摘要:

SUMMARY—Coagulation patterns of slurries prepared with milk and frozen, foam‐spray‐, freeze‐and spray‐dried whole eggs, yolks and albumen were studied. All slurries were heated and stirred at constant rates using a Brabender Visco/Amylo/Graph. Ranked in order of initial gelation temperatures were slurries prepared with frozen, freeze‐, spray‐ and foam‐spray‐dried whole eggs. Slurries prepared with frozen yolks or albumen showed initial gelation at lower temperatures than those prepared with dried yolks or albumen. Viscosity data indicate detrimental effects of drying to gelation properties of whole eggs,

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03286.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—Experimental results show that the level of milk solids‐not‐fat normally used in ice creams, alone, had sufficient emulsifying capacity to emulsify the fat present in a standard ice cream mix. The added chemical emulsifier, regardless of its HLB, contributed little to the stability of the mix. This was true even where butteroil was used as a source of fat. Fat deemulsification during freezing increased with the HLB of the emulsifier while the dryness showed no meaningful trend. The meaning of the terms dryness, stiffness, melt resistance, and stand‐up quality has been cl

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03287.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—The stability of 25% milk fat‐water emulsions containing sorbitan‐fatty acid emulsifiers were compared to determine the influence of single vs. binary emulsifier systems, and saturated vs. unsaturated emulsifier side chains. These variables were compared at emulsifier HLB values of 9.5–10.0 and at usage levels of 0.5–2.0% of the fat. There were no statistical differences (P>0.05) between single and binary emulsifier mixtures or between emulsifiers with saturated or unsaturated side chains. There also was no significant difference (P>0.05) between emulsifier HLB numbers of 9.5 and 10.0. However, as the amount of emulsifier in the system was increased the stability of the emulsion increased

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03288.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—Studies were made on nitrogen (protein) solubility of coconut meal in aqueous media over a range of pH's. The point of minimum solubility was found at pH 3.9 and nitrogen solubility increased toward the acidic and basic sides. Coconut proteins displayed a markedly different pH‐nitrogen solubility profile in salt solutions, showing minimal solubility at acidic pH's (pH 3), a sharp rise of solubility and a maximum at neutrality. Coconut meal prepared from fresh coconuts with and without testa removed, from parings and from a sample of sun‐dried copra showed comparable solubility characteristics. However, meal prepared from commercial desiccated coconut showed low solubility, even under acid and alkaline conditions (pH 2 and 10). The most efficient solvent‐to‐meal ratio was found at 20:1 (v:w) for a single extraction, and a two‐step 15:1 process for multiple extractions. Extractions using salt solutions show that the efficiency of extraction is greatly dependent upon pH; concentrations 0.25M effect maximum extraction. Osborne classification studies of coconut meal indicate that 90% of the proteins would be classified as albumins an

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03289.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—An acidic enzymatic process for a bland soybean protein hydrolysate is described. Cooked suspensions (5.0%) of isolated soybean protein are mixed with small amounts of an acid‐protease preparation from Trametes sanguinea, adjusted to pH 3.3–3.5 with concentrated lemon juice and incubated at 50°C for 8–10 hr. After stopping the proteolysis by heat treatment, the clear supernatant is separated from any insoluble residue by centrifugation. A solubilized nitrogen recovery of 88–90% is obtained. All nitrogenous substances in the hydrolysate are 5% trichloroacetic acid‐soluble, and the dehydrated hydrolysate easily reconstitutes to a clear solution with cold water. After being diluted about twice and sweetened with sugar, the hydrolysate constitutes a clear, slightly yellowish lemonade‐like flavored beverage. The data on chemical analysis, gel‐filtration and rheological behavior of the hydrolysate are also describ

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03290.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—Corn‐soy‐milk (CSM), a high‐protein food supplement for children, contains pregelatinized corn meal, soy flour, nonfat dry milk, vitamins and minerals. To increase the choice of possible ingredients, several formulations were studied. Flavor and chemical tests after storage at 77, 100, and 120°F were made on experimental samples containing corn meals and soy flours, dry whey, increased levels of nonfat dry milk, sucrose and dextrose hydrate. Stability was adequate for all formulations tested except those containing dextrose hydrate or unprocessed whole corn meal. At storage temperatures of 100°F or above, substantial losses in available lysine occurred in the samples containing dextros

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03291.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—CSM is a high‐protein food supplement for infants and preschool children; it consists of partially gelatinized corn meal, toasted soy flour and nonfat dry milk and is fortified with vitamins and minerals. The original CSM formulation contained only 2% fat. Storage stability characteristics were determined for CSM blends containing as much as 6% fat. The fat sources tested were corn germ, full‐fat soy flour, refined soybean oil, expeller crude corn oil and a combination of high‐fat corn meal with full‐fat soy flour. Tests for changes in flavor, free fatty acids, peroxide values and available lysine were made on blends stored at 120°F for 56 days, 100°F for 6 months and 77°F for 1 year. Higher fat content was associated with improved palatability. Flavor scores declined at about the same rate under all test conditions. In experimental blends containing crude corn oil, palatability varied with the particular sample tested. One sample of crude corn oil was satisfactory while another caused off‐flavors

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03292.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—Small white potatoes were heated with microwave energy followed by boiling water to determine the penetration of heat, inactivation of peroxidase and firmness of the potatoes. Treatments consisted of heating potatoes with microwave energy for 0.5, 1, 1.5 and 2 min followed by boiling water for 0, 1, 2, 3, 4 and 5 min. Temperature measurements were made at depths of 0.75 and 1.5 cm using tubers with a mean radius of 1.95 cm. Peroxidase inactivation was measured along the radius of a slice removed from the equatorial region. Firmness was determined by the ALLO‐Kramer shear press. Potatoes, when heated by microwave energy, became hot first at the core with a heat gradient developing toward the periphery. Boiling water produced a heat gradient from the periphery toward the core. Consequently, the tissue located about midway of the radius was subjected to the least amount of heat. The minimum time required to completely inactivate peroxidase and the firmness values of the potato tissue at the time of enzymatic inactivation were as follows: 1.5 min microwaves and 3 min boiling water, 119 lb shear force; and 2 min microwaves and 2 min boiling water, 124 lb shear force. Peroxidase was not completely destroyed when the potatoes were subjected to energy for 1 min or less followed by heating in boiling water up to 5

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03293.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—A rapid, precise technique for determining specific gravity of fruits and vegetables was developed. The method utilized a universal testing machine. The effects of crosshead speed, choice of standard density fluid and weight measurements were studied and optimized. A standard sphere of known volume and weight was used to compare this method with other techniques now used. In addition to using the standard sphere, tomatoes were studied to evaluate the efficiency of this method. Calculation of specific gravity involved determining fruit volume and weight. Other volume measurement techniques investigated proved inaccurate or too time‐consuming. An Instron universal testing machine was used in measuring the buoyancy force of a fruit submerged in a standard density fluid. The buoyancy force is directly related to the fruit volume. Error analysis showed relatively low sensitivity to errors in weight measurement, but was influenced mainly by errors in determining the fluid density. This error was minimized by use of high‐density fluids; thus, saturated salt brines and high‐density organic fluids were used for the experiment

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03294.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

SUMMARY—A numerical technique is presented for evaluating food irradiation processes using cylindrical gamma sources. Dose rate distributions obtained by dividing a container into finite concentric rings permit the use of a nonuniform initial spore load distribution and the determination of both number and distribution of survivors. The double integral giving dose rates was computed using several methods. The computations gave survivors significantly different from those obtained by using approximations given in literature. Accurate evaluations require utilization of dose rate distributions in radial and axial direction

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1971.tb03295.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY