The volatile flavour components of commercial port wines

Gas chromatographic-mass spectrometric examination of aroma extracts from both Ruby and Tawny port has led to the identification of 141 components, notably 2-methoxyphenol, dihydro-2-(3H)-furanone, β-methyl-γ-octalactone, cis-4-hydroxy-methyl-2-methyl-l,3-dioxolane, ethyl pyroglutamate and vitispirane. Odour evaluation of the components separated by gas chromatography indicates five regions as being of potential importance in port. 2-Methoxyphenol and dihydro-2-(3H)-furanone were found in two of these regions, three others being associated with esters of succinic acid. None of these components can, however, wholly explain the port-like odour.     

Effect of exercise and pre-slaughter stress on pork muscle characteristics

The effects of exercise, stress and chill temperature on pork muscle characteristics were studied in a 3 × 2 × 2 factorial experiment in which treatments were assigned to blocks made up of six pigs of the same sex from the same litter. Pigs were fed a corn-soybean meal diet with the two littermate pigs on each treatment fed together. Treatments were (1) a control group receiving no exercise and fed in an 8 m(2) pen; (2) a treatment group fed in an 8 m(2) pen and driven 1·6 km/day for 100 days prior to slaughter; and (3) a treatment group fed in pens with 40 m(2) floor space with feeders placed 5 m from their waterers. When the animals averaged approximately 105 kg in weight, one animal from each pair treated alike was subjected to standardized stress. After slaughter, one side was chilled at 2-3°C and the other at 13-15°C for 24 h. Both sides were then chilled at 2-3°C for an additional 24 h. Exercise did not affect average daily gain (ADG), feed efficiency, yield of total wholesale cuts, muscle pH, protein solubility, fiber diameter and sarcomere length of the Longissimus dorsi (LD) and Quadriceps femoris (QF) muscles or the tenderness of the QF muscle. Exercise decreased backfat thickness and the subjective tenderness of the LD muscle. The effects of stress on the characteristics evaluated were consistent with those that have been previously reported. Chilling temperature and interactions involving chilling temperature did not affect any of the characteristics studied. No exercise × stress interactions were observed. Protein solubility values indicated that pale, soft exudative (PSE) muscle was not a factor in any of the treatments. It was concluded that exercise will produce leaner carcasses but less tender muscle and that exercise will not counteract the effects of pre-slaughter stress.     

THE CONTRIBUTION OF DEXTRINS TO BEER SENSORY PROPERTIES PART I. MOUTHFEEL

The effect of dextrins on the mouthfeel of beer was assessed using instrumental and sensory techniques. By measuring the viscosity of beer with a rheogoniometer, it was shown that beer is a newtonian fluid, i.e., shear stress increased linearly with shear rate. A capillary viscometer and a rheogoniometer gave viscosity measurements that did not differ significantly for six beers ranging in viscosity from 1.1 to 2.6 centipoise (cP). In carbonated beer, the amount of dextrins needed to produce an increase in viscosity detectable by judges was 52 g/litre, which raised the viscosity by 0.31 cP as measured by capillary viscometry. Since beer usually contains between 10 and 50 g/litre of dextrins, it is concluded that dextrins are not the sole determinant of beer viscosity.     

THE CONTRIBUTION OF DEXTRINS OF BEER SENSORY PROPERTIES PART II. AFTERTASTE

We investigated the possibility that dextrins could contribute to the aftertaste of beer by being broken down to sweet sugars by salivary α-amylase after beer Ingestion. The volume, pH and temperature of beer and saliva present in the oral cavity after swallowing were measured on several subjects and found adequate for the hydrolysis of beer dextrins by salivary amylase. The in vitro hydrolysis of a 6% dextrin solution and of commercial beers by pancreatic α-amylase yielded significant amounts of glucose and maltose in addition to maltotriose. Similarly, the hydrolysis of commercial beers by human saliva produced between 2.7 and 7.4 g/litre of sweet-tasting maltose and glucose, depending on the duration of the hydrolysis (30 sec to 2 min) and the amount of saliva added to 2.5 ml of beer (0.5 or 2 ml). This much sugar, because it is produced over a period of time, may not cause a detectable sweet taste but it might partially mask the bitter aftertaste of beer.     

