Jean Weese

Sensory evaluation of no-sugar-added cakes containing encapsulated aspartame

Encapsulated aspartame (APM), developed to protect APM during baking, has not been previously evaluated with respect to sensory acceptability. This project evaluated the sensory properties of cakes formulated with encapsulated APM. A no-sugar-added cupcake was formulated with encapsulated APM. An experienced sensory panel indicated that the sweetness level was similar in the no-sugar-added cakes after three days as compared to a full-sugar cake overall. The no-sugar-added and full-sugar cakes received consumer acceptability ratings which were not significantly different (p>0.05). The results from this project indicate that encapsulated APM can be successfully used to formulate no-sugar-added cupcake mixes for home preparation.

N-Halamine modified thermoplastic polyurethane with rechargeable antimicrobial function for food contact surface

A polymer blend of two N-halamine precursors was prepared and homogeneously incorporated into TPU structure via a solvent casting method, and an N-halamine modified TPU film with rechargeable antimicrobial activity resulted after treating with chlorine bleach. Antimicrobial efficacies were evaluated against both Staphylococcus aureus (S. aureus) and Escherichia coli O157:H7 (E. coli). Results showed that the N-halamine modified TPU film caused 6 log CFU reduction of bacteria reduction within 2 hours of contact. Moreover, the N-halamine modified TPU displayed desirable rechargeability and stability, which maintained sufficient antimicrobial activity after 20 cycles of “discharge–recharge” process and over 4 weeks of storage. Besides, the tensile strength and surface tension of TPU were not adversely affected by N-halamine modification. The N-halamine modified TPU with rechargeable antimicrobial function exhibited great potential as a cheap, safe and effective food contact surface material for preventing food microbial cross-contamination.

Antimicrobial Activity of N-Halamine–Coated Materials in Broiler Chicken Houses

The antimicrobial activity of 1-chloro-2,2,5,5-tetramethyl-4-imidazoidinone (MC), a nonbleaching N-halamine compound, was investigated on materials commonly used in broiler production, including stainless steel, galvanized metal, aluminum, plastic, and pressure-treated wood. MC aqueous solutions at 0.02, 0.04, and 0.06% were challenged with Salmonella Typhimurium and Campylobacter jejuni at 6 log CFU/mL, resulting in complete inactivation of both bacteria in 30 min with 0.06% MC. Follow-up experiments were performed using test materials treated with 0.1 and 1% MC and challenged with Salmonella Typhimurium and C. jejuni at 6 log CFU per coupon. Stability of MC on the various surfaces of testing materials was assessed, and the chlorine content of the materials was measured using iodometric thiosulfate titration over a 4-week period. Antimicrobial activities were evaluated by a sandwich test on each sampling day during 4 weeks of storage. On the samples treated with 1% MC, bacteria at 6 log CFU per coupon were completely inactivated within 2 h of contact time. The antimicrobial activity extended to 4 weeks, and the active chlorine atoms in the treated materials decreased from the initial 1016 to 1015 atoms per cm2. Overall, MC had high stability and long-lasting antimicrobial activity, which suggests that MC has high potential for use as a novel antimicrobial agent to lower the microbial load on broiler house materials.

N-halamine incorporated antimicrobial nonwoven fabrics for use against avian influenza virus

Airborne pathogens are one of the most common avenues leading to poultry diseases. Preventing the avian influenza (AI) virus from entering the chicken hatchery house is critical for reducing the spread and transmission of AI disease. Many studies have investigated the incorporation of antimicrobials into air filters to prevent viruses from entering the indoor environment. N-halamines are one of the most effective antimicrobial agents against a broad spectrum of microorganisms. In this study, 1-chloro-2,2,5,5-tetramethyl-4-imidazolidinone (MC, a variety of N-halamine) was coated on nonwoven fabrics to give the fabric antimicrobial activity against the AI virus. Results showed that MC exhibited potent antiviral activity either in suspension or in the air. Higher concentrations of MC completely inactivated AI viruses and disrupted their RNA, preventing them from being detected by the real time reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Coating the fabrics with MC resulted in remarkably reduced presence of AI virus on the MC-treated fabric in a short period of time. Furthermore, aerosolized AI viruses were completely inactivated when they passed through filters coated with the MC compound. In addition, MC is not volatile and does not release any gaseous chlorine. The active chlorine in the MC compound is stable, and the coating procedure is straightforward and inexpensive. Therefore, this study validates a novel approach to reducing airborne pathogens in the poultry production environment.

Absorbent Pads Containing N-Halamine Compound for Potential Antimicrobial Use for Chicken Breast and Ground Chicken

N-Halamines are a group of compounds containing one or more nitrogen-halogen covalent bond(s), and the high-energy halide bond provides a strong oxidative state so that it is able to inactivate microorganisms effectively. In this study, the shelf life of chicken breast and ground chicken packed with 1-chloro-2,2,5,5-tetramethyl-4-imidazolidinone (MC, a member oft the N-halamines) treated absorbent pads was investigated during refrigerated storage. Fresh, processed chicken meat in packaging trays loaded with or without MC treated absorbent pads were stored at 4 °C for 11 days. The microbial counts in chicken meat as well as in the food pads were analyzed on days 1, 4, 7, and 11. MC treated pads reduced the levels of the main spoilage-related microorganisms (aerobic plate counts, lactic acid bacteria, Enterobacteriaceae, psychrotrophs, and Pseudomonas spp.) present in the absorbent pads by an average of 3.5 log CFU/g compared to the control. Microbial loads in chicken breast packed with MC coated absorbent pads were 0.3 log CFU/g lower than those in the control, and an approximate 0.2 log CFU/g reduction was observed for ground chicken. Neither the color nor the pH of the meat was negatively impacted by the presence of MC. The populations of inoculated Salmonella and Campylobacter in meat loaded with MC treated absorbent pads were on average lower than those in the controls. Pathogens in the control pads increased to 3.7 and 4.9 log CFU/g, while the MC treated absorbent pads lowered these two bacteria to under the detection limit (l.7 log CFU/g) throughout 11 days of storage.