Resistance of 17 mesophilic lacticStreptococcusbacteriophages to pasteurization and spray-drying

1980 ◽  
Vol 47 (1) ◽  
pp. 131-139 ◽  
Author(s):  
Marie-Christine Chopin
Keyword(s):  
Heat Exchanger ◽  
Heat Resistance ◽  
Spray Drying ◽  
Room Temperature ◽  
Milk Powder ◽  
Skim Milk ◽  
Streptococcus Cremoris

SummaryFor 17 phages active againstStreptococcus cremoris, Str. lactisandStr. lactissubsp.diacetylactis, the killing efficiency of pasteurization (logNo/N) at 72°C for 15 s in skim-milk showed large variations from > 6 to 0; the efficienty of killing during spray-drying ranged from 3.7 to 0.2 and phages survived well storage of milk powder at room temperature. Destruction in a heat exchanger was found to be greater than that calculated from biphasic curves obtained by heating phages in sealed ampoules. No relationship was established between lytic classification of phages and their heat resistance.

Addendum: Survie de Staphylococcus aureus au cours de la préparation et de la conservation de lait écrémé en poudre. Problèmes posés par le dénombrement des survivants

1979 ◽  
Vol 25 (2) ◽  
pp. 237-237
Author(s):  
A. Chopin ◽  
Silvia Tesone ◽  
J.-P. Vila ◽  
Y. LeGraet ◽  
G. Mocquot
Keyword(s):  
Staphylococcus Aureus ◽  
Spray Drying ◽  
Room Temperature ◽  
Milk Powder ◽  
Skim Milk ◽  
Egg Yolk ◽  
Test Strain ◽  
Cellular Damage ◽  
Concentrated Milk ◽  
Drying Conditions

Skim milk powders were contaminated with seven strains of Staphylococcus aureus previously isolated from dairy products. These organisms were either added to the concentrated milk before spray-drying or directly to the milk powder. Survival under spray-drying conditions similar to those used in commercial operations was dependent on drying conditions and on the test strain; 1/5 to 1/250 000 of the original populations could be recovered. Survival during storage of milk powder at room temperature depended on the test strain, moisture content, and the method used to contaminate the powder. Our results suggest that powder stored at room temperature for more than 3 months may contain enterotoxin but no detectable surviving S. aureus.Of the different media tested, direct inoculation of Baird–Parker agar and PPSA supplemented with Tweens reliably detected maximal numbers of viable cells. Other selective counting methods gave variable results dependent on the test strain, the age of the powder, and the method by which the powders were contaminated.The nature of cellular damage depended on whether or not the organisms had been exposed to the spray-drying process. Enumeration of populations in spray-dried samples was "superior" when selective media were supplemented with egg yolk or Tweens. [Translated by the journal]

scholarly journals Staphylococcal Food Poisoning Associated with Spray-Dried Milk

1955 ◽  
Vol 53 (4) ◽  
pp. 387-397 ◽  
Author(s):  
P. H. R. Anderson ◽  
Doris M. Stone
Keyword(s):  
Spray Drying ◽  
Clinical Features ◽  
Milk Powder ◽  
Food Poisoning ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Large Numbers ◽  
Heat Treated ◽  
Drying Chamber ◽  
Spray Dried

SummaryEight explosive outbreaks of food poisoning, occurring in school canteens in England during 1953 and affecting 1190 known cases, are described. The clinical features were characteristic of the toxin type of illness. No deaths occurred.The food causing all of these outbreaks was prepared from spray-dried skim milk powder. It was not subsequently heat-treated and was usually consumed 3–4 hr. after preparation.The spray-dried milk powder proved to contain a high content of bacteria, including large numbers of Staph. aureus, of a phage pattern often associated with food poisoning. The assumption was therefore made that these outbreaks were caused by staphylococcal enterotoxin.Because the food was often consumed within 3–4 hr. of reconstitution of the milk powder—before, in fact, the staphylococci had had time to grow—it is concluded that the poisoning must have been due mainly to pre-formed toxin.Consideration is given to the opportunities for the formation of toxin in a spray-drying plant, and reasons are brought forward for believing that it is formed mainly in the balance tank where the warm milk is kept, sometimes for several hours, before passing into the final drying chamber.The processing of the milk and the precautions for preventing contamination of the finished product are discussed.

Refined palm oil fractions: Effect of skim milk powder and maltodextrin on emulsion properties and microencapsulation by spray drying

2021 ◽  
Author(s):  
K. Cevik ◽  
H. Yalcin
Keyword(s):  
Spray Drying ◽  
Palm Oil ◽  
Palm Olein ◽  
Milk Powder ◽  
Skim Milk ◽  
Palm Stearin ◽  
Skim Milk Powder ◽  
Solid Content ◽  
Coating Materials ◽  
Oil Fractions

Abstract The aim of this study was to investigate microencapsulation of palm oil fractions (palm olein (POL) and 90% palm olein+10% palm stearin (POS)) using skim milk powder (SMP) and maltodextrin (MD) by spray drying. Twenty-seven emulsions with POL were prepared to determine appropriate solid content (SC) and oil/coating material ratio (O/CM) of the emulsions to be fed into the spray dryer. Emulsion properties, such as viscosity and stability, were affected by SC and coating materials. The effects of coating materials used in microencapsulation of POL and POS were also tested by using different ratios of SMP and MD. The microencapsulation efficiency (69.28–84.97%), the microencapsulation yield (14.50–31.79%), and the peroxide value (4.12–7.07 meq O2/kg oil) of the powders were affected by the coating materials (P < 0.05).

Changes in Concentration of Aflatoxin M1 during Manufacture and Storage of Skim Milk Powder

2006 ◽  
Vol 69 (3) ◽  
pp. 682-685 ◽  
Author(s):  
ORGUN DEVECİ ◽  
EMEL SEZGİN
Keyword(s):  
Spray Drying ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Aflatoxin M1 ◽  
Weight Changes ◽  
Sample Weight ◽  
Powder Samples ◽  
And Storage ◽  
Different Levels

In this study, skim milk powder was produced from cow's milk contaminated artificially with aflatoxin M1 (AFM1) at two different levels, 1.5 and 3.5 μg/liter (ppb), and the effects of process stages on the AFM1 contents were investigated. Pasteurization, concentration, and spray drying caused losses of about 16, 40, and 68%, respectively, in AFM1 content of the milk contaminated with 1.5 μg/liter AFM1, and losses of 12, 35, and 59%, respectively, in the milk contaminated with 3.5 μg/liter AFM1. These losses were found to be statisticially significant at the level of P &lt; 0.01. After 3- and 6-month storage periods, AFM1 content of the skim milk powder produced from milk with 1.5 μg/liter AFM1 decreased by 2 and 5%, respectively, whereas these rates were 2 and 4%, respectively, for the skim milk powders made from milk with 3.5 μg/liter AFM1 (after adjustment for sample weight). Changes in AFM1 content of milk powder samples were found statistically insignificant (P &gt; 0.05 and P &gt; 0.01) for 3- and 6-month storage periods.

scholarly journals Sensory and Quality Evaluation of Mayonnaise and its Effect on Storage Stability

2016 ◽  
Vol 2 (1) ◽  
pp. 48-53
Author(s):  
Mahalaxmi Pradhananga ◽  
Babita Adhikari
Keyword(s):  
Fatty Acid Composition ◽  
Technical College ◽  
Room Temperature ◽  
Quality Evaluation ◽  
Storage Stability ◽  
Milk Powder ◽  
Skim Milk ◽  
Egg Yolk ◽  
Skim Milk Powder ◽  
Microbial Analysis

This study aimed to evaluate the addition of skim milk powder to replace egg yolk in preparation of mayonnaise. Egg yolk was pasteurized at 150ºF (65.6ºC) about 1 minute for its safety. Mayonnaise was prepared from sunflower oil with the level varied from 65-75% and egg yolk from 9-15%. Mayonnaise made from 70% oil and 12% egg yolk was found to be best. Then skim milk powder (SMP) was added to replace 12% egg yolk in the ratios 0:100, 25:75, 50:50, 75:25 and 100:0 other constituents remaining constant. Sensory evaluation demonstrated that mayonnaise substituted with 25% skim milk powder was best. The chemical composition of the product, as well as fatty acid composition and peroxide value was analyzed. Coliform and Salmonella was not detected in microbial analysis. Sensory studies for its storage stability confirmed that the product was acceptable up to 28th days at refrigerate temperature whereas sample stored in room temperature was deteriorated after 14th days.  Sunsari Technical College Journal 2015, 2(1):48-53

Denaturation, aggregation and heat stability of milk protein during the manufacture of skim milk powder

1991 ◽  
Vol 58 (3) ◽  
pp. 269-283 ◽  
Author(s):  
Harjinder Singh ◽  
Lawrence K. Creamer
Keyword(s):  
Spray Drying ◽  
Milk Powder ◽  
Skim Milk ◽  
Heat Stability ◽  
Skim Milk Powder ◽  
Casein Micelle ◽  
Commercial Plant ◽  
Preheat Treatment ◽  
Solids Content ◽  
Time Required

SummaryThe effect of preheat treatment, evaporation and drying in a commercial plant on the denaturation of βlactoglobulin and α-lactalbumin, their incorporation into the casein micelle and the heat stability characteristics of the milks and powders were determined. Preheat treatments between 110 °C for 2 min and 120 °C for 3 min denatured between 80 and 91% of β-lactoglobulin and between 33 and 45% of α-lactalbumin. Evaporation increased the extent of denaturation but spray drying did not increase it further. The incorporation of α-lactalbumin and βlactoglobulin into the micelles was markedly less than the amount that denatured and was not a constant ratio to it. Heat coagulation times at 140 °C of milks, concentrates and powders diluted to the original milk concentration were measured as a function of pH. In general, the greater the collective heat treatment, the shorter the time required to achieve coagulation. Spray drying shifted the peak positions in the pH-heat coagulation time profiles. In contrast, heat coagulation times (measured at 120 °C) of concentrates and powders diluted to 20% total solids content increased with the severity of the preheat treatment. Surprisingly, spray drying markedly increased the heat coagulation times of the diluted concentrates.

scholarly journals Wall deposition experiments in a new spray dryer

2018 ◽  
Author(s):  
Timothy A. G. Langrish ◽  
Xing Huang ◽  
Chao Zhong
Keyword(s):  
Spray Drying ◽  
Salt Solution ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Solid Content ◽  
Operating Conditions ◽  
Spray Dryer ◽  
Wall Deposition

Wall deposition tests have been conducted on a new spray-drying sytem. Solutions of salt and skim milk powder have been dried with different inlet temperatures (170 °C and 230 °C) and solid contents (8.8 wt% and 30 wt%). The experiment showed that increasing the temperature caused an decrease in the amount of deposition for salt solution, but an increase for skim milk. The experiments also showed that a higher solid content caused an increase in deposition. The trends agreed with the studies using a conventional spray dryer, but the amount of deposition appeared to be lower in the new spray dryer at the same operating conditions Keywords: Spray drying; wall deposition

Application of reverse osmosis to the manufacture of dried whole milk and skim-milk

1979 ◽  
Vol 46 (4) ◽  
pp. 663-672 ◽  
Author(s):  
James Abbot ◽  
Frank A. Glover ◽  
Donald D. Muir ◽  
Paul J. Skudder
Keyword(s):  
Reverse Osmosis ◽  
Spray Drying ◽  
Milk Production ◽  
Protein Denaturation ◽  
Milk Powder ◽  
Skim Milk ◽  
Bacterial Count ◽  
Skim Milk Powder ◽  
Powder Morphology ◽  
Whole Milk

SummaryPowders were prepared from whole and skim-milk using reverse osmosis (RO) as a first stage followed by either evaporation and spray drying or spray drying alone. They were compared with powders made by the conventional method of evaporation and spray drying. Measurements were made of powder solubility, free fat content, whey protein denaturation, vitamin content, powder morphology and bacterial count. The free fat contents of powders prepared from whole milk concentrated by RO were high; otherwise, there were no significant differences in the properties of powders made from milks concentrated initially by RO and those prepared by conventional evaporation. The results indicate that it is feasible to use RO for the manufacture of skim-milk powder and for dried whole milk production where higher free fat levels are not detrimental.

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