Yeasts and Molds: Penicillium camemberti

2020 ◽  
Author(s):  
Jeanne Ropars
Keyword(s):  
Penicillium Camemberti ◽  
Yeasts And Molds

scholarly journals How to Train Your Fungus

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
John G. Gibbons
Keyword(s):  
Experimental Evolution ◽  
Breeding Strategies ◽  
Metabolic Diversity ◽  
Content Type ◽  
Phenotypic Changes ◽  
Human Culture ◽  
Penicillium Camemberti ◽  
Agricultural Revolution ◽  
Yeasts And Molds ◽  
Camembert Cheese

ABSTRACT Domestication led to profound changes in human culture. During this period, humans used breeding strategies to select for desirable traits in crops and livestock. These practices led to genetic and phenotypic changes that are trackable through archaeological and genomic records. Bacteria, yeasts, and molds also experienced domestication during the agricultural revolution, but the effects of domestication on microbes are poorly understood in comparison to plants and animals. Bodinaku et al. used experimental evolution to track the phenotypic changes that occur when wild Penicillium molds specialize and adapt to the cheese environment (I. Bodinaku, J. Shaffer, A. B. Connors, J. L. Steenwyk, et al., mBio 10:e02445-19, 2019, https://mbio.asm.org/content/10/5/e02445-19.long). Amazingly, after only eight generations of growth in a laboratory cheese environment, mutants emerged whose traits resembled those of the Brie and Camembert cheese mold Penicillium camemberti. This study demonstrated that the early stages of microbial domestication can occur rapidly and suggested that experimental evolution may be a viable strategy to exploit the metabolic diversity of wild microbes for food fermentation.

scholarly journals Hemp (Cannabis sativa L.) Flour-Based Wheat Bread as Fortified Bakery Product

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1558
Author(s):  
Iulian Eugen Rusu ◽  
Romina Alina Marc (Vlaic) ◽  
Crina Carmen Mureşan ◽  
Andruţa Elena Mureşan ◽  
Vlad Mureşan ◽  
...  
Keyword(s):  
Mineral Content ◽  
Unsaturated Fatty Acids ◽  
Cannabis Sativa ◽  
New Products ◽  
Wheat Bread ◽  
Human Consumption ◽  
Nutritional Properties ◽  
Bakery Product ◽  
Nutritional Characteristics ◽  
Yeasts And Molds

Hemp flour from Dacia Secuieni and Zenit varieties was added to bread in different proportions (5%, 10%, 15% and 20%) to improve its nutritional properties. The purpose of this paper was to present the advanced nutritional characteristics of these bread samples. The selected varieties of hemp, accepted for human consumption, met the requirements for the maximum accepted level of THC in seeds. The protein content of new products increased from 8.76 to 11.48%, lipids increased from 0.59 to 5.41%, mineral content from 1.33 to 1.62%, and fiber content from 1.17 to 5.84%. Elasticity and porosity decreased from 95.51 to 80% and 78.65 to 72.24%, respectively. K, Mg, Ca, P, Mn and Fe are the main mineral substances in bread with addition of hemp flour from the Dacia Secuieni and Zenit varieties. The total amount of unsaturated fatty acids in the bread samples with hemp flour ranged from 67.93 g/100 g and 69.82 g/100 g. Eight amino acids were identified, of which three were essential (lysine, phenylalanine, histidine). Lysine, the deficient amino acid in wheat bread, increased from 0.003 to 0.101 g/100 g. Sucrose and fructose decreased with the addition of hemp flour, and glucose has not been identified. The amount of yeasts and molds decreased in the first 3 days of storage. Regarding the textural profile, the best results were obtained for the samples with 5% addition. In conclusion, bread with the addition of hemp flour has been shown to have superior nutritional properties to wheat bread.

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

Foods ◽  
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.

Evaluation of Gaseous Chlorine Dioxide as a Sanitizer for Killing Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Yeasts and Molds on Fresh and Fresh-Cut Produce

2005 ◽  
Vol 68 (6) ◽  
pp. 1176-1187 ◽  
Author(s):  
KAYE V. SY ◽  
MELINDA B. MURRAY ◽  
M. DAVID HARRISON ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Chlorine Dioxide ◽  
Foodborne Pathogens ◽  
Escherichia Coli O157 ◽  
Gaseous Chlorine Dioxide ◽  
Sensory Qualities ◽  
A Cell ◽  
Fresh Cut ◽  
Yeasts And Molds

Gaseous chlorine dioxide (ClO2) was evaluated for effectiveness in killing Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes on fresh-cut lettuce, cabbage, and carrot and Salmonella, yeasts, and molds on apples, peaches, tomatoes, and onions. Inoculum (100 μl, ca. 6.8 log CFU) containing five serotypes of Salmonella enterica, five strains of E. coli O157:H7, or five strains of L. monocytogenes was deposited on the skin and cut surfaces of fresh-cut vegetables, dried for 30 min at 22°C, held for 20 h at 4°C, and then incubated for 30 min at 22°C before treatment. The skin surfaces of apples, peaches, tomatoes, and onions were inoculated with 100 μl of a cell suspension (ca. 8.0 log CFU) containing five serotypes of Salmonella, and inoculated produce was allowed to dry for 20 to 22 h at 22°C before treatment. Treatment with ClO2 at 4.1 mg/liter significantly (α = 0.05) reduced the population of foodborne pathogens on all produce. Reductions resulting from this treatment were 3.13 to 4.42 log CFU/g for fresh-cut cabbage, 5.15 to 5.88 log CFU/g for fresh-cut carrots, 1.53 to 1.58 log CFU/g for fresh-cut lettuce, 4.21 log CFU per apple, 4.33 log CFU per tomato, 1.94 log CFU per onion, and 3.23 log CFU per peach. The highest reductions in yeast and mold populations resulting from the same treatment were 1.68 log CFU per apple and 2.65 log CFU per peach. Populations of yeasts and molds on tomatoes and onions were not significantly reduced by treatment with 4.1 mg/liter ClO2. Substantial reductions in populations of pathogens on apples, tomatoes, and onions but not peaches or fresh-cut cabbage, carrot, and lettuce were achieved by treatment with gaseous ClO2 without markedly adverse effects on sensory qualities.

Comparison of the Petrifilm™ Yeast and Mold Culture Film Method to Conventional Methods for Enumerating Yeasts and Molds in Foods

1991 ◽  
Vol 54 (6) ◽  
pp. 443-447 ◽  
Author(s):  
L. R. BEUCHAT ◽  
B. V. NAIL ◽  
R.E. BRACKETT ◽  
T. L. FOX
Keyword(s):  
Correlation Coefficients ◽  
Food Group ◽  
Black Pepper ◽  
Plate Count ◽  
Food Groups ◽  
Plate Count Agar ◽  
Plate Counts ◽  
Yeasts And Molds ◽  
Potential Food ◽  
Film Method

Petrifilm™ Yeast and Mold (YM) plates were compared to acidified potato dextrose agar (APDA) and chloramphenicol-supplemented plate count agar (CPCA) for its suitability to enumerate yeasts and molds in 13 groups of food products. These products consisted of beans (dry and frozen, green), corn meal, flour (wheat), fruit (apple), a meat/vegetable entree (chicken pot pie), a precooked meat (beef), milk (dehydrated, nonfat), nuts (pecans), pasta, potatoes (dehydrated), precooked sausage, and a spice (black pepper). Correlation coefficients of Petrifilm™ YM plates versus APDA and CPCA pour plates for recovering total yeasts and molds from a composite of the thirteen test foods were, respectively, 0.961 and 0.974. Individually, Petrifilm™ YM plate counts were equivalent or higher than APDA and CPCA for some food groups and lower for other food groups. Because food particle interference can make enumeration of yeast and mold colonies on Petrifilm™ YM plates difficult for some food groups, potential food interference will need to be evaluated for each food group tested.

Fate of Listeria monocytogenes During the Manufacture and Ripening of Camembert Cheese

1987 ◽  
Vol 50 (5) ◽  
pp. 372-378 ◽  
Author(s):  
ELLIOT T. RYSER ◽  
ELMER H. MARTH
Keyword(s):  
Listeria Monocytogenes ◽  
Fold Increase ◽  
Original Sample ◽  
Cheese Making ◽  
Penicillium Camemberti ◽  
Shaped Surface ◽  
Standard Procedures ◽  
Whole Milk ◽  
Camembert Cheese ◽  
Made In

The ability of Listeria monocytogenes to survive the Camembert cheese-making process and grow during ripening of the cheese was examined. Pasteurized whole milk was inoculated to contain about 500 L. monocytogenes [strain Scott A, V7, California, (CA) or Ohio (OH)] CFU/ml and made into Camembert cheese according to standard procedures. All wheels of cheese were ripened at 6°C following 10 d of storage at 15–16°C to allow proper growth of Penicillium camemberti. Duplicate wedge (pie-shaped), surface and interior cheese samples were analyzed for numbers of L. monocytogenes by surface-plating appropriate dilutions made in Tryptose Broth (TB) on McBride Listeria Agar (MLA). Initial TB dilutions were stored at 3°C and surface-plated on MLA after 2, 4, 6 or 8 weeks if the organism was not quantitated in the original sample. Selected Listeria colonies from duplicate samples were confirmed biochemically. Results showed that numbers of Listeria in cheese increased 5- to 10-fold 24 h after its manufacture. Listeria counts for strains Scott A, CA and OH decreased to <10 to 100 CFU/g in all cheese samples taken during the first 18 d of ripening. In contrast, numbers of strain V7 remained unchanged during this period. All L. monocytogenes strains initiated growth in cheese after 18 d of ripening. Maximum Listeria counts of ca. 1 × 106 to 5 × 107 CFU/g were attained after 65 d of ripening. Generally, a 10- to 100-fold increase in numbers of Listeria occurred in wedge or surface as compared to interior cheese samples taken during the latter half of ripening. During this period, Listeria growth paralleled the increase in pH of the cheese during ripening.

Microbiological Quality of Commercial Tofu

1984 ◽  
Vol 47 (3) ◽  
pp. 177-181 ◽  
Author(s):  
T. G. REHBERGER ◽  
L. A. WILSON ◽  
B. A. GLATZ
Keyword(s):  
Microbiological Quality ◽  
Plate Count ◽  
Microbial Counts ◽  
Colony Forming Units ◽  
Low Levels ◽  
Microbial Groups ◽  
Yeasts And Molds ◽  
Processing Techniques

A study was done to investigate the microbiological quality of commercial tofu available in local retail outlets. A sampling method was first developed to obtain accurate and representative microbial counts of individual pieces of tofu. Plate count determination of total aerobic organisms, psychrotrophs, coliforms, sporeformers, yeasts and molds, and staphylococci were made on 60 tofu samples (representing three lots each of four different brands) obtained within 24 h after delivery to the retail store. In addition, for two brands that provided manufacturer's pull dates, the same microbial counts were obtained for samples stored in the laboratory at 10°C until the pull date. Of the tofu sampled immediately after purchase, 83% of the lots tested had total counts greater than 106 colony-forming units (CFU)/g and psychrotrophic counts greater than 104 CFU/g. In addition, 67% of the lots tested had confirmed coliform counts greater than 103 CFU/g. Very low levels (less than 10 CFU/g) of all other microbial groups tested for were found in the majority of lots. Samples held until the manufacturer's pull date contained higher total and psychrotrophic counts but lower or stable counts of other organisms compared with samples tested immediately after purchase. To improve the microbiological quality of tofu, processors need to reduce initial loads by improving sanitation and processing techniques, and retailers should provide more consistent and colder refrigerated storage.

Listeria monocytogenes Inhibition by Whey Protein Films and Coatings Incorporating Lysozyme

2005 ◽  
Vol 68 (11) ◽  
pp. 2317-2325 ◽  
Author(s):  
SEACHEOL MIN ◽  
LINDA J. HARRIS ◽  
JUNG H. HAN ◽  
JOHN M. KROCHTA
Keyword(s):  
Elastic Modulus ◽  
Listeria Monocytogenes ◽  
Whey Protein ◽  
Oxygen Permeability ◽  
Protein Isolate ◽  
Lower Percentage ◽  
Growth Media ◽  
Antimicrobial Effects ◽  
Smoked Salmon ◽  
Yeasts And Molds

The effects of whey protein isolate (WPI) films and coatings incorporating lysozyme (LZ) on the inhibition of Listeria monocytogenes both in and on microbial media, as well as on cold-smoked salmon, were studied. The antimicrobial effects of LZ were examined using various growth media by turbidity and plate counting tests. Disc-covering and disc-surface–spreading tests were also used to evaluate the effects of WPI films incorporating LZ. Smoked salmon was used as a model food to test the antimicrobial effects of WPI coatings incorporating LZ, both initially and during storage at 4 and 10°C for 35 days. Tensile properties (elastic modulus, tensile strength, and percentage of elongation), oxygen permeability, and color (Hunter L, a, and b) of WPI films with and without LZ were also compared. LZ inhibited L. monocytogenes in broth and on agar media. The number of cells surviving after LZ treatments depended on the type of media. WPI films incorporating 204 mg of LZ per g of film (dry basis) inhibited the growth of a preparation of 4.4 log CFU/cm2 L. monocytogenes. WPI coatings prepared with 25 mg of LZ per g of coating solution initially inactivated more than 2.4, 4.5, and 3.0 log CFU/g of L. monocytogenes, total aerobes, and yeasts and molds in smoked salmon samples, respectively. The WPI coatings incorporating LZ efficiently retarded the growth of L. monocytogenes at both 4 and 10°C. The anti–L. monocytogenes effect of LZ-WPI coating was more noticeable when the coating was applied before inoculation than when the coating was applied after inoculation. Significantly higher elastic modulus values and lower percentage of elongation and oxygen permeability values were measured with the WPI films incorporating LZ than with the plain WPI films.

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