Nonfat Dry Milk Solids Research Articles

Dairy Versus Calcium Carbonate in Promoting Peak Bone Mass and Bone Maintenance During Subsequent Calcium Deficiency

Dairy products provide most of the calcium in the diet, but consumption of milk has declined steadily over the last six decades. We determined (1) benefits to bone formation in growing female Sprague-Dawley rats when calcium is derived from dairy versus CaCO(3) and (2) residual benefits of calcium provided by dairy to rats subsequently receiving a low-calcium diet. During growth, femurs from rats fed nonfat dry milk solids (NFDM) had 8.4% higher peak breaking force, 6.4% greater Ca content, 4.8% greater weight, 4% greater width, 1.2% greater density, 13.1% greater midshaft cortical thickness, and 16.7% greater midshaft cortical area than from rats fed CaCO(3). These effects were unrelated to differences in calcium absorption or serum IGF-1, but the NFDM group had higher rates of bone formation. If maintained on an adequate calcium diet, many of these advantages disappeared. However, rats fed adequate Ca as NFDM versus CaCO(3) during growth and subsequently switched to deficient Ca as CaCO(3) had significantly (p < 0.0001) higher femoral BMD (1.3%), total bone Ca (7.2%), Ca concentration (4.6%), and cortical thickness (9.4%) and a trend (p = 0.02) toward greater peak breaking force (17%). Thus, NFDMs improved bone measures during growth and protected bone against a subsequent period of calcium depletion compared with CaCO(3).

Lowfat Ice Creams from Freeze-Concentrated Versus Heat-Concentrated Nonfat Milk Solids

Lowfat vanilla ice creams made from freeze- or heat-concentrated nonfat milk solids were compared in sensory and physical tests. Results did not support the hypothesis that lowfat ice cream made from freeze-concentrated nonfat milk solids would be smoother, firmer, slower to melt, lower in cooked flavor, and higher in vanilla flavor than lowfat ice cream made from heat-concentrated nonfat milk solids. Nonfat dry milk solids imparted slightly more smoothness than did dried freeze-concentrated nonfat milk solids. Otherwise, heat-concentrated versus freeze-concentrated products had no effects on sensory attributes when comparisons of liquid and dried forms of the products were made separately. Products from both liquid and dry sources of both types of nonfat milk solids differed little in sensory quality. Apparent viscosity of the mixes and the hardness and melting rate of the frozen products were affected by the source of nonfat milk solids.

Growth of Thermophilic Starters in Whey Permeate Media

Strains of Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus helveticus, Lactobacillus acidophilus, and Streptococcus thermophilus varied in their ability to grow in whey permeate-based media. Whey permeate alone was a poor medium with a relatively low buffering capacity, which supported the growth of L. delbrueckii ssp. bulgaricus and S. thermophilus only. External pH control and the addition of .1% nonfat dry milk solids and .5 to 1% yeast extract improved the growth and activity of L. delbrueckii ssp. bulgaricus, L. helveticus, and S. thermophilus and made whey permeate-based media comparable with 11% nonfat dry milk as a medium for thermophilic lactic acid starters. Internal pH control, using a phosphate buffer, did not significantly improve the growth of the strains used when compared with the unbuffered medium and was inhibitory to L. helveticus 880.

Development of an Acceptable “Ice Cream” Possessing a Reduced Sodium Content

ABSTRACTAcceptable “ice cream” products possessing reduced sodium content were developed. Demineralized whey and demineralized whey protein concentrate were used individually and in various combinations to replace 15, 25, 50, 75, and 100% of the serum solids contributed by nonfat dry milk. Maximum reduction (63%) in sodium was achieved in one product containing 30.5 mg sodium/100g based upon comparison to a control containing 81.5 mg/100g. A descriptive product rating test was used to evaluate experimental products for appearance, flavor, body, texture, and acceptability. A student panel found all whey‐containing experimental products to be acceptable when compared to the control sample, a high quality vanilla ice cream containing nonfat dry milk solids as the only source of serum solids.

Quantitation of Caseins and Whey Proteins of Processed Milks and Whey Protein Concentrates, Application of Gel Electrophoresis, and Comparison with Harland-Ashworth Procedure

Alternate methods for quantitation of caseins and whey proteins in milk products were investigated. The Harland-Ashworth and Leighton procedures, which are used for routine determinations of soluble whey proteins in milk, could not be adapted satisfactorily to quantitation of whey protein in blends of nonfat dry milk solids and whey protein concentrates because of problems of precipitation techniques. Gel electrophoresis in sodium dodecyl sulfate does not require fractionation prior to analysis and works well for nonfat dry milk solids, whey protein concentrates, and blends of these products, as well as total milk protein concentrates. Use of thiourea and hydrogen peroxide as gel catalysts improves band resolution and allows for easy handling and better quantitation. This method, which is an adaptation of the Laemmli procedure, may be of use for detecting adulteration of nonfat dry milk solids or even fluid milk with whey protein concentrates and may find other applications; 10 major milk proteins can be visualized and quantitated on one gel electrophoretogram.

Enumeration of Radiation‐Resistant, Nonsporeforming Bacteria

ABSTRACTA new method was developed to enumerate radiation‐resistant, nonsporeforming bacteria. Micrococcus spp. and two isolates of the Moraxella‐Acinetobacter group were used as representatives of radiation‐resistant bacteria. Soil samples were used to provide spores of a mixed flora. Samples were prepared in reconstituted nonfat dry milk solids, litmus milk and meat serum to evaluate the method in a food system. Three doses of 300 Krad each, separated with 1 hr incubations between each dose, were found to produce a maximum reduction in spores with a minimum reduction in radiation‐resistant bacteria.

A Milk-Like Beverage from Neutralized Direct-Acid-Set Cottage Cheese Whey

An imitation milk was formulated by combining 4 parts of neutralized, direct-acid-set, cottage cheese whey with 6 parts of whole milk, and fortifying with .5% nonfat dry milk solids (NFDM). Whey collected from a commercial plant was neutralized, clarified, blended with milk, fortified with NFDM, pasteurized, homogenized, and packaged in ½-gal. paper cartons in the Kansas State University (KSU) dairy processing plant. Calculated raw material costs were compared for 2.0% low fat milk, 3.25% milk, and for imitation milks with those same milkfat concentrations. The 2.0 and 3.25% imitation milk could be formulated with savings of 35 and 25 cents per gallon, respectively. Coded samples of the product were compared with regular KSU whole milk by 112 persons. Of these, 45% identified the KSU milk samples, 35% thought the experimental product was the KSU milk, and 20% could tell no difference. The milk sample was preferred for flavor by 42% of the consumers, 32% had no preference, and 26% preferred the imitation milk. The imitation milk, containing 11.5% total solids and 2.4% protein, was .5% lower in total solids and 1.0% lower in protein than KSU whole milk.

THE VALUE OF ADDING IRON AND NONFAT DRY MILK SOLIDS TO A MILK DIET IN THE RECOVERY OF ANEMIC RATS

Weanling rats were fed only homogenized vitamin D milk for 3 weeks at which time the body weights were about 105 g and the hematocrit values were 20.4 for males and 22.8 for females. They were then fed milk plus 10 ppm elemental iron in the form of ferric pyrophosphate, milk plus 10% added nonfat dry milk solids, or milk plus 10 ppm iron plus 10% nonfat dry milk solids. After 3 weeks on the milk-plus-iron diets, the hematocrit values for males and females were about 30 and 40, respectively. Weekly body weights and hematocrit values showed the two iron-supplemented diets to be nutritionally similar (P>.05) when rats were fed ad libitum. Rats fed milk plus added nonfat dry milk solids were significantly lower (P<.05) in body weight after 10 weeks of age and significantly lower (P<.05) in hematocrit value after 8 weeks as compared to rats fed either of the iron-supplemented diets.

COMPOSITION OF RAW AND PROCESSED SKIMMILK

Many processors make a more palatable skimmilk by adding nonfat dry milk solids and/or lactose. Compared to the skimmilk portion of raw milk, processed skimmilk contained more solids not fat and its freezing point was lower. The data do not indicate many, if any, processed samples in the study with added lactose, other than that contained in the added nonfat dry milk solids.

Ionic Calcium in Milk and Whey

A calcium-sensitive electrode was used to measure the Ca++ in raw and processed milk. The standard deviation of measurement was±0.24 mmole per liter, and the coefficient of variation was 13%. The Ca++ of milk was in the range of 1.4 to 2.5 mmole per liter and decreased as the milk was processed. After 24-hr storage at 4C, the Ca++ returned to about the same concentration as before processing. Addition of nonfat dry milk solids to skimmilk in sufficient amount to increase the solids-not-fat to 9.8%, increased the Ca++ to 4.2 mmole per liter. Rennet whey and milk had the same Ca++. Treatment of milk with anion exchange resin in the chloride form increased Ca++, presumably because of the removal of phosphates. The resin-treated milk reacted with rennet more rapidly than the untreated. Dilution of milk with water caused a logarithmic decrease in Ca++, with a correlation coefficient of −0.9.

Activity of purified milk lipase in the presence of milk constituents

The effects of varying concentrations of nonfat dry milk solids, purified proteins, lactose, and salts upon the activity of purified milk lipase were investigated. Milk solids inhibited the enzymic activity, and there was a direct but not proportional relationship between the concentration of the solids and the enzyme inhibition. The inhibition of the enzyme by milk solids followed the Freundlich adsorption isotherm, indicating that the inhibition of the enzyme involved adsorption. Purified α-lactalbumin, β-lactoglobulin, acid casein, Hammersten casein, α-casein, α s-casein, β-casein, and γ-casein inhibited the enzyme up to 90%. Usually, the higher the concentration of caseins, the greater the enzyme inhibition. On the other hand, κ-casein, pseudoglobulin, euglobulin, lactalbumin, blood serum albumin, and bovine plasma albumin stimulated the enzyme up to 60%. At higher concentration, however, some of the stimulating proteins inhibited the enzyme. The ultracentrifugal data indicated that the mode of inhibition of the enzyme by β-casein involved the formation of a complex between the protein and the enzyme. Lactose did not inhibit the enzyme significantly, but salts of calcium or magnesium inhibited the enzyme up to 50%. Ca(OH) 2 was the most inhibitory and MgSO 4 was the least inhibitory. These data suggest that in milk the observed lipase activity is the net result of the inhibitory and stimulatory action of the various milk constituents upon the enzyme.

Milk Solids Determination, Rapid Determination of Non-fat Dry Milk Solids in Cereal Bars by Paper Chromatography

Milk Solids Determination, Rapid Determination of Non-fat Dry Milk Solids in Cereal Bars by Paper Chromatography

A Simple Procedure for the Estimation of Total Lipids in Liquid Egg White

Abstract THE estimation of small amounts of lipids in egg white has become an important quality control test in the egg processing industry. Bergquist and Wells (1956) adapted, to egg white, a micromethod described by Heinemann and Rohr (1950) for the determination of fat in skimmilk and non-fat dry milk solids. This method entails an ethyl alcohol, ethyl ether, petroleum ether extraction in an ammoniacal system. The amount of lipid in this extract is determined by observing the area of a monomolecular surface film. Colburn (1960) evaluated several factors affecting the accuracy of this test and devised an alternate method to measure the surface area of the lipid. His method gave comparable accuracy in less time and partially corrects for film pressure variations. Smith (1960) reported that while increasing amounts of natural whole egg yolk results in increasing linear increments of film area, the individual lipid components do not result in…

A Rapid Method of Determining Dispersibility of Nonfat Dry Milk Solids

Summary A mechanical method of determining dispersibility of nonfat dry milk using a Hobart Model 3C Kitchen Aid Mixer is described. A 5-sec. stirring time is used which gives better differentiation of grades than can be obtained by previously described procedures using longer stirring times. The mixture is screened and the amount of solids dispersed is determined by a hydrometric procedure developed for this purpose. The hydrometric procedure used was demonstrated to be as accurate as gravimetric determination of solids by oven drying. The approximate percentages of various types of nonfat dry milks dispersed using this procedure are: instant, 80%; ordinary spray-dried, 37%; and roller-dried, 0%. The differences in dispersibility observed between various brands of instant milks are large enough to be significant for grading purposes. The procedure, besides readily separating nonfat dry milk into dispersibility classes, has the feature of being very fast, the whole procedure requiring only 10min.

The Nutritive Value of Bread Flour Proteins as Affected by Practical Supplementation with Lactalbumin, Nonfat Dry Milk Solids, Soybean Proteins, Wheat Gluten and Lysine

The use of “complete protein” as an index of nutritional value is introduced and shown to be superior to that of crude or “total” protein. Experimental results are reported which show a high degree of correlation between the dietary level of complete protein, the growth rate, voluntary food intake, and the protein content of the carcass. Data are presented which confirm that lysine is the limiting amino acid in diets in which wheat flour supplies the major source of protein, and that the rate of growth is not affected by the inclusion of other amino acids furnished by the supplementary protein. A method is proposed for calculating in numerical terms the supplementary value of one or more proteins for a food primarily deficient in a single essential amino acid. The nutritional effects of supplementing wheat flour with lactalbumin, nonfat dry milk solids, soybean proteins, wheat gluten and lysine were investigated. The results accord with the assumption that a well-balanced or “complete protein” contains 5.3 gm of lysine per 16.0 gm of nitrogen. Isonitrogenous diets in which high-protein or low-protein wheat flours supply all the protein, give equal lysine intakes and equal rates of growth.

Growth Studies with Calves and Rabbits Fed Timothy Hay Grown on Heavily Fertilized Soils ,

Summary This experiment was conducted to identify nutritional deficiencies in timothy hay grown on a heavily fertilized soil. When this hay was fed to calves with a concentrate mixture of degermed corn meal, nonfat dry milk solids or urea, vitamins A and D, cobalt, calcium, phosphorus, and common salt, the ration was deficient in iron, copper, and iodine, resulting in poor growth, poor appetite, anemia, and enlarged thyroids. Feeding iron and copper, either individually or in combination, did not correct these symptoms. Iodine supplementation corrected the thyroid condition but did not stimulate growth. When similar hay was fed to rabbits in a ration supplemented with wheat gluten, hydrogenated vegetable oil, dextrose, sodium chloride, and vitamins A and D, it also resulted in poor growth, anemia, and increased thyroid weight. Feeding of a ration containing 5% alfalfa prevented all these symptoms, but an equivalent amount of alfalfa ash or iodine prevented only the enlarged thyroid. The timothy hay apparently was deficient in iodine and some organic factor(s) which may be found in alfalfa hay.

Freezing of Bovine Semen. II. Effect of Milk Solids Level, Glycerol Level, and Fructose on Freezability of Bull Spermatozoa in Reconstituted and Fresh Skimmilk Diluents1,2,3

This investigation revealed that the level of glycerol required for optimum spermatozoan freezability was related to the total solids content of skimmilk diluents, and that 1.25% added fructose improved the post-thawing motility of spermatozoa frozen in reconstituted skimmilk. Reconstituted skimmilk gave optimum spermatozoan survival when the glycerol percentage by volume equalled the total solids l~ercentage by weight, and when both were 9 or 11%. In fresh skimmilk containing 9% solids, 11% glycerol was significantly better than 9 or 13%, Editor. A recent report from this station (8) cited levels of glycerol found by various workers to give optimum freezability of bovine spermatozoa in heated fresh skimmilk diluent. In egg yolk-citrate diluent, the optinmm glycerol level for freezing bull semen has been found to be dependent both upon the concentration of egg yolk (10) and upon the concentration of sodium citrate (3) in the diluent. Saaeke and Almquist (9) observed that altering the total solids content of skimmilk from 9 to 11% resulted in significantly decreased spermatozoan livability at +5 ° C. The fortification of skimmilk used for human consumption to approximately 10.5% total solids is a common commercial practice. Tlms, it appears that the level of glycerol required for optimum spermatozoan freezability in skimmilk diluent may be influenced by the total solids content of the milk. The inclusion of fructose in heated skimmilk and egg yolk-citrate diluents has been found to improve spermatozoan freezability (1, 7, 8). Reconstituted (Instant Pet) nonfat dry milk solids were found by Johnson et al. (4) to provide a satisfactory diluent for storing bovine spermatozoa at +5 ° C. Use of powdered milk diluent for freezing semen would be especially advantageous in areas where good-quality fresh milk is difficult, or impossible, to obtain. The present study was undertaken to determine, (a) if the level of glycerol required for optimum spermatozoan freezability is related to the total solids

Surplus Export Policy and Domestic Farm Policy

IN THE last three years we have seen a gradual recovery of United States agricultural exports from the post Korean War drop. The current volume of exports is at about the same level as prevailed in the boom years of the late 20's and in the post World War II period. When the historical trend is calculated at constant prices, the 1956 level of farm exports was at a postwar peak and was surpassed in the last thirty years only slightly by 1927. In respect to the recent upturn in agricultural exports, it seems fair to say that there is little likelihood that we will be able to maintain this increased volume of exports over any extended period of time. This judgment is supported by the fact that 41 percent of our farm exports last year went out under foreign loans, grants to foreign governments, special barter deals for strategic materials, and sales for foreign currency. While our total agricultural exports have increased almost 20 percent since 1954, bonafide sales in the open market abroad declined by about 6 percent.1 To put it another way, our agricultural export market is expanding at a slightly lower rate than the rate of increase in Congressional appropriations to pay for exports. Aside from the long-standing reciprocal trade agreements program, our current agricultural trade policy finds expression primarily in the Agricultural Trade and Development Act of 1954. This act authorizes sales for foreign currencies, barter transactions, grants for emergency foreign relief, and donations to private charities for the needy overseas. Sales for foreign currencies have accounted for a major part of the exports under this program. The one remaining new look in our export policy is found in a competitive pricing and export subsidy plan which has been in operation about a year. This is an attempt to hurdle the price gap between the domestic and export markets on price supported products. This gap ranges from as low as 9 percent for some seed crops to around 40 percent of the price for nonfat dry milk solids. To close or narrow this gap the Commodity Credit Corporation sells surplus stocks to exporters at competitive prices or export subsidies are paid to them. Last year C.C.C. released for sale to exporters nearly one billion dollars' worth of surplus products (mostly wheat and cotton) at world prices. This amounted to 28 percent of our total agricultural exports in 1956. The proponents of this plan can

Studies on Starter Metabolism. I. The Relationship between Starter Activity and the Predrying Heat History of Reconstituted Nonfat Dry Milk Solids1,2

Summary The predrying heat history of nonfat dry milk solids was shown to have a marked influence on the subsequent activity of starters propagated in that milk after reconstitution. In general, commercial high-heat powders supported starter activity more favorably than did low-heat powders, and this effect could be illustrated both by acid production and speed of dye reduction. However, NDMS samples with an excessively severe heat history exerted a deleterious effect on starter activity. It was possible to establish that the response of cultures to the heat history of milk-powder samples was not an isolated occurrence, but rather was a general phenomenon for a wide variety of starters. Furthermore, the response of starters could be related rather closely to the heat treatment of the milk before condensing and drying. The practical implications of these results are discussed.

The Selection and Use of Nonfat Dry Milk Solids in the Manufacture of Cottage Cheese

The Selection and Use of Nonfat Dry Milk Solids in the Manufacture of Cottage Cheese