平台化ASIC迅速打开市场

平台化专用集成电路(Platform ASIC)是一类新推出的产品,其应用目标是减少上市时间和降低设计成本.从日渐增多的相应新设计可以看出,平台化ASIC前景一片光明.     

An 80-Msample/s video switched-capacitor filter using a parallelbiquadratic structure

This paper describes a fifth-order, low-pass switched capacitor filter for video applications. It has a 4-MHz cutoff frequency and uses a parallel biquadratic structure with double sampling to achieve an 80-MHz input sampling rate in a 2-μm CMOS process. The prototype filter is fully differential, occupies an active area of 11 mm² , and dissipates 190 mW     

CADRE: An Asynchronous Embedded DSP for Mobile Phone Applications

Asynchronous design techniques have a number of compelling features that make them suited for complex system on chip designs. However, it is necessary to develop practical and efficient design techniques to overcome the present shortage of commercial design tools. This paper describes the development of CADRE (Configurable Asynchronous DSP for Reduced Energy), a 750K transistor, high performance, low-power digital signal processor IP block intended for digital mobile phone chipsets. A short time period was available for the project, and so a methodology was developed that allowed high-level simulation of the design at the earliest possible stage within the conventional schematic entry environment and simulation tools used for later circuit-level performance and power consumption assessment. Initial modeling was based on C behavioral models of the various data and control components, with the many asynchronous control circuits required automatically generated from their specifications. This has enabled design options to be explored and unusual features of the design, such as the Register Bank which is designed to exploit data access patterns, are presented along with the power and performance results of the processor as a whole.     

A second-order double-sampled delta-sigma modulator usingindividual-level averaging

A second-order double-sampled delta-sigma modulator is described. It uses all individual-level-averaging switching scheme to convert capacitor mismatch into high-pass noise. With a sampling rate of 25 MHz and an oversampling ratio of 128, the maximum measured signal-to-noise-and-distortion ratio is 82.2 dB, and the total harmonic distortion is -91.0 dB when the input is 2.5 dB below full scale. The modulator is fully differential, occupies 3.75 mm² in a 1.2-μm CMOS process, and dissipates 25.9 mW (10.2 mW analog and 15.7 mW digital)     

Interaction of tallow and hay particle size on ruminal parameters.

Four nonlactating ruminally cannulated Holstein cows were used in a 4 x 4 Latin square experiment with 4 21-d periods to determine if the effects of dietary fat would be affected by hay particle length. Treatments consisted of two levels of tallow (0 and 5%) and two hay particle lengths (short-cut and long-cut) in a 2 x 2 factorial. Diets contained alfalfa hay, corn silage, and concentrate [1:1:2, dry matter (DM) basis] fed as a total mixed ration (TMR) once per day. Samples of the 0 and 5% tallow TMR were ground and incubated in situ in polyester bags for 24 and 48 h. Ruminal samples were taken on day 21 at 0800 h and at 2-h intervals until 1600 h. The total tract digestibilities of acid detergent fiber (ADF) and neutral detergent fiber (NDF) were not affected by tallow or by hay by tallow interactions. There was a trend for tallow to improve total tract digestibility of crude protein (CP) (70.2 vs. 74.7%). After 48 h of ruminal incubation, tallow significantly decreased the digestibilities of DM, ADF, and NDF. No hay length by tallow interactions for DM, NDF, ADF or CP digestibilities occurred after 24 or 48 h. Tallow increased concentrations of propionate and decreased concentrations of acetate and valerate and the acetate-to-propionate ratio. Total volatile fatty acids increased when tallow was added to diets with short-cut hay, which suggests that when unprotected fat is added to diets with a high level of hay, a short-cut hay length may be advantageous. This result may be due to shorter rumen retention time of feed particles, which reduces the time for fatty acids to exert antimicrobial effects. Or, it may because the increased surface area of the hay particle provides more area for microbial attachment and increased fermentation.