Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2023Effect of oil exposure stages on the heat resistance of Salmonella enterica serovar Enteritidis phage type 30 in peanut flour
Liu, Shuxiang; Qiu, Yan; Ji, Kexin; Ozturk, Samet; Erdogdu, Ferruh; Qin, Wen; Yang, Ren; Wu, Qingping
The oil in low-moisture foods (LMFs) shows protective effects on bacteria during thermal processing. However, the circumstances under which this protective effect strengthens remain unclear. This study aimed to understand which step of the oil exposure to bacterial cells (inoculation, isothermal inactivation, or recovery and enumer-ation step) in LMFs can enhance their heat resistance. Peanut flour (PF) and defatted PF (DPF) were selected as the oil-rich and oil-free LMF models. Salmonella enterica Enteritidis Phage Type 30 (S. Enteritidis) was inoculated into four designated PF groups representing different oil exposure stages. It was isothermally treated to obtain heat resistance parameters. At a constant moisture content (aw,25 degrees C = 0.32 +/- 0.02) and controlled aw,85 degrees C (0.32 +/- 0.02), S. Enteritidis exhibited significantly high (p < 0.05) D values in oil-rich sample groups. For instance, the heat resistance values of S. Enteritidis in the PF-DPF and DPF-PF groups were D80 degrees C of 138.22 +/- 7.45 min and 101.89 +/- 7.82 min; however, the D80 degrees C in the DPF-DPF group was 34.54 +/- 2.07 min. The oil addition after the thermal treatment also helped injured bacterial recovery in the enumeration. For instance, the D80 degrees C, D85 degrees C, and D90 degrees C values in the DFF-DPF oil groups were 36.86 +/- 2.30, 20.65 +/- 1.23, and 7.91 +/- 0.52 min, respectively, which were higher than those in the DPF-DPF group at 34.54 +/- 2.07, 17.87 +/- 0.78, and 7.10 +/- 0.52 min. We confirmed that the oil protected S. Enteritidis in PF in all three stages: desiccation process, heat treatment, and recovery of bacterial cells in plates.
- MakaleAçık Erişim2022Continuous flow microwave processing of peanut butter: A (hypothetical) computational process design study with experimental validation
Coskun, Eda; Ozturk, Samet; Topcam, Huseyin; Karatas, Ozan; Li, Rui; Wang, Shaojin; Mert, Behic; Erdogdu, Ferruh
The increase in foodborne pathogen cases in low moisture foods has raised a significant food safety concern for food industry. One of the most significant outbreaks related with these food products was observed in 2008–2009 due to Salmonella problem in peanut butter. This issue was recently observed again for a multinational case. Challenges of conventional thermal processing due to the lower thermal conductivity – diffusivity value and higher viscosity, microwave (MW) heating might be an efficient processing while the non-uniform heating is a challenging drawback. Therefore, the objective of this study was to develop a mathematical model for MW processing of peanut butter and present industrial scale designs for continuous flow processing. For this purpose, the mathematical model was first experimentally validated using a lab-scale system and validated with experimental data. Following this, continuous flow MW process design studies were carried out with different holding tube configurations to obtain a temperature increase to enable decontamination and improve the temperature uniformity. These design simulations provided a better understanding to enhance the process efficiency of high viscosity low moisture peanut butter samples and for design and optimization of continuous flow MW processing.
- MakaleAçık Erişim2022Microwave decontamination process for hummus: A computational study with experimental validation
Son, Ezgi; Coskun, Eda; Ozturk, Samet; Bulduk, Kubra; Akpinar, Merve; Mert, Behic; Erdogdu, Ferruh
There has been an increasing demand for healthy snacks, and hummus is preferred as a plant-based product its rich protein content. Its increased consumption, on the other hand, has raised food safety issues with linkages to Listeria outbreak and a recent Salmonella related recall. These were observed in ready-to-eat hummus and indicated the requirement of further processing. Conventional thermal processes might require longer times with negative impact on the quality due to the high viscosity of hummus with its solid-like rheology. For an efficient process design, microwave (MW) processing might be considered with its volumetric heating feature. Therefore, the objective of this study was to present MW application for a decontamination process for hummus. For this purpose, a computational model was developed to determine the temperature change during the process. This model was validated using the experimentally obtained temperature data from samples processed in polystyrene petri dishes (60 g – 8.5 cm in diameter and 1.2 cm in height) in a lab-scale MW system. Color changes were determined, and changes in its viscosity were used to understand the variation in the rheological attributes. Hummus samples were also inoculated with Salmonella cocktail to ≈7–8 log10 CFU/g prior to the MW process, and 70 W MW processing for 5 min (to average temperature of 95.3 °C) resulted in >4 log cycle reduction. Changes in color and rheological attributes were not significant with rather limited mass losses, and these indicated the possible MW processing for hummus decontamination with the need of designing an industrial scale processing.
