bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of molecular and free sulphur dioxide in foods by headspace gas chromatography
Authors: DAVIS E. G. , BARNETT D. , MOY P. M. 
Published: July 2010

SummaryA study was made of the equilibria between SO2 in packaged liquid foods and gaseous SO2 in their headspace atmospheres as a basis for a new analytical method for the determination of molecular and free SO,. Using a gas‐chromatographic method developed previously to determine SO2 at the 1 × 10−3 mg/l level in atmospheres saturated with water vapour, studies with aqueous solutions showed that headspace SO2 was directly proportional to molecular SOz in accordance with Henry's law.Using the Henry's law constant for the S02/H20 system, determinations of molecular SOz were made on a white and a red wine and a fruit juice, each adjusted to five levels of pH to achieve different concentrations of molecular SO,. The results observed by the headspace method showed good agreement with those determined by a reference analytical method with white wine and fruit juice, but with red wine the reference method gave values which were more than 45% higher. Free SO2 was determined in a range of white wines by the headspace and reference methods, and the results showed high correlations.The headspace method is rapid, precise and non‐destructive. A major advantage is that, during the analysis, it does not change the complicated equilibria between SO, and its ionised species, hence complexes of SO2 and food constituents are not disturbed.
Preliminary studies on the chemical and weight composition of some commercially important species of fish and shrimp caught in the Nigerian inshore waters
Authors: EMOKPAE A. O. 
Published: July 2010

SummaryThe paper mainly deals with the chemical composition of commercially important marine fish of Nigeria in relation to their nutritive values. The selection is restricted to those species which can readily be obtained by standard fishing techniques, and whose biological characteristics can be studied throughout the year. The paper also includes a study of the changes in the composition according to season of the year. In addition, the work was further extended to an investigation of the carcass composition (i.e. the percentage flesh, head, skin, tail, bones, liver and entrails).
Heat transfer characteristics and process requirements of hot‐filled guava pulp
Authors: NATH N. , SIDDALINGU  , RANGANNA S. 
Published: July 2010

SummaryIn the in‐can processing of canned fruit pulp in batches, the pulp is filled hot into cans, sealed, processed and cooled. The hold‐up time between sealing ad processing may vary from 10 to 30 rnin when the temperature of pulp decreases in the peripheral regions. During processing and cooling, temperature changes in the peripheral regions are rapid but not so in regions near geometric centre. In guava pulp filled into cans at 170F (76.9°C) or above, thc desired F value is achieved at the geometric centre even without processing but not so at other regions. The point of minimum lethality shifts from the geometric centre towards the periphery with an increase in the filling temperature and a decrease in the hold‐up time. Based on these findings, a thermal process schedule has been evolved for canned guava pulp with different filling temperatures and a holdup time of 10 and 30 min.
Moisture desorption isotherms of rough rice
Authors: AGUERRE R. J. , SUAREZ C. , VIOLLAZ P. E. 
Published: July 2010

SummaryDesorptions isotherms of rough rice have been determined at 40, SO, 60 and 70°C and water activities (a,) from 0.036 to 0.823. An attempt is made to describe the experimental equilibrium moisture content data using mathematical relationships available in the literature. A statistical analysis was performed to evaluate the goodness of fit of the different equations. From this analysis it was concluded that Henderson's equation permits to correlate satisfactorily the experimental data for the whole range of water activity investigated. Finally, a simple empirical equation was postulated to take into account the effect of temperature on water sorption isotherms of rough rice grain.
The effect of irregular cooling phenomena on the lethality of thermal processes
Authors: CLELAND A. C. , GESTERKAMP M. F. 
Published: July 2010

SummaryIrregular temperature/time curves in the cooling phase of thermal processes for cans containing semi‐fluid foods have been previously attributed to internal boiling and mixing of the can contents. A physical model is proposed for this behaviour. This model can in part be simulated by numerical (finite difference) heat transfer calculations, but the actual physical behaviour is too complex for complete simulation. Experimental investigation for a baby food showed that substantial variations in total process lethality (±18% around the mean value) occurred as a result of changing process variables that affected the extent of internal boiling. Of these retort pressure during cooling was most important, but there were also complex interactions between this variable and three others: headspace, steam temperature and can pressure during seaming. Because the extent of internal boiling has a substantial effect on the total process lethality, determination of heating phase target F values for foods in which irregular cooling phenomena occur must consider these effects. The canner should consider the sensitivity of Fvalues to variations that could occur in practice of parameters such as can seaming pressure, headspace and retort pressure during cooling, as well as steam temperature.
Collaborative evaluation of universal calibrations for the measurement of protein and moisture in flour by near infrared reflectance
Authors: OSBORNE B. G. , FEARN T. 
Published: July 2010

SummaryCalibrations which had been previously determined for the analysis of protein and moisture in U.K. and Irish milled straight run white flour were set into nine near infrared (NIR) reflectance instruments of the same model situated in different laboratories. One set of samples was circulated to adjust the bias (intercept) which has a component specific to each instrument then a second set was circulated 2 months later to evaluate the adjusted calibrations. Kjeldahl proteins were determined on the first set by seven of the laboratories and on the second set by one reference laboratory for direct comparison of that method with the NIR method and in order to assess the accuracy of NIR as well as precision.On the second set of samples the mean NIR results for the different laboratories varied from 10.92 to 11.30% compared with a mean for the Kjeldahl of 11.03%. The accuracy of NIR calculated separately for each laboratory as the standard deviation (s.d.) of differences between NIR and Kjeldahl from the reference laboratory was between 0.13‐0.33% while the precision or repeatability (within‐laboratory) was 0.07%. For comparison the accuracy of Kjeldahl, calculated separately for each laboratory in the same way as for NIR, was 0.10% ‐0.27% and the precision (within‐laboratory) was 0.04%.In the case of moisture, the NIR results for the second set of samples had mean values ranging from 13.08 to 13.28% compared with a mean for oven drying of 13.13%. The accuracy of NIR was 0.20‐0.29% with no significant biases and the precision was 0.05%.
Physical and chemical changes during roasting of semolina (suji)
Authors: PREMAVALLI K. S. , ARYA S. S. 
Published: July 2010

SummaryA simple laboratory method for uniform roasting of semolina under controlled conditions and for isolation of volatile compounds formed during roasting is described. The changes in sugars, proteins, lipids, gelatinization behaviour and carbonyl compounds formed during roasting of wheat semolina at 160, 175 and 190°C are discussed.
Synergistic effects of various lipases and phospholipase C on milk fat
Authors: GRIFFITHS M. W. 
Published: July 2010

SummaryThe enzyme, phospholipase C, from a number of psychrotrophs isolated from milk was shown to survive HTST pasteurization and UHT sterilization processes. The phospholipase C of Bacillus cereus was able to increase lipolytic activity of a commercial lipase preparation and native milk lipoprotein lipase in raw milk by making the substrate more susceptible to hydrolysis: phospholipase C had no effect on the lipase activity of a fluorescent Pseudornonas spp. The enhancement of lipolysis by phospholipase C was affected by pronase and papain, but not by trypsin. Homogenization of the raw milk had the same effect on lipolysis by lipoprotein lipase as addition of phospholipase C.
Evaluation of a process for obtaining partially concentrated distilled lime oil
Authors: PINO J. A. , TÁPANES R. 
Published: July 2010

SummaryIn this paper we discuss the evaluation of a new process for obtaining partially concentrated oil from distilled lime oil. A qualitative and quantitative analysis was carried out with the aid of gas‐liquid chromatography and the physical, chemical and sensory characteristics were also determined in the processed oil. The results indicated that the partially concentrated oil has a good quality and greater stability compared with the natural oil.
A new type of semi‐hard cheese from recombined milk
Authors: HOFI A. A. , MAGDOUB M. N. I. , ABD'EL‐HAMID LAILA B. , OSMAN SH. G. 
Published: July 2010

SummaryTechnological aspects for achieving a suitable technique for making a new semi‐hard cheese from pasteurized recombined milk were studied. The manufacturing procedure was basically set on setting temperature of 35°C, rennet powder quantity of 8 g/100 kg milk, curd cubes size of 11/4 in, scalding for 1.5 min at 40°C and pressing at 1.50 lb/in2 for 3 hr. The resulting cheese is named ‘Ain Shams’ and is characterized by a mild and slightly acidic flavour, tender body and very slightly open texture. The new cheese contains 40% moisture and 40% fat/dry matter.
A study of the effects of frozen storage on certain functional properties of meat and fish protein
Authors: COLMENERO F. JIMÉNEZ , BORDERIAS A. J. 
Published: July 2010

SummaryThis paper presents a study of the effects of frozen storage on certain functional properties, namely protein solubility, emulsifying capacity, and viscosity, both in meat and in fish.Correlations between these three functional properties were examined in an attempt to find the easiest and most sensitive method of analysis.High correlation among the different functional properties tested was found only in the case of fish. This, together with the significant variations in the viscosity values found during the storage period, suggests that the analysis of apparent viscosity is a valuable indicator method for determining alterations occurring in the functional characteristics of fish protein.
Dissociation constant of sorbic acid in water and water‐glycerol mixtures at 25°C from conductance measurements
Authors: PETHYBRIDGE A. D. , ISON R. W. , HARRIGAN W. F. 
Published: July 2010

SummaryMolar conductivities of dilute solutions of sorbic acid in water, and in the mixed solvents water +lo, 20,30,40 and 50% glycerol by mass at 25°C are reported. The results have been analysed with the Pitts conductance equation and pK, values for sorbic acid in these solvent mixtures are tabulated. Similar data for sorbic acid in water+30% glycerol at 10°C are also included. The implications of the results for the role of sorbic acid in food preservation are discussed.
Selection of judges and assessment of storage‐related flavours in frozen sheepmeats
Authors: WINGER R. J. 
Published: July 2010

SummaryAlthough many subtle flavour changes occur during the frozen storage of lamb, most people appear to be relatively insensitive to these changes. From an initial 125 people, a group of thirty‐four panellists were selected for their ability to detect frozen‐storage flavour changes in lamb. These selected panellists described these changes and helped develop a suitable scoring system for estimating the period of frozen storage.
Influence of gamma radiation on the rheological and functional properties of bread wheats
Authors: PAREDES‐LÓPEZ O. , COVARRUBIAS‐ALVAREZ M. M. 
Published: July 2010

SummaryThe effects of gamma irradiation on some biochemical, rheological and functional properties of bread wheats were studied. Two wheat cultivars were selected to represent medium‐strong and weak dough mixing strengths. Falling number values were severely depressed at doses of 500 and 1000 krad. Rheological dough properties, as assessed with the mixograph and farinograph, were also investigated. Radiation at medium doses produced an increase in the farinograph water absorption for both wheats. Radiation decreased the amount of bound water as compared to the control sample. For the medium‐strong wheat low levels of radiation produced bread with volumes and overall bread quality equal to or slightly better than those of the control flour, whereas for the weak wheat an improvement of the baking performance was obtained at all the low doses of radiation. However, the overall bread quality of both wheats was highly reduced at medium doses of radiation.
Lipids in French fries: a retail and laboratory study
Authors: GREENFIELD H. , MAKINSON J. , WILLS R. B. H. 
Published: July 2010

SummaryThe lipid content of prepared restaurant and takeaway French fries varied from 6.2 to 20.8 g/100 g, and of frozen retail fries from 2.1 to 5.3 g/100 g, as purchased, and from 12.0 to 20.0 g/100 g after finish frying. The lipid composition (fatty acid profile and cholesterol content) of all retail samples reflected the predominant use of animal fat in the Australian industry. Laboratory studies showed that the lipid content of French fries was increased by decreased chip size, and by the common commercial practice of split frying which caused a doubling of fat uptake when compared with single frying. Commercial practices appear to increase the potential of fries as a fat carrier.
Calculation of the variation of the heat of desorption with moisture content on the basis of the BET theory
Authors: AGUERRE ROBERTO J. , SUÁREZ CONSTANTINO , VIOLLAZ PASCUAL E. 
Published: July 2010

SummaryData of water desorption on different food products were analysed from the point of view of the BET theory. A plot of log C against 1/T as used for the independent evaluation of E1‐EL and the pre‐exponential a1b2/b1a2, in the expression for the constant C of the BET theory. It was found that a1b2/b1a2, may range from 10−3 to 10−6 and the E1 ‐ EL values are correspondingly much higher than usual. An equation has been obtained within the framework of the BET theory for the dependence of the net heat of desorption on moisture content. In the present analysis the variation of the monolayer value with temperature is considered by means of a simple empirical equation. The results are compared with the heats of desorption calculated directly by the Clausius‐Clapeyron equation.
Degradation of sorbic acid in fruit squashes and fish paste
Authors: VIDYASAGAR K. , ARYA S. S. 
Published: July 2010

SummaryDegradation of sorbic acid (SA) in fruit squashes and fish paste has been found to be influenced by the nature of the food material and the packaging system. Losses in SA ranged from 60–90% in polypropylene and 41–65% in saran coated cellopoly pouches to 22–30% in paper‐aluminium foil‐polyethylene laminate pouches and glass bottles after 150–210 days at 37°C. The rate of degradation was significantly higher in fish paste than in fruit squashes.The major portion of the added SO, in fruit squashes was lost during the initial stages of storage and the residual SO, (< 100 ppm) did not significantly influence the rate of degradation of SA. Browning intensity in fruit squashes and fish paste was also related to the oxygen permeability of the packaging materials. Addition of 0.1 % SA did not significantly influence the rate of browning but at 0.2%, a slight increase in the rate was observed.
Role of carbohydrates in soya extrusion
Authors: SHEARD P. R. , LEDWARD D. A. , MITCHELL J. R. 
Published: July 2010

SummaryWhen extruded under similar processing conditions, soya flour yielded a far more regular, honeycombed structure than soya isolate, though both had similar expansion ratios. At low concentrations both extrudates were almost totally soluble in solutions containing sodium dodecyl sulphate (SDS) plus 2‐mercaptoethanol (ME), although in SDS or ME the extrudates were only partially soluble. These results suggest that, in both cases, the extrudates are primarily stabilized by disulphide bonds and hydrophobic interactions.When rehydrated in water at temperatures in the range 20–120°C all the extrudates exhibited decreasing toughness and increasing protein solubility with increasing temperature. Also, the soya flour extrudates, but not those prepared from the isolate, exhibited a phenomenon at the lower temperatures characterized by minimum hydratability, pH and carbohydrate solubility at about 30–40°C. It is suggested that the soya flour extrudates are additionally stabilized, compared to the extrudates prepared from the isolate, by hydrophobic interactions involving the embedded carbohydrate.
Note on the economics of batch freeze dryers
Authors: MILLMAN M. J. , LIAPIS A. I. , MARCHELLO J. M. 
Published: July 2010

SummaryAn economic analysis of various operational policies associated with a batch freeze dryer is presented. Skim milk is used as a model material. It is shown that the lowest cost of production corresponds to the highest production rate. This occurs when large sample thicknesses are used, the chamber pressure is at its lowest value and the upper and lower heating plates are independently controlled such that the melting and scorch constraints are both encountered and held during the free water removal phase. Therefore, the operational regime that provides the shortest drying times during the free water removal phase (Millman, Liapis & Marchello, 1984, 1985) will also provide the smallest production costs and highest capacities.
Increase on free fatty acids during ripening of anchovies (Engraulis anchoíta)
Authors: ROLDAN H. A. , BARASSI C. A. , TRUCCO R. E. 
Published: July 2010

SummaryThe changes of free fatty acids (FFA) during the ripening of salted anchovy was studied. In the course of the curing process, the content of free fatty acids (FFA) in the muscle increased fifteen‐fold, mostly in the first 100 days of the process. Each sample was subjected to sensory evaluations. A high correlation between FFA contents and sensory scores was found. Therefore the determination of FFA is proposed as an objective index to assess the ripening of salted anchovies.
Effects of different types of carrageenans and carboxymethyl celluloses on the stability of frozen stored minced fillets of cod
Authors: PONTE D. J. B. DA , HERFST J. M. , ROOZEN J. P. , PILNIK W. 
Published: July 2010

SummaryDifferent types of carrageenans and carboxymethyl celluloses were used as additives (5 g/kg) for minced fillets of cod. Samples of these treatments were stored at −18°C for 10 weeks and were evaluated at regular intervals for pH, water holding capacity, texture, extractable myosin and formation of dimethylamine and formaldehyde.Except Kappa carrageenan the additions improved the water holding capacity of the raw and cooked minced fish and decreased toughening during frozen storage. The addition of Iota carrageenan resulted in samples with remarkable texture stability and so after 10 weeks of frozen storage the texture of this treatment was similar to fresh minced cod. The higher the viscosity of carboxymethyl cellulose, the more it increased the softness and water holding capacity.
Compositional differences of black, green and white pepper (Piper nigrum L.) oil from three cultivars
Authors: BUCKLE K. A. , RATHNAWATHIE M. , BROPHY J. J. 
Published: July 2010

SummaryThe composition of volatile oil from black, green and white pepper products of a local Sri Lankan cultivar has been compared with that for the Panniyur and Kuching cultivars introduced from India and Sarawak respectively. The Local Sri Lankan cultivar is rich in P‐caryophyllene, a major proportion in sesquiterpene hydrocarbons, and is more suitable for the perfumery industry than are the other two cultivars. The high proportion of oxygenated compounds in the Panniyur cultivar makes an important contribution to the overall odour quality of its pepper oil while the Kuching cultivar, containing a higher monoterpene concentration with a significant content of pinenes, is rich in the top peppery notes. Knowledge of the variation in the composition of pepper oils from different cultivars is important when pepper is used as a component of food flavourings.
Studies of the iced storage characteristics and composition of a variety of Bolivian freshwater fish. 2. Parana and Amazon Basins fish
Authors: POULTER N. H. , NICOLAIDES LINDA 
Published: July 2010

Summary.A selection of fish from the warm lowland waters of the Parana and Amazonian Basins were studied to determine their shelf lives and spoilage characteristics when stored in crushed ice. The proximate composition and physical nature of these fish species was also determined. A shelf life of 25 days was estimated for sabalo (Prochilodusplatensis) from the Parana Basin regardless of whether the fish were stored entire or eviscerated. The larger fish from the Amazonian Basin, pacu (Colossoma macropomurn), chincuiiia (Pseudoplatystoma tigrinum) and tambaqui (Colossoma branchypomum) exhibited shelf lives of greater than 40 days. The smaller fish from this location had shelf lives of over 30 days for corvina (Plagioscion squamosissimus) and 25 days for bagrk (Ageneiosus spp.). An evaluation of the methods used to assess fish quality was made. The assertion that tropical fish have longer shelf lives than temperate species when stored in crushed ice is discussed.
Anthocyanin colourants from elderberry (Sambucus nigra L.). 2. Process considerations for production of a freeze dried product
Authors: BRØNNUM‐HANSEN Kirsten , FLINK J. M. 
Published: July 2010

Summary.Freeze drying of elderberry anthocyanin extract under the proper conditions produces an intensely coloured powder with retention of both anthocyanins and physical structure. The various conditions examined included extract concentration, stabilizer concentration, pH and freeze drying conditions. It was found that minimum antho‐cyanin degradation and product structure alteration occur, when the undiluted extract is adjusted to pH = 3, has DE 20 maltodextrin structure stabilizer added to a 2.5% level and is freeze dried at a maximum platen temperature of 75â°C and maximum product temperature of 60â°C. Under these conditions, the recovery of anthocyanin is 94% and physical structure and solubility is preserved.
Selenium losses on cooking Greek foods
Authors: BRATAKOS M. S. , ZAFIROPOULOS T. F. , SISKOS P. A. , IOANNOU P. V. 
Published: July 2010

SummaryThe effect of various cooking practices (frying, grilling, boiling and canning) on the selenium content of selected food items has been determined. All foods examined upon cooking lost selenium and, in general, the harsher the cooking conditions the more selenium was lost. Fish lost 36–46%, meats 13–41%, cereals 20–30%, vegetables 12–37%, pulses and cereal products 5–10% selenium. It is estimated that Greeks receive 110 and c. 95 μg Se/day based on raw, and cooked plus uncooked foods, respectively. Cooking does not make a large difference to the daily selenium intake of Greeks because of their large consumption of bread.