Industrial Processing of Algerian Table Olive Cultivars Elaborated as Spanish Style

Olives from the Sigoise, Verdale, and Sevillana cultivars were elaborated as Spanish-style table olives by four Algerian factories, and the quality and food safety of the industrial table olives have been studied by the analysis of physicochemical and microbiological parameters. Differences were observed between the treatments carried out by the different factories throughout the manufacturing process, especially during the washing stage, but no significant differences were found between the analyzed samples for the concentration of sugars and polyphenols. The final pH values reached at the end of fermentation ranged between 5.04 and 4.27, and the titratable acidity was above 0.4% for all samples. Lactic and acetic acids were produced in mean concentrations of 0.68% and 0.21% as a result of lactic acid bacteria (LAB) and yeast metabolism, respectively. However, the presence of butyric, isobutyric, and propionic acids was also detected, and was related to the growth of undesirable spoilage microorganisms, responsible for secondary fermentations. The high-throughput sequencing of bacterial DNA suggested the dominance of LAB species belonging to genera Lactiplantibacillus, Leuconostoc, Pediococcus, Oenococcus, or Enterococcus. The Enterobacteriaceae family was detected during the first days of brining and in only one sample after 120 days of fermentation. Other spoilage microorganisms were found, such as Lentilactobacillus buchneri or the Pectinatus and Acetobacter genera, capable of consuming lactic acid and these played an essential role in the onset of spoilage. The Clostridium and Enterobacter genera, producers of butyric and propionic acids, were responsible for the malodorous fermentation present in the industrial samples that were analyzed. The study concluded that the safety of the table olives analyzed was compromised by the presence of undesirable microorganisms and microbial stability was not guaranteed. The elaboration process can be improved by reducing the washing steps and the time should be reduced to avoid the loss of fermentable matter, with the goal of reaching a pH < 4.0 after the fermentation and preventing the possibility of the growth of spoilage microorganisms and foodborne pathogens.

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Applications of Lactic Acid Bacteria and Their Bacteriocins against Food Spoilage Microorganisms and Foodborne Pathogens

Molecules ◽

10.3390/molecules26227055 ◽

2021 ◽

Vol 26 (22) ◽

pp. 7055

Author(s):

Mduduzi P. Mokoena ◽

Cornelius A. Omatola ◽

Ademola O. Olaniran

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Foodborne Pathogens ◽

Food Packaging ◽

Viral Infections ◽

Empirical Studies ◽

Fermented Foods ◽

Food Spoilage ◽

Food Preservatives ◽

Spoilage Microorganisms

Lactic acid bacteria (LAB) are Gram-positive and catalase-negative microorganisms used to produce fermented foods. They appear morphologically as cocci or rods and they do not form spores. LAB used in food fermentation are from the Lactobacillus and Bifidobacterium genera and are useful in controlling spoilage and pathogenic microbes, due to the bacteriocins and acids that they produce. Consequently, LAB and their bacteriocins have emerged as viable alternatives to chemical food preservatives, curtesy of their qualified presumption of safety (QPS) status. There is growing interest regarding updated literature on the applications of LAB and their products in food safety, inhibition of the proliferation of food spoilage microbes and foodborne pathogens, and the mitigation of viral infections associated with food, as well as in the development of creative food packaging materials. Therefore, this review explores empirical studies, documenting applications and the extent to which LAB isolates and their bacteriocins have been used in the food industry against food spoilage microorganisms and foodborne pathogens including viruses; as well as to highlight the prospects of their numerous novel applications as components of hurdle technology to provide safe and quality food products.

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Biochemical and microbiological characterization of “Soumbara” from African locust bean (Parkia biglobosa) seeds consumed in Abidjan (Côte d’Ivoire)

The North African Journal of Food and Nutrition Research - July-December 2021 ◽

10.51745/najfnr.5.11.35-42 ◽

2021 ◽

Vol 5 (11) ◽

pp. 35-42

Author(s):

Kohi Alfred Kouamé ◽

Koffi Maïzan Jean-Paul Bouatenin ◽

Wahauwouélé Hermann Coulibaly ◽

Djé Koffi Marcellin

Keyword(s):

Cote D'ivoire ◽

Côte D’Ivoire ◽

Food Poisoning ◽

Titratable Acidity ◽

Cote D’Ivoire ◽

E Coli ◽

Côte D'ivoire ◽

Microbiological Parameters ◽

African Locust Bean ◽

Spoilage Microorganisms

Background: “Soumbara” as well as other traditional foods of Côte d'Ivoire are produced in a traditional way. These foods may contain pathogenic and spoilage microorganisms. Aims: The aim of our work was to assess the sanitary quality of “Soumbara” sold in five communes of Abidjan (Côte d’Ivoire), in order to valorize it as a flavor enhancer. Material and Methods: A consumption survey as well as the analysis of some physico-chemical (pH, titratable acidity, Brix degree, moisture, and organic acids) and microbiological parameters (enumeration of MAG, Clostridium, Bacillus, Staphylococci, Salmonella, E. coli, and coliforms) were carried out in five (05) municipalities of Abidjan (Abobo, Yopougon, Port Bouet, Adjamé, and Treichville) on 75 samples. Results: The results of the survey showed that most of the respondents were familiar with “Soumbara” and often consumed it. These consumers stated that they did not experience any discomfort after consuming this food. Physicochemical analyses showed that the water content of the samples of “Soumbara” ranged from 16.50% to 19.28% and the pH varied from 6.32 ± 0.01 to 7.91± 0.02. “Soumbara” contained little follow-through which ranged from 0.10 ± 0.001 to 0.27 ± 0.05. “Soumbara” also contained phenolic compounds such as coumarins, hydroquinones, and caffeic acid. Microbiological analyses had revealed the presence of spoilage and pathogenic germs such as Bacillus, Staphylococcus, and E. coli at high loads exceeding the 2019/229/EC standard. Conclusions: However, due to the high load of spoilage and pathogenic microorganisms, this food eaten by sprinkling directly on the dish, without passing through a cooking process could expose the consumer to a risk of food poisoning. Keywords: Food poisoning, “Soumbara”, Pathogenic and Spoilage Microorganisms.

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Current Trends in Whey Processing

Food Processing Techniques and Technology ◽

10.21603/2074-9414-2019-2-227-234 ◽

2019 ◽

Vol 49 (2) ◽

pp. 227-234

Author(s):

Игорь Короткий ◽

Igor Korotkiy ◽

Игорь Плотников ◽

Igor Plotnikov ◽

Ирина Мазеева ◽

...

Keyword(s):

Whey Protein ◽

Raw Materials ◽

Titratable Acidity ◽

Raw Milk ◽

Raw Material ◽

Technical Documentation ◽

Industrial Processing ◽

Thermal Coagulation ◽

Physico Chemical ◽

Microbiological Parameters

The integrated use of secondary raw milk is one of the most effective ways to optimize the processing of raw materials in the production of dairy products. The unique composition and properties of curd whey makes it a valuable industrial raw material that can be processed into a variety of foods and feed products. Nowadays, whey protein concentrates (WPC) are extremely popular with consumers. One of the promising areas of industrial processing of acid whey is the extraction of proteins by means of separate freezing (cryoconcentration). This process takes place at low temperatures (from 0 to minus 15°C), which makes it possible to preserve the composition and properties of the raw material, prevents denaturation of whey protein fractions, and preserves its valuable thermolabile components. The authors conducted laboratory tests of curd whey and WPC produced by several dairy companies. The research allowed the authors to determine the composition, sensory, physico-chemical, and microbiological properties of the samples. The research objective was to evaluate the sensory properties of the initial cheese whey and WPC obtained by cryoconcentration, to establish their chemical composition, as well as physico-chemical and microbiological parameters. The research also featured the effect of the whey acidity on the WPC output and the development of technological schemes of WPC production by separate freezing. All the samples of curd whey proved to meet the current standards and can be used for WPC production. The sample of laboratory-obtained WPC sample had 20.19% of dry substances and 12.80% of protein, which corresponds to the standard albumin with its 20.0% of dry substances. The titratable acidity of WPC did not exceed the permissible level of 95°T. The experimental results proved that the cryoconcentration technology produced concentrate that met the requirements of regulatory and technical documentation. The obtained data revealed an increase in titratable acidity from 47°T to 50°T during the storage of curd whey for 7 days. The increase in acidity increased the yield of WPC after 7 days of serum storage by 57.6%. The new WPC production scheme consisted of several stages: (1) the whey was obtained; (2) casein dust and dairy fat were excluded; (3) pasteurization; (4) two-stage cryoconcentration; (5) thermal coagulation of whey concentrate; (6) separation of WPC. The technology of cryoconcentrationcurd whey suggests designing industrial installations in-line type to obtain CSB.

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Occurrence of Listeria monocytogenes in Green Table Olives

Journal of Food Protection ◽

10.4315/0362-028x-67.10.2189 ◽

2004 ◽

Vol 67 (10) ◽

pp. 2189-2194 ◽

Cited By ~ 39

Author(s):

CINZIA CAGGIA ◽

CINZIA L. RANDAZZO ◽

MONIA DI SALVO ◽

FLORA ROMEO ◽

PAOLO GIUDICI

Keyword(s):

Lactic Acid ◽

Listeria Monocytogenes ◽

Lactic Acid Bacteria ◽

Titratable Acidity ◽

Starter Cultures ◽

Table Olives ◽

Olive Cultivar ◽

Lactobacillus Pentosus ◽

Microbiological Safety ◽

Biological Methods

Microbiological safety of green table olives from different cultivars, prepared by both the Spanish-style and biological methods and fermented with starter cultures of lactic acid bacteria (Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus pentosus), was investigated. The fermentation process was monitored by measuring pH values, titratable acidities, and growth of lactic acid bacteria over time. During fermentation, lactic acid bacteria and yeasts were major microbial populations. Microbiological safety was evaluated by analysis for Listeria monocytogenes with the use of an enrichment method during storage (from 55 days to 18 months). Results demonstrated that L. monocytogenes can survive and grow in green table olives. L. monocytogenes was found in one of the commercial (thermally treated) samples analyzed and in all samples older than 2 months, irrespective of olive cultivar, lactic acid bacteria starter used, pH and titratable acidity of brine samples, or treatment applied.

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Flavored Olive Oil as a Preservation Means of Reduced Salt Spanish Style Green Table Olives (cv. Chalkidiki)

Foods ◽

10.3390/foods10020392 ◽

2021 ◽

Vol 10 (2) ◽

pp. 392

Author(s):

Maria Papapostolou ◽

Fani T. Mantzouridou ◽

Maria Z. Tsimidou

Keyword(s):

Essential Oil ◽

Essential Oils ◽

Olive Oil ◽

Population Control ◽

Microbiological Quality ◽

Table Olives ◽

Lemon Balm ◽

Oregano Essential Oil ◽

Microbiological Parameters ◽

Reduced Salt

Reformulation of products fermented in brine is a challenging area of research. Continuing the efforts toward the establishment of table olives as a healthy food for all population groups, this study aimed at examining whether olive oil flavored with essential oils can be used as a preservation means for reduced salt Spanish style green table olives (cv. Chalkidiki). Response surface methodology was applied to organize experimentation and assess data. As independent factors, concentrations of the essential oils used (oregano, lemon balm and bay laurel) and time of storage under vacuum were set. Microbiological parameters (pathogens and fermentation-related microbes), color and firmness attributes were used as responses. Models indicated that each essential oil exerted a preservative role to maintain microbiological quality of reduced salt table olives. Concurrently, appearance attributes of the latter were retained at desirable values. Oregano essential oil had a profound role against pathogens. Lemon balm and bay laurel essential oils were found to be important for yeast population control. The results are promising toward the use of flavored olive oil as a preservation means for tailor-made reduced salt table olives, a practice that may enhance local industry innovative activity in a practical and effective way.

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Expiration Date of Ready-to-Eat Salads: Effects on Microbial Load and Biochemical Attributes

Foods ◽

10.3390/foods10050941 ◽

2021 ◽

Vol 10 (5) ◽

pp. 941

Author(s):

Panayiota Xylia ◽

George Botsaris ◽

Panagiotis Skandamis ◽

Nikolaos Tzortzakis

Keyword(s):

Shelf Life ◽

Foodborne Pathogens ◽

Carbon Dioxide Production ◽

Microbial Load ◽

Expiration Date ◽

Postharvest Management ◽

Minimally Processed Vegetables ◽

Yeasts And Molds ◽

Staphylococcus Spp ◽

Spoilage Microorganisms

When minimally processed vegetables reach their expiration date, expose an increased microbial load. This includes mainly spoilage microorganisms but also foodborne pathogens, thus affecting the quality and safety of highly consumed ready-to-eat salads. A total of 144 ready-to-eat salads from the Cypriot market were analyzed in an attempt to determine the effects of the expiration date on the microbial load and plant metabolic variables of the salads. Possible correlations between them were also investigated for the first time. Furthermore, the impacts of the season (winter, summer), salad producing companies and type of salad and/or their interactions with the tested parameters were investigated. Results revealed that the microbial load (mainly spoilage microorganisms, such as Pseudomonas spp., yeasts and molds) increased towards the end of the shelf life. The microbial load was differentiated among the five salad producers and/or the salad types, highlighting the importance of a common and safe sanitation-processing chain in the preparation of ready-to-eat salads. Summer was the season in which Escherichia coli counts were found to be higher for plain lettuce, while Staphylococcus spp. was increased numbers for the lettuce+endive/radicchio, lettuce+rocket and lettuce+chives type of salads. Additionally, an increased Staphylococcus spp. was observed for plain rocket salads in winter. All samples examined were found negative for Salmonella enterica and Listeria monocytogenes. Moreover, carbon dioxide production and damage indexes (hydrogen peroxide and lipid peroxidation) increased on expiration date on both winter and summer seasons, indicating plant tissue stress at the end of shelf life. These findings indicate that the expiration date and relevant shelf life of processed vegetables are important parameters to be considered when postharvest management is applied to these products, ensuring safety and quality.

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Physicochemical, microbiological, and sensory characteristics of probiotic Bulgarian yoghurts obtained by ultrafiltration of goat’s milk

Zeitschrift für Naturforschung C ◽

10.1515/znc-2021-0064 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Mariya Dushkova ◽

Siyka Kodinova ◽

Zapryana Denkova ◽

Velichka Yanakieva ◽

Nikolay Dimitrov Menkov

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Lactobacillus Acidophilus ◽

Dry Matter ◽

Titratable Acidity ◽

Bifidobacterium Bifidum ◽

Sensory Characteristics ◽

Viable Cells ◽

Goat’S Milk ◽

Goat's Milk

Abstract The purpose of this study was to investigate the microbiological (number of viable lactic acid bacteria and bifidobacteria), physicochemical (dry matter, protein and fat contents, titratable acidity, and pH), and sensory characteristics (appearance of coagulum, taste and aroma, structure at cutting, color, and consistency at shattering) of probiotic Bulgarian yoghurts obtained by ultrafiltration of goat’s milk. These yoghurts were obtained using volume reduction ratios of 2 and 3 with the probiotic starters MZ2f, MZ2f + Bifidobacterium bifidum BB – 87, and MZ2f + Lactobacillus acidophilus LAB – 8. The increase in the level of the concentration by ultrafiltration led to an increase in the dry matter, protein and fat contents of the yoghurts, in the number of lactic acid bacteria and titratable acidity, and to a decrease in the pH. The twofold concentration by ultrafiltration resulted in a higher number of lactic acid bacteria in comparison with yoghurts made without ultrafiltration, and with better sensory characteristics compared to yoghurts without and with threefold ultrafiltration. The higher number of viable cells and better sensory characteristics were obtained for yoghurts with MZ2f + Bifidobacterium bifidum BB – 87 and MZ2f + Lactobacillus acidophilus LAB – 8 in comparison with MZ2f alone.

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