Enhancement of fruity aroma production of Pseudomonas fragi grown on skim milk, whey and whey permeate supplemented with C3-C7 fatty acids

Lipolysis was quantitated during storage of fluid and freezedried human whole and skim milks. Fatty acid accumulation was faster in whole fluid milk stored for 1 week at 4°C than in frozen (−20°C) samples stored for 180 d. The rapid accumulation of fatty acids during 24 h of storage at 4°C was enhanced in previously frozen milk samples. While freeze-dried whole milk showed no lipolysis when stored at −20°C, accumulation of free fatty acids was rapid in samples stored at room temperature. Fluid and freeze-dried skim milk samples exhibited no appreciable lipolysis.

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600. Further observations on the volatile compounds associated with oxidized flavour in skim milk

Journal of Dairy Research ◽

10.1017/s0022029900007895 ◽

1955 ◽

Vol 22 (3) ◽

pp. 345-348 ◽

Cited By ~ 29

Author(s):

D. A. Forss ◽

E. G. Pont ◽

W. Stark

Keyword(s):

Fatty Acids ◽

Volatile Compounds ◽

Previous Investigation ◽

Unsaturated Fatty Acids ◽

Skim Milk ◽

Highly Unsaturated Fatty Acids ◽

Milk Lipids

The C6–C11 2,4–dienals have been identified in distillates from skim milk with oxidized flavour. The C4–C11 2–enals were isolated from the same distillates in a previous investigation. The most abundant individual compounds in the two groups were 2–octenal, 2–nonenal, 2–4–heptadienal and 2,4–nonadienal. These compounds when flavour–tested in skim milk in dilutions of 10–7–10–9 closely resembled oxidized (cardboard) flavour. It is concluded that they are the main constituents of this flavour defect and that they originate from the oxidation of the more highly unsaturated fatty acids in milk lipids.

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INHIBITION OF GROWTH OF AIRBORNE COLIFORMS AND OTHER BACTERIA ON SELECTIVE MEDIA1

Journal of Milk and Food Technology ◽

10.4315/0022-2747-35.3.156 ◽

1972 ◽

Vol 35 (3) ◽

pp. 156-162 ◽

Cited By ~ 5

Author(s):

Attila K. Stersky ◽

T. I. Hedrick

Keyword(s):

Methylene Blue ◽

Skim Milk ◽

Enterobacter Aerogenes ◽

Colony Growth ◽

Coliform Bacteria ◽

Plate Count ◽

Pseudomonas Fragi ◽

Selective Media ◽

Standard Plate Count ◽

Plate Count Agar

Coliforms when sampled from air were inhibited or restricted in growth on regular selective media. For trials, growth on Standard Plate Count Agar ( SPC) was used as 100%. The percentage of colony growth of Escherchia coli and Enterobacter aerogenes on modified selective media or with SPC were respectively as follows: violet red bile/violet red bile (VRB/VRB) (overlay on base) <4, 15; desoxycholate/desoxyeholate (DES/DES) < 1, 17; tergitol/tergitol (TER/TER) 23,49; eosine methylene blue/eosine methylene blue (EMB/EMB) 122, 86; endo/endo (END/END) 40, 104; MacConkey/MacConkey (MAC/MAC) <2, 10; SPC/VRB <2, 22; SPC/DES <2, 23; VRB/SPC 54, 60; TER/SPC 72, 119; EMB/SPC 97, 119; END/SPC 95, 90; 1 VRB: 1 SPC, as overlay and base 14, 50. Recovery percentages of Pseudomonas aeruginosa and Pseudomonas fragi on modified selective media were greater than those of the coliform bacteria. Fewer Serratia marcescens colonies grew on DES or SPC/DES and more grew on the other modified selective media than did coliform colonies. Growth of airborne Salmonella newbrumwick ranged from <1% on SS agar to 118% on MAC/SPC. Aerosolization of coliforms with skim milk compared to distilled water resulted in growth of more colonies on selective media. Desoxycholate, Bile Salts No. 3, Tergitol No. 7, and crystal violet in the media definitely limited growth of airborne coliforms.

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695. On the composition of the phospholipids of cows' milk

Journal of Dairy Research ◽

10.1017/s0022029900009031 ◽

1958 ◽

Vol 25 (1) ◽

pp. 60-69 ◽

Cited By ~ 23

Author(s):

D. N. Rhodes ◽

C. H. Lea

Keyword(s):

Fatty Acids ◽

Experimental Work ◽

Unsaturated Fatty Acids ◽

Skim Milk ◽

Industrial Research ◽

Chromatographic Methods

1. The phospholipids of skim-milk, buttermilk and butter prepared from one bulk of Friesian milk were examined, using chromatographic methods. No major differences were found between the three products.2. The phospholipids of buttermilk contained (in moles %) phosphatidylethanolamine 29, phosphatidylserine 10, phosphatidylcholine 33, sphingomyelin 19. The content of lipid-bound inositol was 5 moles % and of plasmalogens 3 moles %. Nitrogen, associated with the kephalin fraction, equivalent to 14 moles % of the lipid P was not identified. No lysoglycerophospholipids were present.3. Unsaturated fatty acids were present in both the α'- and β-positions of the milk glycerophospholipids, in contrast to those from other animal sources which have usually been found to contain unsaturated acids in the α'-position and predominantly saturated acids in the β-position.The authors are indebted to Prof. H. D. Kay for providing facilities at the National Institute for Research in Dairying, Reading; to Dr R. H. Smith for advice on processing, and to Miss H. R. Chapman and the staff of the Experimental Dairy for carrying out the dairy work.This work forms part of the programme of the Food Investigation Organization of the Department of Scientific and Industrial Research. Mr P. Whiteley contributed to the experimental work.

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Nutritional evaluation of meat meals for poultry. IV. Prevention of growth depression from high levels of bone or calcium by vitamin and antibiotic supplementation

Australian Journal of Agricultural Research ◽

10.1071/ar9650491 ◽

1965 ◽

Vol 16 (3) ◽

pp. 491 ◽

Cited By ~ 6

Author(s):

BS Sathe ◽

GL McClymont

Keyword(s):

Fatty Acids ◽

Calcium Carbonate ◽

Essential Fatty Acids ◽

Skim Milk ◽

Calcium Content ◽

Total Calcium ◽

Growth Depression ◽

Nutritional Evaluation ◽

Meat Meal ◽

Bone Ash

Experiments were conducted to determine the reason for depressed growth in chickens when high levels of bone, bone ash, or calcium were added to diets based on wheat, skim milk, and soybean and/or meat meal, and containing a basal supplement of vitamins and an antibiotic. The growth depression was not due to energy dilution of the diet, nor to an induced deficiency of essential fatty acids or minerals. The growth rates of pair-fed groups of chickens indicated that about half the growth depression was due to a reduced food intake. Depression of appetite and growth was completely prevented by further vitamin . plus antibiotic supplementation of diets containing added bone, bone ash, or calcium carbonate up to a total calcium content of c. 2.5%, but not when calcium exceeded this level. Additions of either vitamins or antibiotics alone produced responses but were not as effective as in combination.

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