scholarly journals Nutritional and quality changes in piglet concentrate affected by the mix

2021 ◽  
Vol 73 (4) ◽  
pp. 955-965
Author(s):  
A. Cella ◽  
J.V. Ludke ◽  
A. Coldebella ◽  
M.C.M.M. Ludke ◽  
G.M. Araújo ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Activity ◽  
Crude Protein ◽  
Quality Changes ◽  
Quality Requirements ◽  
Copper Zinc ◽  
Quality Deviation ◽  
Concentrate Production

ABSTRACT The aim of this study was to evaluate the reasons of quality deviation of a concentrate from a predefined standard. Five treatments were established: T1 - Control, standard concentrate formulation (SCF); T2 - PXMore5, SCF with more 5% vitamin-mineral premix (VMP); T3 - PXLess5, SCF with less 5% VMP. All three treatments used a 400kg batches in an INTECNIAL mixer; T4 - FeedMixer, SCF using a 4,000kg batch in an IMOTO mixer; T5 - PremixMixer, SCF using a 1,200kg batch in an MUYANG mixer. For each treatment, bags of 20 kg were stored in three storage places for four months. Water activity of concentrate was affected by temperature and air relative humidity in different storage places. Regarding the kind of mixer, the greatest variation in concentration of crude protein, mineral residue, copper, zinc, and selenium was observed in the PremixMixer. Adjustments are imperative in the handling and use procedures of this kind of mixer to meet the quality requirements required in the concentrate production. Analyzing the effect of the mineral-vitamin premix level, no difference could be defined with the evaluated parameters.

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 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 EFFECTS OF ADMIXTURES ON THE CRYSTALLISATION RATE OF GYPSUM A BATCH CRYSTALLISATION STUDY

REAKTOR ◽  
2017 ◽  
Vol 8 (2) ◽  
pp. 85
Author(s):  
S. Muryanto ◽  
H. M. Ang
Keyword(s):  
Equilibrium Concentration ◽  
Crystallization Rate ◽  
Supersaturated Solution ◽  
Different Types ◽  
Different Temperatures ◽  
Copper Zinc ◽  
Time Required ◽  
Crystallisation Rate ◽  
Zinc Concentrate ◽  
Concentrate Production

This paper descripbes a study on the effects of admixtures on the crystallization rate of gypsum. Two different types of biodegradable admixtures commonly used as flotation agent in copper/zinc concentrate production, namely, sodium isopropyl xanthate (=SIPX) and isopropyl thionocarbamate were investigated in this study. A laboratory batch crystallizer was used in this study, and the experiments were run using seeded method. The rate of desupersaturation or the time required to reach the equilibrium concentration was  compared for varying admixture oncentrations. It was discovered that the added seed crystals started growing imediately upon addition into the supersaturated solution, i.e. there  was no induction time.Results of this batch crystallizationstudy suggest that addition of admixtures individually or in combination, significantly affects the crystallization kinetics and in particular, reduces the rate of crystallization of gypsum. Activation energies were determined using three different temperatures, and the values obtained  mostly agreed with other published values, i.e. 60.00 ± 3.00, 57.39 ± 2.87, and 37.65 ±1.88 kj/mol, for pure gypsum, isopropyl yhionocarbamate, and SIPX, respectively.Keywords : activation energy; admixtures; CaSO4.2H2O; crystallization, gypsum; reaction rate

scholarly journals Exponentially Increased Thermal Resistance ofSalmonellaspp. andEnterococcus faeciumat Reduced Water Activity

2018 ◽  
Vol 84 (8) ◽  
pp. e02742-17 ◽  
Author(s):  
Shuxiang Liu ◽  
Juming Tang ◽  
Ravi Kiran Tadapaneni ◽  
Ren Yang ◽  
Mei-Jun Zhu
Keyword(s):  
Relative Humidity ◽  
Thermal Resistance ◽  
Silicon Dioxide ◽  
Linear Relationship ◽  
Water Activity ◽  
Enterococcus Faecium ◽  
Content Type ◽  
Low Moisture Foods ◽  
Log Linear ◽  
Insight Into

ABSTRACTSalmonellaspp. exhibit prolonged survivability and high tolerance to heat in low-moisture foods. The reported thermal resistance parameters ofSalmonellaspp. in low-moisture foods appear to be unpredictable due to various unknown factors. We report here that temperature-dependent water activity (aw, treatment temperature) plays an important role in the sharply increased thermal resistance ofSalmonella entericaserovar Enteritidis PT 30 and its potential surrogateEnterococcus faeciumNRRL B-2354. In our study, silicon dioxide granules, as carriers, were separately inoculated with these two microorganisms and were heated at 80°C with controlled relative humidity between 18 and 72% (resulting in corresponding aw,80°Cvalues for bacteria between 0.18 and 0.72) in custom-designed test cells. The inactivation kinetics of both microorganisms fitted a log-linear model (R2, 0.83 to 0.97). Reductions in the aw,80°Cvalues of bacterial cells exponentially increased theD80°C(the time needed to achieve a 1-log reduction in a bacterial population at 80°C) values forS. Enteritidis andE. faeciumon silicon dioxide. The log-linear relationship between theD80°Cvalues for each strain in silicon dioxide and its aw,80°Cvalues was also verified for organic wheat flour.E. faeciumshowed consistently higherD80°Cvalues thanS. Enteritidis over the aw,80°Crange tested. The estimated zaw(the change in aw,80°Cneeded to changeD80°Cby 1 log) values ofS. Enteritidis andE. faeciumwere 0.31 and 0.28, respectively. This study provides insight into the interpretation ofSalmonellathermal resistance that could guide the development and validation of thermal processing of low-moisture foods.IMPORTANCEIn this paper, we established that the thermal resistance of the pathogenS. Enteritidis and its surrogateEnterococcus faecium, as reflected byDvalues at 80°C, increases sharply with decreasing relative humidity in the environment. The log-linear relationship between theD80°Cvalues of each strain in silicon dioxide and its aw,80°Cvalues was also verified for organic wheat flour. The results provide new quantitative insight into the way in which the thermal resistance of microorganisms changes in low-moisture systems, and they should aid in the development of effective thermal treatment strategies for pathogen control in low-moisture foods.

