scholarly journals Basaltic stones with epilithic lichens as a novel substrate for an osmotolerant fungus, Aspergillus glaucus

2017 ◽  
Vol 52 (1) ◽  
Author(s):  
Isabella Grishkan ◽  
Marina Temina
Keyword(s):  
Relative Humidity ◽  
Water Activity ◽  
Low Temperatures ◽  
Water Regime ◽  
Storage Period ◽  
Cellular Mechanism ◽  
Nutrient Source ◽  
Nutrient Sources ◽  
Aspergillus Glaucus ◽  
Epilithic Lichens

<em>Aspergillus glaucus</em><span> is a fungus able to tolerate low water activity of the environment. Its dense growth and sporulation were found on basaltic stones with epilithic lichens after 14 years of storage at a temperature of 4–7°C and relative humidity of 14–18%. Dust and soil particles deposited on the lichen thalli and dissolved in the water condensed on the stones during the storage period, apparently served as a nutrient source for the fungus. Probably, strongly xeric water regime on basaltic stones suitable for <em>A. glaucus</em> did not allow mesophilic fungi to develop and prevented the xerotolerant fungus from competition with other microfungi for nutrient sources. It is also possible that specific cellular mechanism associated with the production of chaotropic compounds (such as glycerol) supported germination and development of <em>A. glaucus</em> at low temperatures, which were considered non-optimal for the fungus.</span>

scholarly journals Screening fungi isolated from historicDiscoveryHut on Ross Island, Antarctica for cellulose degradation

2008 ◽  
Vol 20 (5) ◽  
pp. 463-470 ◽  
Author(s):  
Shona M. Duncan ◽  
Ryuji Minasaki ◽  
Roberta L. Farrell ◽  
Joanne M. Thwaites ◽  
Benjamin W. Held ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Low Temperatures ◽  
Cellulose Degradation ◽  
Hydrolytic Activity ◽  
Nutrient Source ◽  
Glucanase Activity ◽  
Cold Temperatures ◽  
Nutrient Sources ◽  
Cellulose Substrates ◽  
Research Findings

AbstractTo survive in Antarctica, early explorers of Antarctica's Heroic Age erected wooden buildings and brought in large quantities of supplies. The introduction of wood and other organic materials may have provided new nutrient sources for fungi that were indigenous to Antarctica or were brought in with the materials. From 30 samples taken fromDiscoveryHut, 156 filamentous fungi were isolated on selective media. Of these, 108 were screened for hydrolytic activity on carboxymethyl cellulose, of which 29 demonstrated activities. Endo-1, 4-β-glucanase activity was confirmed in the extracellular supernatant from seven isolates when grown at 4°C, and also when they were grown at 15°C.Cladosporium oxysporumandGeomycessp. were shown to grow on a variety of synthetic cellulose substrates and to use cellulose as a nutrient source at temperate and cold temperatures. The research findings from the present study demonstrate that Antarctic filamentous fungi isolated from a variety of substrates (wood, straw, and food stuffs) are capable of cellulose degradation and can grow well at low temperatures.

scholarly journals Storage Stability of Durum Wheat Pasta Enriched with Seaweeds Flours

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2450
Author(s):  
Ana Ramalho Ribeiro ◽  
Goreti Botelho ◽  
Ana Gaspar ◽  
Rui Costa
Keyword(s):  
Relative Humidity ◽  
Durum Wheat ◽  
Water Activity ◽  
Storage Stability ◽  
Storage Period ◽  
Quality Parameters ◽  
Fucus Vesiculosus ◽  
Ulva Rigida ◽  
Health Strategy ◽  
Over Time

The enrichment of semolina pasta with nutritionally rich ingredients has been targeted as a health strategy in recent years. In this work, the storage stability of seaweed-enriched pasta was assessed at different combinations of temperature and relative humidity. After six months of storage, pasta samples did not present variations in their sensory properties. The enrichment of durum wheat pasta with 1% of macroalgae Fucus vesiculosus and Ulva rigida flours, or flours of its extracts, was found to be adequate without influencing or modifying the sensory characteristics of pasta samples during the storage period. Water activity was shown to be the main criteria influencing the quality parameters of pasta during shelf life. A higher water activity during storage will lead to higher cooking losses and a lower firmness of cooked pasta, which will damage pasta quality over time.

