The Potential Benefits of N2 Gas Flushing Technology for Various Dairy Products: A Sustainable Approach That Proved to Be Multiadvantageous for Preserving the Quality and Safety of Raw Milk During Its Storage

Worldwide, food production systems are confronted with multifaceted challenges. In the context of global climate change, the necessity to feed an expanding population while addressing food insecurity and reducing the tremendous losses and wastage of food places all production steps under considerable pressure. In this context, dairies also face extensive pressure to reduce greenhouse gas emissions, wastewater, and sludge; here, as elsewhere, innovative technological solutions must meet sustainable criteria. To preserve the quality and safety of raw milk during its storage, N2 gas flushing technology was devised and implemented at laboratory and pilot plant scales: the treatment proved to be multiadvantageous considering microbiological, biochemical, and technological aspects. The proposed study aims to reconsider the benefits of the patented N2 flushing technology, applied at the “raw milk stage” and evaluate the potential advantages that the treatment would confer, in terms of quality and safety aspects, to various dairy products such as liquid milk products, butters, creams, ice creams, and cheeses, including local and traditional dairy products.

Alterations in health-related fatty acids in buffalo milk after processing to traditional dairy products

Milk provides some beneficial fatty acids which in dairy processing are subjected to pasteurization and fermentation. With the aim to assess such changes, aliquot parts of milk from 12 buffaloes were pooled and processed to germinated yoghurt and brined cheese, and to non-germinated curd – the respective samples of raw and dairy material subjected to lipid analysis. The results show that in cheese positive and negative changes are generally balanced, rumenic acid decreasing and other CLAs altered but not total CLA and PUFA; omega ratio and atherogenicity index worsened to little extent, due to adverse change in n-3, myristic and lauric acid. In yoghurt and curd CLA dramatically decreased, excluding rumenic acid; but vaccenic acid increased, though total trans isomers decreased; the worsened n-6/n-3 ratio and atherogenicity index is mostly because of the adverse effect on PUFAn-3 but also on myristic and lauric acid. In all products SFA and MUFA did not change, including palmitic, stearic, and oleic acid. It can be concluded that the decrease of CLA in yoghurt and curd is partially compensated by the increase in the vaccenic acid, while cheese making altered individual isomers but not groups of beneficial acids.

Antibacterial Activity of Lactic Acid Bacteria Isolated from Fermented Ethiopian Traditional Dairy Products against Food Spoilage and Pathogenic Bacterial Strains

Fermented Ethiopian traditional dairy products containing LAB that show antibacterial activities against various food spoilage and pathogenic bacteria have been used for the preservation of fermented dairy products for a long time. However, there are no comprehensive scientific reports on the antibacterial activity of LAB isolated from various fermented dairy products in Pawe Woreda. The objective of the study was to evaluate the antibacterial activity of LAB isolated from traditionally fermented Ethiopian dairy products against spoilage and pathogenic bacteria. Thirty-five samples of fermented dairy products were collected from three cattle-farming areas of Pawe Woreda. A total of 97 LAB were isolated and screened primarily using the perpendicular streak plate method against 3 Gram-positive and 3 Gram-negative bacterial strains. Out of the 97 strains, 10 were active against at least two of the tested bacteria, of which 7 strains were selected for secondary screening by their broad-spectrum antibacterial activities. The seven in vitro antibacterial activities of the extract ranged from 5 to 16 mm in diameter during the secondary screening. In this study, Z2, Z4, and N2 strains exhibited the highest inhibition zone with broad-spectrum activity against all tested bacteria. The MIC and MBC values range from 0.10 to 0.30 µg/µL and 0.20 to 0.50 µg/µL, respectively. Following morphological, physiological, biochemical, and molecular characteristics, seven potent strains were identified as Lactobacillus acidophilus, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus, Leuconostoc mesenteroides, Streptococcus thermophilus, and Lactococcus lactis. According to the findings of this study, Ethiopian fermented dairy products were the most potent source of bioactive compounds with potential effects against food spoilage and pathogenic bacterial strains.

