. 2023 Jul 5;21(7):e08093. doi: 10.2903/j.efsa.2023.8093

Table D.3.

Summary of the rationale for the consensus of each process, as recorded by the rapporteur

Process	Summary of rationale as recorded by the rapporteur
Method 2 – coincidental 100°C × 5′ – 110°C × 70′ – 120°C × 50′	There was a full agreement between individual experts for this process; all experts provided individual elicited probability ranges of 99–100%. Expert C explained that the model output, without extrapolation, predicts more than 10 log₁₀ inactivation of spores of C. perfringens, based on the time/temperature profile of the treatment. A higher inactivation is expected as the actual process temperature would be higher. The elicitator proposed a consensus judgement of 99–100% and this was agreed.
Method 3 – coincidental 100°C × 40′ – 110°C × 42′ – 120°C × 13′	There was good agreement between individual experts for this process. Five experts provided individual elicited probability ranges of 99–100%, while two experts (expert D and E) provided ranges of 95–99%. Expert D gave a lower probability compared to method 2 considering that the processing time at 120°C is lower compared to the previous process. Expert C stated that the inactivation of spores of C. perfringens in method 3 would still be very high. The predicted inactivation, based on the model output, is beyond 6–8 log₁₀ inactivation of spores of C. perfringens and the actual processing temperature would be higher than that. Expert G confirmed that the probability was 100% for at least a 5 log₁₀ inactivation of spores of C. perfringens and as the temperature is higher than the temperature used for Dref (i.e. 105°C), the inactivation is underestimated. Experts D and E, after hearing the arguments of the other experts, agreed to increase their probability range to 99–100%. The elicitator proposed a consensus judgement of 99–100% and this was agreed.
Method 4 – coincidental 100°C × 3′ – 110°C × 5′ – 120°C × 5′ – 130°C × 3′	There was a large disagreement between individual experts for this process. Expert A (providing a probability range of 0–5%) considered the high probability (82.1%) in the model output that a 5 log₁₀ inactivation of spores of C. perfringens would not be achieved. The expert considered extrapolation. The expert informed that the probability could be revised to values higher than 50% if also the inactivation of spores of C. botulinum would be considered. Expert G (providing a probability range of 95–100%), stated that the probability was about 18% for at least a 5 log₁₀ inactivation of C. perfringens, based on model predictions. There is a very high underestimation as high temperatures were used for short times. Even if C. perfringens is the focus, spores of C. botulinum are more resistant. Therefore, the expert is quite sure that if 5 log₁₀ inactivation of spores of C. botulinum would be met, it would also be the case for spores of C. perfringens. Therefore, this expert increased the probability range, but judged a slightly lower probability range compared to method 3 considering the time/temperature (t/T) combinations. Expert B (providing a probability range of 99–100%) considered the model output using extrapolation as high temperatures were used in this process and the model without extrapolation is ‘truncated’ at 105°C (Tref). As the model did not consider the temperature come‐up time, the expert was certain that a 5 log₁₀ inactivation of spores of C. perfringens is achieved. Expert C (providing a probability range of 99–100%) based the judgement on C. botulinum. The expert informed the group that the actual temperature is almost 30°C higher than Tref. An inactivation equivalent to more than 27 min at 121°C would be expected for spores of C. botulinum, sufficient to ensure 12 log₁₀ reductions of those spores (3 min is enough). Therefore, the expert considered that inactivation of spores of C. perfringens would be almost certain. However, the expert proposes to broaden the probability range to increase the uncertainty. Expert F (providing a probability range of 10–33%) only considered C. perfringens and found it unlikely that there would be a 5 log₁₀ inactivation of spores of C. perfringens, based on the model outputs. Expert A (providing a probability range of 0–5%) asked to agree on the extent to use the data on inactivation of spores of C. botulinum in the judgements. If so, it would become very likely to achieve a 5 log₁₀ inactivation of spores of C. perfringens. Expert B informed that the probability range could be lowered from 99–100% to 95–100%. Expert E stated that the reasoning to consider C. botulinum as a surrogate/indicator for C. perfringens needs to be well explained in the opinion. Also, the underestimation of the model should be better explained in the opinion. This was agreed by expert G. Expert D provided a large probability range (of 50–100%) as the probability of at least a 5 log₁₀ inactivation of spores of C. perfringens is low (about 18%), but there is high probability to achieve between 5 and 6 log₁₀ inactivation of spores of C. perfringens. The expert would stay on the right side of the probability scale but use a range wider than 95–100%. Expert B was asked to explain the model outputs. The expert recalled that the model was truncated at 105°C. When temperatures are above 105°C, there is more uncertainty and underestimation (but not clear to what extent). Expert E then proposed to have a large probability range (of 50–100%), which was agreed by expert F. The elicitator proposed 66% as lower limit of the probability range which was agreed. The upper limit for some experts was 100% and it was agreed to use this value as an upper limit considering also C. botulinum spores' inactivation. Thus, the agreed consensus judgement was 66–100%.
Method 5 – coincidental 80°C × 60′ – 100°C × 60′	There was again a large disagreement between individual experts for this process. Expert A (providing a probability range of 1–33%) based on discussions for other process, believes that spores of C. botulinum have low mortality here, so the expert is not positive to reach a 5 log₁₀ inactivation of spores of C. perfringens in 99% of cases. Expert C (providing a probability range of 95–99%) explained that the predicted inactivation of the temperature profile is higher than 5 log₁₀ with a 99% probability. The actual temperature is within the limits where there are published data available, so the prediction is expected to be close to reality. The inactivation is more likely than not but would broaden the range provided. Expert B (providing a probability range of 95–99%) said that the models output can be trusted without extrapolation considering the temperatures used in this process. Considering additionally the come‐up time, the provided range is believed still valid. This was agreed by expert E. Expert G (providing a probability range of 66–90%) believes the model overestimates the inactivation of spores of C. botulinum because the product would be quite dehydrated through the treatment. Expert F (providing a probability range of 66–90%) considered mainly the model outputs and expects explanations to be added in opinion. Expert A doubted about the upper range of 99% considering the model outputs. The elicitator explained that the model percentages are to be considered also uncertainties. The expert then agreed that ‘more likely than not’ should be the outcome. Adding uncertainty, the expert would agree with a probability range of 66–90%. The elicitator proposed 66% as lower limit of the probability range. According to expert B, it should be rather 90% as explained before, also considering dehydration of the product. Expert D agrees with 90% as lower limit considering the model output and the estimated inactivation of spores of C. perfringens between 5 and 6 log₁₀. The agreed consensus judgement was 80–99%.
Method 7 – scenario 1 80°C × 14′	There was some level of agreement between individual expert judgements for this process. Most extreme were four experts providing individual elicited probability ranges of 0–1%, while one expert (expert E) provided a range of 10–33%. Expert E wanted to give a lower probability as well but then considered the underestimation of the model (through the come‐up time). The expert would agree to lower the probability. Expert D explained that the probability was 100% for less than a 5 log₁₀ inactivation of spores of C. perfringens, and the probability is 0% when between 5 to 6 log₁₀. Expert C considers that method is quite insufficient (based on the t/T profiles) to inactivate spores of C. perfringens, but it also needs to be considered that the data used in the model relies on highly resistant spores. Only if all the spore population would have low heat resistance, a 5 log₁₀ reduction could be accomplished. The agreed consensus judgement was 0–5%.
Method 7 – scenario 2 95°C × 90′	There was again a large disagreement between individual experts for this process, with experts A and F providing the lowest probability ranges. The model output yields a probability of 31.9% that a 5 log₁₀ inactivation of spores of C. perfringens would not be achieved, based on the t/T profile of the method. Expert F would agree to increase the probability range. Expert A informed that there is no need to extrapolate, and C. botulinum inactivation is not to be used. The probability would be rather below 50%. Expert E (providing a probability range of 66–90%) would rather have a probability beyond 50% considering the under‐estimation of the inactivation by the model. Expert C (providing a probability range of 50–100%) considers the probability more likely than not also considering there was no extrapolation needed. The expert would lower the upper limit to 90%. The elicitator questioned if the lower limit should be below or above 50%. According to expert B (providing