Identification of Corrosive Volatile Compounds Found in the Headspace of Chicken Noodle Soup Retorted in Metal Cans.

This study investigated the development of volatile compounds in the headspace of canned chicken noodle soup (and sought to develop appropriate testing methods). The primary objective of this study was to identify compounds in the soup that were responsible for the initiation of the corrosion in the cans. The long-term goal of these studies is to develop an efficient method to investigate how headspace volatile compounds in foods could cause corrosion defects in metal cans and how these could be corrected without undermining the quality and safety of the food. To determine and to evaluate the volatile compounds in the canned soups, selected ion flow tube-mass spectrometry (SIFT-MS) was used. The coatings of the tested cans were carefully stripped off and analyzed using this SIFT-MS method. High levels of sulfur-containing volatile compounds and organic acids were detected in both the soups and the coatings. It was concluded that during the retorting of the sealed cans filled with chicken soup, sulfur-containing volatile compounds formed and entered the headspace of the tested cans and interacted with the coating, leading to the formation of blackened stains.

Role and Importance of Functional Food Packaging in Specialized Products for Vulnerable Populations: Implications for Innovation and Policy Development for Sustainability.

Specialized products can be needed to help meet the nutrition requirements of vulnerable populations, including infants and young children, those who are ill, and older adults. Laws and regulations delineate distinct categories for such products including medical foods or formulated liquid diets, foods for special dietary use (FSDUs), infant formulas, and natural health products (NHPs). Yet, the literature is limited regarding the role and importance of functional and sustainable packaging for specialized products. This perspective review describes these unique product categories and the role of packaging as well as regulatory considerations. Furthermore, reviewed are how waste reduction strategies and emerging legislative/regulatory policies in the United States and Canada may not adequately address the functional packaging requirements for specialized products. The paper concludes by offering perspectives for emerging innovations and policy development for sustainability.

Heat-induced compounds development in processed tomato and their influence on corrosion initiation in metal food cans.

Selected ion flow tube mass spectrometry (SIFT-MS) and ion chromatography (IC) were used to investigate the presence of volatile and nonvolatile compounds in canned tomatoes and in the polymeric lining before and after retorting the cans. This allowed us to observe if these compounds contributed to corrosion and the migration of iron and tin compounds from the cans to the tomatoes. Diced Roma tomatoes and other simulant treatment groups were sealed in two-piece tinplated cans (controls in glass jars), retorted at 121℃ for 30 min, then stored at 49℃ for 50 days. Results showed that thermal degradation of amino acids in the tomatoes gave rise to volatile methyl sulfides and nonvolatile nitrogenous compounds which were subsequently sorbed by the can lining. SIFT-MS showed a 20-fold increase in dimethyl sulfide concentration. Inductively coupled plasma (ICP-MS) results showed fourfold and 16-fold increases in iron and tin compounds, respectively, that migrated from the metal to the tomatoes as a result of acid and electrolyte interactions.

Development of Seed Butter Made with Pumpkin, Sesame, and Sunflower Seeds and the Influence of Natural Antimicrobials and Stabilizers on Its Shelf Life.

This study investigated the antimicrobial efficacies of grape seed extract (GSE) and cinnamaldehyde (CIN) against Salmonella enterica and Listeria innocua and the influence of hydrogenated rapeseed oil (HRO) and palm kernel oil (PKO) on the texture and oil separation in pumpkin/sesame/sunflower seed butter. The results showed that the 10 and 15% GSE significantly reduced both S. enterica and L. innocua. Cinnamaldehyde was effective against S. enterica but did not significantly reduce L. innocua. Hydrogenated rapeseed oil at 2 and 3% concentrations prevented hardening of the seed butter and thus facilitated its spreadability. The 3% HRO-stabilized seed butter had less oil separation and a better texture than the control. Although PKO influenced the hardness of the butter after 35 days, its effect was not as pronounced as that of HRO. The HRO was also more effective in reducing the adhesiveness and thus the stickiness of the seed butter when compared with the PKO. Both HRO and PKO did not influence cohesiveness and adhesiveness changes to the butter after 7 days, although the HRO samples showed a lower level of cohesiveness when initially added to the samples.

Development of antiviral and bacteriostatic chitosan-based food packaging material with grape seed extract for murine norovirus, Escherichia coli and Listeria innocua control.

Edible coatings and films based on chitosan, and containing grape seed extract (GSE), were developed and their activities tested against murine norovirus (MNV-1), Listeria innocua and Escherichia coli K12. Grape seed extract concentrations of 1%, 1.5%, and 2.5% dissolved in deionized water resulted in MNV-1 plaque reductions (p < .05) of 1.75, 2.60, and 3.58 log PFU/ml, respectively after 3 hr. Two percent (w/w) chitosan solutions incorporated with 2.5% and 5% GSE also significantly (p < .05) reduced MNV-1 titers by 2.68 and 4.00 log PFU/ml, respectively after 3 hr. Additionally, incorporation of the GSE into the chitosan films also showed antimicrobial efficacy against MNV-1, L. innocua, and E. coli K12. Chitosan films containing 5%, 10%, and 15% GSE caused MNV-1 reductions of 0.92, 1.89, and 2.27 log PFU/ml, respectively, after 4 hr of incubation. Also, after 24 hr, the 5% and 10% GSE films reduced MNV-1 titers by 1.90 and 3.26 log PFU/ml, respectively, while the 15% GSE film reduced MNV-1 to undetectable levels. For E. coli K12, there were reductions of 2.28, 5.18, and 7.14 log CFU/ml after 24 hr exposure by the 5%, 10%, and 15% GSE films, respectively. Also, L. innocua counts were reduced by 3.06, 6.15, and 6.91 log CFU/ml by the 5%, 10%, and 15% GSE films, respectively. This study demonstrated that GSE in edible films and coatings is effective against the organisms tested, and this shows that they are effective against foodborne microbes of public health concerns.

Antimicrobial Activity of Chitosan-Based Films Enriched with Green Tea Extracts on Murine Norovirus, Escherichia coli, and Listeria innocua.

Edible films can be designed to serve as carriers of antimicrobial agents and be used to control pathogenic foodborne viruses and bacteria. This research tested this concept by dissolving green tea extract (GTE) in chitosan film-forming solutions (FFS) and using it to prepare dried chitosan edible films. As a control, the GTE was also dissolved in deionized water (DW). The FFS and the dried chitosan films with the GTE and the DW without chitosan were all evaluated against murine norovirus (MNV-1), Escherichia coli K12, and Listeria innocua. Both the FFS and the DW with GTE were incubated with ~107 PFU/ml of the virus suspensions for 3 h. The chitosan films with GTE were incubated for 4 and 24 h at 23 ± 1°C. The results showed that the DW containing 1, 1.5, and 2.5% aqueous GTE, significantly (p < 0.05) reduced MNV-1 plaques by 1.7, 2.5, and 3.3 logs after 3 h exposure, respectively. Similarly, FFS containing 2.5 and 5.0% GTE reduced MNV-1 counts by 2.5 and 4.0 logs, respectively, after 3 h exposure. The dried chitosan films with 5, 10, and 15% GTE were also effective against MNV-1 infectivity. After 24 h incubation, the 5 and 10% chitosan GTE films produced significant (p < 0.05) titer reductions of 1.6 and 4.5 logs, respectively. Chitosan films containing 15% GTE reduced MNV-1 plaques to undetectable levels in 24 h. All chitosan GTE films reduced E. coli K12 and L. innocua populations to undetectable levels in tryptic soy broth after 24 h exposure. The results of this study showed that edible films enriched with GTE have potential to reduce both foodborne viruses and bacteria.

Reduction in microbial survival on food contact surfaces by a spray coated polymerized quaternary ammonium compound.

