bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects on bovine 1. dorsi muscle of conventional and microwave heating
Authors: ROBERTS P. C. B. , LAWRIE R. A. 
Published: July 2010

SummaryA sequence of adjacent samples of beef 1. dorsi muscle were alternately exposed either to conventional heating for periods of 0–70 min at temperatures between 45° and 90°C or to microwaves at a frequency of 2450 MHz for periods of 0–10 sec at power levels between 131 and 1050 W. Protein denaturation was assessed by measuring nitrogen distribution between sarcoplasmic and crude myofibrillar fractions and by electrophoresis; and concomitant superficial changes in free water and plasticity measured.The attainment of a given temperature by microwave energy was associated with less detrimental change than when achieved by conventional heating; but this could be attributed merely to further progression of the same type of effects due to the time necessitated with the latter procedure and not to any qualitative difference. The findings suggest that microwave heating might permit microbial inactivation in meat products with minimum loss of organoleptic quality. It is also suggested that the observed initial resistance of myoglobin to heat denaturation and its subsequent loss of electrophoretic mobility between 75° and 88°C could be developed as an index of the temperature attained by meat products.
Post mortem changes and spoilage in rock lobster muscle
Authors: SIDHU G. S. , MONTGOMERY W. A. , BROWN M. A. 
Published: July 2010

SummaryGlycolysis in rock lobster comprising the oblique extensor, oblique flexor and enveloping muscles of Jasus novae‐hollandiae was studied under anaerobic conditions at 20°, 15° and 0°C. After bisecting the muscles along the mediosaggital plane one section was treated by dipping for 4 min in 3% sodium chloride solution containing 15 ppm oxytetracycline (treated). The other (untreated) was immersed in sodium chloride solution containing no antibiotic. In the treated muscles lactate production showed a linear relation to the fall in pH over a range of 7·2–6·0, a fall in one unit of pH corresponding to 118 μmol of lactate per g of tissue. In spite of a relatively high production of lactate the ultimate pH did not fall below 6·0 because of a high buffering capacity of the muscle.Breakdown of phosphoraginine and ATP and accumulation of lactate and inorganic phosphorus at 20° and 15°C followed patterns similar to those observed in mammalian and poultry muscle but at 0°C these processes were slowed down to a much greater extent. There was no accumulation of glucose 6‐phosphate.Concentrations of arginine rose as a result of phosphoarginine breakdown in both treated and untreated samples. However, in the untreated samples at 20° and 15°C, arginine concentrations started to fall 24 hr post mortem probably due to bacterial attack; the fall being more rapid at 20°C.When mounted in a specially designed rigorometer at 20° and 15°C the muscle strips started to shorten concurrently with only a slight drop in ATP concentrations. The extent of shortening did not exceed 10% of the original and in some cases the contraction was immediately followed by a slow lengthening.The findings of this study are discussed in relation to glycolysis and rigor mortis in mammalian and fish muscles.
The effect of cycled‐pressure on drying conditions during freeze drying
Authors: GREENFIELD P. F. , MELLOR J. D. 
Published: July 2010

SummaryCyclic‐pressure freeze drying has been found to improve the drying rate compared to the constant pressure process. This is due principally to the increased thermal conductivity of the semi‐dried region which results from the cyclic operation. The pressure oscillation causes unsteady temperature and mass flux conditions within the material being dried. During the high pressure portion of the cycle, very little sublimation takes place and the temperatures within the material are raised. When the pressure is reduced the temperatures are reduced as sublimation occurs. The temperature oscillations were found to have the same period as the pressure cycles, but to lag behind because of the heat capacity of the material. Additionally, it was found that the cycling produced high intermittent loads on both the heating source and the vapour condenser.
Retention of aroma components in extractive drying of aqueous carbohydrate solutions
Authors: KERKHOF P. J. A. M. , THIJSSEN H. A. G. 
Published: July 2010

