all chilling rates. Muscle pH depended on treatment, although this effect also depended on the time post-mortem. Shear force depended on chilling rate only when there was no electrical stimulation. Without electrical stimulation, the optimal chilling rate was the Moderate treatment. Effects on sarcomere length accounted for some, but not all, of the effects of treatment on shear force. Conclusions: Electrical stimulation therefore reduced the chilling rate required to optimise tenderness with VFC, and could be a component of a practical VFC regime for lamb meat. Implications: VFC could become a practical chilling method, but only when sensory evaluation supports the favourable shear force findings established in this study. This would require evaluation of VFC at a commercial scale.