Flash heating process for efficient meat preservation.

Maintaining food safety and quality is critical for public health and food security. Conventional food preservation methods, such as pasteurization and dehydration, often change the overall organoleptic quality of the food products. Herein, we demonstrate a method that affects only a thin surface layer of the food, using beef as a model. In this method, Joule heating is generated by applying high electric power to a carbon substrate in <1 s, which causes a transient increase of the substrate temperature to > ~2000 K. The beef surface in direct contact with the heating substrate is subjected to ultra-high temperature flash heating, leading to the formation of a microbe-inactivated, dehydrated layer of ~100 µm in thickness. Aerobic mesophilic bacteria, Enterobacteriaceae, yeast and mold on the treated samples are inactivated to a level below the detection limit and remained low during room temperature storage of 5 days. Meanwhile, the product quality, including visual appearance, texture, and nutrient level of the beef, remains mostly unchanged. In contrast, microorganisms grow rapidly on the untreated control samples, along with a rapid deterioration of the meat quality. This method might serve as a promising preservation technology for securing food safety and quality.

Modification and simplification of Rongey's method for measurement of meat batter stability.

The method of Rongey for assessment and quantification of meat batter/emulsion stability has over the years proven useful to many research and industrial laboratories around the world. Unfortunately, its requirement for specialized glassware and a very large centrifugation unit makes the method inaccessible to many modern laboratories. We have, therefore, modified Rongey's original method by adapting it to present-day commercially-available glassware and centrifugation equipment. This modified method was validated by comparing it to Rongey's method on both high-fat (27%) and low-fat (10%) finely comminuted pork batters, each with and without the addition of salt (1.8%) and sodium phosphates (0.5%). This design provided us with batters ranging in stability from very low to very high, thus allowing us to compare the methods across analytical extremes. This modified method:•Utilizes glassware and centrifugation equipment that are commercially-available today.•Maintains the simplicity and speed of the original method of Rongey.•Yields results that are comparable to those of Rongey's traditional method.

Beef Handling Practices Among Consumers in the U.S. Virgin Islands.

U.S. Virgin Islands (USVI) imports more than 95% of its food. Transportation limitations throughout the territory's supply chain can make temperature control of protein foods challenging for consumers. This study aimed to characterize the beef handling practices used by consumers in USVI to determine any educational needs. Printed and online surveys (n = 620 total) were disseminated in USVI through extension agents and local media sources. Three hundred and thirty-four consumers completed a 30-question food handling questionnaire on consumption patterns and food handling from purchasing to their kitchen. Frequencies and Pearson chi-square tests of independence were performed. Beef ranked second among the different meat types consumed, 92% of consumers bought beef from grocery stores, and 55% removed beef from shelves immediately after entering the store. When shopping, 59.1% of respondents always checked the use-by/freeze-by dates of beef, 46.3% always separated beef from other foods, but only 27.5% always used insulated bags. Eighty-three percent of consumers returned home within 1 h of shopping, 92% took less than 30 min to store groceries in either a freezer or refrigerator (98%) and during power outages, 45.1% maintained cold temperatures of beef. Seventy-two percent of consumers washed their hands for more than 10 s, but 33% of those from households with a vulnerable person did not use soap to wash their hands and dried them with reusable towels. When cooking, 44.6% of consumers thawed beef within the temperature danger zone, 80.1% did not check the temperature of beef for doneness, and 34 respondents cooked hamburgers below 160°F. Future consumer food safety education initiatives in the USVI should address hand hygiene among food preparers in homes with vulnerable persons, temperature control practices by promoting the use of insulated bags, safe meat thawing techniques, and the use of thermometers during cooking.

Impact of nitrite-embedded packaging film on quality and sensory attributes of alternatively-cured and nitrite-free bologna.

