Low Temperature Long Time Research Articles

Discrimination of reconstituted milk from fresh skim milk by using lactulose and furosine as milk quality indicators

This study aims to develop a novel and rapid method which uses enzymatic spectrophotometric assay and high-performance liquid chromatography (HPLC) for differentiating adulterated milk from pure fresh milk. Furthermore, this study will use the lactulose and Maillard-derived compounds as indicators to distinguish reconstituted milk from fresh milk. In bottle-sterilized milk, lactulose concentration decreased with the increasing addition of reconstituted skim milk. In addition, the content of lactulose in raw, low-temperature long-time (LTLT), and high-temperature short-time (HTST) skim milk samples increased with the proportion of reconstituted milk. Furosine, which had a retention time (RT) of 4.686 min in standard solution, had the RTs of 4.908, 4.926, 4.940, and 4.973 min in raw, LTLT, HTST, and bottle-sterilized milk samples, respectively. The RT peak increased along with the content of reconstituted milk in raw, LTLT, and HTST milk samples but decreased in bottle-sterilized milk. In conclusion, this work represents an important step toward detecting adulterated milk and tightening food safety regulations.

Enhancing low‐temperature long‐time milk pasteurization process with a C4.5 algorithm‐driven AIoT system for real‐time decision‐making

AbstractThis research is driven by the imperative to improve the milk pasteurization process's efficiency and safety within the Industry 5.0 framework. It introduces the artificial intelligence of things (AIoT) into the pasteurization system and focuses on deploying the C4.5 algorithm, anticipated to render precise real‐time decisions by analyzing critical temperature and duration data essential for the low‐temperature long‐time (LTLT) pasteurization technique. Test results indicate that the C4.5 model is highly effective, demonstrating nearly perfect metrics with a precision of .78, a recall of .77, and an F1‐score of .73, while achieving an overall algorithm accuracy of .76. In terms of heating control, the double jacket method tested on a 300‐L system proved the control design's capability to quickly reach and maintain desired temperatures, hitting the set‐point within 70 min. However, it was observed that systems with larger capacities took longer to reach the set‐point, suggesting a potential for further optimization. The findings affirm that integrating AIoT into control systems can significantly enhance process efficiency and effectiveness, consistent with the goal of incorporating sophisticated technological solutions in the food sector.Practical ApplicationsThe article “Enhancing Low‐Temperature Long‐Time Milk Pasteurization Process with a C4.5 Algorithm‐Driven AIoT System for Real‐Time Decision‐Making” explores an AIoT system's potential to revolutionize the dairy industry's pasteurization methods. This system promises enhanced efficiency by optimizing energy and time, thereby reducing costs. It ensures superior quality control through continuous monitoring, maintaining nutritional integrity and safety. The high automation level minimizes human error and operational demands, while predictive maintenance forecasts prevent downtime. The system's scalability supports production expansion with minimal resource increase. Moreover, it guarantees product traceability and compliance with food safety regulations. The generated data offers insights for further supply chain optimizations. This integration of AI and IoT thus presents significant advancements in process management, quality assurance, and scalable operations for the dairy industry.

Near-Freezing Temperature Storage Improves Peach Fruit Chilling Tolerance by Regulating the Antioxidant and Proline Metabolism

Chilling injury (CI) in peach fruit (Prunus persica cv. Yuhualu) is generally caused by long-time low temperature (5 °C or 0 °C) storage. However, peach fruit stored at near-freezing temperature (NFT in this research is −1 °C), defined as within 0.5 °C above the biological freezing point of biological tissue, does not exhibit CI symptoms. The effect of NFT on the CI, proline metabolism, and antioxidant capability of peach fruit during storage was studied and compared with 5 °C and 0 °C storage as controls. The results exhibit that NFT completely inhibited the occurrence of CI in peach fruit. NFT significantly (p < 0.05) enhanced the activities of superoxide dismutase, catalase, ascorbate peroxidase, and 1,1-diphenyl-2-picrylhydrazyl scavenging capacity. Moreover, the increase of malondialdehyde, ion leakage, and H2O2 accumulation were inhibited remarkably by NFT, and decreases in the contents of phenolics and ascorbic acid were slowed significantly in peach fruit stored at NFT (p < 0.05). Additionally, NFT storage enhanced proline accumulation by modulating the activity of proline metabolizing enzymes. In conclusion, the above results suggest that NFT storage can improve the chilling tolerance of peach fruit by regulating the antioxidant defense and proline metabolism, which might represent a potential novel method to store fruits and vegetables for longer storage times.

Lighter as flame control and temperature control in milk pasteurization system

Milk pasteurization involves heating milk at a specific temperature below its boiling point as a method to keep the resulting dairy product retaining the shape and taste characteristics of fresh milk. In several experiments, the use of fuzzy control systems has been tested to regulate the temperature in the milk pasteurization process and to time the ignition of the stove flame. However, this fuzzy approach still causes the system to give an unstable response and irregular stove flame. In order to study milk pasteurization, the Low Temperature Long Time (LTLT) method is used which is implemented automatically through a PID control system. This method serves to maintain nutritional quality by keeping the pasteurization temperature at a setpoint of 62°C. This control involves the use of servo actuators and electric lighters that are automatically regulated with the help of flame sensors. The flame sensor detects the presence of flame and ensures that the flame remains lit throughout the pasteurization process. At the end of the process, the flame sensor plays a role in breaking the flame by setting a certain threshold. This sensor operates within 10 CM of the flame source and will produce an analog output with a maximum value of 4000 when the flame is lit. When the flame is extinguished, the analog output of the sensor will reach a value of 4095. Testing of the milk pasteurization automation system is given a value for each PID resulting from the value of Kp = 31.8, Ki = 115.6, Kd = 4.4 and obtained a rise time value of 0.39 minutes, 0.61%, settling min of 60.88, and settling max of 62.38.

Comparative Analysis of Pulsed Electric Fields (PEF) and Traditional Pasteurization Techniques: Comparative Effects on Nutritional Attributes and Bacterial Viability in Milk and Whey Products

With the current upsurge in the desire to foster healthy lifestyles and consume nutritious food products, the food industry has been propelled to develop novel food processing technologies. In our study, we critically evaluated the influence of pulsed electric field (PEF) processing by comparing it to conventional thermal pasteurization protocols—low temperature, long time (LTLT), high temperature, short time (HTST), and microfiltration (MF)—and its ramifications on the nutritional properties inherent in raw milk, which comprises vitamins, whey protein, amino acids, cholesterol, and fatty acids. A significant difference in β-lactoglobulin content was observed in PEF-treated liquid whey samples compared to those treated with high-temperature (HT) pasteurization, where 4.8-fold reduction with a concentration of 0.80 mg/mL was observed. Liquid whey samples treated with PEF, LTLT, HTST and MF retained β-lactoglobulin content, PEF-treated samples yielded 3.85 mg/mL, while HTST, LTLT, and MF-treated samples had β-lactoglobulin content of 3.62 mg/mL, 3.63 mg/mL, and 3.62 mg/mL compared to raw whey control (RWC) at 3.81 mg/mL. The concentrations of nutritional properties, like vitamins (A, D, E), amino acids, cholesterol, and fatty acids, remained approximately consistent across all the pasteurization methodologies. Moreover, the bacterial viability in the context of various pasteurization methodologies was scrutinized, with an absence of colonies observed in whey specimens subjected to thermal pasteurization. PEF-treated samples exhibited a substantial 1.6-log reduction in coliform colony count to less than 4 CFU/mL after curd reduction, in contrast to raw milk samples.

