Baking Properties of Bread and Cookies Incorporating Distillers' or Brewer's Grain from Wheat or Barley

The effect of granulation, level of soluble solids, and drying method on the mixing properties and baking performance of distillers’grain products from wheat in yeast-raised breads and cookies were evaluated and compared with products containing barley spent grains (BSG). Grinding had a variable effect on baking properties. Breads containing 8% wheat distillers' grains (WDG) (no solubles) had the lowest loaf volume. Breads made with WDG and BSG had the poorest crumb grain. There were few differences observed in the mixing and baking properties of wheat distillers’grains (DDGS or DDG) regardless of whether the materials were dried by harsh (steam tube, tunnel) or milder (atmospheric drum) drying treatments.     

Effect of Water Activity of Milk upon Growth and Acid Production by Mixed Cultures of Streptococcus thermophilus and Lactobacillus bulgaricus

Acid production and growth rates were determined in pure cultures of Streptococcus thermophilus and Lactobacillus bulgaricus and cocci/ bacilli ratios in mixed cultures of both species, using milk with modified a_w as culture medium. Maximal growth rates were always at a_w lower than 0.992 for all strains whcn a_w of milk was adjusted with glycerol, while maximal acid production rates were at a_w 0.992-0.983. Glucose had an inhibitory effect additional to that caused by lowering a_w. The cocci/bacilli ratio in mixed cultures increased as a_w decreased in most cases, because of the higher susceptibility of L. bulgaricus to a_w decrease. The behavior of a mixed culture could not always be predicted from data of the component strains in a pure culture, showing some kind of symbiotic compatibility between species.     

Evaluation of the Physical, Chemical and Sensory Properties of Fermented Summer Sausage Made from High-Oleate Pork

The processing, visual and sensory characteristics of fermented summer sausage formulated with pork containing varying levels of oleic acid and either 15 or 25% fat was evaluated. Sausage made from the high-oleic acid tissues received lower sensory panel scores for springiness, cohesiveness, texture and overall palatability (P < 0.05). However, low-fat (15%) fermented summer sausages produced from the high-oleate tissues were comparable to the control for sensory and visual characteristics.     

RHEOLOGICAL MODELING of POTATO FLOUR DURING EXTRUSION COOKING

A generalized model for predicting the effects of shear rate, temperature, moisture content, time-temperature history and strain history on viscosity has been evaluated for extruded potato flour doughs. an Instron Capillary Rheometer and a 50 mm Baker Perkins co-rotating twin screw extruder were used to evaluate all effects incorporated in the model, except strain history. the power law model was used to describe shear rate effects in the range 10–10000 s^?1. the generalized model fit observed data for temperatures of 25–95°C and moisture contents ranging from 22 to 50%, wet basis. Since potato flour by its manufacturing process is pregelatinized, it was unnecessary to evaluate the effects of time-temperature history. Strain history was found to have an insignificant influence on the viscosity.     

ORIFICE DISCHARGE COEFFICIENTS FOR POWER-LAW FLUIDS

Orifice discharge coefficients for non-Newtonian (power-law) fluids (5, 7.5 and 10% corn starch solutions) were measured using a closed end pipe with different orifice diameters. Results indicate that orifice discharge coefficients, found to be in the range of 0 – 0.7, are a function of the orifice diameter, fluid velocity in the orifice and the fluid rheological properties (consistency coefficient and flow behavior index). They increase with the fluid velocity, tend to be constant at high velocities and decrease when the consistency coefficient of the solution is increasing. Orifice discharge coefficients are presented as a function of the generalized Reynolds number.     

CHANGES DURING CHEESE CURING

Port-Salut, Gouda and Edam cheeses were analyzed for fat, protein moisture and ammonia evolution during commercial curing (50 days for the first two cheeses and 57 days for the last one). Fat (approximately 33%), protein (approximately 31%) on a wet basis and moisture (between 25 and 37%) content of the cheeses remained practically constant throughout the experiment, while considerable changes were observed for ammonia evolution when analyzed by direct microdistillation and by ammonia sensitive electrode, as well as between whole and defatted samples. Ammonia recovery for the microdistillation method was below the expected value for the 3 cheeses analyzed; the contrary happened with the ammonia sensitive electrode, where higher ammonia values were detected in the whole cheese samples: Gouda, 2089 mg/kg; Edam, 756 mg/kg and Port-Salut, 2857 mg/kg. These data suggest that the use of the electrode can be a useful tool in ammonia determination, avoiding losses during sample preparation, as normally happens during microdistillation that requires defatting.     

DETERMINATION OF COLLAGEN CROSSLINKS IN ROCKFISH SKELETAL MUSCLE

The low collagen content in fish muscle makes the quantitative analysis of collagen crosslinks difficult. We have developed a method for the quantitative determination of reducible difunctional collagen crosslinks in samples containing as little as 0.5 picomoles of crosslink per microgram of hydroxyproline. The low collagen-containing tissue is first enriched by removing most of the non-collagenous protein with cold sodium hydroxide solution. The lyophilized alkali-insoluble extract is then reduced with NaB³H₄ and acid-hydrolyzed. Initial fractionation of hydrolysates on a Bio-Gel P-2 gel filtration column provides partial separation of components with a sharp peak of radioactivity containing more than 90% of the difunctional crosslinks. This peak is ultimately analyzed by HPLC for the quantitative determination of specific difunctional crosslinks. This method has been used to show that the difunctional crosslink composition of muscle collagen from two species of Pacific rockfish differs quantitatively from each other and from that of rat tail tendon.     

EFFECT OF GROWTH TEMPERATURE AND MEDIA ON INACTIVATION OF LISTERIA MONOCYTOGENES BY CHLORINE

The objective of this study was to determine the effect of growth environment on the susceptibility of Listeria monocytogenes to inactivation by hypochlorite sanitizer. Cells were grown in tryptic soy broth (TSB) at 35, 21, and 6°C and in 1:15 dilution of TSB (low nutrient medium, LNM) at 35°C. Late exponential phase cells were harvested, washed, and exposed to a 1 ppm sodium hypochlorite solution for periods up to 5 min. After 30 s exposure, cells grown at 35°C in TSB were reduced in number by 2.1 ± .3, at 21°C, 3.1 ± .3 and at 6°C, 3.4 ± .3 log units. After 30 s exposure to 5 ppm free chlorine cells grown at 35°C in TSB were reduced in number by 5.2 ± .2 and in LNM by 3.1 ± .1 log units. These data demonstrate that growth environment has a significant effect on chlorine inactivation of L. monocytogenes.     

Untersuchung zur PMDI-verteilung in spangemischen und Spanplatten

Microscopic studies on non-pressed chips glued with polymeric diphenylmethane diisocyanate (MDI) and on some particleboard cross-sections showed that due to its good wetting properties this glue effects a good thin-layer spread on the surface of the wooden chips. Due to capillar action MDI completely penetrates cracks in the chips. Moreover, there was evidence that MDI is capable of penetrating the cell walls. Particleoboard cross-sections showed that most of the earlywood portion in chip mixes was evidently completely saturated with MDI.     

Maltose hydrolysis kinetics with glucoamylase immobilized in porous glass fibers in a tubular flow reactor

Glucoamylase has been covalently immobilized in controlled pore glass fibers packed parallel to the axis of a tubular reactor. Flow kinetic studies have been carried out for a range of flow rates and substrate concentrations at 50°C and pH 4.5. Diffusion control has been found negligible with high flow rates and substrate concentrations. The apparent Michaelis constant was three orders of magnitude higher than that of the free enzyme. As flow rate and substrate concentration decrease, the extent of diffusion control increased up to a moderate degree. The immobilized glucoamylase was more stable than the free enzyme when incubated at 50°C.