The objectives were to determine the effects of post-thermal processing nitrite-embedded film (NEF) packaging on the quality attributes of alternatively-cured (nitrite from celery juice powder (AC)) and nitrite-free bologna. Attributes evaluated included lipid oxidation, instrumental color, pigment concentration, and sensory properties such as cured meat flavor, aroma, and color. Three bologna formulations, each packaged with two packaging films were produced. A conventionally-cured control formulation (with nitrite from sodium nitrite; CON), a nitrite-free formulation (UCC), and an alternatively cured formulation (nitrite from cultured celery juice powder; AC) were packaged in conventional (CF) or nitrite-embedded (NEF) film. Instrumental a* values (measured during both light and dark storage at intervals of 7 or 14 days over 126 days of storage) and cured pigment concentration (measured at 14-day intervals over 84 days of storage) were significantly greater (P < 0.05) for the UCC-NEF treatment compared to its conventional film counterpart, UCC-CF. No significant differences (P > 0.05) for lipid oxidation (TBARS values) were observed with NEF. Trained sensory panelists, who evaluated samples at 14-day intervals over 70 days of storage, found significantly greater (P < 0.05) cured aroma, cured flavor, pink color and less off-flavor for uncured bologna packaged in NEF compared to conventional film. For the uncured bologna formulation, NEF packaging provided cured meat attributes comparable to the control formulation that included nitrite. This is the first time that cured aroma and flavor have been observed when nitrite from packaging film is added to a cooked meat product under anaerobic conditions.

Novel biphasic gels can mimic and replace animal fat in fully-cooked coarse-ground sausage.

Four biphasic gels (BPG) were developed and tested as pork fat replacers in coarse-ground fully-cooked sausages. An oleogel (OG) phase (92.5% high-oleic soybean oil, 7.5% rice bran wax) and one of two hydrogel (HG) phases (water and 7% or 8% gelatin) were combined in 7:3 or 6:4 OG:HG ratios, for a total of four test formulations. Control sausages were formulated to 27.5% fat and stored at 0-2 °C for 98 d. BPGs allowed for fat reductions of up to 26%. Visually, all BPGs resembled pork fat. There were no differences in external L* and a* but, internally, controls were darker and redder. Except for one control, there were no differences in Texture Profile Analysis (TPA) hardness, cohesiveness, springiness, and chewiness. Warner-Bratzler Shear (WBS) force was highest in 6:4 samples, which were also highest in Sensory First Bite Firmness and lowest in Smoked Sausage Aroma and Smoked Sausage Flavor. TBARS values remained steady, with no rancid flavors detected by the sensory panel.

Survival of Clostridium perfringens, Staphylococcus aureus and Salmonella enterica in alternatively cured bacon during cooking and process deviations.

Pork bellies were injected with four different alternative curing brines. The bellies were inoculated on the surface and at a depth of 1 cm with multiple strains of Clostridium perfringens, Staphylococcus aureus and Salmonella enterica. The bellies were processed using either a standard process cycle or an interrupted process cycle to simulate a process deviation. Additionally, laboratory simulation of the same cycles was conducted where surface inoculated pork belly samples (22 ± 1 g) were processed in a circulating water bath. Microbiological populations were determined at the beginning, mid-point and end of the cycles, and the change in population was calculated for each bacterium at each time point, by comparing the population to the initial inoculated population. Irrespective of the brine or process cycle, the populations of all of the inoculated bacteria on both the surface and interior samples had decreased by the end of the process. There was no difference in the reductions in bacterial populations for all of the inoculated bacteria by brine type or by sample location (P > 0.30). There were differences in the microbial population reductions for C. perfringens attributable to the processing cycle (P < 0.001), with less population reductions associated with the standard cycle when compared to the interrupted cycle. However, no differences (P > 0.10) were observed in the population reductions between the two processing cycles for either S. aureus or S. enterica.

Synergistic effects of starch nanoparticles and chitin nanofibers on the stability of oil-in-water Pickering emulsions.

Starch nanoparticles (SNPs) and Chitin nanofibers (ChFs) have been recognized to be effective for emulsion stabilization. Hence, the use of multiple solid nanoparticles seems to be a promising approach to improve emulsion stability. This work aims to studyemulsions stabilized by a combination of SNPs and ChFs at different concentrations over storage time and different environmental conditions. Sonicated emulsions were found to have a significantly higher stability compared to non-sonicated emulsions. Furthermore, SNP/ChF-stabilized emulsions showed smaller droplet sizes and higher stability within a wide range of temperatures and pH, suggesting a synergistic effect between both particles as stabilizers. The addition of NaCl showed limited impact, particularly in concentrations up to 200 mM, on the improvement of the stability of emulsions. The combined use of SNPs and ChFs allowed emulsion stabilization at lower solid nanoparticles concentrations than when only either SNPs or ChFs were used.

Curcumin encapsulation in Pickering emulsions co-stabilized by starch nanoparticles and chitin nanofibers.

This study examined the stability and release of curcumin encapsulated in Pickering emulsions stabilized by starch nanoparticles and chitin nanofibers under different conditions. Curcumin stability under UV exposure and the release of curcumin from Pickering emulsions in excess water were evaluated over 24 h; while the storage stability of curcumin was assessed over 16 d. The amount of curcumin remaining in the emulsions was quantified spectrophotometrically to characterize its stability and kinetics of release. The progress of lipid oxidation was also monitored by determining peroxide (PV) and p-anisidine (AV) values. The results of passive release measurements indicated over 60% of curcumin was retained after 24 h. SNP/ChF-stabilized Pickering emulsions showed approximately 50% and 45% of curcumin retention upon 16 d of storage and under UV exposure, respectively. Moreover, significant improvement in the curcumin retention was found when higher concentrations of both solid nanoparticles were used. The degradation kinetics of curcumin over storage time and under UV exposure were found to follow first order kinetics. When both emulsifiers were doubled (C4S2), shelf-life was extended to longer than 60 d (AV < 10). This study provides a promising approach to protect encapsulated curcumin, which could potentially be used in functional food products with extended shelf-life.

Correction: Curcumin encapsulation in Pickering emulsions co-stabilized by starch nanoparticles and chitin nanofibers.

[This corrects the article DOI: 10.1039/D1RA01622A.].

Rheological characteristics of mechanically separated chicken and chicken breast trim myofibril solutions during thermal gelation.

Mechanically separated chicken (MSC) was obtained by two different separation methods (MSC1, Beehive separator, 3-5 d-old bones; MSC2, Poss separator, fresh bones) and compared to chicken breast trim (CBT). Rheological attributes of myofibrillar protein solutions during thermal gelation and cooling were evaluated. All sources exhibited gelation with increased temperature (decreased δ). In all three treatments, a peak, decline, and subsequent increase in both the G' and G″ was observed in the 50-55 °C range, with peak values being higher for CBT than for both MSCs. G' slopes on both sides of the peak (S2, S3) and following the decline (S4) were significantly different between CBT and both MSCs (P < 0.05) and indicated greater instability of the solid-like structure in the temperature range of 50-55 °C (myosin rod denaturation). Myofibrillar protein profiles confirmed fiber type differences among materials, as well as greater myosin fragmentation or modification in the MSC samples.

Evaluation of citrus fiber as a natural replacer of sodium phosphate in alternatively-cured all-pork Bologna sausage.

The effects of sodium tripolyphosphate replacement with citrus fiber on color, texture, lipid oxidation, and sensory characteristics of an alternatively-cured all-pork Bologna sausage during 98 d of storage at storage 0-1 °C were studied. Replacement of sodium phosphates in processed meat with citrus fiber could enable manufacturers to make their products more consistent with the current "clean label" trend. The Bologna sausage was assigned one of five treatments: sodium tripolyphosphate control (0.38%), no-sodium-tripolyphosphate control, or one of several citrus fiber levels (0.50%, 0.75%, 1.00%). Citrus fiber treatments resulted in Bologna sausage with acceptable technological parameters, as indicated by similar cook/chill yields and emulsion stability compared to the sodium tripolyphosphate control. The results showed the replacement of sodium tripolyphosphate with citrus fiber did not significantly alter most physical, chemical or sensory characteristics of the Bologna sausage during refrigerated storage.

Replacement of pork fat in frankfurter-type sausages by soybean oil oleogels structured with rice bran wax.

The objective of this study was to assess the impact of replacing pork backfat with rice bran wax oleogels on the organoleptic properties of frankfurter-type finely-comminuted sausages. Frankfurters were formulated using the following treatments as lipid replacement: 1) pork fat (PF); 2) soybean oil (SBO); 3) 2.5% rice bran wax oleogel (2.5 RBW); 4) 10% rice bran wax oleogel (10 RBW); and 5) 2.5% rice bran wax oleogel sheared less during frankfurter production (RBW/LS). In general, control PF was darker and redder than other treatments. TPA revealed oleogel treatments to be similar (P > .05) to pork fat treatment for firmness, chewiness, and springiness. Additionally, sensory evaluation revealed that replacing pork fat did not influence cured frankfurter aroma, but cured frankfurter flavor was significantly reduced (P < .05). Furthermore, lipid oxidation significantly (P < .05) differed between PF and 10 RBW. The results show that rice bran wax oleogels have the potential to successfully replace pork fat in comminuted products.

Can supplemental nitrate in cured meats be used as a means of increasing residual and dietary nitrate and subsequent potential for physiological nitric oxide without affecting product properties?

The effects of formulated sodium nitrate plus supplemental nitrate (SN) from celery juice powder on residual nitrite, residual nitrate, rancidity, microbial growth, color, sensory properties, and proximate composition of frankfurters, cotto salami and boneless ham during storage (1°C) were studied. The products were assigned one of two treatments, which were each replicated twice: control (156ppm sodium nitrite) or SN (156ppm sodium nitrite and 1718ppm sodium nitrate in combination with 2% VegStable 502). Sensory parameters and proximate composition were measured once for each replication. All other analytical measurements were conducted at regular intervals for 97-98days. The SN showed no increase in residual nitrite compared to the control. No changes (P>0.05) were observed in residual nitrate during storage for any of the products. The results showed that addition of SN did not significantly alter most physical, chemical or microbial properties of cured meat products during refrigerated storage, but some product dependent sensory effects were observed.

Implications of Decreased Nitrite Concentrations on Clostridium perfringens Outgrowth during Cooling of Ready-to-Eat Meats.

Increased popularity of natural and organic processed meats can be attributed to the growing consumer demand for preservative-free foods, including processed meats. To meet this consumer demand, meat processors have begun using celery juice concentrate in place of sodium nitrite to create products labeled as no-nitrate or no-nitrite-added meat products while maintaining the characteristics unique to conventionally cured processed meats. Because of flavor limitations, natural cures with celery concentrate typically provide lower ingoing nitrite concentrations for ready-to-eat processed meats than do conventional cures, which could allow for increased growth of pathogens, such as Clostridium perfringens, during cooked product cooling such as that required by the U.S. Department of Agriculture. The objective of this study was to investigate the implications associated with reduced nitrite concentrations for preventing C. perfringens outgrowth during a typical cooling cycle used for cooked products. Nitrite treatments of 0, 50, and 100 ppm were tested in a broth system inoculated with a three-strain C. perfringens cocktail and heated with a simulated product thermal process followed by a typical cooling-stabilization process. The nitrite concentration of 50 ppm was more effective for preventing C. perfringens outgrowth than was 0 ppm but was not as effective as 100 ppm. The interaction between nitrite and temperature significantly affected (P < 0.05) C. perfringens outgrowth in both total population and number of vegetative cells. Both temperature and nitrite concentration significantly affected (P < 0.05) C. perfringens spore survival, but the interaction between nitrite and temperature did not have a significant effect (P > 0.05) on spore outgrowth. Results indicate that decreased nitrite concentrations (50 ppm) have increased potential for total C. perfringens population outgrowth during cooling and may require additional protective measures, such as faster chilling rates.