Analysis of the Responses to Pasteurization Temperatures of Methicillin Resistant Staphylococcus aureus Derived from Milk Items

Background and Aim: One of the leading causes of both community- and hospital-acquired infections is the superbug," multidrug-resistant Staphylococcus aureus (MRSA). Milk and dairy products seem to be highly vulnerable to a wide range of diseases. Therefore, we require processing procedures that both eliminate pathogens and lengthen the useful life of these products. The purpose of this study was to determine how susceptible MRSA isolates were to pasteurization temperatures after being recovered from dairy products.
 Materials and Methods: For the purpose of pasteurization, ten MRSA isolates were exposed to both a 63°C LTLT (low temperature, long time) therapy for 30 minutes and a 72°C HTST (high temperature, short time) treatment for 16 seconds.
 Results: The findings indicated that all isolates were killed by a pasteurization-like treatment at low temperature for a long time (63°C for 30 minutes), but that particular adaptable isolates could survive a pasteurization-like treatment at high temperature for a short time (72°C for 16 seconds), which may point to a time- and temperature-dependent variation in the thermal tolerance mechanism.
 Conclusion: The results showed that all isolates seemed extremely susceptible to damage from heat using LTLT pasteurization-like treatment (63°C for 30 minutes). Nevertheless, a particular number of these isolates succeeded in establishing colonies because they have quorum sensing structures that survive being handled by using heat damage at 72°C for 16 seconds. Pasteurized milk producers should be alerted to the fact that this microorganism has been found in contaminated milk since it compromises the product's safety and diminishes its value to consumers. As a result, it is strongly advised that manufacturers utilize varied temperatures for milk processing in order to remove the contaminating methicillin- and heat-resistant S. aureus (MHRSA).

Physicochemical analysis as food safety in pasteurized milk in CV. Cita Nasional

Milk is an animal-source food that has a high nutritional with contains 2.8% protein, 3.0% fat, vitamin A, B, C, D, and others. CV. Cita Nasional is one of the dairy processing industries that produces pasteurized milk products. The purpose of this study was to analyze food safety by conducting physicochemical testing of pasteurized milk products with the types HTST (High-Temperature Short Time) or LTLT (Low-Temperature Long Time). The research method used was physicochemical testing on the finished product of pasteurized milk including pH, Fat, Total Solid, Brix and Organoleptic. Physicochemical testing was done by comparing the finished product data in CV. Cita Nasional with the Indonesian National Standard (SNI) data. The Mann-Whitney Test was used for the data analysis. The results showed a significant value for the variables of temperature 0.565; pH 0.104; Fat 0.001; Total Solid 0.000 and brix 0.000. Based on the data analysis results, the overall significance value was <0.05, which means that the Mann-Whitney Test showed a positive effect on the physicochemical quality and that the physicochemical test of pasteurized milk products meets the requirements of SNI.

Evaluating the effects of different processing methods on the nutritional quality of bovine milk

Milk is a universal food that is widely consumed around the world irrespective of age. It has a complex matrix consisting of proteins, carbohydrates, minerals, vitamins, and enzymes that have successfully retained the interest of researchers as yet. The aim of the study was to evaluate the effect of low-temperature long-time (LTLT), ultraviolet light (UV), and ultrasound (US) treatments on physicochemical properties, microbial count, and fatty acid profiling of three types of bovine milk – Country (C), Jersey (J), and Holstein Friesian (HF). The study was conducted in southern India, where these three types of milk are commonly consumed. It was found that no significant (p ˂ 0.05) differences in the proximate composition of milk samples subjected to different treatments compared to untreated milk. However, LTLT treatment resulted in a reduction in ascorbic acid content and significant changes in antioxidant activity and lactose content. LTLT treatment was also able to kill the pathogenic bacteria E. coli, whereas UV and US treatment only showed a notable reduction in the E. coli count. Fatty acid profiling of the treated milk samples was done using GC/MS, and Fourier Transform Infrared Spectroscopy (FTIR) was performed to study the types of chemical bonds present. The results showed that non-thermal treatments (UV and US) were able to sustain the chemical characteristics of milk and had potential for implementation in the dairy industry. Overall, the study highlights the potential benefits of non-thermal treatments such as UV and US in maintaining the chemical properties of milk and reducing pathogenic bacteria count. The findings could be useful in the dairy industry to ensure the safety and quality of milk.

Impact of Physicochemical Modifications in Casein Promoted by UV-C on the Peptide Profile of Gastric Digestion and the Transepithelial Transport of Peptides.

