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Papers by Grainne Redmond

The overall objective was to devise a rapid chilling system for the Irish lamb processing industr... more The overall objective was to devise a rapid chilling system for the Irish lamb processing industry. The objective of the first trial was to assess the effect of ultra-rapid chilling in air at-4ºC,-10ºC and-20ºC and subsequent ageing on the appearance and tenderness of lamb carcasses. Chilling at-20ºC gave less evaporative weight loss than chilling at other subzero temperatures and conventional chilling at +4ºC. This was achieved without causing adverse effects on carcass quality or meat tenderness. Ageing improved the tenderness of ultra-rapidly chilled lamb and had little effect on the visual appearance of the carcasses. 14 1 The payback period is the length of time it takes for the costs of the system to be recouped from the benefits accrued as a result of adopting the system. 2 These prices are projected by the FAPRI-Ireland partnership and are expected to fall.

2002 Chicago, IL July 28-31, 2002, 2002

... Further investigation on the ultra-rapid chilling of lamb carcasses. J. Muscle Foods, 10: 1-1... more ... Further investigation on the ultra-rapid chilling of lamb carcasses. J. Muscle Foods, 10: 1-16. O'Halloran, GR, Troy, DDJ Buckley. 1997. The relationship between early postmortem pH and the tenderisation of beef muscles. Meat Sci. 45: 239–251. O'Neill, E. 2001. ...

Journal of Muscle Foods, Jul 1, 2001

The eflect on tenderness of splitting lamb carcasses longitudinally under veryrapid chilling cond... more The eflect on tenderness of splitting lamb carcasses longitudinally under veryrapid chilling conditions was investigated. Whole (unsplit) and split carcasses were chilled in very-rapid chilling conditions (-20C for 3.5 h followed by chilling at 4C for 20.5 h) and conventional chilling conditions (4C f o r 24 h), giving a total offour treatments. Loin (M. longissimus thoracis et lumborum) shear force was measured at f and S days postmortem by Warner-Bratiler shear force measurement. By S days postmortem, split carcasses were not di#erent (P>O.O5) in shear force to unsplit carcasses when conventionally chilled but differences (P<O. 05) were present between unsplit and split carcasses when very-rapidly chilled (57.7 N vs 41.5 N, respectively).

Journal of Muscle Foods, Jul 1, 2000

The effects of diferent chilling rates on the visual attributes of lamb carcasses and the tendern... more The effects of diferent chilling rates on the visual attributes of lamb carcasses and the tenderness of lamb chops were investigated. Carcasses (n=72) were chilled at-2OC,-lOC,-4C or +4C. After chilling all carcasses were stored at +4C for up to 8 days. Samples were taken at 2, 6 and 9 days postmortem for sarcomere length, Warner-Bratzler shear force and sensory analysis. Carcasses were visually appraised at 2, 6 and 9 days postmortem f o r fat color, frank color, visible vein color, wetness and overall acceptability. Carcasses chilled at-2OC had signlficantly higher Warner-Bratzler shear force values than the other chilling treatments at 2 and 6 days but not at 9 days postmortem. No difference (P> 0.05) was found in Warner-Bratzler shear force or sensory tenderness between any of the treatments by 9 days postmortem. Carcasses did not differ (P>O.O5) in fat color, frank color or overall acceptability at any stage postmortem. Carcasses chilled at-2OC had slightly darker (P< 0.05) vein color at 2 days postmortem but this was not evident by 6 days postmortem. Carcasses that were chilled at-2OC had significantly lower evaporative weight losses than carcasses in any of the other treatments. Rapid chilling did not adversely afect the tenderness of lamb chops or appearance of lamb carcasses at 9 days postmortem compared with conventional chilling.

Food Control, Dec 1, 2010

A stochastic consumer-phase exposure assessment modelling the transport and refrigeration modules... more A stochastic consumer-phase exposure assessment modelling the transport and refrigeration modules indicated that the concentration of Salmonella typhimurium in contaminated Irish pork sausages prior to cooking was on average 1.79 log CFU/g (95% CI: 1.22e2.42 log CFU/g); and that, out of 100 000 refrigerated sausage packs, an average of w83 packs (95% CI: 73e96) would have hazardous mean Salmonella concentrations above 3 log CFU/g prior to cooking (Freq(Y > 3)). Scenario analysis revealed that a decrease in the refrigeration temperature by 2 C and a decrease of the initial prevalence of S. typhimurium by half (w0.02) would have a comparable level of reduction in Freq(Y > 3) (w23e43 packs per 100 000 packs), while a decrease in the storage time by half would have by far the highest level of reduction (Freq(Y > 3) ¼ w2e7 packs per 100 000 packs). Finally, a practical method for the simulation of the product's temperature profile in cold storage has been proposed based on the application of heat transfer equations and actual product's temperature history data.

Meat Science, Nov 1, 2001

The effect of ultra-rapid chilling (-20°C) on the proteolytic degradation of myofibrillar protein... more The effect of ultra-rapid chilling (-20°C) on the proteolytic degradation of myofibrillar proteins during ageing, by the calpain/calpastatin system in lamb was investigated. Carcasses (36) were ultra-rapidly chilled (-20°C for 3.5 h followed by 20.5 h at +4°C) or chilling at +4°C for 24 h. After chilling all carcasses were stored at +4°C for a further 4 days. Samples of M. longissimus thoracis et lumborum were taken for Warner-Bratzler shear force measurement, sarcomere length, SDS-PAGE and enzyme activity analysis. Ultra-rapid chilling (-20°C) had no effect on the proteolytic degradation of myofibrillar proteins by the calpain/calpastatin system compared to conventional chilling (+4°C). However, no difference in tenderness was found between the two chilling regimes at 1 or 5 days postmortem so differences in myofibrillar degradation or enzyme activity would not be expected.

Journal of Food Engineering, Feb 1, 2003

Both freeze-chilling and chilling reduce the vitamin C content of mashed potato in comparison wit... more Both freeze-chilling and chilling reduce the vitamin C content of mashed potato in comparison with freezing. The current trial investigated the potential of encapsulated vitamin C (EVC) for boosting the vitamin C content of mashed potato. Preliminary trials with EVC in aqueous solution indicated that the vitamin C was not released from the capsules until the temperature reached %67°C, i.e. the melting point of the encapsulating fat. Samples of cooled mashed potato (cultivar Rooster) were supplemented with EVC and were subjected to four process treatments, i.e. fresh, chilling, freeze-chilling and freezing. Parallel tests were conducted with ordinary vitamin C (OVC) and with no vitamin C (NVC) (i.e. control samples). The vitamin C content of the reheated samples with added EVC from the four process treatments was 24.4 mg/100 g (fresh), 16.4 (chill), 14.3 (freeze-chill), 22.4 (freeze). Corresponding contents using OVC were 25.3, 2.4, 2.8, and 19.1 mg/100 g and NVC were 2.0, 1.5, 0.5 and 0.8 mg/100 g respectively. These data show that EVC has potential for boosting the vitamin C content of both freeze-chilled and chilled mashed potato.

Innovative Food Science and Emerging Technologies, Mar 1, 2003

Freeze-chilling of food involves freezing and frozen storage followed by thawing and chilled stor... more Freeze-chilling of food involves freezing and frozen storage followed by thawing and chilled storage. In this study, the effect of freeze-chilling on the quality of cooked green beans and carrots was examined, as was the effect of long and short-term frozen storage prior to thawing. Three process treatments were used in the short-term trial; chill, freeze-chill and freeze and the products were tested for firmness, colour, centrifugal drip loss, total viable count (TVC) and taste panel acceptability. Results showed that freeze-chilling and freezing led to softer cooked carrots (P-0.001) than chilling. However, freeze-chilling and freezing had no effect on the texture of cooked green beans (P)0.05) but led to significantly higher drip losses than chilling (P-0.001). Freezechilling and chilling led to paler green beans but this was not reflected in the taste panel acceptability scores. No difference in TVC was found between any of the process treatments for cooked carrots or green beans. In general, frozen storage (y25 8C) for up to 12 months had no effect on firmness, drip loss, colour, total viable count or sensory acceptability of freeze-chilled cooked carrots and green beans compared to freezing.

Food Research International, Mar 1, 2012

A second-order simulation model was built to estimate the risk of Salmonella Typhimurium associat... more A second-order simulation model was built to estimate the risk of Salmonella Typhimurium associated with the consumption of Irish fresh pork sausages. To select appropriate hazard characterization models, an initial appraisal of the current dose-response models was conducted. The cooking modality of grilling was associated with a higher mean risk of infection per serving (1.399 × 10 − 6 ; 95% CI: 7.54 × 10 − 7-2.65 × 10 − 6) than frying (6.246 × 10 − 7 , 95% CI: 2.78 × 10 − 7-1.17 × 10 − 6). When the risk was extrapolated over the consumption in a year period, the mean risk of infection increased considerably to 8.541 × 10 − 5 with an expected number of infections and illnesses of 184.3 (95% CI: 26-664) and 17 (95% CI: 2-63), respectively. Results highlighted the importance of consumer education, as scenario analysis predicted that, for the current level of Salmonella in pork sausage, decreasing the product's cold storage by approximately 8 h and cooking for an additional half minute can reduce the current risk level by ∼ 50%.

Journal of Food Protection, Aug 1, 2010

Prevalence and counts of Salmonella Typhimurium in fresh pork sausage packs at the point of retai... more Prevalence and counts of Salmonella Typhimurium in fresh pork sausage packs at the point of retail were modeled by using Irish and United Kingdom retail surveys' data. A methodology for modeling a second-order distribution for the initial Salmonella concentration (l 0) in pork sausage at retail was presented considering the uncertainty originated from the mostprobable-number (MPN) serial dilutions. A conditional probability of observing the tube counts given true Salmonella concentration in a contaminated pack was built from the MPN triplets of every sausage tested. A posterior distribution was then modeled under the assumption that the counts from each of the portions of sausage mix stuffed into casings (and subsequently packed) are Poisson distributed. In order to model the variability of l 0 among contaminated sausage packs, MPN uncertainties were propagated to a predefined lognormal distribution. Because the sausage samples from the Irish survey were frozen prior to MPN analysis (which is expected to cause reduction in viable cells), the resulting distribution for l 0 appeared greatly underestimated (mean: 0.514 CFU/g; 95% confidence interval [CI]: 0.02 to 2.74 CFU/g). The l 0 distribution produced with the United Kingdom survey data (mean: 69.7 CFU/g; 95% CI: 15 to 200 CFU/g) was, however, more conservative, and is to be used along with the fitted distribution for prevalence of Salmonella Typhimurium in pork sausage packs in Ireland (gamma[37.997, 0.0013]; mean: 0.046; 95% CI: 0.032 to 0.064) as the main inputs of a stochastic consumer-phase exposure assessment model.

2002 Chicago, IL July 28-31, 2002, 2002

The authors are solely responsible for the content of this technical presentation. The technical ... more The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agriculh.ual Engineers (ASAE), and its printing and distribution does not constitute an endorsement of views which may be expressed. Technical presentations are not subject to the formal peer review process by ASAE editorial committees; therefore, they are not to be presented as refereed publications. Citation of this work should state that it is from an ASAE meeting paper. EXAMPLE: Author's Last Name, lnitiaJs. 2002. Trtle of Presentation. ASAE Meeting Paper No. 02xxxx. St. Joseph, Mfch.: ASAE. For information about securing permission to reprint or reproduce a technical presentation. please contact ASAE

Journal of Muscle Foods, Jul 1, 2001

The effect of chilling rate and muscle excision on the shear force of ovine muscle (M. longissimu... more The effect of chilling rate and muscle excision on the shear force of ovine muscle (M. longissimus thoracis et lumborum) was examined. Conventional chilling involved chilling at 4C for 24 h and very-rapid chilling involved chilling at-2OC for 3.5 h followed by conventional chilling for 20.5 h. After 24 h all muscles were aged for a further four days. Approximately 30 min a f e r slaughter, one M. longissimus thoracis et lumborum was excised from each carcass and placed in the same chill as the remainder of the carcass. This gave a total of four different treatments. Shear force was assessed at I and 5 days postmortem by Warner-Bratzler shear force measurement. Excision led to reduced shear force in the very-rapid chilling regime but increased shear force in the conventionally chilled muscles. Aging improved shear force for all chilling treatments. No significant difference was found in the rate of pH fall, between the chilling treatments.

End of Project ReportFreeze-chilling of food consists of freezing and frozen storage followed by ... more End of Project ReportFreeze-chilling of food consists of freezing and frozen storage followed by thawing and then retailing at chill storage temperatures. It offers logistic, transportation and storage advantages to food manufacturers. Freeze-chilling has particular application to ready-meals and their components. Mashed potato (three cultivars), steamed carrots, steamed green beans and beef lasagne were found suitable for freeze-chilling and their quality and sensory properties compared favourably with their frozen, chilled and fresh counterparts. Modified atmosphere packaging was combined with freeze-chilling but it had little impact on shelflife extension for the product range with the outcome similar to that for samples packed in air. Tests on the freeze-chilling of white sauces showed the importance of using freeze-thaw stable starches. Best-practice thawing procedures were established and the importance of stacking configurations for outer boxes (each with a number of lasagne ready-meals) was highlighted in the case of the commercial tempering unit. Trials on the re-freezing of freeze-chilled products indicated that re-freezing is an option provided the normal storage protocols for frozen and chilled foods are observed.Food Institutional Research Measure (FIRM), Department of Agriculture and Food, Irelan

2002 Chicago, IL July 28-31, 2002, 2002

... Further investigation on the ultra-rapid chilling of lamb carcasses. J. Muscle Foods, 10: 1-1... more ... Further investigation on the ultra-rapid chilling of lamb carcasses. J. Muscle Foods, 10: 1-16. O'Halloran, GR, Troy, DDJ Buckley. 1997. The relationship between early postmortem pH and the tenderisation of beef muscles. Meat Sci. 45: 239–251. O'Neill, E. 2001. ...

Meat Science, 2001

The effect of ultra-rapid chilling (-20°C) on the proteolytic degradation of myofibrillar protein... more The effect of ultra-rapid chilling (-20°C) on the proteolytic degradation of myofibrillar proteins during ageing, by the calpain/calpastatin system in lamb was investigated. Carcasses (36) were ultra-rapidly chilled (-20°C for 3.5 h followed by 20.5 h at +4°C) or chilling at +4°C for 24 h. After chilling all carcasses were stored at +4°C for a further 4 days. Samples of M. longissimus thoracis et lumborum were taken for Warner-Bratzler shear force measurement, sarcomere length, SDS-PAGE and enzyme activity analysis. Ultra-rapid chilling (-20°C) had no effect on the proteolytic degradation of myofibrillar proteins by the calpain/calpastatin system compared to conventional chilling (+4°C). However, no difference in tenderness was found between the two chilling regimes at 1 or 5 days postmortem so differences in myofibrillar degradation or enzyme activity would not be expected.

LWT - Food Science and Technology, 2005

The effect of long-and short-term frozen storage prior to thawing, on the quality of freeze-chill... more The effect of long-and short-term frozen storage prior to thawing, on the quality of freeze-chilled, commercially made lasagnes was examined as was the effect of modified atmosphere packaging (MAP). In the short-term trial, four process treatments were used; fresh, chilled, freeze-chilled and frozen. In the long-term trial, the lasagnes were frozen for 3, 6, 9 or 12 months, thawed and tested, or were thawed and then chilled at 4 C for 6 days (freeze-chilled). In the MAP trial, the lasagnes were subjected to either the freezechill treatment or freeze treatment, and before freezing were packed in either (i) air, (ii) 40% CO 2 /60% N 2 or (iii) 40% CO 2 /30% N 2 / 30% O 2. In the short-term trial frozen and freeze-chilled lasagne had significantly higher drip loss than fresh or chilled before reheating, but this was not evident after heating. Similarly, freeze-chilled lasagne had a brighter colour (L/b) than chilled before heating, but again this was not evident after heating. No difference was found in firmness or sensory acceptability of lasagne from the different treatments. Freeze-chilled and frozen lasagne had higher total viable counts (TVC) than chilled or fresh. Packing in CO 2 /N 2 /O 2 (40:30:30) led to a darker unheated lasagne than packing in CO 2 /N 2 (40:60) or air, but this was not evident for heated lasagne. Packing in CO 2 /N 2 (40:60) led to a firmer product than packing in air for the frozen lasagne but not for freeze-chilled lasagne. Atmosphere had no effect on TVC or drip loss values. Lasagnes stored frozen for 12 months were firmer than those stored for 3, 6, or 9 months. Storing frozen for 9 or 12 months also led to higher drip loss values than storing for 3 months for unheated lasagnes but when heated, the opposite effect was seen. Lasagnes stored for 3 months had the highest L/b (white/yellow ratio) values while those stored for 12 months had the lowest. Length of time in frozen storage had no influence on TVC values.

Journal of Muscle Foods, 2001

The eflect on tenderness of splitting lamb carcasses longitudinally under veryrapid chilling cond... more The eflect on tenderness of splitting lamb carcasses longitudinally under veryrapid chilling conditions was investigated. Whole (unsplit) and split carcasses were chilled in very-rapid chilling conditions (-20C for 3.5 h followed by chilling at 4C for 20.5 h) and conventional chilling conditions (4C f o r 24 h), giving a total offour treatments. Loin (M. longissimus thoracis et lumborum) shear force was measured at f and S days postmortem by Warner-Bratiler shear force measurement. By S days postmortem, split carcasses were not di#erent (P>O.O5) in shear force to unsplit carcasses when conventionally chilled but differences (P<O. 05) were present between unsplit and split carcasses when very-rapidly chilled (57.7 N vs 41.5 N, respectively).

Epidemiology, 2009

ABSTRACT A consumer risk assessment model of Salmonella spp. associated with Irish raw pork sausa... more ABSTRACT A consumer risk assessment model of Salmonella spp. associated with Irish raw pork sausages is under development. This preliminary work aimed to estimate the Salmonella levels in raw pork sausages after transport and home refrigeration. Methods: The initial level of Salmonella in retail raw pork sausages for contaminated packs was modelled using Irish survey data (expected value 1.80 log CFU/g; 95% CI 1.17-2.30 log CFU/g). For the entire duration of transport, the temperature profile of the centre of a sausage pack against time was modelled using transient heat transfer equations. In parallel, experiments were conducted to capture the natural temperature oscillations of the centre of a sausage pack stored up to 7 days in a number of domestic fridges. For the refrigeration module, a simulated temperature profile was obtained in two stages: a brief temperature adjustment stage modelled by heat transfer equations until approaching equilibrium, and a randomly-sampled temperature oscillation period from the experiment above until the completion of the total refrigeration time. The Baranyi&#39;s primary growth model was then applied in conjunction with a secondary square-root model to predict the Salmonella levels under the fluctuating temperatures during transport and refrigeration. Results and Conclusion: The results of the simulation model (5000 iterations) showed that, while Salmonella levels of raw pork sausages do not increase significantly during transport and home storage (expected value 1.83 log CFU/g; 95% CI 1.23-2.71 log CFU/g), the probability of finding hazardous Salmonella levels above 5 log CFU/g from contaminated sausage packs is ∼0.38%. Sensitivity analysis showed that, for the Irish conditions, the Salmonella levels in raw sausages are more affected by storage time (R = 0.43) than by average temperature (R = 0.17). Work is still underway for the cooking and dose-response stages of this risk assessment.

Food Research International, 2012

A second-order simulation model was built to estimate the risk of Salmonella Typhimurium associat... more A second-order simulation model was built to estimate the risk of Salmonella Typhimurium associated with the consumption of Irish fresh pork sausages. To select appropriate hazard characterization models, an initial appraisal of the current dose-response models was conducted. The cooking modality of grilling was associated with a higher mean risk of infection per serving (1.399 × 10 − 6 ; 95% CI: 7.54 × 10 − 7-2.65 × 10 − 6) than frying (6.246 × 10 − 7 , 95% CI: 2.78 × 10 − 7-1.17 × 10 − 6). When the risk was extrapolated over the consumption in a year period, the mean risk of infection increased considerably to 8.541 × 10 − 5 with an expected number of infections and illnesses of 184.3 (95% CI: 26-664) and 17 (95% CI: 2-63), respectively. Results highlighted the importance of consumer education, as scenario analysis predicted that, for the current level of Salmonella in pork sausage, decreasing the product's cold storage by approximately 8 h and cooking for an additional half minute can reduce the current risk level by ∼ 50%.

The overall objective was to devise a rapid chilling system for the Irish lamb processing industr... more The overall objective was to devise a rapid chilling system for the Irish lamb processing industry. The objective of the first trial was to assess the effect of ultra-rapid chilling in air at-4ºC,-10ºC and-20ºC and subsequent ageing on the appearance and tenderness of lamb carcasses. Chilling at-20ºC gave less evaporative weight loss than chilling at other subzero temperatures and conventional chilling at +4ºC. This was achieved without causing adverse effects on carcass quality or meat tenderness. Ageing improved the tenderness of ultra-rapidly chilled lamb and had little effect on the visual appearance of the carcasses. 14 1 The payback period is the length of time it takes for the costs of the system to be recouped from the benefits accrued as a result of adopting the system. 2 These prices are projected by the FAPRI-Ireland partnership and are expected to fall.

2002 Chicago, IL July 28-31, 2002, 2002

... Further investigation on the ultra-rapid chilling of lamb carcasses. J. Muscle Foods, 10: 1-1... more ... Further investigation on the ultra-rapid chilling of lamb carcasses. J. Muscle Foods, 10: 1-16. O'Halloran, GR, Troy, DDJ Buckley. 1997. The relationship between early postmortem pH and the tenderisation of beef muscles. Meat Sci. 45: 239–251. O'Neill, E. 2001. ...

Journal of Muscle Foods, Jul 1, 2001

The eflect on tenderness of splitting lamb carcasses longitudinally under veryrapid chilling cond... more The eflect on tenderness of splitting lamb carcasses longitudinally under veryrapid chilling conditions was investigated. Whole (unsplit) and split carcasses were chilled in very-rapid chilling conditions (-20C for 3.5 h followed by chilling at 4C for 20.5 h) and conventional chilling conditions (4C f o r 24 h), giving a total offour treatments. Loin (M. longissimus thoracis et lumborum) shear force was measured at f and S days postmortem by Warner-Bratiler shear force measurement. By S days postmortem, split carcasses were not di#erent (P>O.O5) in shear force to unsplit carcasses when conventionally chilled but differences (P<O. 05) were present between unsplit and split carcasses when very-rapidly chilled (57.7 N vs 41.5 N, respectively).

Journal of Muscle Foods, Jul 1, 2000

The effects of diferent chilling rates on the visual attributes of lamb carcasses and the tendern... more The effects of diferent chilling rates on the visual attributes of lamb carcasses and the tenderness of lamb chops were investigated. Carcasses (n=72) were chilled at-2OC,-lOC,-4C or +4C. After chilling all carcasses were stored at +4C for up to 8 days. Samples were taken at 2, 6 and 9 days postmortem for sarcomere length, Warner-Bratzler shear force and sensory analysis. Carcasses were visually appraised at 2, 6 and 9 days postmortem f o r fat color, frank color, visible vein color, wetness and overall acceptability. Carcasses chilled at-2OC had signlficantly higher Warner-Bratzler shear force values than the other chilling treatments at 2 and 6 days but not at 9 days postmortem. No difference (P> 0.05) was found in Warner-Bratzler shear force or sensory tenderness between any of the treatments by 9 days postmortem. Carcasses did not differ (P>O.O5) in fat color, frank color or overall acceptability at any stage postmortem. Carcasses chilled at-2OC had slightly darker (P< 0.05) vein color at 2 days postmortem but this was not evident by 6 days postmortem. Carcasses that were chilled at-2OC had significantly lower evaporative weight losses than carcasses in any of the other treatments. Rapid chilling did not adversely afect the tenderness of lamb chops or appearance of lamb carcasses at 9 days postmortem compared with conventional chilling.

Food Control, Dec 1, 2010

A stochastic consumer-phase exposure assessment modelling the transport and refrigeration modules... more A stochastic consumer-phase exposure assessment modelling the transport and refrigeration modules indicated that the concentration of Salmonella typhimurium in contaminated Irish pork sausages prior to cooking was on average 1.79 log CFU/g (95% CI: 1.22e2.42 log CFU/g); and that, out of 100 000 refrigerated sausage packs, an average of w83 packs (95% CI: 73e96) would have hazardous mean Salmonella concentrations above 3 log CFU/g prior to cooking (Freq(Y > 3)). Scenario analysis revealed that a decrease in the refrigeration temperature by 2 C and a decrease of the initial prevalence of S. typhimurium by half (w0.02) would have a comparable level of reduction in Freq(Y > 3) (w23e43 packs per 100 000 packs), while a decrease in the storage time by half would have by far the highest level of reduction (Freq(Y > 3) ¼ w2e7 packs per 100 000 packs). Finally, a practical method for the simulation of the product's temperature profile in cold storage has been proposed based on the application of heat transfer equations and actual product's temperature history data.

Meat Science, Nov 1, 2001

The effect of ultra-rapid chilling (-20°C) on the proteolytic degradation of myofibrillar protein... more The effect of ultra-rapid chilling (-20°C) on the proteolytic degradation of myofibrillar proteins during ageing, by the calpain/calpastatin system in lamb was investigated. Carcasses (36) were ultra-rapidly chilled (-20°C for 3.5 h followed by 20.5 h at +4°C) or chilling at +4°C for 24 h. After chilling all carcasses were stored at +4°C for a further 4 days. Samples of M. longissimus thoracis et lumborum were taken for Warner-Bratzler shear force measurement, sarcomere length, SDS-PAGE and enzyme activity analysis. Ultra-rapid chilling (-20°C) had no effect on the proteolytic degradation of myofibrillar proteins by the calpain/calpastatin system compared to conventional chilling (+4°C). However, no difference in tenderness was found between the two chilling regimes at 1 or 5 days postmortem so differences in myofibrillar degradation or enzyme activity would not be expected.

Journal of Food Engineering, Feb 1, 2003

Both freeze-chilling and chilling reduce the vitamin C content of mashed potato in comparison wit... more Both freeze-chilling and chilling reduce the vitamin C content of mashed potato in comparison with freezing. The current trial investigated the potential of encapsulated vitamin C (EVC) for boosting the vitamin C content of mashed potato. Preliminary trials with EVC in aqueous solution indicated that the vitamin C was not released from the capsules until the temperature reached %67°C, i.e. the melting point of the encapsulating fat. Samples of cooled mashed potato (cultivar Rooster) were supplemented with EVC and were subjected to four process treatments, i.e. fresh, chilling, freeze-chilling and freezing. Parallel tests were conducted with ordinary vitamin C (OVC) and with no vitamin C (NVC) (i.e. control samples). The vitamin C content of the reheated samples with added EVC from the four process treatments was 24.4 mg/100 g (fresh), 16.4 (chill), 14.3 (freeze-chill), 22.4 (freeze). Corresponding contents using OVC were 25.3, 2.4, 2.8, and 19.1 mg/100 g and NVC were 2.0, 1.5, 0.5 and 0.8 mg/100 g respectively. These data show that EVC has potential for boosting the vitamin C content of both freeze-chilled and chilled mashed potato.

Innovative Food Science and Emerging Technologies, Mar 1, 2003

Freeze-chilling of food involves freezing and frozen storage followed by thawing and chilled stor... more Freeze-chilling of food involves freezing and frozen storage followed by thawing and chilled storage. In this study, the effect of freeze-chilling on the quality of cooked green beans and carrots was examined, as was the effect of long and short-term frozen storage prior to thawing. Three process treatments were used in the short-term trial; chill, freeze-chill and freeze and the products were tested for firmness, colour, centrifugal drip loss, total viable count (TVC) and taste panel acceptability. Results showed that freeze-chilling and freezing led to softer cooked carrots (P-0.001) than chilling. However, freeze-chilling and freezing had no effect on the texture of cooked green beans (P)0.05) but led to significantly higher drip losses than chilling (P-0.001). Freezechilling and chilling led to paler green beans but this was not reflected in the taste panel acceptability scores. No difference in TVC was found between any of the process treatments for cooked carrots or green beans. In general, frozen storage (y25 8C) for up to 12 months had no effect on firmness, drip loss, colour, total viable count or sensory acceptability of freeze-chilled cooked carrots and green beans compared to freezing.

Food Research International, Mar 1, 2012

A second-order simulation model was built to estimate the risk of Salmonella Typhimurium associat... more A second-order simulation model was built to estimate the risk of Salmonella Typhimurium associated with the consumption of Irish fresh pork sausages. To select appropriate hazard characterization models, an initial appraisal of the current dose-response models was conducted. The cooking modality of grilling was associated with a higher mean risk of infection per serving (1.399 × 10 − 6 ; 95% CI: 7.54 × 10 − 7-2.65 × 10 − 6) than frying (6.246 × 10 − 7 , 95% CI: 2.78 × 10 − 7-1.17 × 10 − 6). When the risk was extrapolated over the consumption in a year period, the mean risk of infection increased considerably to 8.541 × 10 − 5 with an expected number of infections and illnesses of 184.3 (95% CI: 26-664) and 17 (95% CI: 2-63), respectively. Results highlighted the importance of consumer education, as scenario analysis predicted that, for the current level of Salmonella in pork sausage, decreasing the product's cold storage by approximately 8 h and cooking for an additional half minute can reduce the current risk level by ∼ 50%.

Journal of Food Protection, Aug 1, 2010

Prevalence and counts of Salmonella Typhimurium in fresh pork sausage packs at the point of retai... more Prevalence and counts of Salmonella Typhimurium in fresh pork sausage packs at the point of retail were modeled by using Irish and United Kingdom retail surveys' data. A methodology for modeling a second-order distribution for the initial Salmonella concentration (l 0) in pork sausage at retail was presented considering the uncertainty originated from the mostprobable-number (MPN) serial dilutions. A conditional probability of observing the tube counts given true Salmonella concentration in a contaminated pack was built from the MPN triplets of every sausage tested. A posterior distribution was then modeled under the assumption that the counts from each of the portions of sausage mix stuffed into casings (and subsequently packed) are Poisson distributed. In order to model the variability of l 0 among contaminated sausage packs, MPN uncertainties were propagated to a predefined lognormal distribution. Because the sausage samples from the Irish survey were frozen prior to MPN analysis (which is expected to cause reduction in viable cells), the resulting distribution for l 0 appeared greatly underestimated (mean: 0.514 CFU/g; 95% confidence interval [CI]: 0.02 to 2.74 CFU/g). The l 0 distribution produced with the United Kingdom survey data (mean: 69.7 CFU/g; 95% CI: 15 to 200 CFU/g) was, however, more conservative, and is to be used along with the fitted distribution for prevalence of Salmonella Typhimurium in pork sausage packs in Ireland (gamma[37.997, 0.0013]; mean: 0.046; 95% CI: 0.032 to 0.064) as the main inputs of a stochastic consumer-phase exposure assessment model.

2002 Chicago, IL July 28-31, 2002, 2002

The authors are solely responsible for the content of this technical presentation. The technical ... more The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agriculh.ual Engineers (ASAE), and its printing and distribution does not constitute an endorsement of views which may be expressed. Technical presentations are not subject to the formal peer review process by ASAE editorial committees; therefore, they are not to be presented as refereed publications. Citation of this work should state that it is from an ASAE meeting paper. EXAMPLE: Author's Last Name, lnitiaJs. 2002. Trtle of Presentation. ASAE Meeting Paper No. 02xxxx. St. Joseph, Mfch.: ASAE. For information about securing permission to reprint or reproduce a technical presentation. please contact ASAE

Journal of Muscle Foods, Jul 1, 2001

The effect of chilling rate and muscle excision on the shear force of ovine muscle (M. longissimu... more The effect of chilling rate and muscle excision on the shear force of ovine muscle (M. longissimus thoracis et lumborum) was examined. Conventional chilling involved chilling at 4C for 24 h and very-rapid chilling involved chilling at-2OC for 3.5 h followed by conventional chilling for 20.5 h. After 24 h all muscles were aged for a further four days. Approximately 30 min a f e r slaughter, one M. longissimus thoracis et lumborum was excised from each carcass and placed in the same chill as the remainder of the carcass. This gave a total of four different treatments. Shear force was assessed at I and 5 days postmortem by Warner-Bratzler shear force measurement. Excision led to reduced shear force in the very-rapid chilling regime but increased shear force in the conventionally chilled muscles. Aging improved shear force for all chilling treatments. No significant difference was found in the rate of pH fall, between the chilling treatments.

End of Project ReportFreeze-chilling of food consists of freezing and frozen storage followed by ... more End of Project ReportFreeze-chilling of food consists of freezing and frozen storage followed by thawing and then retailing at chill storage temperatures. It offers logistic, transportation and storage advantages to food manufacturers. Freeze-chilling has particular application to ready-meals and their components. Mashed potato (three cultivars), steamed carrots, steamed green beans and beef lasagne were found suitable for freeze-chilling and their quality and sensory properties compared favourably with their frozen, chilled and fresh counterparts. Modified atmosphere packaging was combined with freeze-chilling but it had little impact on shelflife extension for the product range with the outcome similar to that for samples packed in air. Tests on the freeze-chilling of white sauces showed the importance of using freeze-thaw stable starches. Best-practice thawing procedures were established and the importance of stacking configurations for outer boxes (each with a number of lasagne ready-meals) was highlighted in the case of the commercial tempering unit. Trials on the re-freezing of freeze-chilled products indicated that re-freezing is an option provided the normal storage protocols for frozen and chilled foods are observed.Food Institutional Research Measure (FIRM), Department of Agriculture and Food, Irelan

2002 Chicago, IL July 28-31, 2002, 2002

... Further investigation on the ultra-rapid chilling of lamb carcasses. J. Muscle Foods, 10: 1-1... more ... Further investigation on the ultra-rapid chilling of lamb carcasses. J. Muscle Foods, 10: 1-16. O'Halloran, GR, Troy, DDJ Buckley. 1997. The relationship between early postmortem pH and the tenderisation of beef muscles. Meat Sci. 45: 239–251. O'Neill, E. 2001. ...

Meat Science, 2001

The effect of ultra-rapid chilling (-20°C) on the proteolytic degradation of myofibrillar protein... more The effect of ultra-rapid chilling (-20°C) on the proteolytic degradation of myofibrillar proteins during ageing, by the calpain/calpastatin system in lamb was investigated. Carcasses (36) were ultra-rapidly chilled (-20°C for 3.5 h followed by 20.5 h at +4°C) or chilling at +4°C for 24 h. After chilling all carcasses were stored at +4°C for a further 4 days. Samples of M. longissimus thoracis et lumborum were taken for Warner-Bratzler shear force measurement, sarcomere length, SDS-PAGE and enzyme activity analysis. Ultra-rapid chilling (-20°C) had no effect on the proteolytic degradation of myofibrillar proteins by the calpain/calpastatin system compared to conventional chilling (+4°C). However, no difference in tenderness was found between the two chilling regimes at 1 or 5 days postmortem so differences in myofibrillar degradation or enzyme activity would not be expected.

LWT - Food Science and Technology, 2005

The effect of long-and short-term frozen storage prior to thawing, on the quality of freeze-chill... more The effect of long-and short-term frozen storage prior to thawing, on the quality of freeze-chilled, commercially made lasagnes was examined as was the effect of modified atmosphere packaging (MAP). In the short-term trial, four process treatments were used; fresh, chilled, freeze-chilled and frozen. In the long-term trial, the lasagnes were frozen for 3, 6, 9 or 12 months, thawed and tested, or were thawed and then chilled at 4 C for 6 days (freeze-chilled). In the MAP trial, the lasagnes were subjected to either the freezechill treatment or freeze treatment, and before freezing were packed in either (i) air, (ii) 40% CO 2 /60% N 2 or (iii) 40% CO 2 /30% N 2 / 30% O 2. In the short-term trial frozen and freeze-chilled lasagne had significantly higher drip loss than fresh or chilled before reheating, but this was not evident after heating. Similarly, freeze-chilled lasagne had a brighter colour (L/b) than chilled before heating, but again this was not evident after heating. No difference was found in firmness or sensory acceptability of lasagne from the different treatments. Freeze-chilled and frozen lasagne had higher total viable counts (TVC) than chilled or fresh. Packing in CO 2 /N 2 /O 2 (40:30:30) led to a darker unheated lasagne than packing in CO 2 /N 2 (40:60) or air, but this was not evident for heated lasagne. Packing in CO 2 /N 2 (40:60) led to a firmer product than packing in air for the frozen lasagne but not for freeze-chilled lasagne. Atmosphere had no effect on TVC or drip loss values. Lasagnes stored frozen for 12 months were firmer than those stored for 3, 6, or 9 months. Storing frozen for 9 or 12 months also led to higher drip loss values than storing for 3 months for unheated lasagnes but when heated, the opposite effect was seen. Lasagnes stored for 3 months had the highest L/b (white/yellow ratio) values while those stored for 12 months had the lowest. Length of time in frozen storage had no influence on TVC values.

Journal of Muscle Foods, 2001

The eflect on tenderness of splitting lamb carcasses longitudinally under veryrapid chilling cond... more The eflect on tenderness of splitting lamb carcasses longitudinally under veryrapid chilling conditions was investigated. Whole (unsplit) and split carcasses were chilled in very-rapid chilling conditions (-20C for 3.5 h followed by chilling at 4C for 20.5 h) and conventional chilling conditions (4C f o r 24 h), giving a total offour treatments. Loin (M. longissimus thoracis et lumborum) shear force was measured at f and S days postmortem by Warner-Bratiler shear force measurement. By S days postmortem, split carcasses were not di#erent (P>O.O5) in shear force to unsplit carcasses when conventionally chilled but differences (P<O. 05) were present between unsplit and split carcasses when very-rapidly chilled (57.7 N vs 41.5 N, respectively).

Epidemiology, 2009

ABSTRACT A consumer risk assessment model of Salmonella spp. associated with Irish raw pork sausa... more ABSTRACT A consumer risk assessment model of Salmonella spp. associated with Irish raw pork sausages is under development. This preliminary work aimed to estimate the Salmonella levels in raw pork sausages after transport and home refrigeration. Methods: The initial level of Salmonella in retail raw pork sausages for contaminated packs was modelled using Irish survey data (expected value 1.80 log CFU/g; 95% CI 1.17-2.30 log CFU/g). For the entire duration of transport, the temperature profile of the centre of a sausage pack against time was modelled using transient heat transfer equations. In parallel, experiments were conducted to capture the natural temperature oscillations of the centre of a sausage pack stored up to 7 days in a number of domestic fridges. For the refrigeration module, a simulated temperature profile was obtained in two stages: a brief temperature adjustment stage modelled by heat transfer equations until approaching equilibrium, and a randomly-sampled temperature oscillation period from the experiment above until the completion of the total refrigeration time. The Baranyi&#39;s primary growth model was then applied in conjunction with a secondary square-root model to predict the Salmonella levels under the fluctuating temperatures during transport and refrigeration. Results and Conclusion: The results of the simulation model (5000 iterations) showed that, while Salmonella levels of raw pork sausages do not increase significantly during transport and home storage (expected value 1.83 log CFU/g; 95% CI 1.23-2.71 log CFU/g), the probability of finding hazardous Salmonella levels above 5 log CFU/g from contaminated sausage packs is ∼0.38%. Sensitivity analysis showed that, for the Irish conditions, the Salmonella levels in raw sausages are more affected by storage time (R = 0.43) than by average temperature (R = 0.17). Work is still underway for the cooking and dose-response stages of this risk assessment.

Food Research International, 2012

A second-order simulation model was built to estimate the risk of Salmonella Typhimurium associat... more A second-order simulation model was built to estimate the risk of Salmonella Typhimurium associated with the consumption of Irish fresh pork sausages. To select appropriate hazard characterization models, an initial appraisal of the current dose-response models was conducted. The cooking modality of grilling was associated with a higher mean risk of infection per serving (1.399 × 10 − 6 ; 95% CI: 7.54 × 10 − 7-2.65 × 10 − 6) than frying (6.246 × 10 − 7 , 95% CI: 2.78 × 10 − 7-1.17 × 10 − 6). When the risk was extrapolated over the consumption in a year period, the mean risk of infection increased considerably to 8.541 × 10 − 5 with an expected number of infections and illnesses of 184.3 (95% CI: 26-664) and 17 (95% CI: 2-63), respectively. Results highlighted the importance of consumer education, as scenario analysis predicted that, for the current level of Salmonella in pork sausage, decreasing the product's cold storage by approximately 8 h and cooking for an additional half minute can reduce the current risk level by ∼ 50%.