bluuebunny/crossref_metadata_2025_split huggingface dataset:
The relation between the toughness of cod stored at °7°C and °14°C, its muscle protein solubility and muscle pH
Authors: COWIE W. P. , LITTLE W. T. 
Published: July 2010

SummaryProtein extractability, muscle pH and organoleptic toughness have been measured in cod fillets stored for up to 34 weeks at −7°C and −14°C. The decrease in protein extractability and the increase in toughness of fillets stored at −7°C proceeded at a faster rate than in fillets stored at −14°C. In order to assess if a fillet stored at −7°C or −14°C had an acceptable or a tough texture it was necessary to measure both protein extractability and muscle pH.
An assessment of the potential application of the method of attenuated total reflectance (ATR) infrared qualitative analysis to food materials
Authors: CAMERON A. G. 
Published: July 2010

SummaryThe ATR method is described and its application to food materials in the form of solids, powders, solutions and colloidal mixtures is considered. It is shown that the ATR method has several advantages over the conventional infrared technique. In particular the ATR technique eliminates the need to measure sample thickness and also simplifies the experimental procedure. It enables the spectra of aqueous, colloidal, viscous and complex multicomponent materials to be obtained more easily than in transmission measurements and in such cases often yields more useful spectra. ATR spectra generally show less detail than corresponding transmission spectra, and it is this lack of sensitivity that is the main limitation of the technique.
β‐Glucosidase activity in canned plums
Authors: HAISMAN D. R. , KNIGHT D. J. 
Published: July 2010

SummaryThe reasons for enzyme survival in a heat processed pack have been investigated with reference to the β‐glucosidase system in the kernels of plums. This enzyme breaks down the diglucoside amygdalin to glucose, benzaldehyde and hydrocyanic acid. The variation of enzyme activity with the pH of the system and its inactivation by heat have been examined. At 60°C, in aqueous solution, the enzyme was 90% inactivated in 32 min at pH 5.0, and in 0.6 min at pH 3.0. In the presence of its substrate, amygdalin, and in the solid phase the enzyme was much more heat stable. Because the enzyme system in the kernels is at its optimum pH, in contact with its substrate, and in the solid phase, it is not wholly inactivated by the normal heat process given to canned plums. The variation in residual enzyme activity in the stone according to the heat treatment given has been demonstrated, and the subsequent breakdown of amygdalin to benzaldehyde and cyanide measured.
The influence of certain metal ions on the visible spectra of food dyes
Authors: JONES A. V. , THOMAS J. D. R. 
Published: July 2010

Summary.The visible absorption spectra of twenty‐two food dyes have been plotted both in the free state and in the presence of added calcium, magnesium, aluminium, iron (II), iron (III), copper (II) and cobalt (II) ions at the pH values 3.0, 6.4, 7.4 and 12.5.The frequencies of the absorption band maxima of the free dyes are briefly discussed in relation to colour and structure. While added metal ions do not, in general, have an appreciable effect on the spectrum of the dye, the transition metal ions studied frequently bring about a shift in the characteristic frequencies of the free‐dye absorption maxima. Examples of where this effect is greatest are carmoisine in the presence of copper (II) at pH 6.4 and 7.4, and black PN in the presence of iron (II) at pH 12.5.The possibility of dye complexes affecting iron metabolism is also briefly discussed.
The survival of pathogenic bacteria in, and the microbial spoilage of, salads, containing meat, fish and vegetables
Authors: HOLTZAPFFEL D. , MOSSEL D. A. A. 
Published: July 2010

