Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat Milk

Traditional hard Xinotyri cheese was manufactured using raw or pasteurized goat milk, without starter cultures, and the changes in microbiological and biochemical characteristics were studied during ripening and storage. Mesophilic lactic acid bacteria (LAB) predominated (>8.5 log CFU/g) in freshly fermented Xinotyri cheeses (pH 4.5–4.6), regardless of milk pasteurization. Enterobacteria, pseudomonads and staphylococci were suppressed below 6 and 4–5 log CFU/g in fresh cheeses from raw and pasteurized milk, respectively. Salmonella and Listeria spp. were absent in 25 g cheese samples. Coagulase-positive staphylococci exceeded the 5-log safety threshold in fresh raw milk cheeses, which also had 10-fold higher levels of enterococci than pasteurized milk cheeses. Non-LAB groups declined <100 CFU/g, whereas yeasts increased to 5–6 log CFU/g in both cheeses during ripening. Milk pasteurization affected the protein, fat, ash, moisture, nitrogen fractions, total free fatty acids and total free amino acids content of cheeses. Primary proteolysis, detectable by urea-PAGE, was more intense in raw milk cheeses than in pasteurized milk cheeses. However, the hydrophilic and hydrophobic peptides and their ratio in the water-soluble fraction were similar in both cheeses. Cheeses discriminated clearly according to the milk kind (raw, pasteurized) and the stage of ripening, based on the examined biochemical characteristics.

Influence of the drying regime on the quality indicators of dry mare’s milk

The data on the influence of the temperature regime of the spray drying process on the quality parameters of dry mare’s milk are given. The results of experimental studies on the selection of the optimal drying mode for maximum preservation of the quality indicators of the final product are presented. It was revealed that the optimum temperature during the drying process of mare’s milk is the temperature at the entrance to the dryer t = 180°C, at the exit t = 70-80°C. The study of qualitative indicators with this drying mode showed that the particle size (more than 68%) was 117-140 microns, the solubility index was 0.18 ml of insoluble sediment in 50 ml of reconstituted mare’s milk, the moisture in dry mare’s milk was 3.8% (at t = 180°C), which met all the requirements of the standard. In addition, it was found that the correct heat treatment of mare’s milk before drying also affects the quality indicators of the dry product. The most optimal temperature for milk pasteurization is a temperature of no more than 60°C.

Intensification of heat exchange by an ultrasound source for milk pasteurization.

The goal of this article is to investigate the effect of ultrasonic vibrations on the process of milk pasteurization. Ultrasound can potentially intensify heat transfer and reduce the formation of thermal sediment (soot deposit) on the walls of heat-exchange devices. The paper presents the results of experimental studies demonstrating the growth rate of thermal sediment on the wall of the heat-exchange apparatus and its amount in the volume of milk under the influence of ultrasonic vibrations and without it.

Human Milk Growth Factors and Their Role in NEC Prevention: A Narrative Review

Growing evidence demonstrates human milk’s protective effect against necrotizing enterocolitis (NEC). Human milk derives these properties from biologically active compounds that influence intestinal growth, barrier function, microvascular development, and immunological maturation. Among these protective compounds are growth factors that are secreted into milk with relatively high concentrations during the early postnatal period, when newborns are most susceptible to NEC. This paper reviews the current knowledge on human milk growth factors and their mechanisms of action relevant to NEC prevention. It will also discuss the stability of these growth factors with human milk pasteurization and their potential for use as supplements to infant formulas with the goal of preventing NEC.

Technical inventions that enabled artificial infant feeding

Artificial feeding of infants, called hand-feeding, was unsafe well into the 19th century. This chapter aims to identify technical innovations which made artificial feeding less dangerous. In rapid succession from 1844 to 1886, the vulcanization of rubber, production of rubber teats, cooling machines for large-scale ice production, techniques for milk pasteurization, evaporation and condensation, and packing in closed tins were invented or initiated. Remarkably, most of these inventions preceded the discovery of pathogenic bacteria. The producers of proprietary infant formula made immediate use of these innovations, whereas in the private household, artificial feeding remained highly dangerous—mostly because of ignorance about bacteria and hygiene, and partly because the equipment for safe storage, transport, preparation, and application of baby food was lacking.

Impact of Nisin and Nisin-Producing Lactococcus lactis ssp. lactis on Clostridium tyrobutyricum and Bacterial Ecosystem of Cheese Matrices

Clostridium tyrobutyricum spores survive milk pasteurization and cause late blowing of cheeses and significant economic loss. The effectiveness of nisin-producing Lactococcus lactis ssp. lactis 32 as a protective strain for control the C. tyrobutyricum growth in Cheddar cheese slurry was compared to that of encapsulated nisin-A. The encapsulated nisin was more effective, with 1.0 log10 reductions of viable spores after one week at 30 °C and 4 °C. Spores were not detected for three weeks at 4 °C in cheese slurry made with 1.3% salt, or during week 2 with 2% salt. Gas production was observed after one week at 30 °C only in the control slurry made with 1.3% salt. In slurry made with the protective strain, the reduction in C. tyrobutyricum count was 0.6 log10 in the second week at 4 °C with both salt concentration. At 4 °C, nisin production started in week 2 and reached 97 µg/g after four weeks. Metabarcoding analysis targeting the sequencing of 16S rRNA revealed that the genus Lactococcus dominated for four weeks at 4 °C. In cheese slurry made with 2% salt, the relative abundance of the genus Clostridium decreased significantly in the presence of nisin or the protective strain. The results indicated that both strategies are able to control the growth of Clostridium development in Cheddar cheese slurries.

Perbandingan Kinerja Pengontrol PID menggunakan Antarmuka OPC pada PLC dan MATLAB untuk Sistem Pasteurisasi Susu

ABSTRAKPLC digunakan pada pengontrolan suhu pada pasteurisasi susu. Di sisi lain, MATLAB memiliki variasi pengontrol yang lebih luas dan dapat terhubung ke sistem Pasteurisasi Susu menggunakan OPC. Namun, penggunaan OPC dikhawatirkan akan menurunkan kinerja sistem karena waktu tunda dan waktu sampling. Penelitian ini bertujuan untuk membandingkan kinerja pengontrolan PID pada sistem pasteurisasi susu dari MATLAB dan PLC dengan memperhatikan pengaruh antarmuka OPC. Pada penelitian ini, kinerja peralihan sistem diukur dengan pengontrol yang berbeda, menggunakan metode penalaan yang berbeda dan berasal dari PLC dan MATLAB. Hasil penelitian menunjukkan bahwa penggunaan OPC tidak memberikan efek negatif pada kinerja sistem. Nilai rata-rata MSE setelah keadaan stabil pada pengontrol PI adalah 70,66 sedangkan pada pengontrol PID 1,16. Nilai MSE Pengontrol PID dengan Penalaan Cohen Coon adalah 0,356. Dapat disimpulkan bahwa pemilihan piranti pengontrol lebih memiliki efek signifikan terhadap kinerja dibandingkan dengan penggunaan OPC.Kata kunci: Pasteurisasi, Cohen Coon, PLC, MATLAB, OPC ABSTRACTPLC can be used to control temperature in milk pasteurization process. MATLAB has more usable Controllers that can be used in milk pasteurization process through OPC .The concern is that the use of OPC will reduce system performance due to delay and sampling time. This study aims to compare the performance of PID control in the milk pasteurization system usingMATLAB and PLC as controllersregarding the effect of using OPC interfaces. In this research, the transient response performance of the system was measured using different type of controllers, twhich use different tuning methods based on PLC and MATLAB. The results showed that the use of OPC did not have a negative effect on system performance. The MSE average in a steady condition for PI controller is 70,66, and for PID controller is 1,16. MSE result using Cohen Coon controller is 0,356. So it can be concluded that the choice of the control device has a more significant effect on performance than with the use of OPC.Keywords: Pasteurization, Cohen Coon, PLC, MATLAB, OPC

Performance Analysis of Plate Heat Exchanger with Nanofluid using Milk Pasteurization

Experimentally to analyzed the enhance performance of Plate heat exchanger in milk pasteurization process using nanofluid at different concentration of 0.1%,0.15%,0.2% 0.25% and 0.3%. in this work the nanoparticles like Al2O3 and the base fluid like dematerialized water is used to prepare nanofluid by using two steps method. Exchanger is one of the thermal energy transferring devices, which transfer the heat between different fluids. This is widely used in different application because of its compact in size and higher efficiency compared to other type of heat exchanger. The main focus of using nanofluid is that it has improvement in thermal conductivity. Then the hot fluid as milk and cold fluid as nanofluids are used. The heat transfer rate is increased with increasing the concentration of nanofluid. It conducted by varying operating parameters like mass flow rate of hot milk, mass flow rate of nanofluid, inlet and outlet temperatures of hot milk and inlet outlet temperature of nanofluid. The main objective of this work is to find out mass flow rate and overall, all heat transfer coefficient.