The current study aimed to figure out the effect of using a combination of 2% inulin, and 2% Fructo-oligosaccharides (FOS) with Lactobacillus acidophilus and their bacteriocin on some yogurt properties such as coagulation time, extending the shelf life of set yogurt and its microbiological quality, also the acceptance by consumers. The results indicated that coagulation time increased by 22.75% in yogurts prepared with Lactobacillus acidophilus and their bacteriocins compared to the control, and titratable acidity increased gradually in all treatments during storage. Hence control acidity (%) increased from 0.84 ± 0.02^A at zero time to 1.23 ± 0.03^A after 14 days of cold storage, while treatment (T4) was 0.72 ± 0.01^C at zero time and reached 1.20 ± 0.5^A after 39 days at the same conditions. The sensory properties showed the superiority of inulin, FOS, and Lactobacillus acidophilus bacteriocin groups. Lactobacillus bulgaricus, Streptococcus thermophiles, and Lactobacillus acidophilus count increased in the treatments compared to the control group, with an extended shelf life to 39 days of storage in the medicines containing lactobacillus acidophilus bacteriocin. Coliforms, Moulds, and yeasts did not detect in the treatments comprising 2% inulin, 2% FOS, and lactobacillus acidophilus bacteriocin for 39 days of refrigerated storage. This study proved that 2% inulin, 2% FOS, and Lactobacillus acidophilus bacteriocin fortification extended the shelf life by more than 5 weeks.

The present study explored the preservation effect of the garlic and ginger extract (GGE) on herring fish fillets under refrigerated storage (4°C) for 8 weeks. The antioxidant and antimicrobial activity of GGE was evaluated: GGE exhibited a reasonable antioxidant activity and antimicrobial potency against some foodborne pathogens such as Bacillus subtilis DB 100 host, Clostridium botulinum ATCC 3584, Escherichia coli BA 12296, Salmonella senftenberg ATCC 8400, and Staphylococcus aureus NCTC 10788. The effect of GGE on the quality and shelf life of herring fish fillet was screened. The study findings highlight the effects of GGE treatment: significant microbial growth inhibition, postponed lipid oxidation, decreased thiobarbituric acid reactive substances (TBARS) concentration and decreased protein oxidation. Additionally, GGE treatment preserved the pleasant appearance of the fish compared to that of the control after 8weeks of storage. This study verified that GGE effectively maintained herring fish fillet quality and safety compared to the control treatment and the treatments with nisin or butylated hydroxyl-toluene (BHT).

The objective of this study was to evaluate the impact of the antimicrobials nisin and lysozyme to control the growth of spoilage bacteria of pasteurized milk during cold storage. Nisin, lysozyme, and a mixture of them were inoculated into freshly pasteurized milk at 500 IU/ml concentrations each. The acidity, sensory evaluation, and bacteriological quality of the treated pasteurized milk samples were examined at zero time and every 3 days till the samples showed the signs of spoilage, that were checked every day. Obtained results showed that there was a slight increase of the titratable acidity of the control and treated samples during refrigerated storage, but the acidity increase was significantly lower in samples containing lysosomes and/or nisin than the control samples. Nisin and lysozyme at 500 IU/ml concentration possessed inhibitory effect on the total bacterial, aerobic spore-formers, and psychrotrophic bacterial counts and extended the shelf-life of the treated samples. The efficacy of nisin 500 IU/ml combined with lysozyme 500 U/ml was assessed and synergistic activity has been detected, that was expressed in the form of higher inhibitory effect and extending the shelf-life of the samples up to 15 days at cold storage. Moreover, the sensory evaluation showed that nisin and lysozyme does not affect the acceptability of the examined samples. The obtained data indicate that nisin and lysozyme have the potential to enhance the post-process bacteriological safety of pasteurized milk during the storage period and could aid in the elimination of post-process contamination and prolong its shelf-life.

