Document type: Low-acid canned food process filing
Reference: FDA 21 CFR Part 113 / GMA (NFPA) Bulletin 40-L
Generated: {{ generated_date }}
| Filing number | TC-FDA-{{ '%04d'|format(filing_number) }} |
| Version | {{ version }} |
| Status | Draft — for process-authority review |
| Simulation engine | ThermoCraft (1D conduction + kinetic F₀) |
| Applicable regulation | FDA 21 CFR Part 113 — Low-acid canned foods |
| Required process time | {{ '%.1f'|format(required_process_time) }} min |
| Achieved F₀ | {{ '%.2f'|format(F0_total) }} min (target {{ '%.2f'|format(target_F0) }} min) |
| Log reduction achieved | {{ '%.1f'|format(microbial_log_reduction) }} log |
| Heating-rate index f_h | {{ '%.1f'|format(fh_min) }} min |
| Lag factor j_h | {{ '%.2f'|format(jh) }} |
| Overall conformance | {% if F0_total >= target_F0 %}PASS{% else %}REVIEW REQUIRED{% endif %} |
This section identifies the product, its container and its physical and thermal characteristics as used in the process-filing calculation.
| Product name | {{ product_name }} |
| Container geometry | {{ geometry }} |
| Characteristic length | {{ '%.4f'|format(characteristic_length) }} m |
| Initial product temperature | {{ '%.1f'|format(T_initial) }} °C |
| Density | {{ '%.0f'|format(density) }} kg/m³ |
| Specific heat capacity | {{ '%.0f'|format(specific_heat) }} J/(kg·K) |
| Thermal conductivity | {{ '%.3f'|format(thermal_conductivity) }} W/(m·K) |
| pH classification | Low-acid (> 4.6) — process is under 21 CFR 113 |
The scheduled process is defined by the retort temperature, come-up time, holding time and the resulting accumulated lethality at the cold spot.
| Retort / sterilizer temperature | {{ '%.1f'|format(T_retort) }} °C |
| Come-up time | {{ '%.1f'|format(come_up_time) }} min |
| Surface heat-transfer coefficient | {{ '%.0f'|format(h_surface) }} W/(m²·K) |
| Total required process time | {{ '%.1f'|format(required_process_time) }} min |
| Estimated hold phase | {{ '%.1f'|format(required_process_time - come_up_time) }} min |
| Target F₀ | {{ '%.2f'|format(target_F0) }} min |
| Achieved F₀ (cold spot) | {{ '%.2f'|format(F0_total) }} min |
| Achieved log reduction | {{ '%.1f'|format(microbial_log_reduction) }} log |
| Process margin (F₀ − target) | {{ '%.2f'|format(F0_total - target_F0) }} min |
Conformance: {% if F0_total >= target_F0 %}Achieved F₀ meets the scheduled-process target — the process is adequate for the target microorganism. {% else %}Achieved F₀ is below target — process must be reviewed before filing.{% endif %}
The heating-rate index f_h (time for one log cycle of the heating curve) and the lag factor j_h characterise the conduction heating of the product. They are estimated from the simulated cold-spot heating curve.
| Heating-rate index f_h | {{ '%.1f'|format(fh_min) }} min |
| Lag factor j_h | {{ '%.2f'|format(jh) }} |
| Heating regime | Conduction-heated (high Biot number) |
The temperature history below shows centre and surface response to the retort temperature.
For a conduction-heated product the cold spot is at the thermal centre of the container (r = 0). The final temperature profile confirms the cold spot remains the slowest-heating point.
| Cold-spot location | Thermal centre (r = 0) |
| Final centre temperature | {{ '%.1f'|format(center_final) }} °C |
| Final surface temperature | {{ '%.1f'|format(surface_final) }} °C |
Lethality is expressed as F₀ — the equivalent minutes at the reference temperature 121.1 °C with z = 10 °C, integrated over the cold-spot temperature history:
F₀ = ∫ 10((T(t) − T_ref)/z) dt
| Target organism D-value | {{ '%.3f'|format(D_ref) }} min @ {{ '%.1f'|format(T_ref) }} °C |
| z-value | {{ '%.1f'|format(z_value) }} °C |
| Reference temperature | {{ '%.1f'|format(T_ref) }} °C |
| Total accumulated F₀ | {{ '%.2f'|format(F0_total) }} min |
| Required (target) F₀ | {{ '%.2f'|format(target_F0) }} min |
| Equivalent log reduction | {{ '%.1f'|format(microbial_log_reduction) }} log |
F₀ accumulation over the cycle:
| At end of come-up | {{ '%.3f'|format(f0_comeup) }} min |
| At end of hold / cooling | {{ '%.2f'|format(F0_total) }} min |
| Contribution after come-up | {{ '%.2f'|format(F0_total - f0_comeup) }} min |
Thermal process impact on quality attributes (nutrient retention and cook value) is reported for information; it does not affect the scheduled process for safety.
| Quality retention | {{ '%.1f'|format(quality_retention * 100) if quality_retention is not none else 'n/a' }} % |
| Cook value (C₀, z = 33.1 °C) | {{ '%.1f'|format(cook_value) if cook_value is not none else 'n/a' }} min |
Any deviation from the scheduled process (temperature drop, shortened hold, steam failure) must be evaluated for impact on the accumulated F₀ before product release. The following contingency procedure applies:
| Process authority | _______________________ Date: ________ |
| QA / Compliance reviewer | _______________________ Date: ________ |
| Operations | _______________________ Date: ________ |
Generated by ThermoCraft. This filing is an engineering estimate and must be reviewed and approved by a recognised process authority before submission.
The process calculation solves the transient one-dimensional radial heat-conduction equation on the product geometry (slab / cylinder / sphere) using an implicit Crank–Nicolson scheme. A convection boundary condition with heat-transfer coefficient h_surface and retort temperature T_retort is applied at the surface; the domain uses the stated number of spatial nodes.
Lethality is accumulated at the cold spot (thermal centre) as F₀ = ∫ 10^((T−T_ref)/z) dt over the full cycle, using the Bigelow first-order kinetics with the declared D-value at the reference temperature. The holding phase is sized so that the accumulated F₀ reaches the target before cooling.