Using polymerization and immobilization techniques, the loss of antimicrobial efficacy of a quaternary ammonium compound (QAC) was minimized by decreasing its solubility and crosslinking it to metal substrates. The survivability of Listeria innocua and Escherichia coli K12 inoculated to silane QAC coated metal surfaces was compared with uncoated metal surfaces at different treatment conditions for up to 6 months storage. Resilience of the coating material to repeated cleaning, up to 20 washing and rinsing cycles, was also investigated. No evidence of bacteria viability (>5 log reduction of colony-forming unit) was observed for L. innocua when they were inoculated onto coated surfaces stored for 3 months, whereas E. coli was reduced by 3 to 4-logs. For the viable L. innocua cells on the coated surfaces, >5 log reductions were achieved even after the coated surfaces were cleaned by 20 washing and rinsing cycles prior to the cells' inoculation. For the E. coli cells, ~ 2 log reductions were achieved after 5 cleaning cycles and <1 log reduction after 10 or more cleaning procedures. Overall, the results showed that the coating had antimicrobial activity against Gram-positive bacteria while it showed moderate activity to Gram-negative bacteria.

Recovery of microorganisms on fabric materials after low water temperature washing with non-oxidizing acidic bleaching formulation by culture method.

The recovery of microorganisms to different fabrics was evaluated after a washing process combined with a food-grade non-oxidizing acidic formulation and low washing water temperature. Cotton, polyester and a polyester/cotton blend fabric samples were inoculated with Escherichia coli, Listeria innocua and Saccharomyces cerevisiae, then dried for 1 day. They were separately placed in a simulated fabric washer and decontaminated for 1 and 10 min with the acidic formulation at 23 °C water washing temperature. The combination of direct detecting and dilution methods was used to detect survivors on fabrics. The use of ≥ 0.1% acidic formulation in the washing process significantly increased the efficacy of the washing for all fabric samples. Microorganisms on the cotton and mixed fabric appeared to bind more strongly and were more resistant to the washing process. No viability was observed on the fabric swatches at 1 cfu/sample detection limit when the washing process was combined with 0.5% acidic formulation in the 10 min washing cycle. These findings can be used to increase the efficiency of sanitizing fabrics in an environmentally friendly way, for remove harmful microorganisms from them and reduce cross-contamination.

Effect of riboflavin on the photo-oxidative stability of vegetable oil in salad dressing.

Differential scanning calorimetry (DSC), headspace oxygen and solid phase microextraction gas chromatography and peroxide value were used to evaluate the effect of riboflavin on the photo-oxidation of vegetable oil in salad dressing. Salad dressings with 0, 5, 20, 50 and 100 ppm added riboflavin were stored under light (2500 lux) at 25 °C for 5 days. Crystallisation peaks in the DSC thermograms of the oil samples shifted to lower temperatures and enthalpies decreased as the storage time increased. As the riboflavin concentrations increased from 0 to 100 ppm, the crystallisation enthalpies increased from 27 to 31 J/g and the maximum crystallisation temperature increased from -64 to -62 °C during the 5 day storage. Headspace oxygen depletion rates, the formation of volatile compounds and peroxide values of the salad dressing samples simultaneously decreased with the addition of riboflavin, showing that riboflavin protected the oil in salad dressing from photo-oxidation.

Efficacies of sodium hypochlorite and quaternary ammonium sanitizers for reduction of norovirus and selected bacteria during ware-washing operations.

Cross-contamination of ready-to-eat (RTE) foods with pathogens on contaminated tableware and food preparation utensils is an important factor associated with foodborne illnesses. To prevent this, restaurants and food service establishments are required to achieve a minimum microbial reduction of 5 logs from these surfaces. This study evaluated the sanitization efficacies of ware-washing protocols (manual and mechanical) used in restaurants to clean tableware items. Ceramic plates, drinking glasses and stainless steel forks were used as the food contact surfaces. These were contaminated with cream cheese and reduced-fat milk inoculated with murine norovirus (MNV-1), Escherichia coli K-12 and Listeria innocua. The sanitizing solutions tested were sodium hypochlorite (chlorine), quaternary ammonium (QAC) and tap water (control). During the study, the survivability and response to the experimental conditions of the bacterial species was compared with that of MNV-1. The results showed that current ware-washing protocols used to remove bacteria from tableware items were not sufficient to achieve a 5 log reduction in MNV-1 titer. After washing, a maximum of 3 log reduction in the virus were obtained. It was concluded that MNV-1 appeared to be more resistant to both the washing process and the sanitizers when compared with E. coli K-12 and L. innocua.

