摘要:

AbstractVibration instruments and tests previously developed for engineering materials have been applied recently to measuring the vibration properties of agricultural commodities. The vibration properties of some of these commodities are significantly correlated with firmness and ripeness. This paper reviews the current methodology for measuring and characterizing the vibration response of fruits within the frequency region 20–10000 Hz. Sweep‐sine as well as random‐vibration test methods are discussed. Emphasis is placed upon test techniques and sources of variation in test results due to such factors as the vibrator capacity, detector mass, and the manner of coupling the fruit to the test transd

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00632.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractSlabs of uniform agar gels were cut into standard shapes of various sizes and their deformation under a small compressive force was measured in an Instron Universal Testing machine. The deformation of rectangular solids and regular cylinders with vertical axes was found to be directly proportional to the specimen height and inversely proportional to the cross‐sectional area. The deformation of regular cylinders with horizontal axes was inversely proportional to the length and was a linear function of the diameter. Deformation of spheres first increased to a maximum, then decreased as the diameter increased giving an invertedV‐shaped curve. The diameter at which the maximum deformation of spheres occurred depended on the agar concentration in the gel and the magnitude of the deforming fo

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00633.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractTen instrumental characteristics of the mechanical properties of roast beef were derived from an analysis of the force‐deformation curve obtained during compression of the meat between blunt jaws, fitted in the Instron. Equipment is described for recording the curve in a computer readable form on punched tape. Sixty‐nine samples of beef, representing a wide range of textural properties, were examined instrumentally and by a taste panel. The data correlated much more closely with the sensory ‘toughness‐tenderness’ factor than with the sensory ‘juiciness’ factor. All characteristics of cold samples together accounted for 50% of the variance in the ‘toughness‐tenderness’ factor of samples tasted hot and for 75% of those tasted cold. Two or three of the characteristics were almost as effective. Neither single characteristics derived from the compression curve nor their various combinations improved markedly the correlations with sensory assessments reported in the literature and obtained with other textur

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00634.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractSoftening of Loring and Dixieland peaches due to ripening and gamma irradiation has been quantified by sensory evaluation, the Magness‐Taylor pressure tester, the Allo‐Kramer Shear Press, and the Instron Universal Testing Instrument. Irradiation induced immediate reduction in firmness, but the final softness of the stored fruit was largely independent of the radiation d

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00635.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractIrradiated peaches were more capable of recovery from applied stress, exhibited less creep deformation, and longer 35% stress relaxation times than the non‐irradiated or the ripened fruits. Irradiation, the degree of ripening, and the previous stress‐strain history of peaches influenced their response to applied stres

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00636.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractFive 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 recor

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00637.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract‘Setting’ was observed in minced hen meat stored with 3.5% wt/wt added NaCl. When gels were made from the ‘set’ sol the breaking energy was greatly increased and the relaxation modulus was characterized by a wide ‘quasi‐equilibrium’ region. The effect of added pyrophosphate on the rheological properties of the gel prepared at pH 6.0 from ground ‘set’ sol was very similar to that previously observed for ATP in gels prepared at pH 6.0 from ‘unset’ sols. When pyrophosphate or ATP were added at pH 7.0 to the ‘unset’ minced meat sol, the strain at the breaking point and the ratio of the equilibrium to the instantaneous modulus of the heated gel were increased. A comparison with previous results from a model system suggests that pyrophosphate brings about a change in gel structure by dissociating ‘myosin B

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00638.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractA non‐destructive random‐vibration technique was used to test whole intact peaches over the frequency region 250–10000 Hz. Changes in the vibration properties of peaches during maturation and ripening were related to changes in fruit firmness. Vibration measurements in the frequency region 2–5 kHz provided the best correlations with pressure test measurements and with sensory firmness ratings. Such correlations were in general greater th

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00639.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00640.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

G. F. Stewart and C. L. Willey (eds.)Proceedings SOS/70. Third International Congress Food Science and TechnologyH. H. Hartert and A. L. Copley (eds.),Theoretical and Clinical Hemorheology. Proceedings of the Second International Conference.F. F. Nord,Advances in Enzymology

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00641.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY