A PROCEDURE FOR EVALUATION OF COMMERCIAL FCC CATALYSTS

Based on the correlations between laboratory units and commercial plants, a procedure has been developed to guide commercial FCC (Fluid Catalytic Cracking) catalysts selection. Examining the operability of catalyst mixtures during catalyst transition period is emphasized. The testing procedure is simple and reliable. A commercially available catalyst and the catalyst currently in use have been compared to demonstrate the applicability of this procedure. The commercial testing has confirmed the reliability of laboratory results. The use of the catalyst evaluated led to a 30% saving in catalyst cost.     

Transglutaminase from Streptoverticillium ladakanum and application to minced fish product

The transglutaminase (TGase) from Streptoverticillium ladakanum was purified to electrophoretic homogeneity after ammonium sulfate fractionation and Blue Sepharose Fast Flow chromatography. The molecular weight of the purified TGase was 30.5 kDa estimated by Superdex 75HR gel filtration, and 37.5 kDa by SDS-PAGE. This enzyme, with optima at pH at 6.0 and 50°C was very stable at pH 5.0–7.0. It was strongly inhibited by PCMB, PMSF, Pb²⁺, Zn²⁺ and Cu²⁺, but not affected by EDTA and Ca²⁺. This suggested that the purified TGase was calcium-independent and its active center contained cysteine. It catalyzed the crosslinking of fish myosin heavy chain and substantially increased the gel strength of mackerel surimi.     

REDUCTION OF SALMONELLA ON POST-CHILL CHICKEN CARCASSES BY TRISODIUM PHOSPHATE (NA3PO4) TREATMENT

The use of trisodium phosphate (TSP) in rinsing chicken carcasses was evaluated for salmonellae reduction. Post-chill carcasses were dipped into a 10%-TSP solution at 10 or 50C for 15 s. After storing 0, 1 or 6 days at 4C, the incidence and reduction of salmonellae were measured using a nitrocellulose (NC) membrane lifting technique, conventional culture methods and most probable number (MPN) technique. In a trial using non-inoculated carcasses, the incidences of salmonellae were decreased from 12 ∼ 24% in controls to 0 ∼ 8% in TSP-treated groups. When the carcasses were inoculated with S. typhimurium (2×10⁴ CPU/carcass), the NC membrane lifting method detected 27 ∼ 46% less incidences of salmonellae in TSP-treated groups. However, culture methods failed to show any difference between TSP-treated and untreated carcasses. Another trial using MPN method showed a significant reduction of salmonellae (1.6 ∼ 1.8 logs) in TSP-treated groups (P < 0.01) at both 1 and 6 days. Although 50C-TSP treatment gave 0.4 log greater reduction than 10C-treatment, the difference was not statistically significant. Total plate counts (TPC) revealed a similar reduction trend to MPN results of salmonellae.     

TREATMENT of POULTRY CHILLER WATER BY FLOCCULATION1

A laboratory study was conducted to assess the efficiency of using a combination of flocculating substances to remove organic constituents from poultry chiller water. Rice bran in combination with commercial flocculant AP-273 (polyelectrolyte) removed 60% and 72% of chemical oxygen demand (COD) from low and high COD samples, respectively. Addition of granular activated carbon to the flocculant mixture increased COD removal to about 75%, respectively, from the same samples. Turbidity (suspended particles) of the chiller water was reduced by more than 90% using flocculant AP-273 plus rice bran. Chlorine demands were also greatly reduced. Soluble inorganic mineral content was not reduced by the combined flocculating substances. the residues collected after flocculation could be used as a feed ingredient, or as an organic fertilizer. Flocculation of chiller water would be a beneficial pretreatment to further recycling processes or to microfiltration of chiller water for reuse.     

Cocobean Tissue Culture: Lipid Composition and Fatty Acid Metabolism

Cocoabean callus cultures were established and grew satisfactorily on an agar medium for more than 2 yr. Cell suspension cultures were initiated from the callus. The fresh weight of cells increased over 20-fold in 14 days. The lipid content of callus and cells was 5.3 and 6.5%, respectively. The fatty acid composition of cocoa callus and cell suspension cultures resembled that of immature cocoabeans since they contained high amounts of linoleic acid. Stereospecific distribution of fatty acids in triglycerides from cocoa callus and cells was similar to that of ripe cocoabeans. Exogenous acetate and fatty acids were readily incorporated into lipids by cocoa cell suspension cultures. Exogenous stearic acid increased triglyceride content twofold but did not change fatty acid composition of triglycerides. Coconut water alone or in combination with sucrose also increased triglyceride content with a concomitant increase in oleic acid from 10% to 33% and a decrease in linoleic acid from 37% to 19%.     

BROWNING BEHAVIOR OF TAURINE AND PROLINE IN MODEL AND DRIED SQUID SYSTEMS

Model systems containing taurine or proline mixed with glucose at pH 6.4 were adjusted for water activity (Aw) to 0.99, 0.90, 0.84, 0.75 and 0.60 with celite. The browning rates measured during 96 h at temperatures between 5° and 45°C increased with increased temperature and reduced water activity. The model system containing taurine had a higher browning rate than that with proline at the same Aw and temperature. The browning rate with taurine at Aw = 0.60 increased 34 times at 45°C and 7 times at 35°C compared to that at 25°C. Decreases in Aw from 0.90 to 0.60 resulted in increased browning rate, 4.1 times at 45°C and 1.3 times at 35°C. The browning rate in model systems with proline followed the same pattern. Temperature had a more pronounced effect on browning rate than Aw. Browning was very slow in model systems at temperatures below 25°C. Evidence is provided that the Maillard reaction occurred in the mantle of squid (Illex argentinus) during air drying at 35°C. Dehydration resulted in loss of 50% of the taurine (from 22.3 to 11.6 mmoles/100g dry mass) and more than 60% of the proline (from 23.4 to 8.9 mmoles/100g dry mass). Total free amino acids remained unchanged when the moisture level was above 50% or Aw = 0.95. The browning intensity of the squid mantle increased 5 fold during drying. Taurine and proline were digested most at water activity above 0.95, while other amino acids were lost at a greater rate in the intermediate water activity range.     

Cholesterol Oxides in Commercial Dry Egg Products: Quantitation

Cholesterol α-oxide (5α-cholestan-5,6α-epoxy-3β-ol), a suspected carcinogen and/or atherogen, and its β-isomer are found in varying amounts in commercial dried egg products. The level of total cholesterol oxides in dried eggs ranges from undetectable to 311 parts per million of total lipids. The majority of the samples (64%) had total cholesterol oxides content between 6 – 49 ppm. The level of cholesterol α-oxide ranges from undetectable to 62 ppm. The ratio of α-oxide to its β-isomer is found consistantly to be 1 to 4. The formation of cholesterol oxides is greater in samples dried by hot air heated directly with gas burner than those dried by air heated indirectly with steam. Prolonged storage increases cholesterol oxides content in dried egg products.     

A light-weight high-entropy alloy Al_(20)Be_(20)Fe_(10)Si_(15)Ti_(35)

A light-weight high-entropy alloy(LWHEA) Al_(20)Be_(20)Fe_(10)Si_(15)Ti_(35) has been developed to have unique mechanical properties and oxidation resistance. One major and two minor phases are observed in the as-cast microstructure. The density of the alloy is3.91 g cm~(-3), and its hardness is HV 911, which is higher than quartz. The hardness and hardness to density ratio are the highest of all light-weight alloys reported before. In addition, it has excellent oxidation resistance at 700℃ and 900℃, which far exceeds that of Ti-6 A1-4 V. Thus, the combination of properties is promising for high-temperature applications, which require light weight,wear-resistant and oxidation-resistant components.     

Knowledge-based approach to the optimal dock arrangement

A problem frequently encountered in ports is the sequencing of waiting ships for berthing to load or unload so that the total demurrage cost incurred is minimized. Here a knowledge-based approach is applied to solve this problem. The constraints of the port and the working rules adopted by the port are expressed as knowledge rules and embedded into the framework of the logic of dock arrangement. With the inference mechanism of a knowledge engineering language OPS5, the best arrangement of the docks can be inferred. Since the operation rules differ from port to port, the problem is confined to the material docks of the China Steel Corporation. A system entitled DOCK is designed to find the best three available alternatives. The idea can be applied and the DOCK system modified for use by other ports.