Transmission electron microscopic analysis showing structural changes to bacterial cells treated with electrolyzed water and an acidic sanitizer.

UNLABELLED: The effects of various sanitizers on the viability and cellular injury to structures of Escherichia coli and Listeria innocua were investigated. A food grade organic acidic formulation (pH 2.5) and acidic, neutral, and basic electrolyzed water [AEW (pH 2.7, oxidation reduction potential; ORP: 1100 mV, free available chlorine; FAC: 150 ppm), NEW (pH 6.9, ORP: 840 mV, FAC: 150 ppm), BEW (pH 11.6, ORP: -810 mV)] were used to treat E. coli and L. innocua cells. After 10 min of exposure to the sanitizers, changes to the bacterial numbers and cell structures were evaluated by plate counting and transmission electron microscopy (TEM), respectively. It was concluded from the results that the sanitizers reduced the E. coli cells between 2 and 3 log CFU/mL. Except for the BEW treatment, reductions in L. innocua population were greater (>1 log CFU/mL) than that of E. coli for all treatments. Data from the TEM showed that all sanitizers caused changes to the cell envelope and cytoplasm of both organisms. However, smaller changes were observed for L. innocua cells. Decrease in the integrity of the cell envelope and aggregation of the cytoplasmic components appeared to be mainly because of exposure to the sanitizers. The organic acid formulation and AEW were the most effective sanitizers against bacterial cells, indicating that penetration of acidic substances effectively caused the cell inactivation. PRACTICAL APPLICATION: An understanding of the method in which E-water and an acidic sanitizer cause injury to E. coli and L. innocua would be helpful in selecting an effective chemical agent as a food safety tool. This will allow a scientist to target similar microorganisms such as food borne bacteria with structures that are vulnerable to the sanitizer.

Efficacy of sanitized ice in reducing bacterial load on fish fillet and in the water collected from the melted ice.

This study investigated the efficacy of sanitized ice for the reduction of bacteria in the water collected from the ice that melted during storage of whole and filleted Tilapia fish. Also, bacterial reductions on the fish fillets were investigated. The sanitized ice was prepared by freezing solutions of PRO-SAN (an organic acid formulation) and neutral electrolyzed water (NEW). For the whole fish study, the survival of the natural microflora was determined from the water of the melted ice prepared with PRO-SAN and tap water. These water samples were collected during an 8 h storage period. For the fish fillet study, samples were inoculated with Escherichia coli K12, Listeria innocua, and Pseudomonas putida then stored on crushed sanitized ice. The efficacies of these were tested by enumerating each bacterial species on the fish fillet and in the water samples at 12 and 24 h intervals for 72 h, respectively. Results showed that each bacterial population was reduced during the test. However, a bacterial reduction of < 1 log CFU was obtained for the fillet samples. A maximum of approximately 2 log CFU and > 3 log CFU reductions were obtained in the waters sampled after the storage of whole fish and the fillets, respectively. These reductions were significantly (P < 0.05) higher in the water from sanitized ice when compared with the water from the unsanitized melted ice. These results showed that the organic acid formulation and NEW considerably reduced the bacterial numbers in the melted ice and thus reduced the potential for cross-contamination.

Efficacy of electrolyzed water and an acidic formulation compared with regularly used chemical sanitizers for tableware sanitization during mechanical and manual ware-washing protocols.

This study investigated residual bacteria and different food types left on tableware items after various washing and sanitization protocols. Escherichia coli K-12 and Staphylococcus epidermidis were inoculated into whole milk and soft cream cheese. The milk was used to contaminate regular drinking glasses and the cheese was used to contaminate plates and silverware. These tableware items were washed in manual (43 degrees C) and mechanical (49 degrees C) washers and sanitized with different sanitizers (24 degrees C) for 5 s. Quaternary ammonium compound, sodium hypochlorite, peroxyacetic acid, neutral electrolyzed water (NEW), and a combination of citric acid with sodium dodecylbenzene sulfonate (acidic formulation) were used as the chemical sanitizers. Tap water was used as a control. Results showed that at least 5-log reductions in both bacterial numbers were achieved for all sanitizers in both types of washers, except for the control. With mechanical dishwashing, the NEW and acidic formulation treatments reduced bacterial populations by >6.9 and >6.0 log CFU per tableware item, respectively. With the manual operation, bacterial numbers were reduced by >5.4 and >6.0 log CFU per tableware item, respectively. This study revealed that NEW and the acidic formulation are as effective as the other chemical sanitizers for food contact surface sanitization in manual and mechanical ware washing.

