In-package atmospheric cold plasma inactivation of Salmonella in freeze-dried pet foods: Effect of inoculum population, water activity, and storage

2020 ◽  
Vol 66 ◽  
pp. 102543
Author(s):  
Barun Yadav ◽  
M.S. Roopesh
Keyword(s):  
Water Activity ◽  
Cold Plasma ◽  
Freeze Dried ◽  
And Storage

scholarly journals Stability of Vitamins B1, B2, B6 and E in a Fortified Military Freeze-Dried Meal During Extended Storage

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 39
Author(s):  
Ross Coad ◽  
Lan Bui
Keyword(s):  
Water Activity ◽  
Storage Temperature ◽  
Effective Means ◽  
Retention Rates ◽  
Vitamin Content ◽  
Freeze Dried ◽  
Colour Changes ◽  
C 30 ◽  
And Storage

Australian military ration packs contain a variety of processed foods, including some that are fortified with vitamins. In this study, freeze-dried meals, a key component of lightweight patrol ration packs, were fortified at the time of packing by direct addition of a vitamin premix containing vitamins B1, B2, B6 and E. Fortification was at three levels: 50%, 100% and 200% of the recommended vitamin content for military ration packs. Vitamin stability was determined following storage at temperatures of 1 °C, 30 °C and 40 °C for up to 24 months. HPLC methods were used to measure vitamin content; water activity and colour were also determined. Mean 24-month retention rates across all temperatures and fortification levels were 94%, 97%, 86% and 77% for vitamins B1, B2, B6 and E, respectively. Water activity increased with storage temperature, whereas colour changes due to fortification and storage temperature were at the threshold of visual detection. Fortification of freeze-dried meals would be an effective means of improving the quality of light weight military ration packs by addressing shortfalls in vitamin levels.

Storage stability of freeze–dried Lactobacillus acidophilus (La-5) in relation to water activity and presence of oxygen and ascorbate

Cryobiology ◽  
2009 ◽  
Vol 58 (2) ◽  
pp. 175-180 ◽  
Author(s):  
Lone Kurtmann ◽  
Charlotte U. Carlsen ◽  
Jens Risbo ◽  
Leif H. Skibsted
Keyword(s):  
Water Activity ◽  
Lactobacillus Acidophilus ◽  
Storage Stability ◽  
Freeze Dried

The occurrence of pyridoxamine phosphate in milk

1961 ◽  
Vol 28 (3) ◽  
pp. 293-301 ◽  
Author(s):  
Margaret E. Gregory ◽  
L. A. Mabbitt
Keyword(s):  
Acid Treatment ◽  
Vitamin B ◽  
Total Vitamin ◽  
Active Compounds ◽  
Milk Samples ◽  
Fresh Milk ◽  
Freeze Dried ◽  
Processing And Storage ◽  
And Storage ◽  
Mild Acid

SummaryThe presence of pyridoxamine phosphate in extracts of freeze-dried raw and evaporated milks has been demonstrated by separation and identification of the vitamin B6 active compounds by chromatography and electrophoresis on paper. Its presence in the milk extracts is the cause of the higher values for vitamin B6 activity measured with Streptococcus faecalis as compared with those obtained with Str. faecium or Saccharomyces carlsbergensis. This is because Str. faecalis can utilize the phosphate for growth as readily as free pyridoxamine, whereas Str. faecium and S. carlsbergensis cannot. The mild acid treatment used for extracting the vitamin B6 active compounds from the milk samples for microbiological assay was found to be insufficient to hydrolyse the pyridoxamine phosphate. Further treatment of the acid extracts with intestinal phosphatase released the pyridoxamine from its phosphate and increased the vitamin B6 activity measured with S. carlsbergensis and Str.faecium so that the total vitamin B6 activities of the freeze-dried raw and evaporated milks measured microbiologiclly, were then in agreement with the values found in previous tests with chicks and rats.Pyridoxamine phosphate could only be detected in small amounts in a sample of fresh milk. The possibility that more of it was formed during the processing and storage of the freeze-dried samples is discussed.

scholarly journals The effect of freezing-drying, cloudiness and concentration on the keeping quality of various blackcurrant products

1964 ◽  
Vol 36 (1) ◽  
pp. 161-180
Author(s):  
Taina Kuusi
Keyword(s):  
Ascorbic Acid ◽  
Relevant Literature ◽  
Organoleptic Properties ◽  
Black Currant ◽  
Organoleptic Evaluation ◽  
Freeze Dried ◽  
Juice Concentrate ◽  
The Stability ◽  
And Storage

Experiments have been made in the development of various new black-currant products, such as cloudy juice, juice concentrate and various freeze-dried preparations, along with a study of the effect of these different methods of preparation on the initial quality and storage properties. The quality was assessed from the stability of ascorbic acid and colour, the aroma number, and organoleptic evaluation. Storage lasted up to 8 months. It was established that the cloudiness exercised a slight protective effect on ascorbic acid. However, the instability of the cloud meant that the appearance of the cloudy juice was less attractive than that of the clear juice. No well-founded advantage of the cloudy juice could be demonstrated. Concentration proved less suitable, as there occurred harmful changes in ascorbic acid, colour and organoleptic properties. The freezing-drying method was excellent with respect to ascorbic acid and colour. In contrast, considerable losses in aroma occurred, with consequent weakening of the organoleptic properties. This method would be of advantage only in combination with aroma recovery, and solution of the financial problems involved. The results are discussed in the light of relevant literature.

scholarly journals The influence of selected preservation methods and storage time on the content of antioxidants in blackthorn (Prunus spinosa L.) fruits

2019 ◽  
Vol 74 (1) ◽  
pp. 53-62
Author(s):  
KATARZYNA OLESIŃSKA ◽  
DANUTA SUGIER ◽  
ŁUKASZ SĘCZYK
Keyword(s):  
Room Temperature ◽  
Storage Time ◽  
Antioxidant Properties ◽  
Iron Ions ◽  
Polyphenol Content ◽  
Total Polyphenols ◽  
Dried Fruits ◽  
Prunus Spinosa ◽  
Freeze Dried ◽  
And Storage

The aim of the study was to determine the influence of selected methods of preservation and storage time on the content of antioxidants in blackthorn fruit (Prunus spinosa L.). Preserved fruits were stored for 13 and 26 weeks without light at room temperature (freeze-dried and convection dried) and at –20°C (frozen samples). It was shown that both the method of preservation and the storage time had significant influence on the content of polyphenols (anthocyanins, flavonoids, total polyphenols) and antioxidant properties (Fe3+ reduction strength) of blackthorn fruit. As the storage time progressed, the anthocyanins content decreased in all preservation variants. In the case of frozen fruit after 26 weeks of storage, the content of flavonoids (by 12.5%), total polyphenols (by 48%) and the ability to reduce the iron ions were increased (by 55%). In turn, in the dried fruits after this period, the anthocyanins content, the polyphenol content and reduction strength were reduced. The highest values of the parameters evaluated after the assumed storage time has been demonstrated in lyophilizates.

Modeling the Effect of Water Activity, pH, and Temperature on the Probability of Enterotoxin A Production by Staphylococcus aureus

2016 ◽  
Vol 79 (1) ◽  
pp. 148-152 ◽  
Author(s):  
TIAN DING ◽  
YAN-YAN YU ◽  
CHENG-AN HWANG ◽  
QING-LI DONG ◽  
SHI-GUO CHEN ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Water Activity ◽  
Storage Temperature ◽  
Probability Model ◽  
Toxin Production ◽  
Factors Affecting ◽  
Model Predictions ◽  
And Storage ◽  
Storage Temperatures ◽  
Good Agreement

ABSTRACT The objectives of this study were to develop a probability model of Staphylococcus aureus enterotoxin A (SEA) production as affected by water activity (aw), pH, and temperature in broth and assess its applicability for milk. The probability of SEA production was assessed in tryptic soy broth using 24 combinations of aw (0.86 to 0.99), pH (5.0 to 7.0), and storage temperature (10 to 30°C). The observed probabilities were fitted with a logistic regression to develop a probability model. The model had a concordant value of 97.5% and concordant index of 0.98, indicating that the model satisfactorily describes the probability of SEA production. The model showed that aw, pH, and temperature were significant factors affecting the probability of toxin production. The model predictions were in good agreement with the observed values obtained from milk. The model may help manufacturers in selecting product pH and aw and storage temperatures to prevent SEA production.

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