摘要:

AbstractRheological properties of dough are important since they affect the quality of the baked product. In addition, they are interesting since they provide information on dough structure. Instruments used for quality control in mills and bakeries are reviewed. Experiments at constant stress or at constant rate of deformation are discussed as examples of experimental techniques suitable for description of dough properties in physically simple terms. Relationships between dough structure and rheological properties are also covered.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00606.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractUnprocessed steam‐peeled potatoes exhibited lower apparent moduli of deformability and elasticity than unpeeled or abrasion‐peeled potatoes. Both moduli decreased upon thermal processing and on storage of the processed product. The degree of elasticity and energy capacity decreased, while mechanical hysteresis increased, due to peeling prior to processing. The processed Sebago variety showed greater mechanical hysteresis than the Red LaSoda variety. The apparent elastic properties of processed potatoes exhibited varied trends due to the peeling method and storage as evidenced by the significant interaction of these two main variables.The results obtained suggest that apparent elastic moduli are not reliable indices of the degree of firmness of the peeled and processed Irish potatoes. Texture measurements on these potatoes should involve destructive forces and deformations to give true indications of differences in firmn

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00607.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractA new instrument, the MITEX MK II Bending Tester, is described as a means of measuring the following rheological properties of solid foods:bending moment, curvature, bending rigidity, modulus of elasticity, curvature setandbending moment loss.Equations applicable to bending and results of measurements on samples of celery, carrot, apple and potato are presented. Changes of the modulus of elasticity in relation to the time of exposure of sample strips to the ambient atmosphere, and graphical and mathematical treatment of the data for estimating a total ‘adjusted time’ (age) of a particular sample are discus

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00608.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractTwo major types of objective measurements were performed on raw porcinepsoasmuscle (I ‐ shearing and breaking strength tests; II ‐ sarcomere length, elasticity, stress relaxation and break elongation) and compared with taste panel evaluation (tenderness, elasticity, and chew count) of cooked meat. A standard sample of texturized vegetable protein used as a reference by the panel proved useful in reducing variations between the chew count test and the objective evaluation; it was not of significant value with the other sensory evaluations.No significant correlations were found between the two groups of objective measurements. Breaking strengths of small longitudinal strips of tissue, following a brief cyclic or extension stretching on the Instron, were the best predictors of sensory tenderness accounting for 59–90% of variation. Other measurements also gave significant correlations.The major source of variation in breaking strength values was the variation between animals, but the post‐mortem treatment (restraining versus not restraining during rigor) and the interaction between animals and the post‐mortem treatment also were significant in some cases. Breaking strengths of uncooked samples from the same muscle showed a coefficient of variation of up to 54%. It is concluded that there are two major structural contributions of raw muscle to cooked meat tenderness, a connective tissue factor and a contraction factor; different objective methods are best suited for their e

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00609.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractBased on a model of a suspension of interacting particles in a pseudoplastic solvent, a rheological equation was developed which could describe the flow properties of concentrated orange juice. The function was obtained by modifying Casson’s equation and has the following form:The magnitude of the parameterkois affected by the concentration of the suspended particles, the concentration of soluble pectin and by conditions favorable for pectin gel formation. The other two parameters,kandm, are determined mainly by the solvent properties. The mechanism responsible for the flow behaviour of the concentrated orange juice under various conditions could be predicted and explained by the properties of the components in the syste

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00610.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractFresh as well as irradiated Tioga strawberries were softer, required smaller forces to puncture and to compress, and exhibited smaller degrees of elasticity and recoverability from applied stress than the stored berries. Thus, fresh or irradiated strawberries should be more susceptible to mechanical damage during handling, shipping and marketing than the stored fruits.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00611.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractSubjective viscosity and fluidity of water soluble gums were investigated as a function of apparent physical viscosity (in poises), and as a function of the method of presentation. Subjective magnitude (S) appeared to grow as a power function of viscosity (P) withS=kPn, and the exponentnaveraging about + 0.4 for subjective viscosity, and ‐0.4 for subjective fluidity. Stimuli appeared more viscous (and less fluid) when presented in narrow‐mouthed test tubes than in wide‐mouthed bottles. The growth rate of subjective magnitude, indexed byn, did not change, however, suggesting that the dynamics of subjective magnitude for viscosity and fluidity are independent of the presentation proc

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00612.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Abstract69 beef roasts from different breeds, ages, growth histories and joints, were judged for texture, hot or cold, by a panel of 12 tasters. The panel was selected for discrimination and consistency over a series of training sessions during which a descriptive score sheet was developed through repeated discussion. Eight characteristics were decided upon to describe the texture of roast beef; seven on scales (resistance, wetness, juiciness, cohesiveness, hardness, overall texture, chew count) and one qualitative (adjectival descriptions).The panel average scores for the seven quantified characteristics were subjected to factor analysis and the loss of information involved in reducing the matrices to two dimensions was 6.3% (hot tasting) and 4.6% (cold tasting). Factor scores calculated for both sets of data agreed in being highly correlated (0.98>r>0.90); Factor 1 with ‘resistance’, ‘cohesion’, ‘hardness’, ‘overall texture’ and ‘chew count’ and Factor 2 with ‘wetness’ and ‘juiciness’, but poorly with any characteristic in the other group (0.11>r>0.03). Thus, the texture of roast beef was appreciated by this panel in two characteristics describable as ‘toughness‐tenderness’ and ‘juiciness’, and the more elaborate scoring system originally devised did not add appreciably to the precision of measurement.Comparison of factor scores on samples tasted both hot and cold showed that the relative toughness‐tenderness was maintained between samples under bot

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00613.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractRipe Floradel tomatoes were softer, required smaller forces to puncture and to compress, and exhibited less recovery from applied stress than the unripened fruit. Irradiation caused similar but less pronounced changes.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1972.tb00614.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.tb00615.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY