EFFECT OF RAPID COOLING OF SHELL EGGS ON MICROCRACK DEVELOPMENT, PENETRATION OF SALMONELLA ENTERITIDIS, AND EGGSHELL STRENGTH

Eggs were subjected to cryogenic cooling treatments using liquid CO₂ or liquid N_2. In order to minimize the thermal stress in eggshells due to rapid cooling, a two-stage air-cooling method was also evaluated in this study. Eggs were cooled from an initial temperature of 25C to approximately 7C. It was found that cooling produced microcracks on eggshells. However, rapid cooling did not increase the penetration of Salmonella enterica serovar Enteritidis (Salmonella enteritidis) into egg contents. When egg contents alone were sampled for Salmonella enteritidis, extending the immersion time from 24 to 48 h significantly (P < 0.01) increased the penetration of Salmonella enteritidis from 5.0 to 25.0%. When egg contents together with eggshells were sampled, Salmonella enteritidis was detected in 100% of the egg samples at the above two time intervals. There were no significant differences (P > 0.05) in the eggshell strength between control (no cooling) and cooling treatments, indicating that cooling did not weaken eggshell strength.     

MEASUREMENT OF TEXTURE PARAMETERS OF FREEZE-DRIED BEEF*

A modified texture profile analysis with the Instron Universal Testing Apparatus was used to measure hardness and chewiness of precooked freeze-dried beef cubes in order to determine the influence of processing and reconditioning. Two different plate temperatures were used during freeze-drying, and the resulting product was reconditioned at four different water activities in addition to the dry and fully rehydrated product. Reconditioning temperatures of 52, 70, and 100°F were investigated. The results revealed that the hardness and chewiness values were the highest at water activities of 0.4 to 0.6 and with the product freeze-dried at a plate temperature of 105°F. The influence of reconditioning temperature was inconsistent, apparently due to an interaction between the water activity and the plate temperature.     

FIRMNESS MEASUREMENT OF PROCESSED TABLE BEETS *

Abstract. A rapid back extrusion method for estimating textural quality of processed table beets was well correlated with taste panel evaluation of commercial (r= 0.91) and experimental samples (r= 0.98). An estimate of the mean of the fluctuations of the plateau of the force-distance recording was found to provide a less variable value for firmness than the maximum force. The extrusion method was correlated with a puncture method (r= 0.91).     

MEASUREMENT BY COMPRESSION TEST OF IMPACT DAMAGE TO CITRUS FRUITS*

Abstract. Oranges and grapefruit were subjected to single and repeated impact drops from three heights. Subsequent measurements of the force-deformation ratio and hysteresis loss were made with quasi-static compression tests on the impacted whole fruit. Internal damage was indicated by a reduction in the force-deformation ratio and an increase in the hysteresis loss for a single 100 cm drop and two or more drops from 25 or 50 cm heights.     

THE QUALITATIVE AND QUANTITATIVE MEASUREMENT OF PEAT SMOKE ON DISTILLER'S MALT*

In the course of developing a novel peating process it became apparent that the present methods for determining the intensity of peat smoke on distiller's malt are inadequate. While the colorimetric test for peat phenols is fairly accurate at low levels, it can give misleading results with highly peated malts. Furthermore, the 4-aminophenazone reagent used in this test is not sensitive to some of the major phenol constituents of peat smoke. New qualitative gas chromatographic techniques, which monitor a wider spectrum of peat smoke constituents, are now presented together with some suggested improvements to the existing quantitative colorometric analysis.     

蛋壳资源综合利用现状与对策

综述了蛋壳资源现状及研究进展,阐述了蛋壳资源综合利用过程中存在的问题和解决办法,为蛋品深加工及蛋壳资源的开发利用提供新的思路。     

OBSERVATIONS ON TEXTURE MEASUREMENT OF RAW CUCUMBERS WITH THE FRUIT PRESSURE TESTER*

Raw fruit of a ‘firm’ (Explorer) and a ‘soft’ (Green F) cucumber cultivar were puncture tested with the Magness-Taylor fruit pressure tester (FPT) manually, and also with the FPT or only FPT tip mounted in the Instron. Puncture-values for flesh only were 70–75 % of those for intact fruit. Neither the cucumber size (1–2.5 in. diam) nor the test speed (5–50 cm min^-1) appreciably affected the puncture test values.     

MEASUREMENT OF PEA TENDERNESS IV. Development and Evaluation of the Test Cell*

A wire extrusion cell was developed to measure pea tenderness. The area of the cell and the wire grid dimensions affected the readings. The maximum force was linearly related to the total length of the shearing wires and the open area of the grid. Cells could be made interchangeable in testing unsieved peas within 1% or better using economic manufacturing tolerances. Sample temperature, time after harvest and damage to the wires of the test cell had negligible effects on the readings. The effect of variation in compression speed was small and erratic. Sample weight, however, had a marked effect on the results.     

TEXTURE MEASUREMENT IN MEAT BY SENSORY EVALUATION*

Various sensory evaluation methods have been used to measure texture in meat. While some methods are more suitable than others, more work must be done before any one can be recommended as a standard method. Other aspects which require special attention are cooking of samples, selection of reference samples and the multicomponent nature of texture.     

MEASUREMENT OF PEA TENDERNESS: III. Field Comparison of Several Methods of Measurement*

Five objective techniques were compared with pea tenderometers to examine their performance under field operating conditions. The methods were a shear-compression cell of the Kramer Shear Press, a back extrusion cell, wire and plate extrusion cells and a recording grinder. Results from the different methods were highly correlated allowing the choice of a test cell for possible replacement of the pea tenderometer to be based on practical considerations. The method selected for further development was the wire extrusion cell because it was inexpensive and suitable for a quality control instrument, where the maximum force during testing is a convenient value to record.     

MEASUREMENT OF FERMENTABLE SUGARS

A method is described in which the fermentable sugars of wort, beer and syrups are rapidly separated as a group from the unfermentable carbohydrates, by desorption from a charcoal-kleselguhr column using 15% ethanol as the eluting agent. This separation procedure may conveniently be combined with an automated redox electrode procedure for carbohydrate determination.     

MEASUREMENT OF PEA TENDERNESS

The effect of pendulum inertia on Pea Tenderometer readings was examined by recording the pendulum angle and the torque that it applies to the peas during a test. The effect was significant at the critical point in the test cycle where the torque is at a maximum. It was concluded that this affects the standardization of the Tenderometer.     

MEASUREMENT OF DIASTATIC POWER

Modifications to the method of estimating the diastatic power of malt using starch hydrolysis and determination of reducing sugar released with p-hydroxybenzoic acid hydrazide are described. Using 40 g malt, 4% w/v soluble starch reduced with sodium borohydride and a “boiled enzyme blank”, the production of reducing sugar is directly proportional to volume of added extract. Using a constant amount of extract, the reaction is directly proportional to time over a period of 30 min. The method enables the direct estimation of the diastatic power of malts with Windisch-Kohlbach values of up to 434 degrees.     

MEASUREMENT OF PEA TENDERNESS

Abstract Twenty one tenderometers were compared in processing plants for their accuracy of measurement using wax wafers as the test material. The results indicate that there are serious differences among the tenderometers and that the accuracy of measurement is unsatisfactory for the purpose of grading peas to establish the price paid to the grower. If a relationship of compatible trust is to remain between the processor and the grower, serious consideration must be given either to better calibration of currently used tenderometers or to devising some other method of grading and paying for peas.     

CONTRIBUTIONS OF THE US ARMY NATICK RESEARCH AND DEVELOPMENT CENTER TO THE OBJECTIVE MEASUREMENT OF THE TEXTURAL QUALITY OF MEAT*

Several approaches to the problem of objective measurement of the texture of meat, including modification of existing devices and development of new units, are presented. A mathematical-mechanical model is introduced which shows that some of the simpler tests presently used measure only part of the textural properties of meat; additional tests are needed to improve texture evaluation.     

THE MEASUREMENT OF FOAM-LACING

An index of foam-lacing can be obtained by calculating the ratio of ultra-violet light (230 nm) absorbed by the material in the foam to that absorbed by the whole beer. Alternative procedures are described, the first of which is intended for quality control purposes with all beers or for the investigation of the science underlying lacing. The second method is suitable for assessing the lacing property of bottled or canned beer.     

酶法提取鸡蛋壳膜中透明质酸的研究

对酶法提取鸡蛋壳膜中透明质酸的工艺进行了研究,通过单因素试验和正交试验考察了酶解温度、pH、酶用量、料液比和酶解时间对透明质酸提取量影响,确定了胰蛋白酶提取透明质酸的最佳工艺条件为温度50℃,pH为8.5,酶用量为8 000 U,料液比1∶40,提取时间7 h.在此条件下,蛋壳膜中透明质酸的提取量为13.294 mg/g.