东方之珠

在香港这个公认的时装枢纽,创新概念百花齐放,为各种各样的霓裳美服提供创意后盾.由香港贸发局主办的香港时装节凭借这个优势,自创办以来规模不断扩大,声誉日隆,成为时装业者不容错过的盛事,同时也反映出了香港在时装市场上的重要地位.     

MEASUREMENT OF THE RELATIVE TASTE INTENSITY OF SOME L-α-AMINO ACIDS AND 5'-NUCLEOTIDES

SUMMARY— Intensity of glutamate-like and/or inosinate-like taste (umami in Japanese) of various flavor amino acids and flavor nucleotides was studied using sensory analysis and always found proportional to that of monosodium glutamate (MSG) and disodium 5'-inosinate (IMP), respectively. By application of this fact to a previously obtained equation expressing the relationship between the taste intensity of MSG-IMP mixture and that of MSG alone, the intensity of umami of the mixture of any flavor amino acids and nucleotides could be expressed as an elementary equation: y = u +γ uv, where u and v are the concentrations of amino acids and nucleotides in terms of the concentrations of MSG and IMP, respectively, in the mixture; y is the equivalent concentration of MSG alone; and γ is a positive constant. Interrelationships within each group of substances were additive.     

Effects of storage temperature and water activity on the survival of bifidobacteria in powder form

Effects of water activity and storage temperature on survival of bifidobacteria in powder form were investigated and kinetic analyses were performed to reveal characteristics of the stability. A significant positive correlation was observed between water activity and natural logarithm of the inactivation rate constant of bifidobacteria powder, indicating that higher water activity induced lower stability of bifidobacteria in powder form. Also, higher temperature condition induced lower survival rate, which was supported by that the stability was followed the Arrhenius theory. These findings constructed a prediction model for bifidobacteria survival in powder form.     

A self-organizing time-optimal controller†

A kind of self-organizing controller is proposed, which can accomplish time-optimal control of the unknown plant through adaptation. The self-organizing controller consists of the controller which has a variable switching surface and the adaptation logic net which observes the state of the controlled plant and the control signal yielded by the controller. It can improve the parameters of the controller according to the adaptation algorithm. The proposed method required neither information on the plant dynamics nor its identification. Adaptation is carried out on line. Computer simulation shows the effectiveness of the method.     

DIRECT MEASUREMENT OF LIP PRESSURE WHEN INGESTING SEMI-LIQUID FOOD

A spoon sensor to measure lip pressure when slurping liquid food was developed. Several sheet‐type sensors of 3 mm diameter were aligned along the back‐center line of the bowl of a spoon, at intervals of 5 mm and the lip pressure was evaluated while average adults ingested five samples of semi‐liquid foods with varying viscosities. Samples with greater viscosity required correspondingly greater lip pressure and maximum force, as well as a greater impulse or time integral of the force detected by a single sensor. The sum of the force, the impulse, duration and velocity using pressure data from a sequence of four sensors were calculated. Thicker samples required greater force and impulse, and longer duration, but lower velocity. The test subjects slurped semi‐liquid foods differently, adapting to viscosity. Mechanoreceptors in the lips may play an important role in the discrimination of food viscosity.     

EFFECTS OF SAMPLE THICKNESS ON BITE FORCE FOR RAW CARROTS AND FISH GELS

The effects of food thickness on human bite force were investigated using a multiple‐point sheet sensor and electromyography. The total force and contact area were directly measured in real time using the sensor, and the average stress detected between the teeth and a food sample (active stress) was derived from the ratio of the force to the contact area. Raw carrots and fish gels with different thicknesses were bitten between the upper and lower incisors or molars by healthy women. For hard and brittle carrots, the peak force, contact area and active stress at the fracture point were greater in thicker samples when biting with incisors. For soft and tough gels, the peak force and contact area were increased as thickness increased; however, the active stress was similar in incisor bites. These values did not differ significantly with thickness in the molar bites of both samples. Although the force and contact area were greater for molar bites than incisor ones, the active stresses at fracture point were independent of tooth position. The sample thicknesses influenced the bite force of humans and the stress applied to the sample, and the effects differed with sample texture.     

n-Hexanol Formation from n-Hexanal by Enzyme Action in Soybean Extracts

n-Hexanal in soybean homogenates decreased during incubation at alkaline pH. When soybean extracts were dialyzed and then incubated with n-hexanal and cofactors [nicotinamide adenine dinucleotide (NAD⁺), the reduced form (NADH), nicotinamide adenine dinucleotide phosphate (NADP+), and the reduced form (NADPH)], NADH and NADPH stimulated the enzymatic reduction of n-hexanal with NADH being more effective than NADPH. When undialyzed preparations were incubated, all the cofactors stimulated enzymatic activity, with NADH being the most effective. The reaction product in all the incubation mixtures was n-hexanol; n-hexanal was reduced to n-hexanol stoichiometrically. It was suggested that alcohol dehydrogenase was responsible for the decrease of n-hexanal in soybean homogenate at alkaline pH.     

RAPID DETECTION OF A SMALL NUMBER OF VIABLE CELLS BY THE FLUORESCENT GLUCOSE METHOD

A fluorescent glucose, 2NBDG, was rapidly consumed by 4 different species of microorganisms: Escherichia coli, Lactobacillus acidophilus, Saccharomyces cerevisiae, and Candida tropicalis. E. coli and L. acidophilus became fluorescent enough for microscopic observation within 1 min, while S. cerevisiae and C. tropicalis became fluorescent in a longer time span. All of the 14 coliforms that were isolated from various foods consumed 2NBDG and became fluorescent within 1 min. Therefore, 2NBDG is expected to be a useful indicator of viable cells irrespective of species as long as they could assimilate glucose. This 2NBDG method is valid in counting small amount of cells, such as 10–100 cells, accurately and carefully. Also, the 2NBDG method was successfully applied to the rapid detection of a small number of E. coli in milk. The feasibility of the 2NBDG method is discussed from the viewpoint of food safety control.     

An Advanced Effective Capacitance Model for Calculating Gate Delay Considering Input Waveform Effect

In deep submicron designs, predicting gate delay time is a noteworthy work for Static Timing Analysis. The effective capacitance Ceff concept is usually used to calculate the gate delay with interconnect loads. Conventionally, the input-signal to the gate is always assumed as a ramp waveform. However, the input signal is also the output of CMOS gates with interconnect loads and not the ramp waveform. Thus the simple assumption as a ramp signal results in significant influence on the delay calculation. In this paper, an advanced effective capacitance model is proposed to consider both the input waveform effect and the interconnect loads, where the nonlinear influence of input waveform is modeled as one part of the effective capacitance for calculating the gate delay. Experimental results show a significant improvement in accuracy when the input waveform effect is considered.