a probability range of 10–33%), the range should be quite low (below 50%) as the mean inactivation of spores of C. perfringens is 7 log₁₀. Expert G (providing a probability range of 33–66%), also considered that in most of the studies it needs more than 90′ to achieve a 5D inactivation of spores of C. perfringens. The elicitator then asked about upper limit. Expert C agreed to lower it to 90%. Expert B proposes 66%. Expert F proposed to use 33–66% as probability range as this would reflect that there is a high uncertainty. The elicitator questioned whether the upper limit is acceptable considering the model output (68.1% that a 5 log₁₀ inactivation of spores of C. perfringens would be achieved); hence the model must be overestimating. Expert E further questioned the divergence with method 5 where we were more certain. According to expert C the impact of a small change in temperature is significant. A higher value of the upper range (80%) was proposed to reflect uncertainty. Finally expert C proposed 25–75%, which was agreed as consensus judgement.
Method 7 – scenario 3 115°C × 56′	There was a high level of agreement between individual experts for this process; all experts provided high probability ranges. The model output yields a probability of 100% that a 5 log₁₀ inactivation of spores of C. perfringens would be achieved, based on the t/T profile of the method. Expert C (providing a probability range of 99–100%) had a high level of confidence as the predicted inactivation based on the t/T profile is higher than 6–8 log₁₀ and considered that truncation was applicable as the actual temperature is higher. The method would reach 12 log₁₀ reduction of spores of C. botulinum, with an equivalent time at 121°C of 13.7 min. Expert F (providing a probability range of 99–100%) followed the same reasoning based on the t/T profile. Expert E (providing a probability range of 95–99%) considered that the t/T profile is a bit less stringent than method 2 and therefore gave somewhat lower values. The expert informed that the probability could be increased. Expert G (providing a probability range of 95–100%) said that 100% should be included in the range. Expert A (providing a probability range of 95–99%) had the same arguments. The upper limit of 100% as consensus judgement was agreed by all. There was no clear argument for underestimation of the model and 98% as lower limit was agreed.
Method 7 – scenario 4 125°C × 10′	There was a large disagreement between individual experts for this process, with experts A and F again providing the lowest probability ranges. The model output yields a probability of 98.5% that a 5 log₁₀ inactivation of spores of C. perfringens would not be achieved, based on the t/T profile of the method. In this process higher temperatures are used, so there is an extrapolation effect. Expert G (providing a probability range of 99–100%), as in method 4, indicated that there is a huge underestimation in the model outputs as the process relies on high temperature/short time processing and considered inactivation of spores of C. botulinum. The expert would consider revising the probability range to the consensus reached for method 4. Expert C (providing a probability range of 99–100%) followed the same reasoning. When inactivation of spores of C. botulinum is achieved an inactivation equivalent to more than 24.7 min at 121°C would be expected, sufficient to ensure 12 log reductions of C. botulinum, the expert gave a high probability, similarly to method 4. Expert A (providing a probability range of 0–5%) agreed and would be fine to revise the range as agreed for method 4. Expert F (providing a probability range of 0–1%) agreed as well. Expert E (providing a probability range of 33–66%) is in middle of the probability range. The expert is uncertain, and the arguments are the same. The model predictions are high but there is a larger underestimation. The expert did not consider C. botulinum, but only the model output and underestimation. The elicitator asked if a comparable range to method 4, method 7 scenario 4 and method 7 scenario 5 would apply (66–100%) as the arguments are the same. Expert B (providing a probability range of 95–99%) would not include 100% as the highest temperature is different and there are more come‐up times in method 4. Expert C believes that 100% is reasonable as these conditions would lead to a safe process (accepted as a safe for pet food in legislation). The elicitator proposed a consensus judgement of 66–100% and this was agreed
Method 7 – scenario 5 133°C × 5′	The model output yields a probability of 100% that a 5 log₁₀ inactivation of spores of C. perfringens would not be achieved, based on the t/T profile of the method. The elicitator proposed for this process the same consensus judgement as for method 7 scenario 5 (66–100%) comparing the t/T profiles of both methods and the individual expert judgements. This was agreed.

Process

Summary of rationale as recorded by the rapporteur

Method 2 – coincidental

100°C × 5′ – 110°C × 70′ – 120°C × 50′

There was a full agreement between individual experts for this process; all experts provided individual elicited probability ranges of 99–100%.

Expert C explained that the model output, without extrapolation, predicts more than 10 log₁₀ inactivation of spores of C. perfringens, based on the time/temperature profile of the treatment. A higher inactivation is expected as the actual process temperature would be higher.

The elicitator proposed a consensus judgement of 99–100% and this was agreed.

Method 3 – coincidental

100°C × 40′ – 110°C × 42′ – 120°C × 13′

There was good agreement between individual experts for this process. Five experts provided individual elicited probability ranges of 99–100%, while two experts (expert D and E) provided ranges of 95–99%.

Expert D gave a lower probability compared to method 2 considering that the processing time at 120°C is lower compared to the previous process.

Expert C stated that the inactivation of spores of C. perfringens in method 3 would still be very high. The predicted inactivation, based on the model output, is beyond 6–8 log₁₀ inactivation of spores of C. perfringens and the actual processing temperature would be higher than that. Expert G confirmed that the probability was 100% for at least a 5 log₁₀ inactivation of spores of C. perfringens and as the temperature is higher than the temperature used for Dref (i.e. 105°C), the inactivation is underestimated.

Experts D and E, after hearing the arguments of the other experts, agreed to increase their probability range to 99–100%.

The elicitator proposed a consensus judgement of 99–100% and this was agreed.

Method 4 – coincidental

100°C × 3′ – 110°C × 5′ – 120°C × 5′ – 130°C × 3′

There was a large disagreement between individual experts for this process.

Expert A (providing a probability range of 0–5%) considered the high probability (82.1%) in the model output that a 5 log₁₀ inactivation of spores of C. perfringens would not be achieved. The expert considered extrapolation. The expert informed that the probability could be revised to values higher than 50% if also the inactivation of spores of C. botulinum would be considered.

Expert G (providing a probability range of 95–100%), stated that the probability was about 18% for at least a 5 log₁₀ inactivation of C. perfringens, based on model predictions. There is a very high underestimation as high temperatures were used for short times. Even if C. perfringens is the focus, spores of C. botulinum are more resistant. Therefore, the expert is quite sure that if 5 log₁₀ inactivation of spores of C. botulinum would be met, it would also be the case for spores of C. perfringens. Therefore, this expert increased the probability range, but judged a slightly lower probability range compared to method 3 considering the time/temperature (t/T) combinations.

Expert B (providing a probability range of 99–100%) considered the model output using extrapolation as high temperatures were used in this process and the model without extrapolation is ‘truncated’ at 105°C (Tref). As the model did not consider the temperature come‐up time, the expert was certain that a 5 log₁₀ inactivation of spores of C. perfringens is achieved.

Expert C (providing a probability range of 99–100%) based the judgement on C. botulinum. The expert informed the group that the actual temperature is almost 30°C higher than Tref. An inactivation equivalent to more than 27 min at 121°C would be expected for spores of C. botulinum, sufficient to ensure 12 log₁₀ reductions of those spores (3 min is enough). Therefore, the expert considered that inactivation of spores of C. perfringens would be almost certain. However, the expert proposes to broaden the probability range to increase the uncertainty.

Expert F (providing a probability range of 10–33%) only considered C. perfringens and found it unlikely that there would be a 5 log₁₀ inactivation of spores of C. perfringens, based on the model outputs.

Expert A (providing a probability range of 0–5%) asked to agree on the extent to use the data on inactivation of spores of C. botulinum in the judgements. If so, it would become very likely to achieve a 5 log₁₀ inactivation of spores of C. perfringens.

Expert B informed that the probability range could be lowered from 99–100% to 95–100%.

Expert E stated that the reasoning to consider C. botulinum as a surrogate/indicator for C. perfringens needs to be well explained in the opinion. Also, the underestimation of the model should be better explained in the opinion. This was agreed by expert G.

Expert D provided a large probability range (of 50–100%) as the probability of at least a 5 log₁₀ inactivation of spores of C. perfringens is low (about 18%), but there is high probability to achieve between 5 and 6 log₁₀ inactivation of spores of C. perfringens. The expert would stay on the right side of the probability scale but use a range wider than 95–100%.

Expert B was asked to explain the model outputs. The expert recalled that the model was truncated at 105°C. When temperatures are above 105°C, there is more uncertainty and underestimation (but not clear to what extent).

Expert E then proposed to have a large probability range (of 50–100%), which was agreed by expert F.

The elicitator proposed 66% as lower limit of the probability range which was agreed. The upper limit for some experts was 100% and it was agreed to use this value as an upper limit considering also C. botulinum spores' inactivation.

Thus, the agreed consensus judgement was 66–100%.

Method 5 – coincidental

80°C × 60′ – 100°C × 60′

There was again a large disagreement between individual experts for this process.

Expert A (providing a probability range of 1–33%) based on discussions for other process, believes that spores of C. botulinum have low mortality here, so the expert is not positive to reach a 5 log₁₀ inactivation of spores of C. perfringens in 99% of cases.

Expert C (providing a probability range of 95–99%) explained that the predicted inactivation of the temperature profile is higher than 5 log₁₀ with a 99% probability. The actual temperature is within the limits where there are published data available, so the prediction is expected to be close to reality. The inactivation is more likely than not but would broaden the range provided.

Expert B (providing a probability range of 95–99%) said that the models output can be trusted without extrapolation considering the temperatures used in this process. Considering additionally the come‐up time, the provided range is believed still valid. This was agreed by expert E.

Expert G (providing a probability range of 66–90%) believes the model overestimates the inactivation of spores of C. botulinum because the product would be quite dehydrated through the treatment.

Expert F (providing a probability range of 66–90%) considered mainly the model outputs and expects explanations to be added in opinion.

Expert A doubted about the upper range of 99% considering the model outputs. The elicitator explained that the model percentages are to be considered also uncertainties. The expert then agreed that ‘more likely than not’ should be the outcome. Adding uncertainty, the expert would agree with a probability range of 66–90%.

The elicitator proposed 66% as lower limit of the probability range. According to expert B, it should be rather 90% as explained before, also considering dehydration of the product. Expert D agrees with 90% as lower limit considering the model output and the estimated inactivation of spores of C. perfringens between 5 and 6 log₁₀.

The agreed consensus judgement was 80–99%.

Method 7 – scenario 1

80°C × 14′

There was some level of agreement between individual expert judgements for this process. Most extreme were four experts providing individual elicited probability ranges of 0–1%, while one expert (expert E) provided a range of 10–33%.

Expert E wanted to give a lower probability as well but then considered the underestimation of the model (through the come‐up time). The expert would agree to lower the probability.

Expert D explained that the probability was 100% for less than a 5 log₁₀ inactivation of spores of C. perfringens, and the probability is 0% when between 5 to 6 log₁₀.

Expert C considers that method is quite insufficient (based on the t/T profiles) to inactivate spores of C. perfringens, but it also needs to be considered that the data used in the model relies on highly resistant spores. Only if all the spore population would have low heat resistance, a 5 log₁₀ reduction could be accomplished.

The agreed consensus judgement was 0–5%.

Method 7 – scenario 2

95°C × 90′

There was again a large disagreement between individual experts for this process, with experts A and F providing the lowest probability ranges.

The model output yields a probability of 31.9% that a 5 log₁₀ inactivation of spores of C. perfringens would not be achieved, based on the t/T profile of the method.

Expert F would agree to increase the probability range. Expert A informed that there is no need to extrapolate, and C. botulinum inactivation is not to be used. The probability would be rather below 50%.

Expert E (providing a probability range of 66–90%) would rather have a probability beyond 50% considering the under‐estimation of the inactivation by the model.

Expert C (providing a probability range of 50–100%) considers the probability more likely than not also considering there was no extrapolation needed. The expert would lower the upper limit to 90%.

The elicitator questioned if the lower limit should be below or above 50%.

