Main effects of ascorbic acid levels and organic acid type on physicochemical properties, microbial populations, texture, and biogenic amine formation in sucuk.

Effect of ascorbic acid on copper and cholesterol in adult cynomolgus monkeys fed a diet marginal in copper

Regulation of the nitrite, biogenic amine and flavor quality of Cantonese pickle by selected lactic acid bacteria

This article reports on the antilisterial properties of selected organic acids and salt derivatives in order to suggest possible alternatives in food preservation and pathogen control in the poultry meat processing industry. The susceptibility of two Listeria monocytogenes isolates was assessed against five organic acids (lactic, acetic, malic, citric, and propionic) and two acid-salt derivatives (sorbic acid [potassium salt] and benzoic acid [sodium salt]) across a series of pH environments. Minimum inhibitory concentrations (MICs) of the acids were tested against the two strains by means of an agar-dilution method. In general, strain CC60 was found to be more resistant than strain CC77 to both organic acids and salts. At pH values of 7 and above, high MIC levels (low susceptibility) were noted for potassium sorbate, sodium benzoate, and lactic acids, whereas susceptibility at lower pH increased reaching pH5 where the isolates were susceptible to all the organic acids tested. A small increase in pH notably reduced antimicrobial activity against the organisms. At pH 7, the isolates just about lost susceptibility to benzoic, lactic, malic, and sorbic acids. Although the activity of the majority of acids was linked to pH, some acids were not as closely related (e.g., potassium sorbate, sodium benzoate, and citric acid), and this suggests that the type of organic acids plays a role in inhibition. The relatively high MICs reported for compounds that are conventionally used as preservatives against Listeria spp. raise concern. The results furthermore suggest that the type of organic acid used to set pH, and not only pH alone, plays a role in determining inhibition. It was confirmed that a "one size fits all" approach to preservation is not always effective. Furthermore, the need for microbiological data to the subspecies level to inform the selection of preservatives was highlighted.

The study was carried out at the University of Kufa - College of Agriculture for the season 2023-2022 to study the effect of the type and concentration of organic acids on the growth of soil bacteria, the first experiment includes the cultivation of bacteria on optional, broth, four types of organic acids were used (Citric acid, Acetic acid, Oxalic acid, Propionic acid) in concentrations (0,25.50.75.100.150) mM factor included four types of bacteria (Pseudomonas fluorescens, Acinetobacter calcoaceticus, Bacillus subtilis, Enterobacter cloacae). During this experiment, the minimum inhibitory concentration of these organic acids was determined, the second experiment included planting wheat seeds of a local variety by 4-2seeds per pot and used two types of organic acids (Acetic acid, Oxalic acid) and two types of pathogenic bacteria and biological resistance (Enterobacter cloacae and Bacillus subtilis). The results of the laboratory experiment showed a significant effect of organic acids in reducing the growth of bacteria, the addition of organic acids to the soil had a significant effect on the values of (Ec, PH) in the soil as oxalic acid obtained the highest rate of 6.370 dc m-1 At a concentration of 50 mM, oxalic acid obtained the highest rate of soil reaction score of 6.300 at a concentration of 75.50mM. The results indicate the significant effect of organic acids in inhibiting the total bacteria population in the soil, as oxalic acid obtained the highest rate of 106×114.3 g-1 dry soil at 50mM concentration.

The main fermented meat products are fermented sausages in which lactic acid bacteria (LAB) are the essential agents of the ripening process. Their application as starter organisms ensures the dominance of the starter during the whole ripening process. However, when no starter cultures are used, direct addition of acids like a glucono-delta-lactone (GdL) is preferred. The goal of this study was to determine the influence of commercial spices mixtur (containing GdL) on selected technological parameters of fermented dry-cured sausages - Danube sausage in comparison with currently available conventional spices. Comparison was evaluated also with addition of starter cultures. Determinations of technological (value of pH, water activity, color) and microbiological properties (count of Lactobacillus spp., Enterobacteriaceae family, yeasts and moulds) were realized after 24 hours, 5 and 30 days. The sensory analysis of sausages was carried out after 30 days of ripening process. In sausages with the addition of commercial spice mixture in combination with starter culture were determined the lowest values of pH and aw at the end of ripening process (30 days). Bacteria of Enterobacteriaceae family were occurred in the samples with the addition of currently available conventional spices at the beginning of ripening, but after 5 days of ripening were bacteria of this family not detected. The counts of yeasts in analyzed samples were not detected. Counts of LAB at the end of ripening proccess (30 days) were lower in coparison with result obtained after 5 days; however their count was comparable with count determined at the beginig of the ripening. Our results show, that the combination of starter culture and commercial spice mixture containig GdL may cause excesive sour taste and sensory defect of dry fermented meat products.

Panax notoginseng (Sanqi) is a precious traditional Chinese medicine that is commonly cultivated using conventional management methods in agricultural systems in Yunnan, China, where it faces the challenge of continuous cropping obstacles (CCOs). However, the existence of Sanqi CCOs in Sanqi–pine agroforestry systems remains unclear. Here, we applied three types of exogenous organic acids (phthalic acid, palmitic acid, and phthalic + palmitic mixed organic acids) mainly derived from the root exudates of Sanqi to simulate the CCOs; then, we compared the effects on plant growth, soil physicochemical properties, soil microbes, and soil metabolites. We found that organic acid concentrations of >250 mg/kg reduced the fresh weight of Sanqi and the levels of total nitrogen, ammonium nitrogen, soil water content, total phosphorus, and pH value; these concentrations also increased the soil bacterial and fungal α-diversity. The type of organic acid, as opposed to the concentration and duration of treatment, had a vital impact on the structure of the bacterial and fungal community in Sanqi soils. Moreover, the organic acid concentrations of >250 mg/kg also decreased the complexity and stability of the bacterial and fungal network. In addition, the metabolic pathways in the soils under different organic acids included 17 differential metabolites (DMs), which were involved in steroid hormone biosynthesis. The structural equation models (SEMs) revealed that plant growth, soil edaphic factors, and soil metabolites had direct or indirect influences on soil microbial communities under different organic acid conditions. Our results suggest that any phthalic or palmitic acid concentrations at concentrations >250 mg/kg are detrimental to multiple aspects of Sanqi cultivation, confirming the presence of Sanqi CCOs in Sanqi–pine agroforestry systems.

The relationship between histidine decarboxylase-positive (hdc+) lactic acid bacteria (LAB) counts and the amounts of biogenic amines, particularly histamine, in cheeses made with and without LAB starter were investigated. Sixty LAB strains were isolated from ripened cheeses made with raw milk inoculated with lactic starter and cheeses without starter. The strains were identified by carbohydrate fermentation test and the histidine decarboxylase gene was determined by PCR. Biogenic amine contents from the cheeses were determined by HPLC. LAB counts and their diversity were higher in the cheeses without starter. The cheeses contained low concentrations of the studied amines. The lowest concentrations were found for ethylamine and putrescine followed by cadaverine, tyramine, phenyletilamine, and histamine, especially in the cheeses with starter. There was a direct relationship between the percentage of hdc+ LAB strains and histamine and between this percentage and the sum of tyramine, phenylethylamine and ethylamine concentrations. Practical applications It is a well-known fact that the content of biogenic amines in cheeses should be controlled because these compounds can cause toxicity and undesirable flavor. The results of the present study show that LAB starter cultures do not completely prevent the formation of biogenic amines in cheeses manufactured with raw milk. Although the LAB starter helps to reduce the total amount of biogenic amines, histamine concentration is not clearly linked to the use of starter. In order to ensure the safety of cheeses, it is necessary to use high-quality milk, follow hygienic practices and take advantage of the selective pressure of the physicochemical and technological parameters that occur during cheese making.

The transformation of phosphorus in the soil is facilitated by the activity of the phosphate solubilizing microbes. These microbes have the ability to dissolve fixed P in the soil. The mechanism that plays a role for the phosphorus solubilization is the production of different types of organic acids by phosphate solubilizing microbes. This difference is influenced by two factors, namely the stability constant of organic acid complex compounds with ions, and the structure of the hydroxyl and carboxyl molecules in the main carbon chain. By increasing the organic acids produced by phosphate solubilizing microbes, it will be followed by the formation of organic chelate, so that the bound P becomes dissolved. The reaction that occurs due to the binding process between organic acids and various Al phosphate and Fe phosphate ions The ability of each organic acid to chelate the ion also varies. Each microbe produces different quality and quantity of organic acids. This study aims to determine the relationship between the organic acids secreted by PSM to phosphorus solubilization seen through the best regression modeling that connects between the two variables The relationship between the type and amount of organic acid and phosphorus solubilization still needs to be studied. This study showed that there was a positive correlation between the organic acids produced by phosphate solubilizing microbes (Burkholderia/ Pseudomonas, Bacillus and Aspergillus) and phosphorus solubilization.

This study examines the potential use of the spent catalyst as a raw material for rechargeable batteries. The spent catalyst Ni/γ-Al2O3 still contains relatively high amounts of nickel. This indicates the potential use of the spent catalyst to be leached and purified for synthesizing nickel-based compounds so that it can be applied to rechargeable battery cathodes. In this study, the spent catalyst leaching process employed four types of organic acids: citric acid, lactic acid, oxalic acid, and acetic acid. The spent catalyst was leached under atmospheric conditions and room temperature. Organic acid concentrations were also varied at 0.1, 0.5, 1, and 2 M. The leaching process took place for 240 minutes, where sampling was conducted periodically at 30, 60, 120, 180, and 240 minutes. Experimental results showed that Ni (II) and Al (III) ions were successfully leached to the maximum when using 2M citric acids at a leaching time of 240 minutes. The conditions succeeded in leaching Ni (II) and Al (III) ions of 357.8 and 1,975.4 ppm, respectively. Organic acid, notably citric acid, has excellent potential for further development. Citric acid, as a solvent, has the ability to leach metal ions with high recovery. In addition, this acid is categorized as an eco-friendly and green solvent compared to inorganic acid. Thus, the leaching process can take place without harming the environment.

The aim of this study was to analyze changes in the microbiological quality of Longissimus lumborum (LL) muscles collected from young Polish Holstein-Friesian Black-and-White (PHF BW) bulls and stored for 7, 14, and 21 days under different modified atmospheres (MA) (vacuum, 80% O2 + 20% CO2, 60% O2 + 30% CO2 + 10% N2, 40% CO2 + 60% N2, 30% CO2 + 70% Ar). Before and after the specified storage periods, crosssectional samples of the LL muscle were collected under aseptic conditions to determine total microbial counts, and the total counts of psychrotrophic bacteria and mesophilic lactic acid bacteria. The effects of storage time and MA composition on changes in the parameters analyzed were evaluated, and the effectiveness of argon in delaying microbial growth in cold-stored beef was determined. Between days 7 and 14 of storage, total microbial counts were lowest in meat packaged under the MA composed of 30% CO2 + 70% Ar, whereas between days 14 and 21 they were lowest in both MA packages containing O2. The greatest increase in total microbial counts between days 7 and 14 of storage was noted in the MAs containing O2, and between days 14 and 21 of storage in the MA containing Ar. Beef stored for 7 days in the MA containing 60% O2 was characterized by the lowest total microbial counts, whereas the highest total microbial counts were noted in samples stored for 14 days in the MA containing 80% O2. Between days 7 and 14 of storage, the counts of psychrotrophic bacteria increased significantly in all MAs. Between days 14 and 21 of storage, the counts of psychrotrophic bacteria did not increase in meat samples packaged under vacuum or the MA composed of 80% O2 + 20% CO2. The counts of psychrotrophs were significantly lower in beef stored for 7 days in the oxygen-free MAs than they were in both MA packages containing O2. The counts of psychrotrophic bacteria were significantly lower in beef stored for 14 days in the MA containing Ar, compared with samples packaged under vacuum and the MA containing 80% O2. Gas composition in MA packaging had no significant effect on total microbial counts or the counts of psychrotrophic bacteria in meat stored for 21 days. Between days 14 and 21 of storage, the counts of lactic acid bacteria did not increase significantly only in meat packaged in the MAs composed of 60% O2 + 30% CO2 + 10% N2 and 40% CO2 + 60% N2. After 7 days of storage, the counts of lactic acid bacteria were higher in beef packaged in oxygen-free MAs than they were in both MA packages containing O2. After 14 days of storage, the counts of lactic acid bacteria were higher in meat packaged in the MA composed of 80% O2 + 20% CO2 than they were in the other MAs. Beef samples stored for 21 days under the MA composed of 80% O2 + 20% CO2 were characterized by significantly lower counts of lactic acid bacteria, compared with samples stored under the other MAs, except for the MA composed of 40% CO2 + 60% N2. It can be concluded that beef can be stored in the MA composed of 30% CO2 + 70% Ar for shorter periods of time (up to 14 days). The modified atmosphere composed of 30% CO2 + 70% Ar contributed to slower microbial growth in meat and resulted in lower counts of psychrotrophs and lactic acid bacteria, relative to the other samples. However, there is a need for further research on different concentrations of argon in MA packages to confirm that this gas can effectively delay microbial growth in beef. Meat stored for 14 days in the MA composed of 80% O2 + 20% CO2 was characterized by the lowest microbiological quality. The composition of MAs had a minor influence on the growth rates of the microbial groups analyzed in beef stored for 21 days; certain changes were observed only in the counts of lactic acid bacteria.

Different concentrations of potassium sorbate were examined for their effect on the formation of biogenic amines during sausage fermentation using Lactobacillus plantarum and Pediococcus acidilactici as starter cultures. Microbiological examination revealed that there was a slight decrease in bacterial counts during aging period of fermented sausages. No differences in bacterial counts could be observed between treatment up to 0.06% potassium sorbate, although they were lower than that of control. Tyramine development continued, although potassium sorbate was used in concentration up to 0.06%. Histamine, tryptamine and phenylethylamine concentrations increased, then decreased in the later stage of aging to reach undetectable levels. Putrescine, cadaverine and spermidine were not detected in any sample throughout the study. Statistical analyses proved that there was a positive relation between total biogenic amine (TBA) content of fermented sausage and aging period. On the contrary, a negative relation between TBA and potassium sorbate concentration was found. The interrelationship between the concentration of TBA and the two factors (aging period and potassium sorbate concentration) with higher determination coefficient (R2 = 0.94) was given.

A total of 112, day-old broiler chicks were reared under summer temperature of the Sudan (35- 45°C) to study the effect of supplementati on of ascorbic acid on the feed intake, Feed Conversion Ratio (FCR), weight gain, immune status and ratio of weight of bursa, thymus and spleen to body weight. Four level of ascorbic acid 0 (control), 150 (low level), 350 (moderate level) and 550 (high level) mg/kg were used from day 14-42 day. Birds fed low and moderate levels of ascorbic acid (150, 350 mg/kg) show high feed intake compared to those fed high level (550 mg/kg), which resulted in improvement in body weight and feed conversion ratio of the moderate and low levels. Dressing percentage was not affected by different level of ascorbic acid. Total white blood cells were reduced as the level of ascorbic acid was increased. Lymphocytes increased in birds fed moderate or high levels of ascorbic acid. Heterophils were decreased in the group fed the moderate level and high levels of ascorbic acid. Monocytes decreased in the groups fed the high level, However, basophils and esinophils were not affected by the different levels of ascorbic acid. The mean weight of lymphoid organs or the ratio of lymphoid organs to body weight was not affected by the different treatments. Antibody titer against Newcastle virus was increased in birds fed diets supplemented with different levels of ascorbic acid.

Antibacterial mechanism of thermoultrasound combined with potassium sorbate against Pichia membranifaciens

Organic acid type in kimchi is a key factor for determining kimchi starters for kimchi fermentation control

Effect of Dietary Ascorbic Acid Intake on Tissue Vitamin C in Mice