Leak detection in polyethylene terephthalate bottles filled with water and pulped and unpulped orange juice using a vacuum decay system.

This research evaluated an offline vacuum decay leak detection system for 1775-ml polyethylene terephthalate (PET) bottles. These bottles were filled with water and pulped and unpulped orange juice and induction sealed with an aluminum liner and an outer 38-mm continuous thread polypropylene cap. The objectives of this study were to evaluate (i) minimum leak size sensitivity of the instrument; (ii) ability to identify weak but nonleaking seals; (iii) effect of varying fill heights on the equipment's sensitivity; and (iv) percentage of false-positive and negative results likely to be obtained during a normal test run. To meet these objectives, leaks 5, 10, 15, 20, 30, 40, and 50 microm were created in the PET bottles. A second set of bottles was induction sealed at high voltage and 1, 1.5, 2, 2.5, 3, 3.5, and 4 s of dwell time. A third set of bottles with good seals was filled with differing headspace measurements of brimful, 1, 2, 3, 4, and 5 cm. After optimizing the equipment, leak tests on random sets of leaking and nonleaking bottles showed 0.0% false-positive and 0.0% negative identifications. Results showed 5-microm minimum leak size detection for bottles filled with all products. Optimum seal conditions were >2 but <3 s at high voltage. Product fill heights >2 to < or =3 cm did not affect the efficiency of the equipment. These results show that this vacuum decay system has potential for use in identifying leaks in PET bottles used for food packaging.

Evaluation of magnetic resonance for detection of bacterial contamination in low-acid, shelf-stable packaged soymilk.

This study evaluated magnetic resonance (MR) as a nondestructive method for detection of bacterial contamination in shelf-stable soymilk and cheese sauce. To accomplish this, individual 355-ml polymeric trays filled with soymilk and inoculated with Bacillus stearothermophilus and Bacillus subtilis (10(3) CFU) were incubated for up to 28 h at 55 degrees C and 62 h at 37 degrees C, respectively. MR relaxation times (T2) of these samples were then correlated with the bacterial growth as well as viscosity and pH changes caused by the bacteria in the packaged soymilk. In addition, this study investigated the ability of MR to differentiate between regularly processed cheese sauce and cheese sauce that was modified with alpha-amylase as a spoilage simulation. Results showed increased MR T2 relaxation times after the bacterial populations reached 10(8) CFU/ml (after 18 h) and 10(7) CFU/ml (after 44 h) for B. stearothermophilus and B. subtilis, respectively. B. subtilis had an undetectable influence on viscosity but a profound influence on pH. B. stearothermophilus, in comparison, significantly lowered the pH and increased the viscosity of the soymilk. MR was able to distinguish between regularly processed 85-g pouches of cheese sauce and other pouches with sauce that were modified with 0.5 ml of 1% alpha-amylase solution. These results showed that MR has the potential to be used for nondestructive detection of physical changes insoymilk and cheese sauce induced by bacterial growth and enzymatic activities, respectively.

Extended shelf life of soy bread using modified atmosphere packaging.