Viability of Penicillium bilaji and Colletotrichum gloeosporioides conidia from liquid cultures

1990 ◽  
Vol 68 (10) ◽  
pp. 2270-2274 ◽  
Author(s):  
J. E. Cunningham ◽  
C. Kuiack ◽  
K. E. Komendant
Keyword(s):  
Relative Humidity ◽  
Key Words ◽  
Water Activity ◽  
Colletotrichum Gloeosporioides ◽  
Sucrose Solution ◽  
Liquid Cultures ◽  
Shelf Stability ◽  
Effect Of Water ◽  
Agricultural Application ◽  
Penicillium Bilaji

The effect of water activity on Penicillium bilaji Chalabuda and Colletotrichum gloeosporioides f.sp. malvae conidia at 20 °C was examined. The optimal relative humidity for storage at 20 °C was found to be 12–34% for C. gloeosporioides spores and 100% for P. bilaji spores. Retention of viability by C. gloeosporioides spores was improved by drying the spores from a 20% sucrose solution. The data demonstrate the conditions required for adequate shelf stability for commercial, biological products for agricultural application, based on these two organisms. Key words: Penicillium bilaji, Collectotrichum gloeosporioides, water activity, germinability.

Efficacy of Home-Style Dehydrators for Reducing Salmonella on Whole-Muscle Chicken

2011 ◽  
Vol 74 (7) ◽  
pp. 1079-1082
Author(s):  
M. J. D. WEBER ◽  
E. A. E. BOYLE ◽  
K. J. K. GETTY ◽  
N. M. HARPER ◽  
C. G. WEBER ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Activity ◽  
Temperature Control ◽  
Subsequent Reduction ◽  
Log Reduction ◽  
Home Style ◽  
Whole Muscle

Home-style dehydrators commonly used by consumers have limited relative humidity (RH) and temperature control. To evaluate the effect of dehydrator load on temperature and RH and subsequent reduction of Salmonella on whole-muscle chicken, chicken breasts were rolled and cut into samples (1 to 2 mm thick, 6 by 6 cm2) and inoculated with a five-strain Salmonella cocktail. The samples were allowed to air dry for 15 min and then were loaded into home-style three-tray (3T) or five-tray (5T) dehydrators, with 12 chicken pieces per tray. No difference (P &gt; 0.05) was observed in RH or temperature between the 3T and 5T dehydrators. Peak RH was 38% and gradually deceased to 8.5% after 6 h of drying. Temperatures peaked at 57°C after 6 h of drying. Dehydrator load had no effect (P &gt; 0.05) on lethality for Salmonella. A reduction of 3.3 ± 0.2 log CFU/cm2 was observed after 6 h of drying. However, sample location affected Salmonella reduction (P &lt; 0.05). Samples from the bottom tray had a 1.5-log reduction, whereas samples from the top and middle trays had 4.1- and 3.9-log reductions, respectively. The water activity of samples after 6 h of drying was 0.71 ± 0.17 regardless of tray location or dehydrator type. When chicken was dried in home-style dehydrators, increasing the dehydrator load did not increase RH or achieve greater Salmonella lethality. Tray location had a significant impact on Salmonella lethality. Adequate reduction of Salmonella on chicken was not achieved when chamber temperatures were below 57°C with limited RH throughout drying.

scholarly journals What properties of non-electrolyte solutions does a DNA molecule feel?

2021 ◽  
Vol 13 (2) ◽  
pp. 129-136
Author(s):  
George G. Malenkov ◽  
Keyword(s):  
Relative Humidity ◽  
Ethylene Glycol ◽  
Water Activity ◽  
Hyperfine Splitting ◽  
Solvent Polarity ◽  
Electrolyte Solutions ◽  
Water Solutions ◽  
Hyperfine Splitting Constant ◽  
Splitting Constant ◽  
In The Beginning

As early as in 1953 it was reported that at low relative humidity of the atmosphere (about 70 %) DNA films were in A-form, while at higher humidity (more than 80%) they were in B-form. Relative humidity of the atmosphere corresponds to the water activity in the system. It was found in the beginning of the 70th that DNA transfers to the A-form when non-electrolytes, such as monoatomic alcohols, dioxane, tetrahydrofurane were added to water. It was reasonable to suppose that B to A transition of DNA occurs in the non-electrolyte solutions at the same values af water activity as in the moist atmosphere. This prediction was borne out. But in water solutions of very polar non-electrolytes such as methanol and ethylene glycol B to A DNA does not occur even at very low water activity values. It was supposed that A form of DNA can arise only in the medium with sufficiently low polarity. We used hyperfine splitting constant (A) of a nitroxide spin label determined from the EPR spectra as a measure of the liquid solvent polarity. It was found that DNA transition into B form occurs when A reached a certain value. Polarity of methanol and ethylene glycol is much higher than that of the solutions in which B to A DNA transition takes place. This transition also occurs in water solutions of trifluoroethanol. But in these solutions the transition takes place at hyperfine splitting values, which are much greater than in other non-electrolyte solutions. Water activity in the zone of B-A DNA transition in trifluoroethanol solutions does not correspond water activity which was calculated for other nob-electrolyte solutions in which B-A transition is observed.

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