α-Lactose Monohydrate from Ultrafiltered Whey Permeate in One-step Crystallization Using Ethanol-Water Mixtures

A one-step crystallization process was developed for production of edible grade a-lactose monohydrate from ultrafiltered sweet cheese whey permeate at room temperature. Concentration of permeate to 30% total solids followed by clarification lowered the ash of the permeate. Constant agitation during crystallization with 80% ethanol (v/ v) at pH 2.5 yielded almost 88% lactose in 3 hr. Alcoholic acid addition (1%) at the end of crystallization time and agitation for 10 min was optimum to reduce entrapped impurities in the form of ash and protein. Lactose quality factors were comparable to commercial edible grade lactose. United States Pharmacopeia grade lactose was also produced using the ethanol-water mixtures.     

EFFECT OF CARAMELIZATION AND MAILLARD REACTION PRODUCTS ON PEROXIDASE ACTIVITY

Solutions of D-fructose and sucrose were heated, alone and in the presence of glycine. The reaction products were examined in terms of their effects on peroxidase (POD) activity. Compared with glucose mixtures, fructose products had a great inhibiting effect on POD activity, while in the case of Maillard reaction products (MRPs), the differences in antibrowning activity between fructose-glycine and glucose-glycine mixtures were slight. As regards the sucrose and sucrose-glycine solutions, a slight inhibiting effect on POD activity was observed only after sugar hydrolysis. Measurements of the reducing power of sugar and sugar-amino acid solutions showed a correspondence between antioxidant properties of caramelization and Maillard reaction products and their antibrowning effects.     

EFFECT OF A KAPPA CARRAGEENAN/LOCUST BEAN GUM MIXTURE ON BIND AND COOKING LOSS IN HIGH MANNURONATE ALGINATE RESTRUCTURED BEEF

Raw and cooked bind properties, cooking loss and pH were evaluated when adding three levels (0%, 0.25%, 0.50%) of a kappa carrageenan and locust bean gum mixture (C/LBG) to finely and coarsely ground high mannuronate alginate restructured beef. Treatments included variable levels of the following dry additives: Alginate (0.50%-1.00%), calcium carbonate (0.10%-0.20%) and glucono-delta-lactone (GDL, 0%-0.80%). Raw breaking strength of finely ground formulations was increased by elevated alginate levels (P<0.05), but was not affected by C/LBG addition (P>0.05). The effect of alginate and C/LBG on cooked bind properties depended on whether finely or coarsely ground meat was used. Sensory evaluations of coarsely ground treatments suggest that sufficient raw and cooked bind was achieved using 0.50% alginate, 0.10% calcium carbonate and 0.60% GDL. Addition of 0.50% C/LBG and/or 0.75% alginate to coarsely ground formulations further reduced cooking loss (P<0.05) by relatively 13% and 17%, respectively. No interaction between C/LBG and alginate was found (P>0.05).     

Wetting of Original and Metallized High-Alumina Surfaces by Molten Brazing Solders

An apparatus using the sessile-drop method is described for determining surface tension and wettability data of liquid-solid systems at elevated temperatures in vacuum and in controlled atmospheres. The relative merits of some of the current methods of metallizing alumina ceramics are evaluated in terms of solder wetting. The wetting by molten brazing metals and alloys is reported as a function of time in terms of contact angle on surfaces of high-alumina ceramics with and without various types of hightemperature metal coatings.     

Fabrication and Characterization of Isostatically Hot-Pressed MgO

Isostatic hot-pressing was used to fabricate solid MgO bodies of high purity (with respect to metallic impurities) to 90 to 95y0 density with high translucency and a grain size of approximately 0.2μ. The densified material contained significant amounts of brucite as a result of water in the starting material which was not removed during vacuum baking. The fabricated pieces showed many cracks which were apparently introduced into the compacts before densification. When the hot-pressed pieces were reheated, the brucite decomposed, the density increased, and the porosity coalesced while grain growth occurred. The general technique appears to be usable for fabricating finely divided powders if powder degassing and predensification procedures are improved.     

Mechanical Properties of Hot-Pressed Zirconium Carbide Tested to 2600°C

Tensile, creep, and modulus of elasticity data were determined for hot-pressed zirconium carbide. The material was relatively impure, containing 1 to 2% nitrogen and 1 to 2% free carbon. Tension and creep properties, which were measured to 2600° C, indicated that above 2100°C the strength was 2000 psi or lower and the elongation was 40% or more, thus signifying little structural usefulness. It is proposed that the results were influenced by impurities at the grain boundaries. Room-temperature modulus of elasticity values averaging 51.6 × 10⁶ psi were obtained by dynamic methods.     

Taxus globosa S. cell lines: Initiation,selection and characterization in terms of growth,and of baccatin III and paclitaxel production

Of the initial six cell lines originating from explants of Taxus globosa, or Mexican yew (stem internode, leaves and meristematic tissue), three were selected for their microbial and oxidation resistance, two from leaves and the other from stem internode. A study of their behavior, both in terms of cell growth, and of baccatin III and paclitaxel production, was developed in suspension cultures with an initially standardized biomass (fresh weight 0.23 g/L) using modified Gamborg’s B5 medium, and an elicitor (methyl jasmonate), on either the first or seventh day of culture, at several levels (0, 0.1, 1, 10, 100 μM). In most of the conditions used, the three cell lines showed growth associated baccatin III production. The cell line from stem internode was the highest producer of baccatin III using 1 μM elicitor, sampling at 10 days (p < 0.01, 6.45 mg/L). This same line also had the highest biomass production (6.85 g/L, p < 0.01) at 10 days of culture but at the higher elicitor concentration of 10 μM. All three cell lines did not produce paclitaxel under experimental conditions used.     

COLD-CONDITIONING TREATMENT REDUCES CHILLING INJURY IN MEXICAN LIMES (CITRUS AURANTIFOLIA S.) STORED AT DIFFERENT TEMPERATURES

Induction of different antioxidant enzymes by high and low temperatures prior to storage has been reported to produce tolerance to chilling injury (CI). Thus, different prestorage temperatures have been suggested to decrease CI in citrus fruits. In this work, the effectiveness of a cold‐conditioning treatment (13C for 48 h) to prevent CI was evaluated in Mexican limes (Citrus aurantifolia S.) stored at 4, 10 and 25C, and 90% relative humidity. Cold conditioning reduced 1.6‐fold CI symptoms, induced a significant increase of 2.2‐fold peroxidase activity and maintained the activity of superoxide dismutase in limes kept at 4C. Our results suggest that the effectiveness of the cold‐conditioning treatment in increasing chilling tolerance in Mexican limes depends on the induction or maintenance of antioxidant enzymatic systems during the entire storage period.