SummaryA new drying technique, extractive drying, has been studied experimentally. The retention of the components methanol, n‐propanol and n‐pentanol in extractive drying of a model liquid food was investigated. The model liquid food consisted of an aqueous solution of mixtures of dextrin and malto‐dextrin, to which the alcohols were added in low concentrations. As extraction liquid polyethylene glycol (PEG) 400 was used. The solution to be dried was dispersed in the PEG in the form of droplets.High losses of the alcohols were found when the feed droplets were distorted upon contact with the extraction liquid. This distortion does not occur when the viscosity of the feed solution is higher than approximately 150 cP. For such feed solutions, containing 40% water and on dry basis 25% dextrin and 75% malto‐dextrin, very high aroma retentions were found. The effects observed agree with the selective diffusion theory.
Production of an enzymic hydrolysate of casein on a kilogram scale
Authors: CLEGG K. MARY , SMITH G. , WALKER A. L. 
Published: July 2010

The scaling‐up of a method for the production of an enzymic hydrolsate of casein is descrived; minor modifications of the laboratory procedure were required. The spray‐dried product is relatively free of the bitterness often associated with proteins subjected to enzymic treatment. The bacteriological load of the raw materials, the intermediate stages, and the final product was monitored.The production of hydrolysed casein in quantity is providing an opportunity to investigate the dietary potential of pre‐digested protein for patients suffering from digestive disorders as a result of pancreatic malfunction.
Water vapour adsorption on whole corn flour, degermed corn flour, and germ flour
Authors: KUMAR MAHESH 
Published: July 2010

SummaryAdsorption isotherms for whole corn, degermed corn, and germ flours were obtained at 78°F and 122°F and at relative humidities in the range of 11–97%. Various empirical equations for the isotherms were tried and the parameters were calculated for the equations. Brunauer‐Emmett‐Teller (BET) surface areas of the various materials were calculated to describe the sorption phenomenon. The BET surface areas based on water sorption were higher for degermed corn flour than for germ flour. The free energy changes for whole corn, degermed corn, and germ flours were determined and represented by empirical equations.
The incidence of Clostridium botulinum in Danish trout farms: II. Measures to reduce contamination of the fish
Authors: HUSS H. H. , PEDERSEN ANETTE , CANN D. C. 
Published: July 2010

SummaryA number of experiments have been carried out to develop methods for the reduction of the contamination of farmed trout by the food poisoning organism Clostridium botulinum.Starvation studies of fish gave variable results. When carried out under hygienic conditions in artificial containers and a clean water supply the contamination was reduced. Gutting of fish, either by hand or machine, always reduced the contamination to a low level.Quick liming effectively reduced the contamination of pond bottoms and may be useful as a control measure against Clostridium botulinum.
Pectinesterase activity in the component parts of different Israeli citrus fruit varieties*
Authors: CHILD GERDA ROTHS , MOYAL ZEHAVA , KARSENTY ANNA 
Published: July 2010

SummaryPectinesterase activity in whole fruits and single fruit components was established for grapefruit and orange (shamouti and valencia) varieties. It was found to range, in terms of pectinesterase units per gram of test material, from PE.u. x 104=5·1 for hand‐reamed or 11·2 for commercially extracted juice to PE.u. x 1044=821 for pulp and rag. Enzyme activity in each of the different components was highest in valencia. The comparative distribution of component activity was similar for all three fruit varieties. When test materials of low pH were allowed to stand even for short periods prior to examination, partial inactivation occurred, whereas at pH 3·5 and above, pectinesterase activity remained stable for 8 hr or more. Therefore, in order to obtain reproducible results, stabilization of the more acid samples by raising the pH level to at least 3·5 was necessary.
Collagen fibre arrangement in intramuscular connective tissue. Changes associated with muscle shortening and their possible relevance to raw meat toughness measurements
Authors: ROWE R. W. D. 
Published: July 2010

SummaryCollagen fibres of ovine and bovine perimysium are shown to have a crimped appearance. The size of the crimp is smaller than in the collagen fibres from tendon (e.g. perimysium 19 μm; tendon 79 μm). The collagen fibres are laid down in a well‐ordered criss‐cross lattice at an angle to the muscle fibre long axis. Muscle contraction changes the angles of this lattice and also changes the crimp length. These changes are related to differences between samples of meat of uniform size such as are tested for toughness. It is demonstrated that any explanation of changes in meat toughness resulting from shortening can no longer be related only to changes in ‘myofibrillar toughness’, but must also include extensive changes in ‘connective tissue toughness’.
Retention of volatile organic compounds in a complex freeze‐dried food gel
Authors: KAYAERT G. , TOBBACK P. , MAES E. , FLINK J. , KAREL M. 
Published: July 2010

SummaryThe retention of 14G‐labelled ethyl acetate, n‐propanol and acetone in freeze‐dried food gels is studied. Fractional retention of the initially present volatiles increases with increasing solids concentration and decreases with increasing initial volatile content. Retention also decreases with increasing sample thickness in fast‐frozen samples, and is lower in rapidly frozen than in slowly frozen samples.Humidification causes release of retained volatiles, the new level of retention depending upon relative humidity. The results indicate that the predominant retention mechanism is entrapment in microregions, with a small contribution due to adsorption.
The vitamin C content of quick frozen green beans
Authors: MORRISON MARY H. 
Published: July 2010

SummaryThe effect of maturity, variety, post‐harvest delay and various stages in processing, including cleaning, blanching and end‐cooking, on the vitamin C content of quick frozen green beans (Phaseolus vulgaris) has been studied. The vitamin C content of eight varieties showed considerable variation but no correlation with maturity was observed. Post‐harvest delay and processing caused a noticeable reduction in vitamin C content. The overall retention of vitamin C in both whole and sliced frozen beans was approximately 75%. After cooking, fresh manually sliced beans retained 59% of the original vitamin C content compared with 44% for the commercially frozen sliced beans.
Pasteurization conditions for juices and comminuted products of Israeli citrus fruits*
Authors: ROTHSCHILD GERDA , VLIET CHRISTINE VAN , KARSENTY ANNA 
Published: July 2010

SummaryTime‐temperature curves were established for heat inactivation of pectin‐esterase in citrus juices and comminuted materials of different citrus varieties, pH, and enzyme activities; a highly sensitive analytical method was used as criterion for adequacy of pasteurization. Inactivation temperatures were lower in materials of lower pH, ranging from 75 to 90° for juices and 80 to 95° for comminuted products. But, in order to exploit the‘low pH‐low temperature effect, longer holding times had to be applied to the more acid test materials. Fifteen sec were sufficient for orange juice, and longer holding times had no effect on the inactivation temperature required for this variety (90°). However, for grapefruit juice, an increase in holding time, e.g. from 15 to 30 sec resulted in an inactivation temperature change from 90° to 85° and from 90° to 80° for lemon juice.
The analysis of strawberries as a means of determining the fruit content of manufactured products
Authors: GOODALL H. , SCHOLEY J. 
Published: July 2010

SummaryMultivariate statistical analysis was examined as a means of obtaining more reliable assessments of fruit contents from analytical determinations than are possible by the current use of average values of insoluble solids, nitrogen, phosphorus and potassium contents. The major portion of the investigation dealt with the fruit itself.Twenty‐three parameters were determined on fifty‐four samples of strawberries, culled during three successive seasons, and representing a wide span of cultivars, their origins and growing areas. To derive the weighting factors to be applied to the analytical determinations in order to obtain the optimum estimate of fruit content, the analytical results were submitted to multivariate statistical analysis. This approach led to a marked improvement in the estimations of fruit content when compared with conventional techniques.Wide variations were found in the levels of all of the parameters determined, but there were highly significant correlations between many pairs, in which the free amino acids figured largely. A limited study to assess the usefullness of these parameters for determining the fruit content of manufactured products showed that the amount of free amino acids recovered from fresh fruit jams and from frozen fruit were very similar. However, the amounts recovered from sulphited pulp and sulphited fruit jams did not fall into any clear pattern. Further investigation of the effect of sulphiting on the free amino acids is therefore necessary before the statistical approach can be applied in these circumstances.
The production of polyunsaturated tallows and their utilization in margarine manufacture
Authors: HERBERT L. S. , KEARNEY K. J. 
Published: July 2010

SummaryOffal materials were collected from sheep and cattle, which had been slaughtered after a period of feeding with a protected polyunsaturated oil supplement. Tallows produced from these offals by methods simulating batch dry rendering and low temperature wet rendering processes contained about 19% linoleic acid and had a saturated/unsaturated ratio lower than in normal tallows. Pilot scale refining and margarine manufacturing processes were used to convert the tallows to margarines. No unusual or unexpected processing or quality effects are expected in commercial production using standard ‘good practice’ rendering, refining and margarine manufacturing procedures.
A national survey of muscle pH values in commercial pig carcasses
Authors: KEMPSTER A. J. , CUTHBERTSON A. 
Published: July 2010

SummaryMeasurements of muscle pH at 45 min post mortem (pH1) and after overnight cooling (pH2) were taken in a total of 6015 commercial pig carcasses at sixteen bacon factories in Great Britain. Measurements were made in the M. longissimus in the area of the last rib and in the M. semimembranosus.Differences between muscles in the overall distribution of pH1 and pH2 were negligible. The overall mean for pH1 measured in the M. longissimus was 6.55 ± 0.32 (s.d.) and 5.7% of the values were below pH 6.0. The overall mean for pH2 in this muscle was 5.81 ± 0.25 and 2.1% of the values were above pH 6.5. Wide differences were recorded between factories in the distribution of pH1 values; means ranged from 6.98 to 6.20 and the percentage of values below pH 6.0 from 0.3 to 20.6.pH was independent of muscle temperature and carcass weight. Low and positive correlations were recorded between pH measurements and backfat thickness.Comparison of the overall results with those of a similar survey carried out in 1964 indicated that the distribution of pH values in commercial British pigs has changed very little in the last decade.
The Stomacher—its use for homogenization in food microbiology
Authors: TUTTLEBEE J. W. 
Published: July 2010

SummaryA new homogenizer, the Stomacher, was compared with other methods of homogenization. Various food samples were homogenized on the Stomacher and also in Ato‐mix blenders (prawns and other cooked foods) by simple mixing (raw meats, powdered egg and milk), or by using a pestle and mortar (cheese).Microbiological examination of various foods indicated that the Stomacher released significantly larger numbers of viable micro‐organisms, calculated on the basis of a colony count, than other methods of homogenization, except from samples of cheese and powdered egg and milk. The advantage of using the Stomacher is that no sterilization or maintenance is required as with Ato‐mix blenders and other equipment.
Scanning electron microscope studies of membrane deposits from whey ultrafiltration
Authors: LEE DORETTA N. , MIRANDA MARY G. , MERSON RICHARD L. 
Published: July 2010

SummaryScanning electron microscopy (SEM) was used to study the fouling deposits from cottage cheese whey on ultrafiltration membranes. Several types of deposits were observed: micro‐organisms, granules, thin strands, coarse fibres and sheets of varying thickness. Surface deposits of sheet forming materials appear to be the principal cause of membrane flux decline. The progressive build‐up of deposits was demonstrated directly on ultrafiltration membranes and by simulation of fouling on membranes having uniform pores discernible by SEM. SEM was found to be a simple and effective tool for study of membrane fouling.
Wiltshire curing with and without nitrate
Authors: TAYLOR A. A. , SHAW B. G. 
Published: July 2010

SummaryUnsmoked bacon has been made by a factory Wiltshire process incorporating hand pumping and immersion using brines with and without nitrate and with diminishing concentrations of nitrite. The quality and stability of the bacon during storage in vacuum packs has been compared.Curing with a nitrate‐free brine containing 26% salt and 1000 ppm nitrite produced back bacon with 57–81 ppm nitrite and approximately 4% salt in the lean and this, when sliced and vacuum packed, was still acceptable after 5 weeks at 5°C and 2 weeks at 15°C. Brines with nitrite concentrations of 500 ppm and less gave back bacon which was more prone to souring during storage due to increased growth of lactic acid bacteria.
The ascorbic acid content of quick frozen Brussels sprouts
Authors: ABRAMS C. I. 
Published: July 2010

SummaryThe effect of maturity, variety, stage of the season, post‐harvest delay, processing procedures and end‐cooking on the ascorbic acid content of commercially quick frozen Brussels sprouts has been studied. The ascorbic acid content of sprouts decreased with increasing size and the distribution of the vitamin within the sprout showed the meristem to have the highest concentration which decreased through the inner light green leaves to the outer dark green leaves. The progressive reduction in ascorbic acid content during the 3 1/2 month harvesting period prevented the establishment of any significant findings for differences in the nutrient level of nine varieties of Brussels sprouts. Post‐harvest delay caused no reduction of ascorbic acid content and, during processing, losses were only incurred at the blanching stage. Retention values of 76‐89% ascorbic acid on a dry weight basis were found in the frozen product and, after cooking, fresh and frozen sprouts reained 59‐64% of the original vitamin C content. Loss of ascorbic acid due to leaching during commercial processing and end‐cooking appears to be considerably less for sprouts than for sliced green beans and marginally less than for peas.
The gas chromatographic determination of trimethylamine and dimethylamine in fish, fishery products and other foodstuffs
Authors: RITSKES T. M. 
Published: July 2010

SummaryBaseline separation of trimethylamine (TMA) and dimethylamine (DMA) is obtained on a Carbowax 400/polyethylene imine column provided with an alkaline pre‐column. Based on this separation, a method of analysis for these amines in fish and other foodstuffs was worked out.Quantitative distillation of traces of DMA could be achieved by addition of ethylamine prior to distillation. A sensitivity increase up to the ppm range was found to be possible. Amine oxides, after reduction with titanous chloride, can be determined in the same way. The automation of the gas chromatographic injection procedure is described.
Ultrastructural changes during frozen storage of cod (Gadus morhua L.)
Authors: JARENBÄCK L. , LILJEMARK A. 
Published: July 2010

SummaryThe ultrastructure of myofibrils from cod white muscle has been studied using the freeze etching technique. Unfrozen post‐rigor samples were compared with thawed samples stored for a short period at −40°C and also with samples stored at −20°C for a period known to result in severe toughness.Transverse fractures from unfrozen muscle reveal the regular hexagonal arrangement of thick myofilaments and the vesicular material of the sarcoplasmic reticulum between the myofibrils. Muscle stored for a long period at −20°C shows, after thawing, disturbances in the hexagonal pattern and deformation of the sarcoplasmic reticulum. Longitudinal fractures both from unfrozen and frozen stored muscles sometimes reveal the arrangement of cross‐bridges between thick and thin myofilaments. Gross‐bridges lie at an angle to the thick filaments and their repeat along the filament can be seen.Measurements of distances between thick myofilaments showed a significant reduction in the interfilament spacing after prolonged frozen storage. This shrinkage together with the observed disorders within and between myofibrils may reflect an impaired ability to reabsorb water following thawing.
The effect of plating technique and incubation temperature on bacterial counts
Authors: NOTTINGHAM P. M. , RUSHBROOK A. J. , JURY K. E. 
Published: July 2010

SummaryA comparison of plating methods and incubation temperatures for aerobic bacterial counts, carried out on samples from lamb, beef and meat processing equipment, showed that the spread plate counts were generally higher than those by the pour plate procedure. This was particularly so for samples which had been exposed to low temperatures for long periods. Incubation of plates at 25 and 30°C gave similar results but the 37°C counts were usually lower and more variable. Replication of dilutions or plates was found to give little or no increase in accuracy.
Ultrastructural changes during frozen storage of cod (Gadus morhua L.)
Authors: JARENBÄCK L. , LILJEMARK A. 
Published: July 2010

SummaryMyofibrillar proteins from post‐rigor unfrozen and stored frozen cod muscle have been studied by electron microscopy. Changes in extracted proteins and corresponding myofibril residues were followed by negative staining and ultrathin sectioning throughout a frozen storage period of 120 weeks.In myofibrillar extracts a decrease in the number of actomyosin filaments and an increase in the number and size of large aggregates was found. A decrease in the length and amount of attached myosin was noticed in actomyosin filaments. The changes observed were most extensive at — 10°C, less pronounced at — 20°C and hardly noticeable at — 30°C.According to the appearance of the myofibril residues thick myofilaments had been almost completely extracted from unfrozen muscle and were increasingly resistant towards extraction the higher the temperature during frozen storage.