ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00843.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract. A critical review of the literature on the staling of bread has been presented with particular emphasis on developments during the last decade. The staling of bread has been discussed from a structural point of view with separate contributions due to starch retrogradation, a modification in the gluten structure and a partial re‐distribution of moisture from the gluten to the starch fraction of the crumb. Both model systems and studies on the natural crumb are considered including the contribution to staling of macroscopic moisture re‐distribution and deterioration in flavour volatiles. The staling of baked goods has also been reviewed and it is proposed that certain analogies from the bread situation might provide a suitable basis for an overall theory of cake staling. It seems possible that a considerable contribution to the staling of cake sponge may be due to changes undergone by the various proteins; the free moisture produced from the transforming proteins may be absorbed by the sugars and gelatinised starch. Retrogradation of starch appears to be less important than changes in the proteins during the staling of cake. Dehydration of the cake crumb is perceived to play an important role in the sensory evaluation of cake stalen

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00844.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract. An instrument is described to measure pea tenderness for establishing the price paid to the grower. Peas are forced through a wire grid by a plunger and the maximum force is recorded automatically in digital form by electronic apparatus. Provision is made for rapid electric calibration of the recording system which can be checked by weights.Readings from the new machine, the shear‐compression cell of the Texture Test System and the pea tenderometer were highly correlated, but there was a different relationship for each pea variety tested. This introduces complexity into establishing a new pricing scale if the pea tenderometer is replaced. The data indicate the importance of using test samples having a wide range of textural properties to compare instrument

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00845.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract. Analysis of published chewing force patterns indicates that the ‘first bite’ involves an approximately linear application of force. The Instron Universal Testing Machine also offers a linear pattern of force application making it possible to obtain information about textural properties identified during the ‘first bite’ from force‐compression tests. However, the data obtained in such tests are influenced not only by the applied force but also by the rate at which it is applied. Both variables must be taken into account when analysing the data, since the applied force in chewing and also the rate of force application depend on the textural characteristics of the food being evaluated. Based on a correlation of sensory responses with instrumental force‐compression‐rate of force application data, a procedure is described for establishing the mechanical force conditions that should be used in Instron tests so that they simulate those associated with the senso

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00846.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract. The time required to apply the force in force‐compression studies with the Instron Universal Testing Machine is long enough for short time relaxation processes to operate, possibly via intermolecular attraction forces. A theoretical analysis is presented whereby stress relaxation can be determined for the stress‐strain region in which the Boltzmann Superposition Principle is valid. Application of the analysis is demonstrated using force‐compression data obtained on cheeses of different textural properties. After correction for stress relaxation, the calculated and experimental relaxation modulus‐time curves agree satisfactorily over a much longer time interval for Edam cheese than for Cheddar cheese. The latter cheese becomes non‐linear at much smaller compressions than does Edam cheese, possibly by the propagation of cracks through the sample during compression. Firmness is one of the textural properties evaluated during the first bite of mastication. Since the time associated with the first bite is longer than that required for application of force during the first compression of a sample with the Instron in this study, it is possible that the sensory evaluation of firmness is made under conditions involving stress r

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00847.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract. Structural changes produced in strawberries when made into jam were studied by light microscopy. The results indicated that only the epidermal and vascular tissues retained their structural integrity, whereas the bulk of the cells were collapsed and in some instances ruptured. The extent to which fruit of different cultivars broke down during the jam making process was determined, and an expression representing fruit wholeness was derived. It is concluded that a relationship exists between the extent to which strawberries disintegrate during jam boiling and the density of achenes on the surface of berries of a given size.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00848.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract. A method is described for measuring the force and the rate at which it is applied to fruits and vegetables by the consumer's hands in judging firmness. Halves of the product were mounted on a force transducer, squeezed and the forces recorded. Preliminary results from an untrained panel indicated that the rates and maximum forces used by males and females are different and depend on the firmness of the product. The data also suggest that the rate of force application in sensory testing is significantly greater than that customarily used in instrumental tests.Limitations of the technique and its potential usefulness in establishing more rational conditions for objective firmness tests are discussed.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00849.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract. A word association test administered to 102 respondents indicated that the consumer understands the qualitative meaning of texture words in the same manner as people experienced in texture evaluation. A few words such as thin, thick, dry, smooth, hard, etc. were found to have additional meanings related to characteristics other than texture. The responses were used to compile a tabulation of foods having specific recognizable textural characteristics. This tabulation should be useful in explaining the meaning of texture words to people unfamiliar with the nomenclature or in situations where a language barrier exists.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00850.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00851.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Book reviews in this article:Roland Harper,Human Senses in Action,Toshimaro Sone,Consistency of Foodstuffs,P. Sherman,Industrial Rheology, Academic Press,W. C. McCrone and J. G. Sally,Particle Atlas,

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00852.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY