Chilling Process Research Articles

Temperature Monıtorıng of Chıllıng System Usıng IoT Technıques

The chilling of milk in dairy sector is important to increase the life time of the milk as well as the quality of milk. The chilling of milk means rapid cooling of raw milk sufficiently at low temperature so that the growth of microorganisms present in the milk is tested. During the chilling process the temperature of milk should be reduced to less than 10°C. The manual process of monitoring the temperature of chilling system continuously is impossible and the continuous running of the compressor is not feasible. Maintaining the chill water temperature at the required level increases the efficiency and the cost of electricity is reduced due to the compressor maintenance. This project aims to continuously monitor the temperature of chiller using IoT techniques. The temperature monitoring sensor helps to send the reading of chiller temperature regularly. If the chiller temperature goes at high rate NodeMCU (Node Micro Controller Unit)-ESP8266 and IFTT application are used as an interface between the user and microcontroller to generate and send the notification to the end users.

Accelerated de-chelation of EDTA-metal complexes: A novel and versatile approach for wastewater and solid waste remediation

Industrial waste, including wastewater and solid waste, often contains toxic heavy metals that necessitate extraction and separation prior to safe disposal or reusing them. Sewage sludge incineration ash (SSIA), a non-incinerable waste, holds significant amounts of heavy metals such as iron, zinc, copper, nickel, chromium, and lead. Recovery and reuse of heavy metals from SSIA and further application of treated SSIA sludge remain challenging. Ethylenediaminetetraacetic acid (EDTA) is widely used for heavy metals chelation in different applications. While its chelation with heavy metals is rapid and easy to achieve, the de-chelation of the metal complexes is otherwise slow (∼3 days) and challenging due to their high stability constants. In this study, we investigate the recovery of heavy metals from SSIA through chelation using EDTA, and develop, for the first time, a method to rapidly de-chelate the EDTA-metal complexes through the facile chilling process (1 – 3 h) that accelerates the separation of EDTA and metal ions. A sequential precipitation of high-purity heavy metals from the EDTA-metal complexes was demonstrated with and without de-chelation. This novel and versatile method allows the separation of many valuable compounds from the treated SSIA, including regenerated EDTA, potassium hexafluorosilicate, iron phosphate, iron(III) hydroxide, iron silicate, titanium phosphate, calcium phosphate, copper(I) thiocyanate, nickel bis(dimethylglyoximate), lead(II) sulfate, and zinc sulfide. This approach opens doors for more sustainable waste management and the recovery of valuable resources from industrial waste.

Exergetic and exergoeconomic analyses of a large-scale industrial beer processing system

This research evaluated the performance of components and sections involved in industrial beer production using exergetic and exergoeconomics methodologies. The system was segmented into five production sections, and three energy input types were considered. The exergetic studies showed an operational exergetic efficiency of 3.33%, with an overall exergetic destruction rate of 5.54 MW and a specific destruction rate of 9.72 kW/hl for beer production. The overall improvement potential and sustainability index were estimated at 4.98 MW and 1.03, respectively. The brewhouse and packaging hall were identified as the sections with the highest production inefficiency, 58.73% and 30.40%, respectively. The exergoeconomic studies revealed a cost rate of 0.1704 USD/s for beer production, with the wort kettle, filling and cocking machine, Kieselguhr candle filter, whirlpool, and brite beer tank identified as the top five significant components in descending order. The efficiency of the system was critically affected by the activities in the packaging hall, particularly those involving energy inputs that cannot be recovered or attributed to the processed stream, beer. Further research is required to determine the cost savings of optimization measures identified from additional steam throttling, downsizing of some main pumps, and exergy loss during heating of wort and beer chilling processes.

Cold-induced damage in boar sperm cooled to 5°C in Lactose Egg Yolk (LEY) medium with different Glycerol concentrations

Boar sperm is highly susceptible to cold damage. When temperature drops to 5°C, the plasmatic membrane is destabilized. The freezing process causes a reduction of the fertility window because frozen/thawed boar sperm has less survivability. The aim of this work was to analyze the effect on sperm characteristics and response to capacitation stimuli of cooling to 5°C using a controlled protocol. Also, we evaluated if the addition of Glycerol 2% or 3% at 5°C was able to modify these parameters. For this purpose, we assessed motility, plasmatic membrane integrity and acrosomal membrane status. Capacitation was induced using Tyrode´s capacitating medium (TCM) and assessed by chlortetracycline stain and induction of acrosomal reaction with Progesterone. Motility patterns were analyzed using a CASA system. These tests were performed at three different points of the freezing curve: 37°C; 17°C and 5°C. Response to TCM vs TBM was only significant at 37°C. While at 37°C and 17°C capacitated sperm was below 20%, at 5°C reached 50% both in the TBM and TCM. CASA analysis showed that spermatozoa exposed to TCM had higher LIN and WOB than those in TBM. All parameters were similar in the Glycerol concentrations studied. These results suggest that the chilling process may be causing an effect similar to cryocapacitation along the cooling curve, starting subtle at 17°C and reaching 50% of the sperm population at 5°C, being independent of Glycerol concentration.

High Salmonella load with serovar virchow dominance pose major public safety risk in postchill broiler carcasses

The objective of this study was to determine Salmonella contamination levels, presence and serovar distribution in broiler carcasses before and after chilling, as well as to evaluate the effectiveness of chilling process. A total of 96 pooled neck skin samples (PNSS) of 48 prechill (PreC) and 48 postchill (PosC) carcasses, representing 480 broilers collected in 6 mo' period were analyzed using ISO 6579-2:2012 Miniaturized Most Probable Number (ISO-mMPN) technique. Species confirmation and serovar identification was performed by Salmonella-specific real-time PCR (Salm-PCR) and conventional serotyping, respectively. Mean Salmonella count was 1.84 log10 MPN/g in PreC, and 1.48 log10 MPN/g in PosC samples, indicating a statistically significant reduction of 0.36 log10 MPN/g (p < 0.05) in the counts by plant's air chill system. Salmonella positivity reduced from 97.9% (47/48) in PreC to 85.42% (41/48) in PosC samples, confirmed by Salm-PCR with identified serovars as S. Virchow (89.77 %) followed by S. Schwarzengrund (9.09%) and S. Bredeney (1.14%). Persistence of high load and prevalence of Salmonella with serovar Virchow dominance (other than the ones mandated in current guidelines) in the final product contributes significant and up to date data to relevant literature, and provides unbiased epidemiological reference to legal authorities for future relevant revisions.

Involvements of membrane lipid and phenolic metabolism in reducing browning and chilling injury of cold-stored Chinese olive by γ-aminobutyric acid treatment

The influences of 1.0 mM γ-aminobutyric acid (GABA) treatment on browning, chilling injury (CI), membrane lipid metabolism, and phenolics metabolism in 2 °C-stored Chinese olive were explored. In comparison with the control Chinese olive, GABA-treated Chinese olive manifested lower CI index, browning index, browning degree, and cell membrane permeability. Additionally, GABA-treated Chinese olive exhibited lower values of saturated fatty acids (SFAs) and phosphatidic acid, lower activities of lipoxygenase, lipase, and phospholipase D, but higher levels of unsaturated fatty acids (USFAs), phosphatidylinositol, and phosphatidylcholine. Moreover, GABA-treated Chinese olive displayed lower PPO and POD activities, but higher activity of PAL, higher values of flavonoids and total phenolics. These data indicate that GABA treatment contributed to alleviating browning and CI occurrences in Chinese olive during the chilling process. This effect was achieved by postponing the degradations of membrane lipid and USFAs, preventing the oxidation of phenolic substances, as well as maintaining the integrity of cellular membranes.

Investigations on the forming mechanism of high-moisture extruded fish noodles based on computational fluid dynamics simulation

High-moisture extrusion technology could improve the added value of fish products. This study explored the forming mechanism of fish noodles in a twin-screw extrusion process by computational fluid dynamics (CFD) simulation and detecting the structural information of the raw material during the extrusion process. The results showed that the screw mainly functioned as a conveyor in the transport and cooking zones, and the disordered degree of protein structure increased, with hydrophobic interactions acting as the primary chemical forces. However, as the material entered the mixing zone, the fluid did a turbulent motion, resulting in the formation of a significant number of disulfide bonds. The fibrillated structure of materials was generated in the forming zone, and disulfide bonds were the predominant chemical bonds. During the chilling process, some hydrogen bonds were restored, and the protein structure was gradually organized, eventually forming the shape of fish noodles. This provided the theoretical foundation to fully understand the high-moisture surimi state during the extrusion process and the development of protein-based food.

Multi-criteria optimization of Cook&amp;Chill processes for network catering establishments

The article presents innovative Cook&amp;Chill technologies, describes the stages of technological production of products. The nature of the technological processes of a catering company is the main factor that determines which types of automated thermal equipment should be used at this enterprise in order to ensure high economic efficiency of its use, facilitate the work of workers engaged in its operation, increase the level of labor automation, the optimization of Cook and Chill processes is shown to be associated with a variety of criteria for choosing the optimal option includes criteria for min deviations from the reference structures: amino acid composition of the product; fatty acid composition; vitamin content; composition of trace elements, as well as criteria for food digestibility, nutritional, biological and energy value of the product. Cook&amp;Chill meets absolutely all the requirements in this regard, allowing you to rationally manage the cost of the product by reducing the cost of producing a dish. The effectiveness of the method has been proven by practical world experience. Cook and Chill technology allows you to increase the yield of batches by three or four times. When preparing dishes, no changes in recipes are required and the current technological standards can be used. Cook and Chill technology can be effectively applied at enterprises with any range of products, up to the widest, and of any capacity. This technology provides for the use of fairly familiar pieces of equipment, such as a convector or microwave oven, air-type intensive cooling systems (blast-chiller) or water-type (tumbler-chiller or turbojet-chiller).

Effect of slaughter age and postmortem aging time on tenderness and water-holding capacity of yak (Bos grunniens) longissimus thoracis muscle

The present study investigated the effect of slaughter age (2.43 ± 0.20, 4.15 ± 0.19, 6.62 ± 0.18, 10.59 ± 0.74 years) and postmortem aging time (1, 24, and 72 h) on the tenderness and water-holding capacity (WHC) of yak longissimus thoracis muscles to determine the most suitable age for slaughter to ensure product consistency. Under conventional postmortem aging conditions (4 °C), muscles of each age group exhibited the effect of cold shortening. Once the cold shortening occurred, the age effect on thickening muscle fiber and developing cross-links of collagen, considered to intensify the meat toughness, became less important. Owing to greater carcass weight and intramuscular fat, muscles of the older carcass (over 6-year-old) were less influenced by the cold shortening effect during the chilling process and showed lessened sarcomere contraction, delayed formation of drip loss channels, and increased level of myofibril fragmentation index (MFI) and myofiber structural disintegration, resulting in greater tenderness and WHC, especially 6–7 years group. Aging of 72 h structurally disintegrated the collagen cross-linking and integrity of muscle fibers and elevated the MFI, improving the meat tenderness. Therefore, the suitable slaughter age for yak is 6–7 years old and after 72 h aging, improved quality of yak meat can be obtained.

Effect of chilling on pupal developmental arrest and subsequent impact on quality control parameters of adult blowfly, Lucilia cuprina (Diptera: Calliphoridae)

The chilling process will surely be a very cost-effective measure for repeated mass rearing and be an effective source for the requirements of a huge number of pupae collected and supplied for the sterile insect technique (SIT) program. In Bangladesh, blowfly (Lucilia cuprina) is a main cause of damage of marine fish during sun drying in coastal areas. The chilling for a certain duration at a certain temperature may store pupae for a specific time by reducing their metabolism. In this study, the effect of chilling temperature and exposure period on pupal developmental arrest was assessed and the subsequent impact on quality control parameters of the adult blowfly, L. cuprina was also observed. We considered the effects of three temperature (4, 7, and 10 °C) regimes and three exposure periods (10, 20, and 30 days) on 3-day-old pupae. Results showed that all the parameters were affected significantly by all the chilling temperatures and durations. Adult emergence, flight ability, pupal weight, adult longevity, fecundity, and fertility decreased with the increase of exposure duration, but partial emergence and pupal duration increased with exposure durations. Storages at 4 °C for 20 and 30 days had no adult emergence. Emergence occurred before the chilling duration at 10 °C for 20 and 30 days which clearly indicated the unsuitable condition for storage parameters. Though the emergence, flight ability, pupal weight, and longevity at 10 °C for 10 days had no significant difference with control, the fecundity and fertility did have a significant difference. In addition, treatment at 7 °C for 10days, the adult emergence, flight ability, pupal weight, longevity, fecundity, fertility, pre-oviposition, and oviposition period had no significant difference with control. Considering all the parameters, it can be concluded that the pupae of L. cuprina can be stored at 7 °C of chilling temperature for 10 days long without any deterioration towards the quality of adult flies.

Effect of mitochondria-targeted antioxidant Mito-TEMPO addition to the sperm herbal extender on ram chilled sperm quality

The aim of this study was to evaluate the sperm quality preservation in sheep using mitochondria-targeted antioxidant Mito-TEMPO during chilling process. In this experiment, semen samples were collected from five Zandi rams and added to the extender containing 0, 0.5, 1, 5, 50 and 500 µM Mito-TEMPO and stored at 4 ˚C until 48 hours. Sperm quality was evaluated at 0, 24 and 48 hours after chilling and total motility, progressive motility, viability, membrane integrity, mitochondrial activity and lipid peroxidation were assessed. No difference was observed between treatments at time 0 of cooling. During 24 and 48 hours cooling periods, using 5 and 50 µM Mito-TEMPO increased total motility, progressive motility, viability, membrane integrity, mitochondrial activity and decreased lipid peroxidation in ram chilled sperm. In conclusion, using 5 and 50 µM Mito-TEMPO in chilling herbal extender could be a suitable method to conserve ram sperm quality during chilling process.

Cold thermal energy storage for milk chilling: A numerical and experimental study

One of the main challenges in small holding dairy production systems is the commencement of cold-chain from the point of milk production. Such systems often rely on pooled milk in a supply chain, with the chilling operations being initiated once substantial quantities of milk (>500 L) are collected. Hence, there is a need to develop an energy efficient and passive thermal storage device for chilling of small volumes of milk. The present study explored a novel approach of developing the phase change materials (PCM) encapsulated inside a spherical module as an immersion cooling device to chill a pool of milk (5 L) held in a vessel. The application of TiO 2 nanoparticles at (0.05–1.00% by wt. ) for developing nanoparticle enhanced water based PCM with improved energy storage was also explored. Transient energy exchange and phase-transition of the PCMs during the milk chilling process was numerically simulated using enthalpy-porosity and volume of fluid model of computational fluid dynamics (CFD). The CFD simulated results were validated through the experimental observations and the flow visualization of the temperature distribution and melting fronts clearly affirmed the rapidity of energy exchange due to the addition of nanoparticles into the PCM. • TiO 2 nanoparticle enhanced phase change materials (PCM) were capsuled inside a portable stainless steel spherical module. • Experimental and numerical transient energy storage (charging) and discharge during passive milk chilling inside a milking vessel were studied. • Nanoparticles accelerated the energy storage, discharge and milk chilling rates significantly. • Studies revealed the scope of deploying TiO 2 nanoparticle enhanced PCM in energy-efficient real-time passive milk chillers.

Distribution of Extremely Heat-Resistant Escherichia coli in the Beef Production and Processing Continuum

Understanding the dynamics of stress-resistant Escherichia coli (E. coli) across the meat production and processing continuum is important for tracking sources of such microbes and devising effective modes of control. The Locus of Heat Resistance (LHR) is a ∼14–19 Kb genetic element imparting extreme heat resistance (XHR) in Enterobacteriaceae. It has been hypothesized that thermal and antimicrobial interventions applied during meat processing may select for LHR+E. coli. Thus, our goal was to study the prevalence and molecular biology of LHR+E. coli among lots of beef cattle (n = 3) from production through processing. Two hundred thirty-two generic E. coli isolated from the same animals through seven stages of the beef processing continuum (cattle in feedyards to packaged strip loins) were examined. LHR+E. coli were rare (0.6%; 1 of 180) among the early stages of the beef continuum (feces and hides at feedlot, feces and hides at harvest, and preevisceration carcasses), whereas the prevalence of LHR+E. coli on final carcasses and strip loins was remarkably higher. Half (14 of 28) of the final carcass E. coli possessed the LHR, while 79.2% (19 of 24) of the strip loin E. coli did. Eighty-five percent (29 of 34) of the LHR+E. coli presented with the XHR phenotype. The selection or enrichment of LHR+E. coli from harvest steps to the final products appeared unlikely as the LHR+E. coli isolates were effectively controlled by antimicrobial interventions typically used during beef processing. Further, whole-genome sequencing of the isolates suggested LHR+E. coli are persisting in the chilled processing environment and that horizontal LHR transfer among E. coli isolates may take place.

Biomapping salmonella serovar complexity in broiler carcasses and parts during processing

Salmonella contamination of poultry remains a food safety challenge for broiler processors. The objectives of this study were to measure the efficacy of antimicrobial interventions in commercial broiler processing plants to reduce Salmonella and to assess changes in the Salmonella serovars before and after the chilling process. Three commercial processing plants were visited during 2020–2021 and 660 carcass rinse samples collected at three locations (before and after the pre-chiller, and after the main chiller) plus 80 drumstick samples across eight independent visits were collected and screened for Salmonella. Overall, Salmonella was detected in carcass rinse samples collected at 66% (145/220) pre pre-chill, 13.2% (29/220) post pre-chill and 2.3% (5/220) post-chill locations. Serovars Typhimurium, Infantis, and Kentucky were most commonly identified. CRISPR-SeroSeq was used to assess serovar populations and approximately 40% of carcasses (41.2% pre pre-chill and 37.0% post pre-chill) contained more than one serovar (range 1–4 serovars per carcass). Two out of five post-chill carcasses also contained multiple serovars. The low Salmonella incidence post intervention limited any conclusions about survival of particular serovars. Our data shows that serovar presence varies between flocks, even within the same broiler complex and CRISPR-typing also reveals evidence of multiple strains of the same serovar within a flock processed on the same day. We also compared Salmonella serovar populations across 128 paired samples (256 total samples), encompassing samples enriched in both RV and TT broths and found high concordance (Bray-Curtis <0.3) in 93% of samples. This study shows that antimicrobial interventions significantly reduce Salmonella on the carcasses during chilling and demonstrates effective use of a novel deep serotyping technology to track Salmonella serovars through processing.

Encapsulation of Rich-Carotenoids Extract from Guaraná (Paullinia cupana) Byproduct by a Combination of Spray Drying and Spray Chilling.

Guaraná byproducts are rich in carotenoids, featuring strong antioxidant capacity and health-promoting benefits. However, these compounds are highly susceptible to oxidation and isomerization, which limits their applications in foods. This research aimed to encapsulate the carotenoid-rich extract from reddish guaraná peels by spray drying (SD), chilling (SC), and their combination (SDC) using gum arabic and vegetable fat as carriers. The carotenoid-rich extract was analyzed as a control, and the formulations were prepared with the following core–carrier ratios: SD20 (20:80), SD25 (25:75), SD33 (33:67), SC20 (20:80), SC30 (30:70), SC40 (40:60), SDC10 (10:90), and SDC20 (20:80). The physicochemical properties of the formed microparticles were characterized, and their storage stability was evaluated over 90 days. Water activity of microparticles formed during the SD process increased during storage, whereas those formed by SC and SDC processes showed no changes in water activity. The formed microparticles exhibited color variation and size increase over time. Carotenoid degradation of the microparticles was described by zero-order kinetics for most treatments. Considering the higher carotenoid content and its stability, the optimum formulation for each process was selected to further analysis. Scanning electron micrographs revealed the spherical shape and absence of cracks on the microparticle surface, as well as size heterogeneity. SD increased the stability to oxidation of the carotenoid-rich extract by at least 52-fold, SC by threefold, and SDC by 545-fold. Analysis of the thermophysical properties suggested that the carrier and the process of encapsulation influence the powder’s thermal resistance. Water sorption data of the SDC microparticles depended on the blend of the carrier agents used in the process. Carotenoid encapsulation via an innovative combination of spray drying and spray chilling processes offers technological benefits, which could be applied as a promising alternative to protect valuable bioactive compounds.

Effect of Adding Different Vitamin D3 Concentrations on Chilled Storage of Awassi Ram Semen

Prolong semen quality following the chilled process is important for assistant reproductive techniques such as artificial insemination. The objective of the current study is to evaluate the effect of adding different concentrations of vitamin D3 to the Tris-egg yolk extender on some semen parameters stored at 5ºC. Three Awassi rams were used in this study. Semen samples were collected pooled and diluted with an egg-yolk extender (1:10). Four Aliquots were divided into three treatments with vitamin D3 (T1= 0.02, T2=0.004, T3= 0.002 gm) and one control (T0). All samples were chilled to 5ºC. Samples were estimated at time h0 and after 24, 48,72, and 96 hours following treatment. Individual motility, dead sperm, abnormal sperm, and hypo-osmotic swelling test (HOST) was used in this study. The individual motility significantly decreased in T1 compared to T0, T2, and T3 in all studded hours. Also, the individual motility in T3 was significantly greater at h48, h72, and h96, compared to T0, T1. The dead sperm was significantly greater in T1 on h0 compared to T0, T2, and T3. The HOST test was significantly greater in T0, T2, and T3 on h0 compared to T1. In conclusion, low vitamin D3 supplementation to the Awassi semen might potentiate the individual motility for up to 72 hours and trend to enhance some semen parameters.

Investigation of effect of cold plasma on microbial load and physicochemical properties of ready-to-eat sliced chicken sausage.

Sausage may be contaminated with spoilage microorganisms during the processing after cooking and during the chilling process. Non-thermal decontamination such as cold plasma (CP) can be used to prevent the growth of spoilage microorganisms in sausage after packaging. The objective of this study was to investigate the effects of CP on sliced chicken sausage during 60days of storage. The sausages were divided into three groups: negative control, ultraviolet (UV)-radiated (positive control for 200 and 400s), plasma (power of 30 and 70 w for 200 and 400s). The microbial load, pH, color, peroxide value (PV), and textural parameters of the sausages were compared with those of the negative and positive controls. According to the results, total count decreased significantly (p < 0.05) about 1.87 log CFU/g after 400s of the CP treatment and at the end of storage at 70 w. CP reduced the lightness (L*) and increased redness (a*) more than the UV rays. The PV more increased by UV rather than by plasma. There were no significant changes in pH value and textural parameters after the CP and UV treatments. Although CP more affected some of the physicochemical properties, compared with UV, CP was shown to efficiently inhibit the rapid growth of microorganisms, resulting in a longer shelf-life.

Survey of Meat Collected from Commercial Broiler Processing Plants Suggests Low Levels of Semicarbazide Can Be Created during Immersion Chilling

Semicarbazide (SEM) is routinely employed as an indicator for the use of nitrofurazone, a banned antimicrobial. The validity of SEM as a nitrofurazone marker has been scrutinized because of other possible sources of the compound. Nonetheless, a U.S. trade partner rejected skin-on chicken thighs because of SEM detection and suspected nitrofurazone use. Because nitrofurazone has been banned in U.S. broiler production since 2003, we hypothesized that incidental de novo SEM formation occurs during broiler processing. To assess this possibility, raw leg quarters were collected from 23 commercial broiler processing plants across the United States and shipped frozen to our laboratory, where liquid chromatography-mass spectrometry was used to quantitatively assess for SEM. Leg quarter samples were collected at four points along the processing line: hot rehang (transfer from the kill line to the evisceration line), prechill (before the chilling process), postchill (immediately following chilling), and at the point of pack. Thigh meat with skin attached was removed from 535 leg quarters and analyzed in triplicate for SEM concentrations. The concentrations ranged from 0 to 2.67 ppb, with 462 (86.4%) of 535 samples below the regulatory decision level of 0.5 ppb of SEM. The 73 samples over the 0.5-ppb limit came from 21 plants; 53 (72.6%) of positive samples were in meat collected after chilling (postchill or point of pack). The difference in both prevalence and concentration of SEM detected before and after chilling was highly significant (P < 0.0001). These data support our hypothesis that SEM detection in raw broiler meat is related to de novo creation of the chemical during processing.

Bio-Mapping of Microbial Indicators to Establish Statistical Process Control Parameters in a Commercial Beef Processing Facility.

The objective was to conduct a bio-mapping of microbial indicators to determine statistical process control (SPC) parameters at a beef processing plant to establish microbiological baselines and process control parameters to support food safety management decisions. EZ-ReachTM swabs were used to collect 100 cm2 area samples at seven different locations throughout the beef processing line at four different regions on the carcass. Each of the eight sampling days evaluated included three samples collected per sampling location/carcass region for a total of 84 samples per day. Enumeration of total aerobic bacteria, Enterobacteriaceae, and Escherichia coli was performed on each sample. Microbial SPC parameters were estimated for each sampling point. Statistical differences between sampling points for all carcass locations (p < 0.001) followed an overall trend with higher values at pre- and post-evisceration with a continuous decrease until final interventions with a slight increase in counts during the chilling process and a final increase after fabrication. Variability at sampling points is the result of the nature of the process and highlights open opportunities for improvement of the food safety system. Microbial baselines and SPC parameters will help support decision making for continuous process improvement, validation of intervention schemes, and corrective action implementation for food safety management.

73 Commercial Management of Fresh Pork Quality Using Post-Mortem pH and Temperature Declines

Abstract Historically, research involving the pH decline of pork has been conducted under university conditions with the use of electrical stunning and conventional chilling (minimum temperature &amp;gt; -10). Most large commercial slaughter plants in the U.S. currently use CO2 stunning and many have some form of accelerated chilling of the carcass. With ante-mortem stress level of the pig and post-mortem carcass temperature decline being 2 of the major factors affecting post-mortem pH decline rate, it should be expected that the pH decline rate may be different in current commercial conditions when compared with the literature. Our work has focused on developing methods to measure pH and temperature decline in short intervals (5 min, 15 min, 30 min, or 1 h) and determine the critical time periods to manage the chilling process in order to slow pH decline and obtain higher ultimate pH levels (20h). This research indicates the potential to alter the carcass chill curve to make precision adjustments in the quality of pork.