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During commercial production of liquid egg yolk (LEY), phospholipase A2 (PLA2) is used to improve its emulsification capacity and thermal stability. The enzymatic treatment may occur at elevated temperatures such as 50 °C, potentially allowing foodborne pathogens, such as Bacillus cereus, to grow. Little knowledge is available concerning growth of B. cereus in LEY during PLA2 treatment. Therefore, the objective of this study was to investigate the growth kinetics of B. cereus during PLA2 treatment using pathogenic B. cytotoxicus NVH391-98, the most thermotolerant member in the B. cereus group, as a surrogate. Inoculated LEY samples were placed in precision programmable incubators to observe the growth of B. cytotoxicus NVH391-98 under multiple isothermal and dynamic temperature conditions between 20 and 53 °C. The bacterial growth was described using the differential Baranyi model coupled with two different secondary models. The kinetic parameters were determined using one-step dynamic inverse analysis of multiple growth curves. The least square method was used in combination with the 4th order Runge-Kutta method to solve the differential Baranyi model using multiple growth curves to determine the cardinal kinetic parameters. The results showed that B. cytotoxicus NVH391-98 can grow prolifically at 50 °C. The estimated minimum, optimum and maximum temperatures were 16.7 or 18.5, 47.8 or 48.1, and 52.1 or 52.4 °C, respectively, depending on the secondary models, with an optimum growth rate of 2.1 log colony-forming-unit (CFU)/g per hour. The dynamic model is validated using isothermal curves with reasonable accuracy. B. cytotoxicus died off slowly at 15 °C. At 55 °C, thermal inactivation was observed, with a D value of approximately 2.7 h. Holding at 55 °C or below 15 °C can effectively prevent the growth of B. cytotoxicus in egg yolk.

L. plantarum strains displayed different abilities to exhibit high survivability to acid (pH 3.0), bile salts (3%), enzyme (pepsin), and temperature (40 °C) and good antibiotic susceptibility. The isolates were further supplemented in traditional tapai pulut to study the immunomodulation properties of tapai pulut based on the splenic T- and B-cell populations. The mice groups were divided into group one (unfermented glutinous rice), group two (tapai pulut group), and group three (probiotic tapai pulut group). Group one showed consistent body weight gain, with the highest observed after four weeks. Group three exhibited the most significant reduction in the percentage of CD19+ B-cells. The CD3+ T-cells population of Group three increased significantly compared with the control mice, followed by Group two. The results suggest that traditional tapai pulut supplemented with L. plantarum has a high potential for supporting the immune system’s immunomodulatory effect.

This multi-institutional study assessed the efficacy of Enterococcus faecium NRRL B-2354 as a nonpathogenic Salmonella surrogate for thermal processing of nonfat dry milk powder, peanut butter, almond meal, wheat flour, ground black pepper, and date paste. Each product was analyzed by two laboratories (five independent laboratories total), with the lead laboratory inoculating (E. faecium or a five-strain Salmonella enterica serovar cocktail of Agona, Reading, Tennessee, Mbandaka, and Montevideo) and equilibrating the product to the target water activity before shipping. Both laboratories subjected samples to three isothermal treatments (between 65 and 100°C). A log-linear and Bigelow model was fit to survivor data via one-step regression. On the basis of D80°C values estimated from the combined model, E. faecium was more thermally resistant (P < 0.05) than Salmonella in nonfat dry milk powder (DEf-80°C, 100.2 ± 5.8 min; DSal-80°C, 28.9 ± 1.0 min), peanut butter (DEf-80°C, 133.5 ± 3.1 min; DSal-80°C, 57.6 ± 1.5 min), almond meal (DEf-80°C, 34.2 ± 0.4 min; DSal-80°C, 26.1 ± 0.2 min), ground black pepper (DEf-80°C, 3.2 ± 0.8 min; DSal-80°C, 1.5 ± 0.1 min), and date paste (DEf-80°C, 1.5 ± 0.0 min; DSal-80°C, 0.5 ± 0.0 min). Although the combined laboratory D80°C for E. faecium was lower (P < 0.05) than for Salmonella in wheat flour (DEf-80°C, 9.4 ± 0.1 min; DSal-80°C, 10.1 ± 0.2 min), the difference was ~7%. The zT values for Salmonella in all products and for E. faecium in milk powder, almond meal, and date paste were not different (P > 0.05) between laboratories. Therefore, this study demonstrated the impact of standardized methodologies on repeatability of microbial inactivation results. Overall, E. faecium NRRL B-2354 was more thermally resistant than Salmonella, which provides support for utilizing E. faecium as a surrogate for validating thermal processing of multiple low-moisture products. However, product composition should always be considered before making tha

Introduction. Mayonnaise is a widely consumed product all over the world. Nowadays, the number of vegetarians, egg allergy cases, and heart diseases are increasing. This makes manufacturers develop alternatives. The research objective was to select the optimal concentration of emulsifiers for egg-free mayonnaise made from virgin coconut oil. Study objects and methods. We produced 20 egg-free mayonnaise samples with different amounts of emulsifiers. We also determined physicochemical properties of the samples, as well as performed proximate and statistical analyses. Results and discussion. The response surface methodology made it possible to define such parameters as viscosity, stability, and firmness as affected by the following concentrations: cashew nut protein isolates - 5-15%, xanthan gum - 0-1%, and modified starch -0-0.5%. The optimal values of emulsifiers were obtained as follows: cashew nut protein isolates - 13 g, xanthan gum - 1.0 g, and modified starch - 0.4 g. The optimized mayonnaise had the following parameters: viscosity - 120.2 mPa.s, stability - 98.7%, and firmness - 25 g. The study revealed no significant differences (P > 0.05) between the actual and predicted data, which confirmed the efficiency of the suggested models. Conclusion. The obtained low-fat egg-free mayonnaise was relatively similar to the traditional commercial products. However, virgin coconut oil should be emulsified with a combination of cashew nut protein isolates, modified starch, and xanthan gum.

Ice cream has been selected as a good carrier of beneficial effects through the health-promoting component incorporated into the product to meet the needs of functional food. The majority of people in the globe adore ice cream because it has distinct texture and sensory features. Ice cream is a promising carrier for the unhindered distribution of bioactive elements due to its composition, colloidal form, and low-temperature system. The development of functional ice cream has consolidated numerous health-promoting ingredients such as probiotics, prebiotic, synbiotic, and natural antioxidants (e.g., polyphenols). In this review, recent advances in the attempts of developing alternative ice cream formulation and functional ice cream (a product supplemented or fortified with bioactive substances) are presented: the highlighted contents encompass the aspects that include—defining the bioactive component with its beneficial effect, strategies for the successful integration with potential hurdles during the product manufacture, ideal consumption model with possible side-effect, and current scenario of the functional ice cream development.

Microbial challenge studies using nonpathogenic surrogates provide a practical means for validating thermally based pathogen controls for low-moisture foods. Because the relative thermal resistance, or kill ratio, of Enterococcus faecium NRRL B-2354 (a nonpathogenic surrogate) to Salmonella is greatly influenced by food composition, this study assessed relative thermal resistance of a five-strain Salmonella cocktail and E. faecium in skim milk powder (SMP), lactose-free skim milk powder (LSMP), 90% milk protein isolate (MPI), and lactose powder (LP). The impact of sugar composition (lactose versus glucose-galactose) on resuscitation of bacterial survivors, by using SMP and LSMP, was also determined. Dairy powders were inoculated with agar-grown cultures, mixed, preequilibrated at 0.25 water activity (aw), ground to achieve homogeneity, reequilibrated, and subjected to isothermal treatment. After enumeration on nonselective differential media, log-linear and Bigelow models were fit to the survivor data via one-step global regression. The aw changes and glass transition temperature were assessed at elevated temperatures by using uninoculated, equilibrated powder samples. Estimated D90°C-values were approximately two times higher for E. faecium (P < 0.05) than for Salmonella in SMP, LP, and MPI, but statistically similar (P > 0.05) in LSMP. Addition of sugars to recovery media did not influence survivor resuscitation from heat-treated SMP and LSMP, confirming that microbial inactivation was impacted primarily by the thermal treatment, not the recovery step. Thermally induced changes in aw were seen only for LP and MPI, with the glass transition temperature observed only for SMP and MPI. In conclusion, rather than always requiring greater lethality of E. faecium than Salmonella, these findings suggest that sufficient pathogen controls for low-moisture foods can also be validated by thoroughly documenting the appropriate kill ratios of E. faecium to Salmonella.

Table eggs are an affordable yet nutritious protein source for humans. Unfortunately, eggs are a vector for bacteria that could cause foodborne illness. This study aimed to investigate the effectiveness of a quaternary ammonium compound (quat) sanitizer against aerobic mesophilic bacteria, yeast, and mold load on the eggshell surface of free-range and commercial farms and the post-treatment effect on microbial load during storage. Total aerobic mesophilic bacteria, yeast, and molds were enumerated using plate count techniques. The efficacy of the quaternary ammonium sanitizer (quat) was tested using two levels: full factorial with two replicates for corner points, factor A (maximum: 200 ppm, minimum: 100 ppm) and factor B (maximum: 15 min, minimum: 5 min). Quat sanitizer significantly (p < 0.05) reduced approximately 4 log10 CFU/cm2 of the aerobic mesophilic bacteria, 1.5 to 2.5 log10 CFU/cm2 of the mold population, and 1.5 to 2 log10 CFU/cm2 of the yeast population. However, there was no significant (p ≥ 0.05) response observed between individual factor levels (maximum and minimum), and two-way interaction terms were also not statistically significant (p ≥ 0.05). A low (<1 log10 CFU/cm2) aerobic mesophilic bacteria trend was observed when shell eggs were stored in a cold environment up to the production expiry date. No internal microbial load was observed; thus, it was postulated that washing with quat sanitizer discreetly (without physically damaging the eggshell) does not facilitate microbial penetration during storage at either room temperature or cold storage. Current study findings demonstrated that the quat sanitizer effectively reduced the microbial population on eggshells without promoting internal microbial growth.

Microbial polysaccharides can serve as renewable sources for hydrocolloids used in food, pharmaceutical, and other industrial applications. Xanthan, gellan, dextran, and alginate are among the common microbial polysaccharides in current use. Although only limited numbers of microbial polysaccharides are commercialized, several approaches to modify microbial polysaccharides are laid out to improve their functional and technological properties via physical and chemical cross-linking reactions. This review discusses the properties of microbial polysaccharides as well as several methods of physical and chemical cross-linking for polysaccharides modification.

Microbial polysaccharides can serve as renewable sources of hydrocolloids that have great function as viscosifying, stabilizing, emulsifying or gelling agents which are important to improve texture and stability of food and pharmaceutical products. Similar functions are currently being offered by gelatin however the use of gelatin would give rise to health and religious concerns for particular group of consumers. Plant based polysaccharides have been utilized as gelatin substitute but plant requires longer harvest maturity and susceptible to geographical and seasonal changes. Viscosity and gel rigidity are important parameter to determine adequate food texture for mouth feel properties. Phase separation also could affect consumer perception on food products. The aims of this study are to investigate rheological properties that measure flow behaviour, viscosity and gel rigidity to be compared with gelatin as well as to predict molecular interaction between gellan (G) and dextran (D) in their binary blends (1:1, 1:2, 1:3 ratios) in varying concentration range of 0.5%, 1.5% and 3% (w/v) using spectral and thermal characteristics. For rheological measurements, all samples were subjected to steady shear and dynamic shear viscosity tests using rheometer. Spectral analysis and thermal analysis were performed using Fourier Transform Infrared (FTIR) and Differential Scanning Calorimetry (DSC) respectively. Rheological analyses revealed that during blending, dextran plays a significant role and transforms the solid-like characteristics to liquid-like behaviour of gellan with an increase in dextran concentration of G/D blends. The steady flow behaviour was well characterized by the Herschel-Bulkley model (standard error lower than 10) and G/D blends exhibited similar flow behaviour (shear thinning) as bovine and porcine gelatin at 1.5% and 3% concentration as compared to dilute concentration, 0.5% . For dynamic viscoelastic, G/D blends exhibit similar gel characteristic with b