This study investigated the use of modified atmosphere packaging (MAP) to extend the shelf life of soy bread with and without calcium propionate as a chemical preservative. The bread samples were packaged in pouches made from low-density polyethylene (LDPE) as the control (film 1), high-barrier laminated linear low-density polyethylene (LLDPE)-nylon-ethylene vinyl alcohol-nylon-LLDPE (film 2), and medium-barrier laminated LLDPE-nylon-LLDPE (film 3). The headspace gases used were atmosphere (air) as control, 50% CO2-50% N2, or 20% CO2-80% N2. The shelf life was determined by monitoring mold and yeast (M+Y) and aerobic plate counts (APC) in soy bread samples stored at 21 degrees C +/- 3 degrees C and 38% +/- 2% relative humidity. At 0, 2, 4, 6, 8, 10, and 12 days of storage, soy bread samples were removed, and the M+Y and APC were determined. The preservative, the films, and the headspace gases had significant effects on both the M+Y counts and the APC of soy bread samples. The combination of film 2 in the 50% CO2-50% N2 or 20% CO2-80% N2 headspace gases without calcium propionate as the preservative inhibited the M+Y growth by 6 days and the APC by 4 days. It was thus concluded that MAP using film 2 with either the 50% CO2-50% N2 or 20% CO2-80% N2 was the best combination for shelf-life extension of the soy bread without the need for a chemical preservative. These MAP treatments extended the shelf life by at least 200%.

Minimum leak size determination, under laboratory and commercial conditions, for bacterial entry into polymeric trays used for shelf-stable food packaging.

This study sought to determine the minimum leak size for entry of Enterobacter aerogenes under laboratory conditions, and normal flora under commercial conditions, into tryptic soy broth with yeast extract (TSBYE), homestyle chicken, and beef enchilada packaged in 355-ml polyethylene terephthalate/ethylene vinyl alcohol/polypropylene trays. Channel leaks (diameters of 50 to 200 microm) were made across the sealing area of the trays. Pinholes (diameters of 5 to 50 microm) were made by imbedding laser-drilled metal and plastic disks into the tray lids. For the laboratory simulation, all trays were submerged and agitated for 30 min at 25 degrees C in phosphate-buffered saline that contained 10(7) CFU/ml of E. aerogenes. Under commercial conditions, trays with channel leaks were processed in retorts to achieve commercial sterility. All trays were subsequently incubated at 37 degrees C for 2 weeks, and their contents plated onto eosin-methylene blue agar (for laboratory simulation) to enumerate E. aerogenes and brain heart infusion agar (for commercial conditions) to determine the presence of any bacteria. Under laboratory conditions, minimum pinhole sizes for E. aerogenes entry approximated 5 microm (TSBYE, metal disks; homestyle chicken, plastic disks), 20 microm (beef, plastic disks), and 30 microm (beef, metal disks). The minimum channel leak sizes for entry of E. aerogenes approximated 10 microm (TSBYE), 70 microm (chicken), and 200 microm (beef enchilada). Under commercial conditions, the minimum channel leak size for bacterial entry approximated 40 microm (TSBYE), 50 microm (homestyle chicken), and more than 200 microm (beef). Results showed that E. aerogenes can enter pinholes as small as 5 microm under a worst-case scenario. This information can be used to set pass and fail parameters for leak detection devices.

Uptake of polychlorinated biphenyls (PCBs) from an aqueous medium by polyethylene, polyvinyl chloride, and polystyrene films.

The sorption of selected polychlorinated biphenyl (PCB) congeners (from tri to deca chlorinated) by three food-packaging plastic films [polyethylene, polyvinyl chloride (PVC), and polystyrene] from an aqueous solution was investigated. From the data generated, PCB uptake, partition, and diffusion coefficients were calculated for the various films. Polyethylene exhibited the highest PCB uptake, diffusion, and partition coefficients when compared to the other materials. Although PVC indicated larger sorption diffusion and partition coefficients for the lower chlorinated congeners than polystyrene, a reversal of this trend was observed for the higher congeners. For polyethylene and PVC, the PCB uptake decreased as the chlorine numbers in the congeners increased, confirming the correlation between increasing chlorination and increasing cohesive density within the PCB molecules. For polystyrene, the uptake decreased from tri to penta congeners, but showed an increase for the hexa, and then a decreased uptake until the deca chlorination. A comparison of the molecular sizes of the PCB congeners showed that the partition (Ke) and sorption diffusion (Ds) coefficients generally decreased with their increasing molar volumes. The resulting Ke values were used to determine the extent of sorption because these values indicate the affinity of PCBs for the plastic films. Results from this study can be of practical importance for cases of product quality related to the transfer of contaminants from the product to the packaging materials.