According to expert B (providing a probability range of 10–33%), the range should be quite low (below 50%) as the mean inactivation of spores of C. perfringens is 7 log₁₀.

Expert G (providing a probability range of 33–66%), also considered that in most of the studies it needs more than 90′ to achieve a 5D inactivation of spores of C. perfringens.

The elicitator then asked about upper limit. Expert C agreed to lower it to 90%. Expert B proposes 66%.

Expert F proposed to use 33–66% as probability range as this would reflect that there is a high uncertainty.

The elicitator questioned whether the upper limit is acceptable considering the model output (68.1% that a 5 log₁₀ inactivation of spores of C. perfringens would be achieved); hence the model must be overestimating.

Expert E further questioned the divergence with method 5 where we were more certain. According to expert C the impact of a small change in temperature is significant.

A higher value of the upper range (80%) was proposed to reflect uncertainty. Finally expert C proposed 25–75%, which was agreed as consensus judgement.

Method 7 – scenario 3

115°C × 56′

There was a high level of agreement between individual experts for this process; all experts provided high probability ranges.

The model output yields a probability of 100% that a 5 log₁₀ inactivation of spores of C. perfringens would be achieved, based on the t/T profile of the method.

Expert C (providing a probability range of 99–100%) had a high level of confidence as the predicted inactivation based on the t/T profile is higher than 6–8 log₁₀ and considered that truncation was applicable as the actual temperature is higher. The method would reach 12 log₁₀ reduction of spores of C. botulinum, with an equivalent time at 121°C of 13.7 min.

Expert F (providing a probability range of 99–100%) followed the same reasoning based on the t/T profile.

Expert E (providing a probability range of 95–99%) considered that the t/T profile is a bit less stringent than method 2 and therefore gave somewhat lower values. The expert informed that the probability could be increased.

Expert G (providing a probability range of 95–100%) said that 100% should be included in the range.

Expert A (providing a probability range of 95–99%) had the same arguments.

The upper limit of 100% as consensus judgement was agreed by all. There was no clear argument for underestimation of the model and 98% as lower limit was agreed.

Method 7 – scenario 4

125°C × 10′

There was a large disagreement between individual experts for this process, with experts A and F again providing the lowest probability ranges.

The model output yields a probability of 98.5% that a 5 log₁₀ inactivation of spores of C. perfringens would not be achieved, based on the t/T profile of the method. In this process higher temperatures are used, so there is an extrapolation effect.

Expert G (providing a probability range of 99–100%), as in method 4, indicated that there is a huge underestimation in the model outputs as the process relies on high temperature/short time processing and considered inactivation of spores of C. botulinum. The expert would consider revising the probability range to the consensus reached for method 4.

Expert C (providing a probability range of 99–100%) followed the same reasoning. When inactivation of spores of C. botulinum is achieved an inactivation equivalent to more than 24.7 min at 121°C would be expected, sufficient to ensure 12 log reductions of C. botulinum, the expert gave a high probability, similarly to method 4.

Expert A (providing a probability range of 0–5%) agreed and would be fine to revise the range as agreed for method 4. Expert F (providing a probability range of 0–1%) agreed as well.

Expert E (providing a probability range of 33–66%) is in middle of the probability range. The expert is uncertain, and the arguments are the same. The model predictions are high but there is a larger underestimation. The expert did not consider C. botulinum, but only the model output and underestimation.

The elicitator asked if a comparable range to method 4, method 7 scenario 4 and method 7 scenario 5 would apply (66–100%) as the arguments are the same. Expert B (providing a probability range of 95–99%) would not include 100% as the highest temperature is different and there are more come‐up times in method 4. Expert C believes that 100% is reasonable as these conditions would lead to a safe process (accepted as a safe for pet food in legislation).

The elicitator proposed a consensus judgement of 66–100% and this was agreed

Method 7 – scenario 5

133°C × 5′

The model output yields a probability of 100% that a 5 log₁₀ inactivation of spores of C. perfringens would not be achieved, based on the t/T profile of the method.

The elicitator proposed for this process the same consensus judgement as for method 7 scenario 5 (66–100%) comparing the t/T profiles of both methods and the individual expert judgements. This was agreed.