L. plantarum 299V as a starter probiotic in fermented egg white drink

Egg white (albumen) is the sticky, colorless part of the egg surrounded by the eggshell. It consists of many functional proteins, especially ovalbumin, ovotransferrin, ovomucoid, ovomucin, and lysozyme. Probiotics are living microorganisms that have a beneficial effect on the human intestine. Recently, supplementing food with probiotics has become an important approach to prevent the adhesion of some harmful bacteria to the intestinal mucosa and reduce the symptoms associated with lactose intolerance and milk protein allergy. Egg white drink is a functional drink that is cholesterol and fat-free, and rich source of protein. In this study egg white drink was fermented by L.plantarum 299v as a starter culture using two different carbohydrate sources (fructose and fructooligosaccharides) as samples, and without added sugar were serving as controls.The survivability and pH value of probiotic beverages was investigated during three weeks of cold storage. After 24 hours of fermentation, the pH decreased to a value of 6.15 and the cell count increased to 8.2 log10 CFU/ml in the control samples. During 3 weeks of storage, the cell count was higher than 108 CFU/ml in all samples with or without added sugar, which is the recommended daily dose of probiotic bacteria. Moreover, the pH decreased to 3.8 when fructose and fructooligosaccharides were added, while the control samples had the highest pH (6.1) during the storage period

Effects of HPH processing at 400 MPa on proteins of liquid egg products

In food preservation technologies there are pursuits to apply minimal processing technologies which don’t influence product quality attributes like protein structure. High hydrostatic pressure (HHP) is one of the minimal processing technologies. The effect of high hydrostatic pressure (HHP) was studied at 400 MPa 600 s on proteins of liquid egg products (egg yolk, LEY and whole egg, LWE). Thermo-physical, calorimetrical properties were examined on Micro DSC III (differential scanning calorimeter). Our result show that whole egg’s proteins are not desaturated by HHP, but 40% of egg yolk’s proteins had denaturation caused by processing. Aggregation and separation of protein groups can be observed by both products. Changes in protein structures caused texture modifications

Effects of HPH processing at 400 MPa on proteins of liquid egg products

In food preservation technologies there are pursuits to apply minimal processing technologies which don’t influence product quality attributes like protein structure. High hydrostatic pressure (HHP) is one of the minimal processing technologies. The effect of high hydrostatic pressure (HHP) was studied at 400 MPa 600 s on proteins of liquid egg products (egg yolk, LEY and whole egg, LWE). Thermo-physical, calorimetrical properties were examined on Micro DSC III (differential scanning calorimeter). Our result show that whole egg’s proteins are not desaturated by HHP, but 40% of egg yolk’s proteins had denaturation caused by processing. Aggregation and separation of protein groups can be observed by both products. Changes in protein structures caused texture modifications

Production of Hypoallergenic Antibacterial Peptides from Defatted Soybean Meal in Membrane Bioreactor: A Bioprocess Engineering Study with Comprehensive Product Characterization

Hipoalergeni antibakterijski peptidi male molekularne mase proizvedeni su iz nemasne sojine sačme u membranskom bioreaktoru. U prvom su koraku proteini sojine sačme razgrađeni pomoću tripsina u šaržnom bioreaktoru. Optimalni uvjeti za razgradnju tripsinom bili su: koncentracija sojine sačme od 75 g/L, temperatura od 40 °C i pH=9. Nakon toga su peptidi male molekularne mase pročišćeni pomoću „cross-flow“ membrane (veličina pora 100 μm), a zatim pomoću keramičke cjevaste membrane (veličine pora koja ne propušta molekule veće od 5 kDa). Ispitan je utjecaj transmembranskog pritiska i primjene statičkih promotera turbulencije na smanjenje koncentracijske polarizacije blizu površine ultrafiltracijske membrane, te je potvrđen njihov pozitivan učinak. Transmembranski pritisak od 3•105 Pa i diskontinuirana dijafiltracija provedena u tri koraka bili su optimalni za filtraciju pomoću ultrafiltracijske membrane. Distribucija molekularne mase peptida pročišćenih pomoću ultrafiltracijske membrane utvrđena je pomoću metode LC-ESI-Q-TOF-MS. Više od 96 % peptida (izraženih kao relativna frekvencija) iz permeata ultrafiltracijske membrane imalo je molekularnu masu manju od 1,7 kDa, a najveća je molekularna masa bila 3,1 kDa. Smanjenje alergenih svojstava proteina za više od 99,9 % nakon obrade tripsinom i membranske filtracije utvrđeno je imunoenzimskim testom. Također je zaključeno da peptidi pročišćeni pomoću ultrafiltracijske membrane pozitivno djeluju na rast bakterije Pediococcus acidilactici HA6111-2, te sprečavaju rast bakterije Bacillus cereus.Hypoallergenic antibacterial low-molecular-mass peptides were produced from defatted soybean meal in a membrane bioreactor. In the first step, soybean meal proteins were digested with trypsin in the bioreactor, operated in batch mode. For the tryptic digestion of soybean meal protein, optimum initial soybean meal concentration of 75 g/L, temperature of 40 °C and pH=9.0 were determined. After enzymatic digestion, low-molecular-mass peptides were purified with cross-flow flat sheet membrane (pore size 100 μm) and then with tubular ceramic ultrafiltration membrane (molecular mass cut-off 5 kDa). Effects of transmembrane pressure and the use of a static turbulence promoter to reduce the concentration polarization near the ultrafiltration membrane surface were examined and their positive effects were proven. For the filtration with ultrafiltration membrane, transmembrane pressure of 3·10^5 Pa with 3-stage discontinuous diafiltration was found optimal. The molecular mass distribution of purified peptides using ultrafiltration membrane was determined by a liquid chromatography–electrospray ionization quadrupole time-of-flight mass spectrometry setup. More than 96 % of the peptides (calculated as relative frequency) from the ultrafiltration membrane permeate had the molecular mass M≤1.7 kDa and the highest molecular mass was found to be 3.1 kDa. The decrease of allergenic property due to the tryptic digestion and membrane filtration was determined by an enzyme-linked immunosorbent assay and it was found to exceed 99.9 %. It was also found that the peptides purifi d in the ultrafi tration membrane promoted the growth of Pediococcus acidilactici HA6111-2 and they possessed antibacterial activity against Bacillus cereus

Effect of Combination of Time and Temperature on Quality Characteristics of Sous Vide Chicken Breast

The use of minimal thermal processing techniques such as sous vide technology to improve the quality of meat-based foods has gained a special focus in recent years. A proper combination of temperature and time parameters in sous vide processing plays an important role in the water-holding capacity, texture properties, and juiciness of the meat. The present study aimed to assess the impact of the one-step and two-step sous vide processing on different quality properties of chicken breast with special emphasis on the cooking loss, color, texture properties, protein solubility, and lipid oxidation. According to the results, chicken breast treated with a two-step temperature (50 and 60 °C) showed improved texture parameters (shear force, hardness, chewiness, and gumminess), lower cooking loss, acceptable redness values, and decreased lipid oxidation levels than the chicken breast treated with the one-step temperature of 60 °C. Moreover, the two-step sous vide technique revealed significantly higher total protein solubility of the chicken breast than the one-step sous vide. Based on pasteurization values, the two-step sous vide technique was equally safe as the one-step sous vide technique for vegetative cells’ inactivation for the main pathogens of interest (C. perfringens and L. monocytogenes)

Investigating the shelf-life of probiotics fermented egg white-based beverage using prebiotics

With growing attention to health and lifestyle changes, functional foods have become crucial and in demand. These foods are a rich source of probiotics and prebiotics, but most probiotic products are dairy-based, making them inappropriate for people with lactose intolerance or milk protein allergies. Nevertheless, egg white offers a viable substitute and is considered one of the best sources of functional proteins. As an alternative food matrix, they come highly recommended for those who are hypersensitive to dairy products or who follow a high-protein diet, such as athletes. In this context, egg-white drink with different carbohydrate sources, including monosaccharide (fructose) and oligosaccharide (fructooligosaccharide), was fermented by Lacticaseibacillus casei 01. After 24 h of fermentation, the total cell count was higher than 8 log 10 CFU mL −1 thus, the egg white drink was suitable for L. casei 01 to grow. Additionally, the survival of L.casei 01, the pH value, and the rheological properties of fermented beverages within three weeks of refrigerated storage were also investigated. Throughout the storage period, the control samples exhibited considerably lower cell count and higher pH values compared to the samples with carbohydrate sources, also, samples containing the same carbohydrate source showed no noticeable changes. Viscosity measurements of the studied samples showed a shear thickening behaviour during the time