Caseins are the main proteins in milk, and their structure and spatial conformation are responsible for their slow digestion rate. The release of bioactive and β-casomorphin peptides from casein digestion may induce allergic responses during consumption. Spectroscopic techniques were used to observe the structural changes in casein conformation induced by Ultraviolet light irradiation (UV-C). Raman spectroscopy results showed more pronounced peaks at 618 and 640 cm-1 for phenylalanine and tyrosine moieties of the photolyzed micellar casein, respectively, suggesting changes in the micelle structure. The decrease in the intensity of Raman signals for tryptophan and tyrosine corroborates to the UV-C-induced modifications of the micelle structure. Particle size distribution showed a decrease in the average micelle size after 15 min of UV-C exposure, while low-temperature, long-time (LTLT) pasteurization led to the formation of large aggregates, as observed by atomic force microscopy. UV-C did not impact the formation or transport of peptides, as observed by using the Caco-2 cell as a model for peptide absorption. However, the absence of the opioid peptide SRYPSY from κ-casein and only 20% of the concentration of opioid peptide RYLGY were noted. This work demonstrated that UV-C can be utilized to induce the physicochemical modification of dairy products, promoting a higher digestion rate and reducing allergenicity.

Impact of UV-C pretreatment on β-lactoglobulin hydrolysis by trypsin: Production and bioavailability of bioactive peptides

The effects of UV-C light irradiation and low-temperature long-time (LTLT) pasteurization on protein structural changes, degree of hydrolysis (DH) by trypsin, peptide profile of tryptic hydrolysates by MALDI-TOF/TOF-MS, and bioavailability of β-lactoglobulin were compared. Compared with native or LTLT pasteurised samples, the hydrolysis rate constant of β-lactoglobulin treated with UV-C increased significantly, implying that the protein backbone cleavage sites became more accessible, whereas thermal treatment produced aggregates that impede trypsin activity. Tryptic hydrolyses of UV-C light treated β-lactoglobulin yielded more peptides and a more diverse peptide mass profile. Six bioactive peptides were revealed in β-LG tryptic hydrolysates of UV-C-treated protein; transepithelial transport in Caco-2 cell monolayers showed intermediate in vivo transport and absorption for three (β-LG f87–91, β-LG f91–99, and β-LG f158–164). The moderate allergen peptide LSFNPTQLEEQCHI β-LG was absent after tryptic hydrolysis of UV-C-treated protein, indicating that UV-C photolysis may be a useful tool for allergenicity reduction.

Polyphenol Release and Antioxidant Activity of the Encapsulated Antioxidant Crude Extract from Cold Brew Spent Coffee Grounds under Simulated Food Processes and an In Vitro Static Gastrointestinal Model

An ionic gelation technique based on an alginate-calcium-based encapsulation process was prepared as the delivery matrix for antioxidant crude extracts from cold brew spent coffee grounds (350 mg/mL). All the encapsulated samples were treated with different simulated food processes, namely pH 3, pH 7, low-temperature long-time (LTLT) pasteurization, and high-temperature short-time (HTST) pasteurization, to evaluate the stability of the encapsulated matrices. The results showed that alginate (2%, w/v)/maltodextrin (2%, w/v) (CM), and alginate (2%, w/v)/inulin (5%, w/v) (CI) could enhance encapsulation efficiency (89.76 and 85.78%, respectively) and provide lower swelling behavior after being treated using the simulated food processes. Both CM and CI could control the release of antioxidants during the gastric phase (2.28-3.98 and 2.52-4.00%, respectively) and gradual release in the intestinal phase (6.80-11.78 and 4.16-12.72%, respectively) compared to pure alginate (CA). In addition, pasteurization treatment at pH 7.0 produced the highest accumulated release of total phenolic content (TPC) and antioxidant activity (DPPH) after digestion in the in vitro gastrointestinal system compared to the other simulated food processes. The thermal process resulted in a greater release of compounds from the encapsulated matrix during the gastric phase. On the other hand, the treatment with pH 3.0 resulted in the lowest accumulated release of TPC and DPPH (5.08 and 5.12%, respectively), which indicated phytochemical protection.

Thermal inactivation kinetics of uropathogenic Escherichia coli in sous-vide processed chicken breast

Chicken is a suspected reservoir of uropathogenic Escherichia coli (UPEC), resulting in foodborne urinary tract infections (UTIs). Sous-vide ready-to-eat (RTE) food products may be associated with microbial hazards due to the low-temperature long-time (LTLT) process. However, little is known regarding the survival of UPEC during sous-vide cooking. The aim of this study was to evaluate the heat resistance of UPEC in chicken breast during sous-vide processing and establish predictive inactivation models. Chicken breast samples were inoculated with a four-strain cocktail of UPEC, including reference strains from UTI patients and chicken isolates. The inoculated samples, with or without 3% NaCl solution for marination, were vacuum sealed in bags, immersed in a temperature-controlled water bath, and cooked at 50 °C, 55 °C, 60 °C, and 63 °C. The change in survival of populations of UPEC was fitted with the linear and Weibull inactivation models to obtain the survival curves at different temperatures; the D- and z-values were also calculated. The goodness-of-fit was evaluated using the root mean square error (RMSE), sum of squared errors (SSE), adjusted R2, and Akaike information criterion (AIC). The results showed that the linear model with tail was better than the Weibull model in terms of fitting performance. With the addition of salt marinade, D-values at 50 °C, 55 °C, 60 °C, and 63 °C determined by the linear model with tail decreased from 299.78 to 166.93 min, 16,60 to 13.87 min, 4.06 to 3.05 min, and 1.05 to 0.87 min, respectively, compared with the controls. The z-values of control and salt-marinated samples were 6.14 °C and 5.89 °C, respectively. The model developed for predicting UPEC survival under sous-vide cooking was validated using an additional survival curve at 58 °C. The validation results showed that the RMSE was 0.122 and 0.133 log CFU/g, and the proportion of relative error was 0.875 and 0.750 in the acceptable prediction zones for the control and salt-marinated samples, respectively. In conclusion, the heat resistance of an emerging foodborne pathogen, UPEC, in sous-vide processed chicken breast was revealed for the first time. Our results showed that salt marinade (3% NaCl) increases the heat sensitivity of UPEC during the sous-vide processing. The developed survival functions based on the linear model with tail can be applied to control the thermal lethality of UPEC.

Radiofrequency-assisted low-temperature long-time (LTLT) pasteurization of onion powder

Recent outbreaks associated with Salmonella in low-moisture foods (LMFs) have urged the necessity to design and implement the pasteurization process. Sugar-rich LMFs, such as dates, confections, and some spices, may show severe quality loss due to the sugar phase transitions and Maillard reactions at elevated temperatures. Low-temperature long-time (LTLT) pasteurization can potentially eliminate pathogens in sugar-rich LMFs without compromising the products' quality. Here, we chose onion powder (water activity 0.32 ± 0.01, moisture content 7.4 ± 0.1%, w.b.); studies documented its foodborne pathogen contamination. Isothermal inactivation studies of Salmonella enterica Enteritidis PT 30 (S. Enteritidis) in onion powder were conducted at 60 °C, 65 °C, and 70 °C. An orthogonal experimental design optimized the radiofrequency (RF) heating parameters of 500 g onion powder. We accomplished the microbial validation study with RF-assisted hot-air pasteurization and assessed the quality changes before and after the process. The cold spot of RF-heated onion powder reached 66 °C within 180 s. We obtained a 3.4-log reduction of S. Enteritidis at 38 h of LTLT treatment, whereas only 2.10-log reductions were obtained in the control group. No significant quality loss was observed in onion powder after the process.

Effect of Storage on The Chemical Quality of Pasteurized Milk with Supplemented Soybean Oil and Phycocyanin

The interaction between the addition of soybean oil and phycocyanin extract on the protein, fat, and solid non-fat content of pasteurized milk after a one-week storage period is highly important to investigate. Soybean oil is used to improve the quality of pasteurized milk, particularly its chemical quality, consisting of fat, protein, and Solid Non-Fat (SNF). Phycocyanin extract provides a source of protein, whereas soybean oil contains healthy fatty acids. Before the fresh milk is pasteurized, soybean oil and phycocyanin are added. The LTLT (Low Temperature Long Time) technique was used to pasteurize the milk at 63 °C for 30 minutes. After the pasteurization procedure was completed, the milk samples were refrigerated for one week at a temperature of 4 °C. Following the storage period, the chemical composition of pasteurized milk is examined. With the addition of soybean oil and phycocyanin extract, the protein content of milk rose, as shown by the findings. The sample T1 with a concentration of 0.45% soybean oil and 0.50% phycocyanin extract had the greatest amount of protein (3.58). The sample T2 with 0.45% soybean oil concentration and phycocyanin extract (1%) had the greatest fat content (6.4%). Adding soybean oil and phycocyanin extract enhanced the total SNF concentration. On the basis of the study conducted, it can be concluded that the addition of soybean oil and phycocyanin extract to pasteurized milk has an influence and interaction on the milk's protein, fat, and SNF content. The addition of soybean oil and phycocyanin extract to pasteurized milk held for one week may boost protein, fat, and SNF concentrations.

Preparation and characterisation of active component in nabeez water of ajwa dates (Phoenix dactylifera L.) mixed in healthy brown rice milk (BRM) as halal beverage

Nabeez water or dates infused water is the Prophet Muhammad’s favourite drinks. Flavonoids, phenols, alkaloids, and beta D-glucan in dates have anticancer and antitumor activity. This study aims to prepare and characterise the active component of nabeez water made with ajwa dates, applied in BRM (Brown Rice Milk) products. BRM is an innovative plant-based beverage made with brown rice and nabeez water from ajwa dates as a halal beverage for immune booster in the era of the covid-19 pandemic. The methods to analysis the products are the preparation of nabeez water, the pasteurisation method for halal drinks with the LTLT (Low-Temperature Long Time) method, toxicity testing, pyrochemical testing, functional group analysis using FTIR instrument, milk dye degradation analysis and stability test. The results showed phenolic, flavonoids, catechol tannins, saponins, alkaloids, Mayer's test, and Wagner's test in halal drinks but not shown the tannin of gallate, anthraquinone, steroid test, and triterpenoid test. The toxicity test using the Brine Shrimp Lethality Test (BSLT) method of the LC 50 value showed the Concentration 50 (LC 50 ) value is 721.56 ppm. Analysis of functional groups using FTIR showed absorption of functional groups such as OH (hydroxide), C=O, C=C, C=CH, and Ar-H.

Improving curcumin retention in oil-in-water emulsions coated by chitosan and their disperse stability exposed to thermal treatments

Curcumin-loaded (6% medium-chain triglyceride oil in water) emulsions were coated with chitosan and then treated with different thermal processes, including LTLT (low-temperature, long-time), HTST (high-temperature, short-time), and autoclave treatments. The mean size and zeta-potential of the emulsions linearly increased with increasing chitosan concentrations. All emulsions maintained their initial mean size after LTLT and HTST, but autoclaving increased the emulsion sizes. The size increment diminished with increasing chitosan concentrations. Moreover, 26.1% of the curcumin in non-coated emulsions was degraded during the autoclaving, whereas 83.1% of the curcumin was retained in emulsions coated with 1.0% chitosan. Thus, the emulsions coated with 1% chitosan are applicable to various thermal processing including LTLT, HTST, and autoclaving. All emulsions showed Newtonian fluid behavior, but viscosity increased with increasing chitosan concentrations. Therefore, the emulsion coated with a high chitosan concentration (more than 0.5%) showed enhanced storage stability in turbidimetric analysis despite its high polydispersity index. • Curcumin loaded emulsions were coated with different concentrations of chitosan. • Curcumin retention in emulsions was determined after thermal processing. • Chitosan coating protected the curcumin encapsulated in emulsions against heat. • Chitosan coated emulsions exhibited Newtonian fluid behavior. • Chitosan coating prevented creaming formation of emulsions by destabilization.

A Review on Optimal Temperature Control of Milk Pasteurization Using Extremum Seeking Based Proportional Integral Derivative Controller

Milk is a rich nutrient white liquid food produced by the mammary gland of mammals vulnerable to bacteria that cause diseases to the human health. In a dairy plant, pasteurization process is the best heating procedure for a milk. It can be performed under High Temperature Short Time (HTST) or Low Temperature Long Time (LTLT). However, optimal temperature stability control has been a major challenge for milk pasteurization in a dairy plant due to non-linearity, time delay schemes, inaccuracy and unrealistic parameter variation of the modern and manual tuning techniques used without incorporate a numerous adaptive tuning control method. Therefore, this article proposed an optimization tuning technique of Extremum Seeking (ES) based Proportional Integral Derivative (PID) controller to optimize the heating process and eliminate the external perturbation of the system. In this article, a closed loop mathematical equation model using ES-PID controller was developed proposed to achieve the optimal performance characteristics. The due technique is expected to eliminate the offset of the system and minimize the percentage overshoot.Keywords- Milk Pasteurization, Temperature Control, Extremum Seeking, Proportional Integral Derivative.

Study of Heat Transfer and Product Characterization in Spouted Bed Coffee Roaster

Roasting is one of the essential coffee production processes, which significantly influences the quality of roasted coffee. There are many approaches for roasting, applying rotating cylinder (a standard method of the roasting process), fixed bowl, and fluidized bed method. A study of heat transfer and product characterization was conducted in a spout fluidized bed coffee roaster with a 2000-gram capacity. In this research, Temanggung Robusta Coffee beans were processed with two different operating temperature settings, performing 225°C for a low-temperature long time (LTLT) and 240°C for a high-temperature short time (HTST). At both operating temperatures, the overall heat transfer coefficient for coffee roasting was 26,63 – 92,02 W/m2K for the LTLT process and 44,85 – 139,98 W/m2K for the HTST process. The products, then, were analyzed for moisture and ash content. The results showed that a low-temperature long-time process resulted in lower moisture content. Furthermore, there was no significant difference in ash content compared to the high-temperature short-time process (HTST).

Denaturation kinetics and storage stability of Osteopontin in reconstituted infant milk formula

Osteopontin (OPN) is a multifunctional whey protein with numerous health benefits and is recommended to supplement Infant Milk Formula (IMF) with it. For the first time, the denaturation kinetics and storage stability of bovine OPN were studied in reconstituted IMF. The effect of thermal treatments (63–90 °C) and High Pressure Processing (HPP) were investigated. OPN showed higher retention (around 90%) after both LTLT (Low Temperature Long Time) and HTST (High Temperature Short Time) treatments, however higher temperature and longer treatment induced substantial denaturation indicating UHT may not suit OPN-added items. Significant denaturation occurred at higher pressure (>400 MPa), and more pronounced OPN denaturation was observed after HPP at elevated temperature. OPN remained stable during4 °Cstorage for 14 days. This investigation deduced thermal stability of OPN as α-Lac > OPN > LF, whereas the pressure resistance observed as α-Lac > LF > OPN > β-Lg.

Rheological properties of fermented milk from heated and high pressure-treated camel milk and bovine milk

Gelation of camel milk is a challenge to the industrial utilization. This study investigated the impact of low-temperature long-time (LTLT) and high-temperature short-time (HTST) pasteurization, ultra-high temperature (UHT) treatment, and high-pressure processing (HPP), at 300 and 600 MPa, on the rheological properties of the fermented milk. Both camel and bovine milk were fermented by Lactiplantibacillus plantarum and Ligilactobacillus salivarius. Both milk treated at 300 and 600 MPa showed the highest Lb. plantarum and Lb. salivarius numbers, with ∼9 log.HTST and UHT-treatment increased particle size in bovine milk but decreased it in camel milk. HPP-treatment decreased particle size in both camel and bovine milk. All fermented milk showed shear-thinning behavior, regardless of milk type, processing, culture type and storage time. For both camel and bovine milk, fermented UHT-treated milk had the highest viscosity followed by fermented HPP-treated milk. Lowest viscosities were observed for fermented LTLT-treated and HTST-treated milk. Small deformation rheology showed consistently lower tan δ values for fermented HPP-treated camel milk than for fermented heated camel milk, with the latter only giving tan δ < 1 at elevated frequencies. UHT- and HPP-treatment of milk can enhance the rheological properties of fermented camel milk compared with other heat treatments.