Protein Isolation from Tomato Seed Meal, Extraction Optimization

Water extraction of tomato seed meal proteins was studied to find optimal conditions for protein extraction and isolation. A central composite design including temperature, pH, time and water/solids was used and second order models were employed. Optimum conditions were: 50°C, pH 11.5, 20 min and water/solids = 30/1 (v/w). Experimental values were: extraction yield (extracted protein to that in raw material) 66.1%, protein content of product 72.0%, and total protein yield (protein in isolated product to that in raw material) 43.6%. Estimated values were in good agreement with experimental values. Optimum conditions were confirmed by a larger scale experiment.     

WHAT'S THE 'HOOD GOT TO DO WITH IT? PARENTAL PERCEPTIONS ABOUT HOW NEIGHBORHOOD MECHANISMS AFFECT THEIR CHILDREN

ABSTRACT: During the past decade, a rapidly expanding body of empirical research has emerged that statistically links disadvantaged neighborhood environments with social and economic outcomes of low‐income, minority children. Nonetheless, the mechanisms by which neighborhoods putatively affect children remain poorly understood. This article examines the perceptions of low‐income parents regarding how their neighborhood might affect their children. We examine quantitative and qualitative data gathered from phone interviews with 246 parents who live in subsidized housing scattered across a wide variety of neighborhoods in Denver, Colorado. We supplement this information with data obtained through a series of focus group interviews with a subset of these parents. Our findings indicate that low‐income parents perceive the following primary neighborhood mechanisms: (1) the degree (or lack) of social norms and collective efficacy (24%); (2) influence of children's peers (12%); (3) exposure to crime and violence (11%); and (4) the presence and quality of institutional resources (3%). Approximately one‐third of all parents reported that their neighborhood had no impact at all on their children, citing that their children were either “too young” to be affected by these mechanisms or that parents had sufficient resources to buffer any deleterious effects of the neighborhood. Parents residing in high‐poverty neighborhoods were much more likely to perceive a neighborhood effect, however. Binary and multinomial logistic regression analyses were employed to identify the extent to which an array of demographic characteristics and neighborhood type correlated with parents' perceptions. Latino parents were significantly less likely than other low‐income parents to report a neighborhood impact mechanism. Relative to those who reported no particular neighborhood impact mechanism, those who identified: (1) safety issues were more likely to have a spouse or parent present, and have low self‐esteem; (2) peer influences were more likely to have higher levels of education and live in a high‐poverty but low‐crime area.     

Mass Market Entry of Wireless Telecommunications

Although cellular wireless telecommunication is now availableworldwide, it still constitutes only a small percentage of overalltelecommunications traffic. Even in advanced countries suchas the USA, wireless service still remains somewhat élitist,with no more than 16% of the population having cellular phonesin 1996. As various national governments make new spectrum availablefor wireless personal communications services (PCS), and existingcellular service transforms itself into PCS, the public is demandingubiquitous, affordable high-quality wireless service. PCS willbe defined not only by its advanced technological capabilities,but also by its universal affordability. This paper describessome of the strategies new PCS service-providers are adoptingto meet this challenge. While the penetration of wireless telecommunicationin any market depends on many factors, price is a fundamentalfactor. We analyze the trends in the US and Israeli marketsusing principles of marketing science to illustrate this point.Specifically, we analyze the Israeli wireless market, with itsrevolutionary low tariff structure and project the effect asimilar tariff would have on the US cellular market. But lowerprices would also create a highly competitive, low-revenue per-minute-of-useenvironment for the operator. In the rest of the paper, we discusschanges in traffic patterns, new marketing strategies, wirelessdigital technologies, advanced planning techniques, and innovativenetwork management systems that enable companies to succeedin this new environment.     

Supercritical CO2 Extraction of β-Carotene from Sweet Potatoes

Using supercritical CO₂ to extract β-carotene there was approximately a five-fold or a three-fold increase in amount of carotenoids extracted from freeze-dried tissue relative to the amount extracted from oven-dried or fresh tissue, respectively. The most efficient conditions were at 48°C and 41.4 MPa. Of the total carotenoid content ～20% was inaccessible to supercritical CO₂. The HPLC carotenoid profile of sweet potatoes showed that the unextracted tissue contained 90%β-carotene, primarily as all-trans (ca. 99%). Supercritical CO₂ extracts contained up to 94%β-carotene. The isomer composition of β-carotene of supercritical extracts showed ～ 14% 13-cis and 11% 9-cis.     

Sintering of Low-Density Glasses: III, Effect of a Distribution of Pore Sizes

The sintering model presented in Part I is extended by considering a Gaussian distribution of pore sizes in the body. The effect of the breadth of the distribution on the densification kinetics is demonstrated; this effect is small except for very broad distributions. The greatest change occurs in the last few percents of shrinkage since the largest pores close relatively slowly. The range of pore sizes typically found in flame hydrolysis preforms or silica gel is narrow enough that the sintering kinetics are adequately described in terms of a single pore size. The specific surface area is shown to be independent of the breadth of the distribution.     

Two Lipoxygenases from Germinated Barley-Heat and Kilning Stability

Using ammonium sulfate precipitation followed by hydrophobic and ion exchange chromatography, two lipoxygenase isoenzymes, LOX 1 and LOX 2, were 18.3- and 44.5-fold purified from germinated barley, with 18 and 24% recovery of activity respectively. LOX 1 and LOX 2 were characterized by isoelectric points 4.9 and 6.4, and molecular weights of 90 kd and 110 kd, respectively. Apparent Km values for linoleic acid were 0.06 mM for LOX 1 and 0.18 mM for LOX 2. LOX 1 converted linoleic acid to 9 and 13 hydroperoxides at about 4:1, whereas the 13 hydroperoxide was the major product formed by LOX 2 (ratio 3:7). For both isoforms, thermal inactivation data indicated first order kinetics with activation energies influenced by ionic strength and pH. Isoenzymes composition was analyzed for three kilning schemes: the 1:3 ratio between LOX 1 and LOX 2 observed in germinated barley increased during the course of kilning.     

Corrosion of Phosphorus Oxynitride Glasses in Water and Humid Air

Phosphorus oxynitride (PON) glasses, prepared by remelting phosphate glasses in anhydrous ammonia vapor, are more resistant to dissolution in water and corrosion in humid environments than the parent phosphate glasses. The chemical durability of PON glasses is directly related to their nitrogen content. Solution analyses, pH stat titrations, and hydrogen depth profiles suggest that nitrogen improves the durability of phosphate glasses by cross-linking the polymeric phosphate chains in the network structure.     

CHLORINATED HYDROCARBON TISSUE RESIDUES FROM BOVINE FEED SUPPLEMENTS: APPLE POMACE AND FISH MEAL

Beef cattle were fed corn silage with or without apple pomace andlor fish meal. Trace levels of dicofol, an acaricide used on apples, were found in tissues of animals fed apple pomace. Detectable levels of p, p'-DDE were also found in tissues of these cattle since dicofol, as formulated, contains about 2.5% p, p'-DDT. The addition of fish meal containing traces of p,p'-DDE to the ration did not consistently increase p, p'-DDE concentrations since this supplement only comprised 3% of the diet. The corn silage and fish meal each contained trace concentrations of polychlorinated biphenyls (PCBs) but PCBs were not detectable in tissues of any of the cattle.