Probiotics and their bacteriocins have increasingly attracted interest for their use as safe food preservatives. This study aimed to produce soft white cheese fortified with Lacticaseibacillus MG847589 (Lb. paracasei MG847589) and/or its bacteriocin; cheese with Lacticaseibacillus (CP), cheese with bacteriocin (CB), and cheese with both Lacticaseibacillus and bacteriocin (CPB) were compared to control cheese (CS) to evaluate their biopreservative and anti-mycotoxigenic potentials for prolonged shelf life and safe food applications. The effects of these fortifications on physiochemical, microbial, texture, microstructure, and sensory properties were studied. Fortification with Lacticaseibacillus (CP) increased acidity (0.61%) and microbial counts, which may make the microstructure porous, while CPB showed intact microstructure. The CPB showed the highest hardness value (3988.03 g), while the lowest was observed with CB (2525.73 g). Consequently, the sensory assessment reflected the panelists’ preference for CPB, which gained higher scores than the control (CS). Fortification with Lb. paracasei MG847589 and bacteriocin (CPB) showed inhibition effects against S. aureus from 6.52 log₁₀ CFU/g at time zero to 2.10 log₁₀ CFU/g at the end of storage, A. parasiticus (from 5.06 to 3.03 log₁₀ CFU/g), and P. chrysogenum counts (from 5.11 to 2.86 log₁₀ CFU/g). Additionally, CPB showed an anti-mycotoxigenic effect against aflatoxins AFB₁ and AFM₁, causing them to be decreased (69.63 ± 0.44% and 71.38 ± 0.75%, respectively). These potentials can extend shelf life and pave the way for more suggested food applications of safe food production by fortification with both Lb. paracasei MG847589 and its bacteriocin as biopreservatives and anti-mycotoxigenic.

Egyptian cheeses are considered an important part of the Egyptian diet. This study aimed to examine 60 random samples of different types of commercial cheeses in Egypt, including soft cheeses (Domiati and Tallaga) and hard cheeses (Cheddar and Ras). The samples were subjected to chemical and microbial examination. Biogenic amines (BAs) are nitrogenous compounds found in a variety of foods; their presence is undesirable and related to spoilage, and can result in toxicological effects in humans. Thus, BAs were determined by using a high-performance liquid chromatography (HPLC) analysis. Moreover, the ability of Bacillus polymyxa D05-1 to reduce levels of experimentally added biogenic amines during the manufacturing of Tallaga cheese was investigated. The obtained results revealed variations in the chemical composition between the investigated samples. Furthermore, many cheese samples contained high levels of BAs, including histamine, tyramine and putrescine. Domiati cheese had the highest levels of BAs, followed by Tallaga and Cheddar, whereas Ras cheese had the lowest levels. The existence of yeasts, molds, coliforms and the high levels of BAs in cheese samples indicate the unsanitary conditions in which they were made and stored. Furthermore, addition of B. polymyxa D05-1 during Tallaga cheese manufacturing resulted in a reduction in BA levels.

This study investigated the impact of thermal treatments on the quality, antioxidant, and antibacterial properties of fermented camel milk during refrigerated storage. Two thermal treatment categories were applied: moderate (63 °C for 30 min and 72 °C for 15 s) and high (85 and 90 °C for 15 s and 30 min). Findings indicated that raw camel milk was found to be microbiologically unacceptable. Heating milk to 90 °C for 30 min notably reduced fermentation time, increased fermented milk viscosity, and altered whey protein electrophoretic patterns. While thermal treatments below 90 °C boosted lactic acid bacteria count in fermented milk compared to raw milk-derived samples (control), all treatments exceeded the recommended standards throughout storage. Thermal treatment decreased the proteolysis degree and DPPH radical scavenging activity but enhanced the ferric-reducing power of fermented milk compared to the control. Among, thermal treatments, samples from milk heated at 90 °C exhibited the highest scavenging activity and reducing power. Antibacterial efficacy against Salmonella Typhimurium surpassed that against Escherichia coli and Staphylococcus aureus; the most pronounced effect was observed in samples from milk heated at 90 °C. In conclusion, thermal treatment of camel milk is crucial to ensure sufficient hygiene for safe milk consumption. Heating camel milk at 90 °C before fermentation positively impacted most of the studied properties.