Total Lactic Acid Bacteria Counts Research Articles

The Effect of Fermented Jicama Extract with Lactobacillus plantarum B1765 as the Culture Starter on the Product Quality and Flavonoid Contents

Jicama (Pachyrhizus erosus) is a functional food containing phenolic compounds, with the main compounds being flavonoids. However, the presence of polyphenol oxidase and the structure of flavonoid compounds are still bound in the form of glycosides, so the bioactivity of jicama is not maximized. This study aims to determine the effects of jicama extract fermentation on product quality and increased flavonoid content in jicama. Fermentation was performed for 0, 12, 24, and 36 hours with 5% (v/v) of the starter culture, Lactobacillus plantarum B1765, at 37ºC. The result showed that fermentation times could increase Total Lactic Acid Bacteria (LAB), Total Tertitrable Acid (TTA), Total Phenolic Content (TPC), and Total Flavonoid Content (TFC). It also influenced a decrease in pH. The total LAB count was determined using the Total Plate Count method, the Total Tertitrable Acid was determined using acid-base titration, and the pH was determined using a pH meter. Total Phenolic Content was measured using the Folin-Ciocalteu method, and Total Flavonoid Content was measured using AlCl3 and potassium acetate. The analysis of the data revealed that jicama extract fermented optimum after 24 hours, with a total LAB count of 9.7x107±0.31 CFU/mL, a pH value of 4.21±0.22, a TTA of 0.376±0.025%, but TPC and TFC still increasing until 24 hours of fermentation to 16.22±0.312 mg GAE/g, and of 29.01±0.641 mg QE/g respectively. Fermentation of jicama extract with Lactobacillus plantarum B1765 increased total phenolic and total flavonoid contents and could be used as a functional food product.

Design and Examination of Yogurt Maker Machine with Sensor Temperature DS18B20

Many commercial yogurt brands do not have a minimum total lactic acid bacteria count (107 CFU/g) due to long distribution with inappropriate storage condition. This leads local producers to produce yogurt. However, commercial yogurt maker machines commonly have a low capacity of 0.5 to 2 L. This study aims to design a yogurt maker machine with a capacity of 15 L with a temperature setting of 37 – 45 ℃. The design and flow system were conducted by arranging the electronic components consisting of 5V 4 channel relay, ESP32 module, DS18B20 temperature sensor, RTC, 12V fan (along with 12 VDC connecting components), 220V heater, 20×4 LCD and plugs (adapter) 220 VAC cable. The yogurt maker machine was evaluated for accuracy of temperature readings (DS18B20 sensor and thermometer), response to incubation time and plain yogurt making. The T-Test was used to compare the differences between the two types of sensors measuring instruments. The results showed that the accuracy of temperature readings using the DS18B20 sensor was better than a thermometer, with a distance scale of 0.35-0.75 ℃ (P-value ≤ 0.05). Temperature testing using milk can be carried out with a temperature range of 37-45 ℃ for 12 h. Keywords: DS18B20, Temperature, Yogurt maker machine, Sensors

Bacteriological Analysis of Cow Milk (Nono) Sold Within Gusau Metropolis, Zamfara State

Fresh cow milk popularly called Nono was collected from ten (10) different sellers at different areas within Gusau metropolis and one control was collected directly from a lactating cow and transported immediately to Microbiology Laboratory of Federal University Gusau where they wereassessed for their bacteriological quality. The total bacteria viable count of the ten Nono samples ranged between 6.6 x105 to 2.7 x106 cfu/ml, the total coliforms count ranged between 4.2x105 to 2.2x106cfu/ml, the range of the total Staphylococcal count and total lactic acid bacterial count were 2.5x105 to 4.0x106 cfu/ml and 5.9x105 to 1.7x106 cfu/ml respectively. The control sample had total viable count of 5.6 x 103 cfu/ml, total staphylococcal count of 3.2 x 103 cfu/ml, total lactic acid bacteria count of 4.2 x 103 cfu/ml whereas the coliform count gotten was too few to count (TFTC). The isolates were identified based on their morphological characteristics, Gram's reactions and biochemical profiles and a total of seventy-four (74) bacterial isolates belonging to the genus Lactobacillus, Leuconostoc, Streptococcus, Micrococcus, Pediococcus, Escherichia coli, Pseudomonas, Proteus, Klebsiella, Enterobacter and Staphylococcus spp. were identified from the eleven samples analyzed. The presence of Lactic Acid Bacteria in Nono is very good as they are one of the most significant groups of probiotic which not only enhance lactose digestion but also stimulate the immune system, However, the presence of E. coli and the other enterobacteriaceae and Staphylococcus sp. is of public health concern because they can cause several diseases therefore it was concluded that the bacterial loads of the Nono samples were not satisfactory with the exception of the control which had organisms within the acceptable limit of 30,000/ml for raw milk. The presence of potential pathogenic bacteria in all of the Nono samples is an indication that the samples were contaminated and this can potentially cause diseases to the consumers, Hence the need for public enlightenment for handlers and producers of Nono to observe good manufacturing practices in production and storage of the product to avoid outbreak of infections associated with the organisms encountered in this study.

Effect of adding bacteriocin from Lactobacillus pentosus strain MIL 195 on the quality of chicken sausage as an alternative natural preservative

One of the preservatives often used in processed meat, such as sausages, is nitrite; however, bacteriocins produced by lactic acid bacteria (LAB) offer a natural concentration of bacteriocin from Lactobacillus pentosus st MIL 195 to use as a natural preservative for chicken sausages. A completely randomized design was employed with five bacteriocin concentrations (0.0%, 0.2%, 0.3%, 0.4%, and 0.5% v/w) and three replications. Parameters analyzed included water content, ash, fat, protein, total LAB count, and sensory characteristics. The results indicated that 0.4% bacteriocin provided the most effective preservation. After nine days, these sausages met SNI-01-3820-2015 quality standards, exhibiting 57.52% water content, 2.54% ash, 15.40% protein, 5.55% fat, and a total microbial count of 5.23 log cfu.g-1. Sensory analysis revealed a grayish-white color, a slightly chicken aroma, a slightly meaty taste, and a chewy texture. Importantly, consumer preference was highest for sausages treated with 0.4% bacteriocin. Bacteriocins can inhibit the growth of spoilage bacteria; therefore, the effect can extend the shelf life of food goods and improve food security.

Effects of Dietary Supplementation of Peppermint Extract on Growth Performance, Intestinal Microbiota, Liver and Intestine Histopathology of Cyprinus carpio

Abstract This study aimed to evaluate the effects of Mentha piperita methanolic extract (MPE) on Cyprinus carpio intestinal microbiota, including total microorganisms gram-negative bacteria, lactic acid bacteria, and fungi count. Liver and intestinal histopathology, and the activity of liver enzymes, were also used to evaluate the possible side effects of MPE. A total of 96 healthy C. carpio fries (76.76±20.26 g) were allocated to four treatment groups with three replications in a completely randomized design. The fries were fed with diets containing 0, 0.5, 1, and 2% extract for 56 days at the rate of 2% of body weight during the experiment. Results showed a significant decrease in total microorganisms, enteric gram-negative bacteria, and total fungi counts (p<0.05). The total lactic acid bacteria count in 0.5% treatment was significantly lower than in control and 2% treated fish (P<0.05). MPE did not affect AST, leading to a significant increase in ALT levels. Simultaneously, ALP represented significantly higher activity in the control group (P>0.05). Microscopic findings revealed marked lesions, including congestion and cell degeneration in the livers of the three groups of fish fed with the extract. The intestinal folds were shortened and blunted in the treatment groups. Furthermore, the intestinal mucosa was necrotic, and the lamina propria was significantly thickened with mononuclear inflammatory cells (P<0.05). Although MPE significantly affects intestinal microbiota, its consumption at 2% is not recommended for C. carpio due to the lesions made in the liver and intestine.

Potency of fermented jicama extract cultured with Lactobacillus plantarum B1765 for producing short chain fatty acid

Short-chain fatty acid (SCFA) is the end product of inulin metabolism, which has various health benefits, such as affecting lipid metabolism and as an antidiabetic agent. This research studied the effect of the fermentation time of jicama extract with Lactobacillus plantarumB1765 as a starter culture on producing SCFA. Fermentation was conducted for 2, 12, 24, and 36 hours at a temperature of 37°C with 5% (v/v) of the starter culture, then determined the growth of LAB, pH, Total Titratable Acid (TTA), fructose, and Short Chain Fatty Acid content. The total LAB count was measured using the Total Plate Count; fructose was measured using the Nelson-Somogyi method, while SCFA was measured using HPLC with eluents H3PO4 0.1% and acetonitrile 25%. The length of fermentation affected the increase in total Lactic Acid Bacteria (LAB), Total titratable acidity (TTA), fructose, SCFA, and the decrease in pH. The results showed that the optimal growth of Total LAB at 24 hours of fermentation correlated with fructose content, but increasing TTA and SCFA until 36 hours of fermentation and pH decreased to 3,92 at the end of fermentation and decreasing pH due to lactic acid and SCFA producing. SCFA was identified as consisting of acetic acid (1.31±0.006 mg/mL), propionic acid (1.58±0.0055mg/mL), and butyric acid (1.05±0.0038mg/mL), with the highest SCFA was propionic acid. Therefore, fermented jicama extract with Lactobacillus plantarum B1765 has the potential to produce SCFA, which could be used for various health benefits.

Fermentation and Quality Characteristics of Yogurt Treated with Bifidobacterium longum.

The fermentation and quality characteristics of yogurt were investigated according to the inoculation concentration of Bifidobacterium longum. The total sugar content of yogurt decreased as the fermentation time increased, and with an increased concentration of B. longum treatment the fermentation time decreased rapidly. As fermentation progressed, the lactose content decreased rapidly at the beginning and gradually decreased as the pH decreased. Depending on the B. longum treatment concentration, the lactose content varied from 0.29 ± 0.01 to 0.47 ± 0.01% and was 0.5% or less in all experimental groups. The experimental group inoculated with 0.0015% of B. longum displayed the best results in all categories, including pH, total acidity, lactic acid content, solid non-fat content, and total lactic acid bacteria count, which are factors that determine the quality of yogurt. In summary, the experimental group inoculated with 0.0015% of B. longum was determined to be the highest quality yogurt.

Application of optimized Streptococcus thermophilus and Lactobacillus bulgaricus on coconut milk in the production of niyoghurt

This research aimed to optimize the growth of commercial yogurt starter cultures (Streptococcus thermophilus and Lactobacillus bulgaricus) on coconut milk before they were applied in the production of coconut yogurt, which is known as niyogurt or cocogurt. The research consists of three steps. Firstly, both microbes were grown on 100% cow’s milk and were analyzed for pH and total lactic acid bacteria (LAB) to examine the length of fermentation time. Secondly, both microbes were gradually grown on cow’s milk and coconut milk media, with samples ranging in combinations of the two kinds of milk from 100% milk to 100% coconut milk. Finally, the optimized starter cultures were then applied to niyogurt production. The results showed that the pH of the starter cultures obtained in 100% milk after 48 hours of fermentation was 4.41±0.04 for Streptococcus thermophilus and 4.44±0.03 for Lactobacillus bulgaricus. Meanwhile, the total lactic acid bacteria counts were 8.62±3.03 log cfu/ml for Streptococcus thermophilus and 9.55±2.22 log cfu/ml for Lactobacillus bulgaricus. These results showed that both commercial starter cultures need long periods to reach the targeted pH and total lactic acid bacteria (LAB) suggesting that enrichment was needed before commercial starter cultures were used. Furthermore, after analyzing six samples of growth on different ratios of milk and coconut milk, it was seen that both starters could grow optimally on 100% coconut milk. The total LAB after 24 hours of fermentation was 11.07 log cfu/ml with pH 4.05. Based on chemical and microbiological analyses, the characteristics of niyogurt have met Indonesia’s Standard for food consumption (SNI 2981:2009). The niyogurt consisted of 3.15% protein content, 8.3% fat content, 0.83% total acid, 0.76% mineral content, and 11.48 log cfu/ml total LAB.

Safety and efficacy of a feed additive consisting of Lacticaseibacillus rhamnosus CNCM I‐3698 and Companilactobacillus sp. CNCM I‐3699 for weaned piglets (STI Biotechnologie)

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Sorbiflore® ADVANCE, a feed additive consisting of Lacticaseibacillus rhamnosus CNCM I-3698 and Companilactobacillus sp. CNCM I-3699 intended to be used as a zootechnical additive (functional group: other zootechnical additives) in feed for weaned piglets to improve their performance. In a previous opinion, the additive was described as containing viable but not cultivable cells of the two strains in a 1:1 ratio, with a minimum of total lactic acid bacteria counts of 5× 108 viable-forming units (VFU)/g additive. However, in that opinion, the Panel could not fully characterise the additive or conclude on its dermal/ocular irritancy or sensitisation potential. In the current assessment, the applicant provided supplementary information to address the missing information for the characterisation of the additive. The proposed methodology to discriminate and individually quantify the two strains composing the additive still presented limitations. Therefore, the Panel concluded that the data available do not allow to fully characterise the additive. The Panel was not in the position to conclude on the taxonomical identification of the strain CNCM I-3699, and consequently, on its eligibility for the application of the qualified presumption of safety (QPS) approach. Therefore, the previous conclusions on the safety of the additive based on the QPS approach could not be confirmed. The Panel was not in the position to conclude on the safety of the additive for the target species, consumer and the environment. Sorbiflore® ADVANCE is not irritant to skin. The Panel could not conclude on the eye irritancy or skin sensitisation potential of the additive.

Safety and efficacy of a feed additive consisting of Lacticaseibacillus rhamnosusCNCM I-3698 and Companilactobacillus sp. CNCM I-3699 for all animal species (STI Biotechnologie).

Following a request from the European Commission, the Panelon Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety andefficacy of a feed additive consisting of Lacticaseibacillus rhamnosus CNCM I-3698 and Companilactobacillus sp. CNCM I-3699 intended to be used as a technological additive (functional group: silage additives) in forage for all species. In a previous opinion, the additive was described as containing viable but not cultivable cells of the two strains in a 1:1 ratio, with a minimum of total lactic acid bacteria counts of 5× 108 Viable Forming Units (VFU)/g additive. However, in that opinion the Panelcould not fully characterise the additive or conclude on its dermal/ocular irritancy or sensitisation potential. In the current assessment, the applicant provided supplementary information to address these gaps. The proposed methodology to discriminate and individually quantify the two strains composing the additive still presented limitations. Therefore, the Panelconcluded that the data available do not allow to fully characterise the additive. The Panelwas not in the position to conclude on the taxonomical identification of the strain CNCM I-3699, and consequently, on its eligibility for the application of the qualified presumption of safety (QPS) approach. Therefore, the previous conclusions on the safety of the additive based on the QPS approach could not be confirmed. The Panelwas not in the position to conclude on the safety of the additive for the target species, consumer and the environment. The additive is not irritant to skin. The Panelcould not conclude on the eye irritancy or skin sensitisation potential of the additive. The Panelreiterated its previous conclusions that no conclusions can be drawn on the efficacy of the additive to improve the ensiling process of forage.

Safety and efficacy of a feed additive consisting of Lacticaseibacillus rhamnosus CNCM I-3698 and Companilactobacillus sp. CNCM I-3699 for chickens for fattening (STI Biotechnologie).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Sorbiflore® ADVANCE, a feed additive consisting of Lacticaseibacillus rhamnosus CNCM I-3698 and Companilactobacillus sp.CNCM I-3699 intended to be used as a zootechnical additive (functional group: other zootechnical additives) in feed for chickens for fattening to improve their performance. In a previous opinion, the additive was described as containing viable but not cultivable cells of the two strains in a 1:1 ratio, with a minimum of total lactic acid bacteria counts of 5× 108 viable forming units (VFU)/g additive. However, in that opinion, the Panel could not fully characterise the additive or conclude on its dermal/ocular irritancy or sensitisation potential. In the current assessment, the applicant provided supplementary information to address the missing information for the characterisation of the additive. The proposed methodology to discriminate and individually quantify the two strains composing the additive still presented limitations. Therefore, the Panel concluded that the data available do not allow to fully characterise the additive. The Panel was not in the position to conclude on the taxonomical identification of the strain CNCM I-3699, and consequently, on its eligibility for the application of the qualified presumption of safety (QPS) approach. Therefore, the previous conclusions on the safety of the additive based on the QPS approach could not be confirmed. The Panel was not in the position to conclude on the safety of the additive for the target species, consumer and the environment. Sorbiflore® ADVANCE is not irritant to skin. The Panel could not conclude on the eye irritancy or skin sensitisation potential of the additive.

Changes and machine learning-based prediction in quality characteristics of sliced Korean cabbage (Brassica rapa L. pekinensis) kimchi: Combined effect of nano-foamed structure film packaging and subcooled storage

The prevention of over-ripening during storage and distribution is crucial for commercial kimchi products with a short shelf life. This study evaluated the effects of nano-foamed structure (NFS) film packaging and subcooled storage on the characteristics and stability of sliced Korean cabbage (Brassica rapa L. pekinensis) kimchi (KCK). The experiments were performed as factorial tests based on completely randomized designs. Subcooled storage (−3 °C) delayed total lactic acid bacteria (TLAB) growth and suppressed the changes in pH, titratable acidity (TA), and reducing sugar content (RSC) of KCK compared to refrigerated storage (4 and 10 °C). The headspace CO2 concentrations in NFS-1 and NFS-2 film packaging were maintained at < 6.1% throughout the storage (36 d), irrespective of the storage conditions. These results indicate that NFS film suppresses CO2 accumulation wherein subcooled storage prevents the over-ripening of KCK. Furthermore, we combined machine learning (ML) algorithms with experimental results to predict the quality of KCK. The ML-based algorithms, random forest and extreme gradient boosting trees were more accurate in predicting TA, RSC, and TLAB counts than multivariable linear regression. The study demonstrates an improved packaging system and optimal storage conditions for KCK, which can be extended to other kimchi and fermented products.

Effect of nano-foamed structure film packaging on the quality of young radish (Raphanus sativus L.) kimchi during storage under supercooled and refrigerated conditions

This study investigated changes in the quality and headspace O2/CO2 concentrations of young radish (Raphanus sativus L.) kimchi (YR-kimchi) packaged using a multilayer (ML) film with or without sachets containing a CO2 absorber and nano-foamed structure (NFS) film, respectively, during storage at −2.2 or 4.0°C. Compared to that in YR-kimchi samples stored at 4.0°C, the total lactic acid bacteria count and titratable acidity of YR-kimchi samples stored at −2.2°C increased rapidly until 21 days of storage, irrespective of the packaging. After 32 days of storage at 4.0°C, the reducing sugar content of young radish kimchi packaged in ML film, ML film with a CO2 absorber sachet, and NFS film decreased by 54.9, 80.7, and 79.9%, respectively, compared to before storage. However, the salinity of YR-kimchi samples packaged with different film types showed negligible differences during storage at −2.2 and 4.0°C. No significant O2 reduction or CO2 accumulation was observed in the headspace of NFS film-packaged young radish kimchi stored at either temperature. Hence, these results indicated that NFS film packaging combined with supercooled (−2.2°C) storage improved the shelf life of YR-kimchi without packaging expansion during storage.

Feeding Nigella sativa oil to broilers affects their performance, serum constituents and cecum microbiota

The objective of this study was to assess the effect of supplementation of Nigella sativa oil (NSO) as a growth promoter in broiler diets. A total of 300 unsexed one-day-old Arbor Acre broiler chicks were randomly divided into five treatment groups (60 chicks/group). Each group was divided into five replicates with 12 chicks per replicate. Group 1 was fed on the basal diet with no additives (control). Group 2 was fed the basal diet supplemented with oxytetracycline (OTC) at the level of 50 ppm. Groups 3, 4 and 5 were fed the basal diet supplemented with 500, 1000 and 1500 ppm NSO, respectively. Birds fed on 1500 ppm NSO diet showed the heaviest body weight at 14, 28 and 42 days of age. Feed conversion ratio was significantly improved at all ages with the inclusions of OTC and NSO generally superior to the control group. The relative weight of spleen was increased significantly by the addition of NSO at various levels. However, relative weights of thymus and bursa were not altered by the treatments. Total bacterial count, total yeast and moulds count, E. coli and salmonella spp. counts were reduced significantly, whereas the total lactic acid bacteria count was increased in OTC and NSO groups compared with control. Nigella sativa oil could be used in broiler chicken feeds as a natural alternative to antibiotic growth promoters to improve gut health and consequently growth performance.

Whey protein isolate- and carrageenan-based edible films as carriers of different probiotic bacteria

The use of polymer blends as carriers for probiotic cells or using multi-strain probiotic culture mixture in film formulations has a high potential to maintain the stability of probiotics throughout storage. In this study, the survival of Lactobacillus acidophilus, Lactobacillus plantarum, and mixed culture (Lactobacillus spp., Lactococcus spp., and Bifidobacterium spp.) in whey protein isolate (W), carrageenan (C), and W/C blend (W to C on a wt/wt basis at 100 to 0, 75 to 25, 50 to 50, and 0 to 100) films were investigated during 30 d of storage at 4 and 25°C. The water vapor, mechanical, optical, and morphological properties of film samples were also determined. A significant decrease in total lactic acid bacteria counts of all strains (5-6 log cfu/g in reduction) for W and C films was observed during storage at 25°C, whereas blended films had 2 to 3 log cfu/g reduction. The mixed culture-incorporated films had higher cell counts during all storage temperatures. The incorporation of probiotic bacteria significantly influenced the water vapor permeability and color values of films while decreasing tensile strength and elongation at break values. This study reveals that a multi-strain mixed culture presented more chance for survival inside the polymer matrix, especially when carbohydrate- and protein-based polymers were blended.

The amount of lactic acid bacteria in fermented natural lactic acid bacteria liquids prepared with varying sucrose inclusion at different incubation periods

Characterization of lactic acid bacteria that naturally occurs during silage formation is important for determining the quality of silage feeds which are required in terms of meeting the need for high quality roughage in cattle breeding. In this study, the aim was to determine the total lactic acid bacteria (LAB) count and pH values of fermented natural LAB liquids as a result of different levels of sucrose addition as microbial silage additive (1%, 3%, 5% and 10%) and different incubation periods (5, 7, 9, 11, 13 and 15 days). Considering the incubation periods of LAB liquids, while the highest LAB count was obtained from the 10% sucrose added groups (3.7x1011, 2.6x1011 and 2.53x1012 colony forming unit (cfu/ml) at the 7, 9 and 13 days of incubation periods, the highest LAB count was obtained from the 5% sucrose supplemented group (9.13x1011cfu/ml) at the end of the 15-day incubation period. In general, for each incubation period, the total LAB counts in the obtained fluids increased due to the increase in the sucrose level (P&lt;0.05). Depending on the increase in the incubation period, there was an increase in the total LAB counts in the 10% sucrose supplemented group, while a decrease in the total LAB counts occurred after a 15-day incubation period. In general, pH values decreased depending on the increasing with sucrose levels in each incubation period. Considering the pH values of the LAB liquids, there were no differences of pH values depending on the increase the incubation period from the 1% and 3% sucrose added groups (P&lt;0.05). The pH values obtained from the 10% sucrose added group decreased with the increasing incubation periods. The highest pH value was obtained from the 1% sucrose group (4.49) during the 15-day incubation period, whereas the lowest pH value (3.78) was obtained from the 10% sucrose group in the same incubation period. Considering the LAB counts (1011-12cfu/ml) in the study, it has been evaluated that the obtained LAB liquids can be used as silage additives and it has a high potential of commercialization.

Composition of Kashkaval cheese manufactured from different levels of somatic cell counts in sheep milk

The purpose of the present study was to investigate the influence of somatic cell count (SCC) on the composition of Kashkaval cheese. Kashkaval cheese samples were produced from three different batches of sheep milk with low (610 000 cells/ml), medium (770 000 cells/ml), and high (1 310 000 cells/ml) SCC, respectively. The main chemical parameters, such as pH, titratable acidity, moisture content, fat content in the dry matter, protein content, sodium chloride content, and microbiological parameters (lactic acid bacteria count, pathogenic microorganisms, coliforms, psychrotrophic, yeasts and molds) were studied during the ripening and storage periods. No statistically significant (P&lt;0.05) changes were found in the values of the chemical parameters during the ripening period. At the beginning of ripening, the total lactic acid bacteria count for all cheese samples was about 4.1 log cfu/g, then increased to 6.2 log cfu/g (at 60 days of ripening) for test samples. The data collected in this study showed a slight decrease in pH values and a gradual increase in the titratable acidity, which was an indication for retarded fermentation during storage at low temperature. The lactic acid bacteria showed good survival, but higher sensitivity was observed inLactobacillusspp. in comparison withStreptococcusspp.

Quality characteristics of white brined cheese produced from goat milk with different somatic cell count

This experimental work aimed to investigate the quality characteristics of white brined cheese during ripening, produced from goat milk with different somatic cell count: I group – with low somatic cell content (CL) with about 1 200 000 cells/ml; II group – with high somatic cell content (CH) with about 1 750 000 cells/ml and III group – with medium somatic cell content (CM) with about 1 600 000 cell/ml (CM). Chemical, microbiological, and sensorial evaluations were performed on the 1 st and 45th day of cheese ripening. The obtained results showed that the differences in the composition of goat milk during the different stages of lactation as well as the level of somatic cell count had a significant effect (p &lt; 0.05) on the chemical composition of the cheese samples. It was established that the total lactic acid bacteria count in the experimental samples decreased from 8.2 to 7.9 log cfu/g for CL and CM and to 7.5 log cfu/g for CH at the end of the ripening period respectively. It was found that the psychrotrophic microorganisms and total yeast and molds decreased during the ripening period. The sensorial evaluation demonstrated a higher score for CL and CM samples in comparison with the CH sample.

The effect of ellagic acid on performance, digestibility, egg quality, cecal bacterial flora, antioxidant activity, and some blood parameters in laying quails reared at different temperatures

In this study, the effect of ellagic acid on the performance, egg quality, digestibility, cecal microflora, serum malondialdehyde (MDA) level, and biochemical parameters in quails reared under normal conditions and at high environmental temperatures was investigated. The animals (n = 240; 5-weeks old) reared at 2 environmental temperatures [thermoneutral (TN) and heat stress (HS)] and in 4 diet groups containing different ellagic acid doses (0, 100, 200, and 400 mg/kg) were randomly assigned to 8 groups according to the 2 × 4 factorial design. Feed intake, egg weight, and egg production were higher (P < 0.001) and feed conversion (P < 0.01) was better in the TN groups compared to the HS groups. Egg (P < 0.01) and shell weights (P < 0.001) were higher in the TN groups compared to the HS groups. The effect of ellagic acid supplementation on shell weight was statistically significant in the TN and HS groups (P < 0.05). The effects of environmental temperature and the supplementation of ellagic acid on digestibility of dry matter (P < 0.05), ether extract (P < 0.01), and crude protein (P < 0.01) were statistically significant in the TN and HS groups. Supplementation of ellagic acid reduced the total coliform bacteria count (P < 0.01) and increased the total lactic acid bacteria count (P < 0.001) in the cecum. Serum MDA levels increased with heat stress (P < 0.001) and decreased with the supplementation of ellagic acid (P < 0.001). The effect of environmental temperature on serum glucose (P < 0.001), cholesterol (P < 0.05), total protein (P < 0.05), alanine aminotransferase (ALT) (P < 0.001), sodium (P < 0.05), and magnesium was significant. In conclusion, the supplementation of ellagic acid decreased oxidative stress and total coliform bacteria count and improved the feed conversion and egg quality in quails under heat stress. Moreover, ellagic acid increased the digestibility of nutrients and had a positive effect on lactic acid bacteria. It was observed in this study that these beneficial effects of ellagic acid increased with an increasing dose, and 400 mg/kg was the most effective dose.

Formulation of goat's milk yogurt with fig powder: Aromatic profile, physicochemical and microbiological characteristics.

Fig (Ficus carica L.) is an excellent source of sugars, dietary fibers, minerals, vitamins, organic acids and phytochemicals. The aim of the present work was to investigate the effect of fig powder supplement, as a natural sweetener and flavoring agent, on the physicochemical, microbiological and sensory characteristics of goat's milk yogurt. It aimed also to determine antioxidant capacity and volatile profile using gas chromatography/mass spectrometry (GC/MS) analysis. Pyrolysis-GC/MS (Py-GC/MS) was also used for the characterization of fig powder. Fig powder exhibited an important antioxidant activity against DPPH. Radical (IC50 = 1.92 ± 0.05 mg per mL). Volatile compounds, from several classes (acids, alcohols, aldehydes, esters, triterpenoids and others) were identified in fig powder. Py-GC/MS data revealed that degradation of fig powder macromolecules leaded to the formation of several aromatic and volatile compounds such as fatty acids, ketones, aromatic phenols, lactones among others. The addition of fig powder increased significantly (p < 0.05) the titrable acidity, the total solids, the carbohydrate content, and the total lactic acid bacteria count of yogurts. Likewise, fig powder supplement improved yogurt taste, texture and aroma and covered the unpleasant flavor of goat's milk. Thus, fig powder is a natural sweetener and flavoring agent that can be used to formulate a new stirred goat's yogurt of good quality.