scholarly journals Proteolysis in kashkaval cheese stored at different temperatures

2020 ◽  
Vol 3 (2) ◽  
pp. 111
Author(s):  
Galin Ivanov ◽  
Atanaska Vasileva Markova
Keyword(s):  
Free Amino ◽  
Storage Temperature ◽  
Amino Groups ◽  
Protein Nitrogen ◽  
Temperature Regimes ◽  
Different Temperatures ◽  
Weight Protein ◽  
Kashkaval Cheese ◽  
Hydrolysis Of ◽  
Storage Temperatures

The aim of the present study was to evaluate the effect of refrigerated storage temperature on the proteolysis in cow's milk Kashkaval cheese. The Kashkaval samples were stored for 12 months at four different temperature regimes - cooled at 4,0 ± 1,0 °C, cooled at 1.0 ± 1.0 °C, superchilled at -7,5 ± 0,5 °C and frozen at -18.0 ± 1.0 °C. The proteolysis in cheese samples was evaluated by determining the non-casein nitrogen (NCN/TN), non-protein nitrogen (NPN/TN) as a percentage of total nitrogen and content of free amino groups. It was found that the storage temperature had a significant impact on the hydrolysis of cheese paracasein. Complete inhibition of the proteolysis was established only in frozen stored Kashkaval. Slight, but statistically significant (P<0,05) increase in the NCN/TN values indicating for retarded proteolysis in samples stored at -7,5 ± 0,5 °C was established. The increasing of the storage temperatures results in increased NCN/TN, NPN/TN values and free amino groups content. The highest proteolysis rate was observed at the refrigeration temperatures of 4.0 ± 1.0 °C. The samples stored at this temperature regime had the highest values of both high molecular weight protein fractions (NCN/TN) and products of deep proteolysis (NPN/TN and free amino groups).

scholarly journals Shelf Life Studies of Three Wasabi Flavoured Sauces

1970 ◽  
Vol 44 (2) ◽  
pp. 147-156
Author(s):  
Tamanna Sultana ◽  
GP Savage ◽  
NG Porter ◽  
DL McNeil ◽  
JR Sedcole
Keyword(s):  
Shelf Life ◽  
Storage Temperature ◽  
Initial Level ◽  
Tomato Sauce ◽  
Wasabia Japonica ◽  
Different Temperatures ◽  
Small Change ◽  
Shelf Life Studies ◽  
The Stability ◽  
Storage Temperatures

Isothiocyanates (ITCs) contained in purees extracted from wasabi (Wasabia japonica (Miq) Matsum) can be used to manufacture a range of interesting spicy foods. In New Zealand, local manufacturers are showing interest in producing various forms of processed wasabi based sauces. However, isothiocyanates have been shown to degrade quickly in some situations. Therefore, in this study, the stability of allyl ITC was investigated in three wasabi flavoured products stored at four different temperatures (4, 10, 20 and 30°C) for 22 weeks. Two creamy (mayonnaise and tartare) sauces and a non-creamy sauce were prepared from an original recipe and flavoured with a known volume of "wasabi oil". Two types of pouches (clear and metallic plastic) were used to store each product and allyl ITC content was measured in the stored sauces at two week intervals. The initial level of allyl ITC found in mayonnaise, tartare and smoky tomato sauces were 415.3, 411.4 and 144.7 mg/ kg respectively, prior to storage. Temperature showed a strong influence in reducing allyl ITC (P=0.005 to <0.001) but no significant effect was identified for the two types of packets used. The non-creamy smoky tomato sauce was very unstable at 10°C or higher temperatures and the allyl ITC contents reduced rapidly with increasing storage temperatures. For instance, at 30°C, a 66% loss occurred by week 2 and a 90% loss occurred by week 6 in the smoky tomato sauce. However, mayonnaise and tartare sauces had a shelf life of 8 to 9 weeks with only a marginal reduction in allyl ITC (2% overall) at all the stored temperatures (4-30°C). These creamy sauces were characterized by a sudden fall in 10 weeks ending in a 69-70% loss of allyl ITC at 22 weeks. No microbial growth occurred in any of the sauces stored at any of the temperatures during the course of this storage experiment though very small change of colour was noticed for the sauces when stored at 30°C. Keywords: Bangladesh J. Sci. Ind. Res. 44(2), 147-156, 2009DOI: 10.3329/bjsir.v44i2.3665Bangladesh J. Sci. Ind. Res. 44(2), 147-156, 2009

scholarly journals Characterization of the Spoilage Microbiota of Hake Fillets Packaged Under a Modified Atmosphere (MAP) Rich in CO2 (50% CO2/50% N2) and Stored at Different Temperatures

Foods ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 489 ◽  
Author(s):  
Adriana Antunes-Rohling ◽  
Silvia Calero ◽  
Nabil Halaihel ◽  
Pedro Marquina ◽  
Javier Raso ◽  
...  
Keyword(s):  
Storage Temperature ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Modified Atmosphere ◽  
Modified Atmospheres ◽  
Different Temperatures ◽  
Rrna Gene Sequencing ◽  
Storage Temperatures

The aim of this study was to characterize the spoilage microbiota of hake fillets stored under modified atmospheres (MAP) (50% CO2/50% N2) at different temperatures using high-throughput 16S rRNA gene sequencing and to compare the results with those obtained using traditional microbiology techniques. The results obtained indicate that, as expected, higher storage temperatures lead to shorter shelf-lives (the time of sensory rejection by panelists). Thus, the shelf-life decreased from six days to two days for Batch A when the storage temperature increased from 1 to 7 °C, and from five to two days—when the same increase in storage temperature was compared—for Batch B. In all cases, the trimethylamine (TMA) levels measured at the time of sensory rejection of hake fillets exceeded the recommended threshold of 5 mg/100 g. Photobacterium and Psychrobacter were the most abundant genera at the time of spoilage in all but one of the samples analyzed: Thus, Photobacterium represented between 19% and 46%, and Psychrobacter between 27% and 38% of the total microbiota. They were followed by Moritella, Carnobacterium, Shewanella, and Vibrio, whose relative order varied depending on the sample/batch analyzed. These results highlight the relevance of Photobacterium as a spoiler of hake stored in atmospheres rich in CO2. Further research will be required to elucidate if other microorganisms, such as Psychrobacter, Moritella, or Carnobacterium, also contribute to spoilage of hake when stored under MAP.

THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: III. SOME CHARACTERISTICS OF EXTRACELLULAR PROTEASES PRODUCED IN SUBMERGED CULTURE

1950 ◽  
Vol 28c (6) ◽  
pp. 600-612 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Low Temperatures ◽  
Free Amino ◽  
Submerged Culture ◽  
Culture Medium ◽  
Proteolytic Enzymes ◽  
Amino Groups ◽  
Extracellular Proteases ◽  
Egg Albumin ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of

Some of the general characteristics of the proteases liberated into the culture medium by molds and actinomycetes grown in submerged culture have been studied. Species of Alternaria, Streptomyces, Mortierella, and Gliocladium were used. The enzymes resemble trypsin in that they are most active at a pH slightly above 7 and are inhibited by a preparation of egg albumin. They are stable at low temperatures but suffer marked losses in activity when stored for 16 hr. above 40 °C. The most rapid hydrolysis of gelatin occurs at temperatures between 40 °C. and 50 °C. The enzymes from different organisms show definite differences with respect to their ability to attack different proteins, gelatin and casein being in general the most readily digested. The protease systems from different organisms also vary with respect to the extent to which they can digest gelatin; some enzymes are able to release about three times as many amino groups from gelatin as others. The limit of the hydrolysis is not dependent upon substrate concentration but is slightly affected by the concentration of enzyme. The enzymes were effective in liberating free amino acids from gelatin.

scholarly journals Changes in Biochemical Characteristics and Activities of Ripening Associated Enzymes in Mango Fruit during the Storage at Different Temperatures

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Md. Anowar Hossain ◽  
Md. Masud Rana ◽  
Yoshinobu Kimura ◽  
Hairul Azman Roslan
Keyword(s):  
Shelf Life ◽  
Biochemical Parameters ◽  
Storage Time ◽  
Storage Temperature ◽  
Starch Content ◽  
Titratable Acidity ◽  
Different Temperatures ◽  
Soluble Solid ◽  
Storage Temperatures ◽  
Carbohydrate Contents

As a part of the study to explore the possible strategy for enhancing the shelf life of mango fruits, we investigated the changes in biochemical parameters and activities of ripening associated enzymes of Ashwina hybrid mangoes at 4-day regular intervals during storage at −10°C, 4°C, and30±1°C. Titratable acidity, vitamin C, starch content, and reducing sugar were higher at unripe state and gradually decreased with the increasing of storage time at all storage temperatures while phenol content, total soluble solid, total sugar, and nonreducing sugar contents gradually increased. The activities of amylase,α-mannosidase,α-glucosidase, and invertase increased sharply within first few days and decreased significantly in the later stage of ripening at30±1°C. Meanwhile polyphenol oxidase,β-galactosidase, andβ-hexosaminidase predominantly increased significantly with the increasing days of storage till later stage of ripening. At −10°C and 4°C, the enzymes as well as carbohydrate contents of storage mango changed slightly up to 4 days and thereafter the enzyme became fully dormant. The results indicated that increase in storage temperature and time correlated with changes in biochemical parameters and activities of glycosidases suggested the suppression ofβ-galactosidase andβ-hexosaminidase might enhance the shelf life of mango fruits.

scholarly journals Effect of Dry and Wet Storage at Different Temperatures on the Vase Life of Cut Flowers

2001 ◽  
Vol 11 (2) ◽  
pp. 199-202 ◽  
Author(s):  
Juan-Carlos Cevallos ◽  
Michael S. Reid
Keyword(s):  
Storage Temperature ◽  
Dianthus Caryophyllus ◽  
Vase Life ◽  
Cut Flowers ◽  
Tulipa Gesneriana ◽  
Wet Storage ◽  
Different Temperatures ◽  
Narcissus Pseudonarcissus ◽  
C 32 ◽  
Storage Temperatures

After storage at different temperatures for a simulated transportation period, the vase lives at 20 °C (68 °F) of carnations (Dianthus caryophyllus `Imperial White'), daffodils (Narcissus pseudonarcissus `King Alfred'), iris (Iris hollandica `Telstar'), killian daisies (Chrysanthemum maximum), paperwhite narcissus (Narcissus tazetta `Paperwhite'), roses (Rosa {XtimesX}hybrida `Ambiance'), and tulips (Tulipa gesneriana) decreased with increasing storage temperature. There were no significant differences between the vase life of flowers stored dry and flowers stored in water when storage temperatures were from 0 to 10 °C (32 to 50 °F). The vase life after wet storage at temperatures of 12.5 °C (54.5 °F) and greater was significantly higher than vase life after dry storage at those temperatures for all the flowers studied. Iris and carnation flowers survived storage at 15 and 20 °C (59 and 68 °F) only when stored in water.

Effects of Storage Temperature on Tyramine Production by Enterococcus faecalis R612Z1 in Water-Boiled Salted Ducks

2014 ◽  
Vol 77 (10) ◽  
pp. 1804-1808 ◽  
Author(s):  
FANG LIU ◽  
LIHUI DU ◽  
HAIHONG WU ◽  
DAOYING WANG ◽  
YONGZHI ZHU ◽  
...  
Keyword(s):  
Quantitative Pcr ◽  
Enterococcus Faecalis ◽  
Reverse Transcription ◽  
Storage Temperature ◽  
Enzymatic Activities ◽  
Expression Level ◽  
Reverse Transcription Quantitative Pcr ◽  
Different Temperatures ◽  
Meat Samples ◽  
Storage Temperatures

Tyramine production by Enterococcus faecalis R612Z1 in water-boiled salted ducks was evaluated during storage at different temperatures. The results showed that E. faecalis R612Z1 could produce tyramine in meat samples when the storage temperature was no less than 4°C. The E. faecalis R612Z1 counts of the meat samples reached 108 CFU/g on day 7 at 4°C and on day 4 at 10°C. However, the tyramine content of the meat samples stored at 10°C increased to 23.73 μg/g (on day 10), which was greater than the level in the samples stored at 4°C (7.56 μg/g). Reverse transcription quantitative PCR detection of the expression level of the tyrDC gene in E. faecalis R612Z1 in the meat samples revealed no significant changes at different storage temperatures. Thus, the changes in tyramine production of E. faecalis R612Z1 may be due to the different enzymatic activities at different storage temperatures.

scholarly journals Fate of Salmonella spp. in the Fresh Soft Raw Milk Cheese during Storage at Different Temperatures

2021 ◽  
Vol 9 (5) ◽  
pp. 938
Author(s):  
Adriana Lobacz ◽  
Justyna Zulewska
Keyword(s):  
Goodness Of Fit ◽  
Storage Temperature ◽  
Raw Milk ◽  
Microbial Count ◽  
Salmonella Spp ◽  
E Coli ◽  
Different Temperatures ◽  
Raw Milk Cheese ◽  
Kinetics Of ◽  
Storage Temperatures

The aim of this study was to determine the survival kinetics of Salmonella spp. in unripened, fresh raw milk cheese during storage at 5, 15 and 25 °C. Microbiological (coliforms and E. coli, S. thermophilus, Lactococcus sp., total microbial count and Enterobacteriaceae) and physicochemical (pH and aw) characteristics were also determined. Two primary models were used to estimate the kinetic parameters of Salmonella spp., namely Weibull and Baranyi and Roberts (no lag) models. Additionally, goodness-of-fit of the primary models was assessed by calculating the R-Square and mean square error. Salmonella spp. growth in the unripened raw milk cheese was inhibited during storage, but nevertheless bacteria survived at 5 °C for 33 days (2.5 log cfu/g) and 15 °C for 18 days (1.8 log cfu/g). A decrease in the number of Salmonella spp. populations from an initial concentration 6.6 log cfu/g to below a detection limit was observed at 25 °C after 7 days of storage of contaminated cheese samples. It was concluded that the storage temperature significantly influenced the inactivation rate of Salmonella spp. in fresh raw milk cheese and proceeded faster at 25 °C compared to remaining storage temperatures.

scholarly journals Study of storage on seed germination of Chresta sphaerocephala DC. – Asteraceae

2021 ◽  
Vol 10 (9) ◽  
pp. e50110917893
Author(s):  
Amanda Domingas Ediodato de Sousa ◽  
Luciana Botezelli ◽  
Patrícia Neves Mendes
Keyword(s):  
Seed Germination ◽  
Storage Temperature ◽  
Morphological Difference ◽  
Seed Storage ◽  
Seed Vigor ◽  
Significance Level ◽  
Different Temperatures ◽  
And Storage ◽  
Storage Temperatures ◽  
Germinated Seeds

High-altitude fields have been subjected to an intense anthropization process. Due to this, studies on germination, seed storage and propagation of species that compose this plant formation become fundamental. Among such species is the Chresta sphaerocephala DC., Asteraceae. The purpose of this work was to study different temperatures for germination and storage of this species. Four germination temperatures (15°C, 20°C, 25°C and 30°C) and two storage temperatures (-5°C and +5°C) were tested. In order to assess seed vigor, the germination speed index (GSI) and average seed germination time were calculated. ANOVA and Tukey's test were performed at a 5% significance level. In addition, a morphological difference was observed in the analyzed Chresta sphaerocephala seeds, with these being classified as C1 (small seeds), C2 (long thin seeds), C3 (thicker seeds) and C4 (dark colored seeds). As for the storage temperature, 5°C was shown to be the best. When correlated with the germination temperature, 20°C resulted in a statistically higher number of germinated seeds.

Influence of Storage Temperature and Apple Variety on Patulin Production by Penicillium expansum

2009 ◽  
Vol 72 (5) ◽  
pp. 1030-1036 ◽  
Author(s):  
BEATRIZ C. M. SALOMÃO ◽  
GLÁUCIA M. F. ARAGÃO ◽  
JOHN J. CHUREY ◽  
OLGA I. PADILLA-ZAKOUR ◽  
RANDY W. WOROBO
Keyword(s):  
Drug Administration ◽  
Storage Temperature ◽  
Food And Drug Administration ◽  
Penicillium Expansum ◽  
Juice Quality ◽  
Apple Variety ◽  
Apple Varieties ◽  
Different Temperatures ◽  
Storage Temperatures ◽  
The U.S

This study examined the potential for patulin production in six different varieties of apples (Red Delicious, Golden Supreme, Gala, Fuji, Empire, and McIntosh) inoculated with Penicillium expansum spores and stored at two different temperatures (11 and 20.5°C). Samples for patulin analysis were randomly taken from apples stored at different times, ranging from 21 to 93 days. While patulin was produced at both storage temperatures, apples incubated at 20.5°C yielded significantly higher patulin concentrations than did those incubated at 11°C. All apple varieties showed mold spoilage at both temperatures, except Red Delicious and Empire. A total of 44% of the samples analyzed showed patulin concentrations above the U.S. Food and Drug Administration regulatory limit (50 ppb). The highest patulin productions occurred in Golden Supreme (54,221 ppb) and McIntosh (52,131 and 48,457 ppb) varieties. Our results showed that careful culling of apples is essential for high juice quality, since high patulin levels in some apples varieties could result in a level greater than 50 ppb of this mycotoxin in the finished juice or cider, even when only one contaminated apple occurs in 1,000 apples.

The Microbiological Profile of Chilled and Frozen Chicken

2000 ◽  
Vol 63 (9) ◽  
pp. 1228-1230 ◽  
Author(s):  
J. S. BAILEY ◽  
B. G. LYON ◽  
C. E. LYON ◽  
W. R. WINDHAM
Keyword(s):  
Escherichia Coli ◽  
Broiler Chickens ◽  
Storage Temperature ◽  
Mesophilic Bacteria ◽  
Microbiological Profile ◽  
Different Temperatures ◽  
Phosphate Buffered Saline ◽  
Storage Temperatures

To determine the effect of different refrigeration and freezer temperatures on the microbiological profile of chicken, 50 commercially processed broiler chickens were each split in half on the day of processing. Equal groups were held at 4, 0, −4, −12, and −18°C (40, 32, 26, 10, and 0°F), respectively for 7 days. One half of each group was then transferred to a 0°F holding chamber for an additional 7 days. Carcass halves were rinse sampled with 100 ml of phosphate-buffered saline and the diluent sampled for mesophilic, psychrotropic, coliform, and salmonellae counts after the initial 7 days at different temperatures and after 7 additional days at −18°C. Ten carcass halves were sampled on the day of processing to give baseline counts. Mesophilic bacteria counts/ml were about log 4.6 on day 0, increased by 2 log after 7 days on carcasses held at 4°C, and were unchanged at all other storage temperatures. Psychrotropic counts/ml were about log 3.6 on day 0 and increased during the initial 7 days by about 3.9, 1.9, and 1.4 logs, respectively on carcasses held at 4, 0, and −4°C and had less than 1 log increase at −12 and −18°C. Coliform counts were about log 2.2/ml on day 0 and had declined to about log 1.5/ml or less by day 7 for all storage temperatures. Escherichia coli counts/ml were about log 2 on day 0 and were reduced about 1 log or more at other storage days. Salmonellae counts were about log 1.5 on salmonellae-positive carcasses and did not change appreciably at any storage temperature. No counts for any organism significantly changed after placement at −18°C.

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