Summary. An investigation was carried out on the fate at 9° and 20°C of: (i) two types of non‐spore‐bearing bacteria, causing food‐borne disease, viz. Staphylococcus aureus and Salmonella spp., and two spore‐bearing entero‐pathogens (Clostridium perfringens and Bacillus cereus); and (ii) Lactobacillaceae and yeasts in one type of meat and vegetable salad (pH = 4.2, acetic acid content 0.5%) and in one type of shrimp salad (pH = 5.3, acetic acid content 0.3%), preserved at two levels of benzoic acid plus sorbic acid. the pathogens were inoculated at initial densities of 104‐109/g; for lactic acid bacteria and yeast reliance was placed on naturally occurring organisms.The non‐spore‐bearing pathogens died out under all conditions, albeit much faster at 20°C. Spore‐bearing cells of the Bacillaceae tested remained mostly dormant under the conditions of the tests. Lactobacillaceae developed fast, also at 9°C and eventually caused souring of the products. Yeasts appeared to play a role at 3°C only. the main antibacterial effect of the salads was demonstrated to be due to its vinegar content and pH.
The connective tissues of fish. II. Gaping in commercial species of frozen fish in relation to rigor mortis
Authors: LOVE R. M. , LAVÉTY J. , STEEL P. J. 
Published: July 2010

Summary. Fish of different species frozen whole, thawed and filleted gape according to the time after death at which they were frozen. Those frozen immediately after death gaped least, a marked increase accompanying the onset of rigor mortis. Thereafter, there was a steady increase in gaping as the fish were held for longer periods in melting ice prior to freezing. the cause of this second type of gaping is unknown.There was a marked difference between species, haddock showing the most gaping and catfish and skate none at all. the three species of flat fish gaped less than the four round fish (apart from catfish) species, which fact may relate to the shape of the fish, especially as the roundest‐bodied of the flat fish, halibut, gaped the most of the group.The site of gaping was identified histologically, and different degrees of gaping are illustrated by means of photographs.
Diffusion coefficients of water and organic volatiles in carbohydrate‐water systems
Authors: MENTING L. G. , HOOGSTAD B. , THIJSSEN H. A. G. 
Published: July 2010

Summary. The diffusion coefficients of water, Dw, and acetone, Da, in aqueous solutions of malto‐dextrin have been determined over a range of moisture contents of the malto‐dextrin above 10%. At a few selected moisture contents, the diffusion coefficients of ethyl acetate, benzene, carbon tetrachloride, camphor and methane have also been determined. Diffusion coefficients were derived from measurements of sorption and desorption by a malto‐dextrin layer.The diffusion coefficient was found to be dependent on both the moisture contents and the size of the diffusing molecule. Over the range of moisture contents investigated, log Dw was found to be proportional to Cw‐1 and log Da proportional to Cw‐1/2, where Cw is the concentration of water (kg/m3) in the malto‐dextrin. For the compounds studied, the logarithm of the diffusion coefficient measured at a moisture content of 20.1% was found to be approximately proportional to the molecular ‘diameter’ of the diffusant.This knowledge helps to explain the phenomenon of flavour retention during the drying of liquid foods.
A study of some factors affecting the methylene blue test and the effect of freezing on the bacterial content of ice cream
Authors: ALEXANDER JEAN , ROTHWELL J. 
Published: July 2010

SummaryThe effect of E. coli and B. cereus on methylene blue reduction time in ice cream was studied. A general correlation was established between reduction time and numbers of organisms. Lower numbers of B. cereus than E. coli were required to bring about reduction in the same times.Considerable destruction of bacteria was observed during freezing in vertical and soft serve freezers accompanied by an increase in reduction time. This was shown to occur very rapidly after a critical point of ice crystal formation was reached, irrespective of temperature. Increased concentration of total solids did not increase this destruction and bacterial destruction was attributed to mechanical damage.
Microbiological assessment of surfaces
Authors: PATTERSON J. T. 
Published: July 2010

SummaryThe main methods in use in laboratories for the microbiological assessment of surfaces are examined, viz. (1) the swab‐rinse, (2) the rinse, (3) the agar contact, and (4) the direct surface agar plating. The advantages and disadvantages of these are discussed and their suitability for particular purposes in the food industry. Methods employed in the author's laboratory are discussed for sampling surfaces in milk plants, farm dairies, canneries, meat and poultry processing plants. Consideration is given based on actual investigations of the use and limitations of the swab‐rinse technique and its variations and the rinse and the agar sausage techniques. The importance of careful interpretation of and use of the results is stressed. Microbiological standards are suggested for cleaned surfaces, working surfaces in meat and poultry processing plants and for cattle, sheep and poultry carcases.
A note on the aerobic microflora of fresh and frozen porcine liver stored at 5°C
Authors: GARDNER G. A. 
Published: July 2010

SummaryThe microbiological contamination on porcine liver is predominantly on the surface. Storage at 5°C in air resulted in a proteolytic type of spoilage brought about mainly by Gram negative bacteria such as Alcaligenes and Pseudomonas. Other types such as Escherichia, Microbacterium thermosphactum, and lactic streptococci were also found.When stored at 5°C in polythene bags, the level of contamination was much higher in the ‘drip’, and this appears to be related to the load on the surface of the liver. The souring type of spoilage could be attributed to the predominance in the flora of lactic streptococci and Leuconostoc.Freezing was not found to change the spoilage characteristics.
Some observations on the mechanism of starch gelation
Authors: FREKE C. D. 
Published: July 2010

SummaryThe temperature at which starch gelled in systems with varying dielectric constants was examined. Starch was also examined by differential thermal analysis (DTA) and thermogravimetric analysis (TG). Findings showed that the temperature at which starch gels depended on the polarity of the environment. Implications of this and of the DTA and TG findings are discussed.
A method for measuring the firmness of whole loaves of bread
Authors: BISHOP E. C. , WREN J. J. 
Published: July 2010

SummaryThe firmness of whole loaves of bread, unsliced or sliced, can be measured by using an Instron Universal Testing Machine in a constant deformation method which simulates the purchaser's squeeze‐test. A loaf is mounted on a frame and subjected to a small, recoverable compression with a pivoted bar on the oven‐spring line. The method is rapid and facilitates the plotting of firming curves or the calculation of rate constants.
Some aspects of the theory of comminuted meat adhesion
Authors: GORBATOV V. M. , SPIRIN E. T. , GORBATOV A. V. 
Published: July 2010

SummaryAn apparatus has been designed and built to study adhesive properties of plastic/viscous meat products. It allows for change of geometrical, kinematic and dynamic characteristics within a broad range. A procedure for studying adhesion has been developed. Using a model, theoretical relationships to determine adhesion have been derived, which relate comminuted sausage meat thickness between the plates to the speed of external force application. Tests showed a good agreement between theoretical and experimental data.On the basis of the theoretical relationships, the effect of preliminary contact time, material and plate area on sausage meat adhesion has been experimentally studied. Invariant characteristics of the meat have been found, such as the rate of decrease of contact area and surface tension coefficient; the order of the adhesive activities of various materials towards sausage meat has been determined.
Retention of volatile compounds in freeze‐drying slabs of malto‐dextrin
Authors: RULKENS W. H. , THIJSSEN H. A. C. 
Published: July 2010

SummaryA study was made of the effect of a number of process variables on the retention of some volatile compounds during freeze‐drying of ‘model’liquid foods. As a model liquid food, aqueous solutions of malto‐dextrin were chosen. To these solutions acetone, methanol, n‐propanol and n‐pentanol were added in low concentrations.The retention of volatiles strongly increased with increasing molecular size of the volatiles but was independent of the relative volatility. For constant dissolved solids concentration and constant temperature at the sublimation front in drying slabs or granules, process conditions leading to a maximum drying rate always resulted in maximum volatile retention. Retention increased with decreasing freezing rate when solids concentration, sublimation front temperature, and drying rate were constant. Retention always increased with decreasing temperature of the sublimation front. In drying granules, retention exhibited a maximum with respect to particle diameter, and increased with decreasing layer thickness. In the dissolved solids concentration range between 5 and 20% (w/w) the retention strongly increased with increasing concentration, whereas above 20% the retention became independent of initial solids concentration.The observed effects of process variables on volatile retention can be explained qualitatively with the selective diffusivity concept.
Studies of the behaviour of stored carrots with respect to their invasion by Rhizopus stolonifer Lind
Authors: THORNE S. N. 
Published: July 2010

SummaryCarrots of variety ‘Nantes’were stored in air containing spores of Rhizopus stolonifer Lind. at a range of temperatures, humidities and air flow rates; temperatures from 2 to 30°C, relative humidities from 35 to 90%, and air flow rates from 20 cm sec‐1 to 500 cm sec‐1. The rates of loss of weight from carrots stored under these conditions and the conditions under which invasion by R. stolonifer would occur were investigated.It was found that, irrespective of the storage conditions, predisposition of the carrot by the loss of at least 8% of its fresh weight was necessary before invasion would occur. Above this critical weight loss, the percentage of carrots invaded by the mould increased rapidly with increasing weight loss. An empirical method for predicting the rate of weight loss from stored carrots was devised.
Investigation of ginger storage in salt brine
Authors: BROWN B. I. , LLOYD ANNICE C. 
Published: July 2010

SummaryGinger storage in salt brines with and without fermentation was investigated. Conditions were designed to promote natural and acid‐controlled fermentations, as well as a pure culture Lactobacillus fermentation. Vigorous natural and acid‐selective yeast fermentations were obtained, but brined ginger did not support a lactic acid fermentation because of lack of sufficient natural nutrients.The natural fermentation resulted in less satisfactory colour, texture and recovery of sound ginger than acid‐controlled or no fermentation in salt brines. However, ginger storage in salt brines resulted in much higher recovery and crisper texture than storage in acidified sodium metabisulphite solutions.This stage of the investigation has been essentially exploratory, covering a wide range of treatments, and the main leads which have emerged are currently being checked and extended in a further series of trials.
An improved alkali reaction test for rice quality
Authors: BHATTACHARYA K. R. , SOWBHAGYA C. M. 
Published: July 2010

SummaryAn improved 9‐point scoring scale for the alkali reaction test for rice (Little, Hilder & Dawson, 1958) has been devised by studying the successive stages of degradation of rice kernels of individual varieties by increasing concentrations of alkali. Each variety was just attacked by a certain concentration of potassium hydroxide and was essentially fully degraded by a 0.7‐0.8% higher concentration of the alkali. Nine distinct stages could be distinguished in this degradation process based on the amount of residual chalky substance in the degraded kernel, the diameter of the collar, and the consistency of the collar. A concentration of 1.4% KOH was found to give the maximum spread of the scores among different varieties. The test could be conducted in ordinary Petri dishes and at room temperature for 18–24 hr.Different rice varieties exhibited three types of reaction. Reaction type A was characterized by progressive cracking and corrosion; type B by progressive grilling and cottony transformation; and type C by opening and splitting with gradual dense cottony transformation of the kernel when treated with successively higher concentrations of KOH. The implication of this reaction type on the quality characteristics of a variety is not known, but most indicas gave reaction of type A, and japonicas type C.
Structural and textural changes in brown onions during pickling
Authors: JEWELL G. G. 
Published: July 2010

SummaryThe morphological and textural changes which occur during the pickling of brown onions have been studied using the electron microscope and Instron Universal Testing Rig.The structural studies revealed that the brining process gradually degraded the cell contents to leave just cell walls. The rate of degradation was shown to be dependent on the brine strength used: the most rapid rate being produced by the strongest brine.Electron histochemical staining showed that the cell walls were also degraded, with the pectin and hemicellulose components being modified.During the initial 24 hr in brine the marked changes in the texture parameters: hardness, elasticity and cohesion correspond to plasmolysis of the tissue and reorganization of cell wall materials. A recovery of texture values observed after 3 and 4 days’brining was attributed to the stabilization of turgor pressure. After 5 days’brining, rupture of the protoplast and subsequent loss of turgor pressure resulted in lower texture values.It was concluded that the optimum treatment for onions which would be stored in vinegar for 1 month was a brining period of between 3 and 4 days.
The connective tissues of fish VII. Post‐mortem hydration and ice crystal formation in myocommata, and their influence on gaping
Authors: LOVE R. M. , LAVETY J. 
Published: July 2010

SummaryFrozen and thawed cod are known to gape more and more with the passage of time between death and freezing. It was found in the present work that the myocommata become increasingly hydrated after death, permitting increasing proportions of ice to crystallize within and around them on subsequent freezing. It is probably this which disrupts the tissue: photomicrographs of staler fish after freezing revealed much more ice forming between the ends of the muscle cells and the myocommata, presumably assisting in their separation or causing it. Radioactive tracer studies showed that at least some of the hydrating water comes from the melting ice in which the fish are packed. Further experiments demonstrated that the exclusion of this water by wrapping the fish prior to icing does in fact reduce the gaping.
Wholesomeness of some types of semi‐preserved foods
Authors: MOSSEL D. A. A. , RATTO M. A. 
Published: July 2010

SummaryOver 300 samples of different foods packed in hermetically sealed containers were examined for wholesomeness, subsequent to a pre‐incubation suitably adapted to their mode of processing and intrinsic antimicrobial parameters: aw, pH and concentration of inhibitory substances. Those in Group 1 were incubated for 5 days at 171°C, those in Group 2 for 10 days at this temperature and Group 3 for 30 days at 30°C.Among ninety‐one samples examined in Group 1, 14% did not meet generally accepted criteria for microbiological wholesomeness and 35% showed minor deficiencies. This indicates that the pre‐incubation period of 5 days at 17°C applied to these commodities was excessive. More desirably a period of 3 days should be employed for such products. On the other hand, none of the seventy‐four samples from Group 2 showed serious bacteriological deficiencies after incubation for 10 days at c. 17°C and only in 9.5% of the samples total counts exceeded the specified levels. Among 145 shelf‐stable canned ‘appertized’ samples only 1.4% showed minor deficiencies after incubation for 4 weeks at 30°C, i.e. counts slightly over 102/g, a level already previously found generally not to be exceeded in correctly appertized foods, subsequent to such an incubation.
The hydrolysis of sodium triphosphate in cod and beef muscle
Authors: SUTTON A. H. 
Published: July 2010

SummaryPolyphosphates can be used in meat and fish products to reduce liquor loss during processing. However, there have been indications that triphosphate and pyrophosphate are hydrolysed in muscle. This effect has been studied in cod and beef using P3 2 labelled triphosphate and it is found that the kinetics conform to a typical ‘consecutive’ reaction of the type
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For cod, k1∼k2 and only orthophosphate remains after 30–40 hr at 0°C. In beef k2≥k1, and also k2 (beef) k2 (cod). This results in higher levels of pyrophosphate being formed in beef muscle from the triphosphate and the hydrolysis takes place over a much longer time period than in cod. S nce triphosphate is generally more effective than orthophosphate for reducing liquor loss, it is concluded that its effect on the muscle is an irreversible one.
Polyphosphates and fish: some chemical studies
Authors: GIBSON D. M. , MURRAY C. K. 
Published: July 2010

SummaryPolyphosphates are widely used for treating fish, but little information is available on the amounts taken up by fish and the suitability of some commercial polyphosphate mixtures. Phosphorus assays were performed on extracts of fish muscle which had been treated or not treated with polyphosphate mixtures. Fish‐to‐fish variation in natural phosphorus content was so large that it was difficult to determine whether or not fish had been treated with polyphosphate. The amount taken up under the conditions of treatment adopted was equivalent to 50–100 mg P/100 g fish muscle.Earlier experiments showed that sodium tripolyphosphate and sodium pyrophosphate were the most active condensed phosphates for preventing drip in prepacked chilled fish. The commercial mixtures found to give the best anti drip effect contained a high proportion of one or both of these two phosphates.
Factors affecting flavour release and uptake in O/W emulsions:I. Release and uptake models
Authors: McNULTY P. B. , KAREL M. 
Published: July 2010

SummaryFlavour release in the mouth was described by a model which assumes that flavour compounds are transferred from oil to water when the interphase equilibria are disturbed by dilution with saliva, and that only the aqueous concentration stimulates perception. The release equations predict high potential extents of flavour release in the mouth at high values of flavour partition coefficients, emulsion dilution, and/or initial emulsion oil fraction. Application of the release model to n‐alkanal threshold concentrations in oil and water (Lea & Swoboda, 1958) revealed that n‐alkanal partition coefficients and threshold concentrations in O/W emulsions could be satisfactorily predicted. The release and uptake models are general in nature and may be applied to interphase transport in any liquid dispersed system following dilution with the continuous phase.