Nitrogenous Constituents of Selected Grain Legumes

Nitrogenous constituents of four legume species and their varieties were investigated. The total N of whole seeds ranged from 3.16 4.21%, of which 8.3–14.5% was nonprotein N. Water- and salt-soluble proteins together constituted 72–94% of the total seed protein. The mean protein contents of the water- and salt-soluble fractions were 67% and 87%, respectively, while the carbohydrates associated with them ranged from 17–30% and 4–14%, respectively. The albumin: globulin ratios were characteristic of the variety. The SDS-PAGE patterns for proteins of Phaseolus showed a more complex profile than those of the other legume species investigated.     

Heat Inactivation of Native Plasminogen Activators in Bovine Milk

Inactivation of plasminogen activators appeared to follow first-order kinetics in the temperature range tested. The Arrhenius plot was linear (correlation coefficient 0.990). The Arrhenius equation for heat inactivation was deduced, from which the rate of inactivation at any temperature in the range 60–140°C could be calculated. The decimal reduction time (D-value) was 109 min at 70°C and 32 set at 140°C. This indicated that native plasminogen activators in bovine milk are not affected by pasteurization, and to a large extent are not inactivated by UHT dairy processing conditions.     

Composition of bacterial flora in sliced vacuum packed Bologna-type sausage as influenced by nitrite

The influence of the addition of 0, 100 and 200 p.p.m. nitrite to sliced vacuum packed Bologna-type sausage was studied at 2, 5, 10 and 20°C. An increasing inhibition of growth of Brochothrix thermosphacta, Enterobacterinceae and MoraxellalMoraxella-like organisms was found with increasing nitrite concen- tration andlor decreasing temperature. The gram positive cocci, the yeasts and lactic acid bacteria were only inhibited to a limited extent. Consequently the lactic acid bacteria became more dominant in vacuum packed cooked meat product with added nitrite. The gram negative bacteria often constitute the major flora in packages produced without nitrite, and may proliferate at higher temperatures even in samples produced with nitrite.     

Light‐induced protein and lipid oxidation in low‐fat cheeses: Effect on degree of enzymatic hydrolysis

The effect of proteolysis on oxidation in low‐fat cheese was investigated. The accumulation of dityrosine during storage increased significantly in the cheese with a high degree of proteolysis, while hexanal and heptanal were lower in the cheese with high proteolytic activity, indicating that the peptides/free amino acids acted as antioxidants on the propagating step in lipid oxidation. Dimethyl disulphide concentration was also lower in the cheese with a higher level of peptides. Therefore, oxidation of tyrosine residues seemed to function as antioxidants both regarding secondary lipid oxidation products and protein‐derived oxidation products through formation of dityrosine, being a termination reaction.     

COMPARISON OF INVERTASE AND PECTINESTERASE INACTIVATION IN PROCESSED TOMATO PULP1

The heat stability of pectinesterase (PE) and invertase in tomato pulp was investigated to examine the feasibility of using invertase inactivation to predict pectinesterase inactivation. Both invertase and PE were inactivated at 80C in macerated tomato pulp. Between temperatures of 65C to 75C invertase was less heat stable than PE. Results indicate that when temperatures above 80C are reached, almost instantaneously, it would be feasible to use invertase activity as measured by sucrose level to predict PE activity.     

Limonene and Myrcene Sorption into Refillable Polyethylene Terephtalate Bottles, and Washing Effects on Removal of Sorbed Compounds

The sorption of two orange volatile compounds, myrcene and limonene, into refillable polyethylene terephtalate bottles, different types of polyethylene terephtalate strips, and polycarbonate strips, was studied. The bottles were washed with sodium hydroxide solutions and remaining aromas in the plastic were analyzed. Sorption continued during the 12 wks storage, but the major part was sorbed during the first week. Bottles stored at 25°C absorbed considerably more myrcene and limonene than bottles stored at 4°C. A simulated industrial washing procedure removed small amounts of the aromas but 50–80% remained in the packaging material. Polycarbonate absorbed flavors to a much larger extent than did polyethylene terephtalate.     

Physiological Characterization of Common Fungi Associated with Cheese.

A multivariate statistical method (PLS) was used for a physiological characterization of fungi associated with the cheese environment. The combined effects of pH, salt content, oxygen and carbon dioxide levels on growth and sporulation were studied. Significant factors affecting growth were salt content, level of carbon dioxide and temperature. Interactions between those factors were illustrated and showed that some fungi were especially sensitive to carbon dioxide levels and salt content, at low temperature. Sensitivity to the factors often was more pronounced in the early growth phase. Results may aid in eliminating unwanted fungal growth during cheese production.     

On texture formation of nickel electrodeposits

Electrodeposited nickel has been investigated by cross-sectional transmission electron microscopy and X-ray diffraction. The <100> fibre texture and fine-grained, dislocated columnar microstructure has been considered with respect to the mechanisms of growth during electrodeposition. Fine, codeposited nickel oxide hydroxide precipitates which have formed on the {111} planes appear not to have influenced texture formation. Although strong inhibition by adsorbed hydrogen or organic species is suggested from the work of others, this has not resulted in any codeposition of other species, either crystalline or amorphous.     

Potential of anticlostridial Lactobacillus isolated from cheese to prevent blowing defects in semihard cheese

Five anticlostridial Lactobacillus strains isolated from cheese were selected for a mixed adjunct culture. Cheese with the mixed adjunct culture (experimental) and without (control) was made in triplicate and ripened as vacuum‐packed and surface‐ripened cheese. Cheese gross composition was similar. Excessive gas formation occurred only in control cheeses. In contrast to control cheeses, the experimental cheeses were dominated by the added adjunct Lactobacillus strains (repetitive‐PCR). Casein breakdown was not influenced, however, the total amount of amino acids and pH was slightly lower in the experimental cheeses. Anticlostridial nonstarter Lactobacillus strains have potential as protective adjunct cultures against blowing defects in cheese.     

Inhomogeneous plastic flow investigated by X-ray absorption microtomography of an aluminium alloy containing marker particles

By combining a synchrotron X‐ray source and the microtomography technique, the displacement gradient tensor components can be measured directly throughout the volume of a metal sample containing highly absorbing marker particles to detect material flow. The present article describes application of these techniques to compression of a rectangular Al–W specimen with a central hole. The results show that the externally imposed axial displacement gradient is accommodated mainly in two 45° shear bands passing through the hole. A simple deformation analysis provides insight into shear band formation.