scholarly journals Penurunan mutu dan pendugaan umur simpan sup krim instan labu kuning diperkaya tempe untuk lansia dengan metode accelerated shelf life testing (ASLT)

2020 ◽  
Vol 8 (2) ◽  
pp. 134-142
Author(s):  
Salma Shafrina Aulia ◽  
Budi Setiawan ◽  
Tiurma Sinaga ◽  
Ahmad Sulaeman
Keyword(s):  
Lipid Oxidation ◽  
Shelf Life ◽  
Water Content ◽  
Water Activity ◽  
Critical Parameter ◽  
Storage Period ◽  
Life Testing ◽  
Quality Of Water ◽  
Long Time

Background: Instant pumpkin cream soup enriched with tempeh had fulfilled 10% Recommended Dietary Allowances (RDA) for elderly so that it can be used as an easy-to-serve snack, but decreasing quality of instant cream soup will be happened if the instant cream soup was stored for a long time. Objectives: This study aimed to analyze quality of water content, water activity and lipid oxidation in instant pumpkin cream soup during storage and estimated the shelf life of pumpkin cream soup enriched with tempeh.Method:  Quality storage was analyzed using of water content, water activity (aw) and lipid oxidation. Estimation of shelf life was analyzed using Arrhenius Accelerated Shelf Life Testing (ASLT) model.Results: The results showed that the water content, aw levels and lipid oxidation of instant pumpkin cream soup increased during the storage period. The critical parameter used in this study was lipid oxidation. Instant cream soup without the addition of tempeh can last 447 days  while the cream soup with the addition of tempeh has a shelf life of 433 days.Conclusion: Quality of instant pumpkin cream soup decreased during the storage period and it would be expired over a year.

scholarly journals Microbiota indigenous milk, mesophilic lipolytic and proteolytic colonial cheese matured, produced at different times of the year

2017 ◽  
Vol 18 (4) ◽  
pp. 549-559
Author(s):  
Elisângela Borsoi Pereira ◽  
Magali Soares dos Santos Pozza ◽  
Paula Martins Olivo ◽  
Osmar Dalla Santa ◽  
Suzana da Cruz Pires ◽  
...  
Keyword(s):  
Weight Loss ◽  
Lactic Acid ◽  
Experimental Design ◽  
Relative Humidity ◽  
Water Activity ◽  
Cultural Importance ◽  
The Third ◽  
Randomized Experimental Design ◽  
Double Factorial ◽  
Production Period

SUMMARY Cheese is the oldest form of preserving milk nutrients having nutritional, economic and cultural importance. The objective of this study was to identify the best time of the year for production, and period, in months, for maturation of traditional colonial cheese, through analysis of water activity, weight loss and counts of lactic acid, mesophilic microorganisms—proteolytic and lipolytic. Records of temperature and relative humidity (RH) were maintained. A completely randomized experimental design was used in a double factorial scheme, considering production periods and maturation times. For all production periods evaluated, there was a significant reduction in the periods for water activity values. The counts of lactic acid bacteria ranged from 104 to 109 CFU/g. There was also stability in the number of colonies for lipolytic mesophilic microorganisms, until the third month of maturation. Low counts of proteolytic mesophiles were observed for the samples produced in May and June (5.70 and 5.53 log), respectively. The production period for the months of May and June corresponding to RH of 80% and average temperatures of 15°C were the most effective for production. Due to the presence of Listeria, it is recommended to respect the minimum time of 60 days of maturation for commercialization.

scholarly journals Use of Chlorella sp. for coating ‘tommy atkins’ mango fruits stored under refrigeration

2018 ◽  
Vol 39 (2) ◽  
pp. 565 ◽  
Author(s):  
Agda Malany Forte de Oliveira ◽  
Railene Hérica Carlos Rocha ◽  
Wellinghton Alves Guedes ◽  
George Alves Dias ◽  
José Franciraldo de Lima
Keyword(s):  
Relative Humidity ◽  
Raw Materials ◽  
Storage Period ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Edible Coatings ◽  
Fruit Maturation ◽  
Chlorella Sp ◽  
Randomized Design ◽  
Completely Randomized Design

The number of studies on edible coatings that are used for extending the shelf life of fruits has steadily increased. For this purpose, it is necessary to choose raw materials with characteristics that maintain product quality. The objective of this study is to evaluate the effect of coatings of Chlorella sp. on the post-harvest conservation of ‘Tommy Atkins’ mango fruits. The experiment was conducted using a completely randomized design, and spray treatments (T) with 0%, 1%, 2%, 3%, or 4% of Chlorella sp. were applied to the fruits. After the treatments, the fruits were stored for 28 days (21 days at 10 °C and 42% relative humidity and 7 days at 25 °C and 42% relative humidity), and were analyzed on day 28. There was higher pulp firmness in fruits as the concentration of Chlorella sp. was increased, and the concentration of ascorbic acid was comparatively higher (22.17%) in fruits treated with 3% Chlorella sp. The percentage of soluble solids and the soluble solids/titratable acidity ratio were decreased as the coating concentrations were decreased. The use of Chlorella sp. at 1% and 2% allowed fruit maturation without compromising fruit quality attributes during the 28-day storage period.

Effects of High Temperature and Relative Humidity on Mold Content and Quality of Stored Popcorn†

1995 ◽  
Vol 58 (9) ◽  
pp. 1018-1022 ◽  
Author(s):  
SARATH K. KATTA ◽  
LLOYD B. BULLERMAN
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Storage Time ◽  
Gradual Increase ◽  
Mold Growth ◽  
Internal Mold ◽  
Aspergillus Glaucus ◽  
Plastic Bag ◽  
Open Container

White and yellow popcorn were stored in different containers at high temperature (35°C) and high relative humidity (85%) conditions for 3 months. Gradual decreases in popping volumes with the lengthening of storage time were observed in both white and yellow popcorn. Internal mold infection was quite low in both white (5.7%) and yellow (3.0%) popcorn at the beginning of storage tests. Few differences were found in total infection levels up to 60 days of storage, except that the Aspergillus glaucus group became established in place of field fungi. A gradual increase in mold infection levels was then observed during the remaining 30 days of storage. Visible mold growth was also observed on the tips of some kernels by the end of storage studies. Internal mold infection in white popcorn stored in an open container was lower (18.3%) than white popcorn stored in a closed plastic bag (75.0%) and closed plastic jar (85.3%), whereas the internal mold infection in yellow popcorn stored in an open container was higher (23.3%) than yellow popcorn stored in a closed plastic bag (6.3%) and closed plastic jar (2.6%). The A. glaucus group were the predominant molds found at the end of storage tests. The ability of toxigenic molds to invade the popcorn was determined using a dry spore inoculum. None of the inoculated molds, which included Aspergillus flavus, Penicillium martensii, and Penicillium viridicatum, were able to invade the popcorn during storage. However, the A. glaucus group predominated at the end of storage tests in the inoculated samples.

scholarly journals Survivability of Salmonella Pathogens and Physicochemical Characteristics of Powder Goat Milk Stored under Different Storage Treatment Regimens

Dairy ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 269-283
Author(s):  
Roshan Paswan ◽  
Abhinav Mishra ◽  
Young W. Park
Keyword(s):  
Water Activity ◽  
Salmonella Enteritidis ◽  
Storage Temperature ◽  
Goat Milk ◽  
Storage Period ◽  
Behenic Acid ◽  
Physicochemical Characteristics ◽  
Treatment Regimens ◽  
Two Temperatures ◽  
Salmonella Serotypes

Survivability of Salmonella pathogens in commercial powdered goat milk (PGM) under different storage treatments was investigated using three batches of PGM products stored at two temperatures (4 °C and 25 °C) and ten storage periods (0, 3, 7, 14, 21, 30, 60, 90, 120 and 180 days). A cocktail of three Salmonella serotypes (Salmonella agona, Salmonella enteritidis and Salmonella tennessee) was inoculated to the PGM samples and then survival of Salmonella counts was enumerated in the inoculated and non-inoculated control groups. Results showed that the initial Salmonella counts were 7.103 Log CFU (colony forming unit)/g at both temperatures. At the first 3 days, the viable Salmonella counts were reduced about 0.94 and 1.40 Log CFU/g at 4 °C and 25 °C, respectively, where the same levels were sustained for 14 days. Further reductions continued and at the end of 180 days storage, Salmonella survivability was 1.15 Log CFU/g higher at 4 °C than at 25 °C under the same water activity condition. As the storage period advanced, viable pathogen counts were gradually decreased. The pH of samples stored at 4 °C for 0 and 4 month were higher than those stored at 25 °C except for 2 months, while no differences were found in water activity (aw) between treatments of the PGM products. With regard to physicochemical characteristics, the samples stored at 25 °C showed higher POV (peroxide value) values than those stored at 4 °C for 2 and 4 month periods, indicating that the rate of lipid oxidation in the PGM was elevated by a higher storage temperature and a longer storage period. The basic nutrient compositions of the experimental PGM were similar to those reported in recent studies. Oleic acid (C18:1) was the highest, caprylic acid (C8:0) was the second highest, and behenic acid (C22:0) was the lowest concentration among all fatty acids identified in the PGM samples. Most of the fatty acid concentrations tended to decrease with advanced storage periods. This research indicates that the survivability of Salmonella pathogens in the PGM products stored at 4 °C for 180 days was higher than those stored at 25 °C under the same aw condition.

scholarly journals AVALIAÇÃO DE PRODUTOS OBTIDOS PELA DESIDRATAÇÃO OSMÓTICA DE BANANA SEGUIDA DE SECAGEM

2003 ◽  
Vol 21 (1) ◽  
Author(s):  
PAULO HENRIQUE MACHADO DE SOUSAPAULO HEN MACHADO DE SOUSA ◽  
GERALDO ARRAES MAIA ◽  
MEN DE SÁ MOREIRA DE SOUZA FILHO ◽  
RAIMUNDO WILANE DE FIGUEIREDO ◽  
RENATA TIEKO NASSU ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Storage Stability ◽  
Osmotic Dehydration ◽  
Storage Period ◽  
Sensory Characteristics ◽  
Sensorial Analysis ◽  
Physico Chemical ◽  
Microbiological Stability

Foram obtidos dois produtos de banana por desidratação osmótica, um sob pressão atmosférica e outro sob vácuo, com complemento de secagem em estufa. A estabilidade dos produtos foi estudada, durante 120 dias, mediante análises físico-químicas, microbiológicas e sensoriais. Nesse período, os produtos ficaram armazenados em temperatura ambiente (23,4-34,1oC) e umidade relativa entre 33-81%. Concluiu-se que os produtos mantiveram suas características químicas, físico-químicas e sensoriais, além de estabilidade microbiológica (pouca variação durante o período de armazenamento). Somente a cor dos produtos apresentou variação expressiva. Sugere-se o tratamento utilizando osmose com vácuo seguido de secagem para produção de banana passa. EVALUATION OF PRODUCTS OBTAINED BY THE BANANA’S OSMOTIC DEHYDRATION FOLLOWED OF DRYING Abstract It was obtained two bananas products through osmotic dehydration, one under atmospheric pressure and other under vacuum, with drying complement in stove. The storage stability of these products was studied, during 120 days, through physicalchemical, microbiological and sensorial analysis. In this period, the products were stored at room temperature (23,4-34,1oC) and relative humidity between 33-81%. It was concluded that the obtained products maintained their chemical, physico-chemical and sensory characteristics, beyond microbiological stability (small variations during the storage period). Only the color of the produtcs presented more expressive variations. Therefore it is suggested the treatment using osmosis with vacuum followed by oven drying for the production of banana fig.

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