Assessment of microbial quality of industrial and traditional creams in Alborz province, Iran

Milk and dairy products play an important role in the human diet and society's health. The aim of this study was the assessment of the microbial quality of industrial and traditional breakfast cream in Alborz province, Iran. In this study, 40 different samples of breakfast cream (20 samples of traditional breakfast cream and 20 samples of industrial pasteurized breakfast cream) were collected randomly in Alborz province in 2018. Microbial quality tests were performed according to Iran National Standards on Coliforms, Escherichia coli, and Staphylococcus aureus, and then the collected data were analyzed. The microbiological examinations revealed that 43% of the samples were contaminated with coliform bacteria that 12 samples (60%) out of 20 samples of traditional cream, 5 samples (25%) out of 20 samples of industrial cream were higher than the allowable microbial limit of the national standard of Iran. About 15% of samples of traditional creams and 10% of industrial creams were contaminated with Escherichia coli. 10% of samples of traditional cream were contaminated with Staphylococcus aureus, which was not observed in industrial creams. High contamination with bacteria, needs using different methods to control microbial growth, including the promotion of sanitary awareness among laborers, the codification of microbial standards for traditional dairy products, training to staff for preparing the cream and disinfection of tools.

PROBIOTIC PROPERTIES AND RELEVANCE OF PRACTICAL APPLICATION L. ACIDOPHILUS

Creating probiotic complex starter cultures and increasing the probiotic activity of traditional dairy products is an urgent task today. The active principle of these products is live lactobacilli, in particular, L. Acidophilus, which have a wide range of probiotic activity. The article is devoted to the description of the probiotic culture of Lactobacillus acidophilus. The article describes the probiotic and biochemical properties of Lactobacillus Acidophilus, provides examples of the practical use of this culture in the medical and food industries.

MICROENCAPSULATION OF L. FERMENTUM ISOLATED FROM TRADITIONAL DAIRY PRODUCTS AND ITS STABILITY ON EXPOSURE TO SIMULATED GASTROINTESTINAL CONDITIONS

The physiological state of food may affect the survival potential of health promoting microorganisms. The current research was thus undertaken for comparing the invitro stability of two similar species of L. fermentum isolated from two different dairy products. The isolates were analyzed for their viability after microencapsulation in sodium alginate and were also compared using the non-encapsulated strain in simulated gastric and intestinal conditions. Viability of the cultures were also compared against reference standard (i.e) Lactobacillus acidophilus procured from MTCC Chandigarh. The percentage log reduction of non- encapsulated cultures i.e curd, raw milk and MTCC was 58.32%,58.28%,58.43% while that of encapsulated cultures was 10.19%, 10.03% and 11.18% as observed in gastric juice. The log reduction of non -encapsulated cultures as observed was 3.80%, 3.10% and 2.23% for curd raw milk and MTCC cultures respectively while that of encapsulated cultures was 1.54%, 1.52% and 1.16%in simulated intestinal conditions. The raw milk isolate was found with slightly better adaptation in response to the viability both in case of gastric and intestinal juice. The result thus justifies the physiological state of food which may affect the osmotic response and stress of similar microflora although isolated from two different food consortiums.

Enterococcal Species Associated with Slovak Raw Goat Milk, Their Safety and Susceptibility to Lantibiotics and Durancin ED26E/7

Goat milk has become a popular item of human consumption due to its originality. Enterococci are ubiquitous bacteria, and they can also be found in traditional dairy products. This study focuses on the safety of enterococci from Slovak raw goat milk and on their susceptibility to lantibiotic bacteriocins and durancin ED26E/7, which has not previously been studied. Biofilm formation ability in enterococci, virulence factor genes, enzyme production and antibiotic profile were investigated. Samples of raw goat milk (53) were collected from 283 goats in Slovakia. MALDI-TOF mass spectrometry identified three enterococcal species: Enterococcus faecium, E. hirae and E. mundtii, with dominant occurrence of the species E. faecium. Low-grade biofilm formation ability (0.1 ≤ A570 < 1.0) was found in four strains of E. faecium.Gelatinase, hyaluronidase, aggregation substance and enterococcal surface protein genes were absent in these enterococci. Gene efaAfm (adhesin) was detected in five E. faecium strains. However, it was not detected in biofilm-forming strains. Enterococci detected in Slovak raw goat milk were found not to have pathogenic potential; four strains even produced high amounts of useful β-galactosidase. The strains were susceptible to lantibiotic bacteriocin treatment and to durancin ED26E/7 as well, which represents original information in dairy production.