- MakaleYalnız künye2021Effect of far infrared heating process on surface decontamination and quality attributes of whole yellow and white onions
Coskun, Eda; Ozturk, Samet; Akpinar, Merve; Halkman, A. Kadir; Erdogdu, Ferruh
This study aimed to develop an effective decontamination process for whole yellow and white onions with maintained quality attributes. For this purpose, a far infrared radiation (FIR) process was evaluated to determine its effects on microbial safety and quality of the onions. Prior to the FIR process, samples were inoculated with Salmonella culture to about 7–8 log10 CFU/cm2 and stored for 1–48 h at room temperature. Inoculated samples were then processed up to 120 s at 400 °C infrared source temperature. Temperature chance of the onions was recorded by using T-type thermocouples, and surface temperature distribution was obtained with an infrared thermal camera. Quality attributes (color changes, mass losses and textural changes) were also evaluated following the FIR process. The results indicated that 3.3 and 2.4 log10 CFU/cm2 reductions in the Salmonella counts were obtained for the whole yellow and white onions, stored for 1 h at room temperature after 120 s FIR processing. The background microbial population on the outer skin of the onions was under the detection limit (<1 log10 CFU/g). It was observed that the effectiveness of FIR treatment on Salmonella decontamination decreased as the storage time increased from 1 to 48 h at room temperature. FIR process did not significantly affect the quality attributes of the onions, and the results confirmed the potential use of FIR process for surface decontamination of the onions. Further studies were suggested to design an effective FIR system for industrial scale applications.
- MakaleAçık Erişim2021Effect of cellulose nanofiber-based coating with chitosan and trans-cinnamaldehyde on the microbiological safety and quality of cantaloupe rind and fresh-cut pulp. Part 2: Quality attributes
Ozturk, Samet; Zhang, Jin; Singh, Rakesh K.; Kong, Fanbin
The quality characteristics of fruits and vegetables can be protected with coatings. The presented study aimed to evaluate the effect of cellulose nanofiber (CNF) based coatings with chitosan (CHI) and trans-cinnamaldehyde (TC) on the quality attributes, including weight loss, total soluble solid (TSS) content, firmness, and color of whole and fresh-cut cantaloupe during storage at 22 °C and 4 °C, respectively. Results showed that CNF-based coating was effective in protecting whole cantaloupes from firmness reduction and color change in redness/greenness (a*) and yellowness/blueness (b*) during room-temperature storage for up to 11 days. Coating containing only CNF was not able to prevent the quality changes of fresh-cut cantaloupe during the cold storage, but CNF + CHI/CNF + CHI + TC significantly decreased the weight loss, decelerated the firmness increase and maintained the lightness (L*) of fresh-cut cantaloupe for up to 7 days. The incorporation of chitosan (1%, w/w) improved the protection effect of CNF-based coatings against quality changes during storage for both whole and fresh-cut cantaloupes, but TC (1%, w/w) did not show significant enhancement on the protection effects of coatings for most quality attributes. This study indicates that the CNF-based coatings have the potential to maintain quality attributes of whole and fresh-cut fruits during storage and distribution.
- MakaleAçık Erişim2020Effect of cellulose nanofiber-based coating with chitosan and trans-cinnamaldehyde on the microbiological safety and quality of cantaloupe rind and fresh-cut pulp. Part 1: Microbial safety
Zhang, Jin; Ozturk, Samet; Singh, Rakesh K.; Kong, Fanbin
This study aimed to evaluate the effect of cellulose nanofiber (CNF)-based coating containing chitosan (CHI) and trans-cinnamaldehyde (TC) on microbial growth of foodborne pathogens and spoilage microorganisms on cantaloupe rind and fresh-cut pulp. Coated/uncoated cantaloupe rind and pulp samples were inoculated with Salmonella enterica, Escherichia coli O157:H7 and Listeria monocytogenes and subsequently subjected to storage for 20 d at 4 °C or 12 d at 22 °C. Results showed that coating with only CNF (0.5%, dry-base) was effective in the elimination of S. enterica and E. coli O157:H7. Adding CHI (1%, w/w) and TC (1%, w/w) into CNF-based coating enhanced film formation on the surface and increased the antimicrobial activity on rind sample, but the reduction effect was less significant on pulp samples. The CNF (0.5%, dry-base) +CHI (1%, w/w) +TC (1%, w/w) coating resulted in 2.23, 2.43 and 3.22 log10 CFU/cm3 reduction of S. enterica, E. coli O157:H7 and L. monocytogenes, respectively, on pulp samples after 20 d at 4 °C. The formulation also significantly inhibited the growth of natural spoilage microorganisms, and no growth was observed up to 18 d at 4 °C. Results indicated that CNF-based coating significantly improved microbial safety of cantaloupe rind and fresh-cut pulp during storage by forming a physical barrier reducing activities of oxygen-dependent microorganisms.
- Kitap BölümüYalnız künye2020Process Uniformity During Electro-Thermal Applications and Modeling Approaches
Altin, Ozan; Ozturk, Samet; Topcam, Huseyin; Karatas, Ozan; Marra, Francesco; Erdogdu, Ferruh
This chapter brings a perspective to issues related to heating uniformity and modeling approaches of novel electrothermal technologies such as radio-frequency (RF) and microwave (MW) heating. Both RF (3 kHz–300 MHz) and MW (300 MHz–300 GHz) waves within the electromagnetic spectrum cause heat generation within foods as a result of molecular polarization and dipole rotation of existing water molecules (polar). RF and MW heating shows a great potential to achieve volumetric and rapid heat generation within food products, maintaining food quality and satisfying safety regulations in food industry compared with conventional heating systems.